CN106130701B - HARQ process transmission method and device, base station and terminal in unauthorized frequency range - Google Patents

Abstract

The present invention provides a HARQ process transmission method and device on an unlicensed frequency band, a base station and a terminal, wherein the HARQ process transmission method includes: the statistical data sender executes a channel detection mechanism on an unlicensed frequency band to make each HARQ process The number of missed retransmissions, and/or statistics of the time elapsed from the establishment of each HARQ process to the data sender receiving the ACK message; according to the number of missed retransmissions of each HARQ process, and/or each HARQ process from the establishment The length of time elapsed until the data sender receives the ACK message determines the transmission priority of each HARQ process when retransmitting; when it detects that the channel in the unlicensed frequency band can be occupied each time, according to the progress of each HARQ process Transmission priority for retransmissions to which transmission resources are allocated. The present invention can avoid the problem that the HARQ process cannot send data because the channel is always occupied, reduces the average time delay of the HARQ process, and is beneficial to improving the throughput of the system.

Description

HARQ process transmission method and device, base station and terminal in unlicensed frequency band

technical field

The present invention relates to the field of communication technology, in particular, to a HARQ process transmission method on an unlicensed frequency band, a HARQ process transmission device on an unlicensed frequency band, a base station and a terminal.

Background technique

With the rapid increase of communication traffic, the 3GPP authorized spectrum is increasingly insufficient to provide higher network capacity. In order to further improve the utilization of spectrum resources, 3GPP proposes the concept of LAA (LTE Assisted Access, LTE Assisted Access), which is used to use unlicensed spectrum with the help of LTE (Long Term Evolution, Long Term Evolution) licensed spectrum. In order to make the LTE system coexist harmoniously with different systems such as Wi-Fi on the unlicensed frequency band, 3GPP proposed the LBT (Listen Before Talk, Listen Before Talk) mechanism to ensure that the unlicensed frequency band The fairness of using spectrum resources by different systems. Wherein, the working mode of the LTE system in the unlicensed spectrum may be a TDD (Time Division Duplexing, Time Division Duplexing) mode, a supplemental downlink (SDL, Supplemental Downlink) mode or a dynamic uplink and downlink mode.

Among them, the physical layer frame structure of TD-LTE is 10ms, including two half-frames of 5ms, and its uplink and downlink subframe configuration is shown in Table 1:

Table 1

As shown in Table 1, for a TDD structure with a 5ms downlink-to-uplink conversion period, one frame contains 8 normal subframes and 2 special subframes, and whether the 8 normal subframes are used for uplink or downlink can refer to Table 1 . For the TDD structure with a 10ms downlink-to-uplink conversion period, a frame contains 9 normal subframes and a special subframe, and whether the 9 normal subframes are used for uplink or downlink can refer to Table 1. Each normal subframe It also contains 14 symbols (symbols).

The HARQ (Hybrid Automatic Repeat Request) mechanism is an important part of ensuring transmission reliability in the LTE system, and the timing of the HARQ process in different subframe configurations ensures efficient use of time-frequency resources. The traditional HARQ timing downlink adopts an asynchronous method, that is, the receiving end does not know the time when the transmission occurs in advance, so in asynchronous HARQ, signaling is required to indicate the HARQ process number of the current transmission. Asynchronous HARQ does not need to consider the timing of first transmission and retransmission, so the protocol only defines the timing relationship from sending downlink data to uplink feedback of ACK/NACK through PUCCH (Physical Uplink Control Channel, Physical Uplink Control Channel), as shown in Table 2. Show:

Table 2

As shown in Table 2, the number k in the table represents: if the downlink data is transmitted in subframe n, the corresponding ACK/NACK information will be fed back in the subframe whose subframe number is n+k; if n+ k>9, it means that ACK/NACK information should be fed back in the subframe whose subframe number of the first radio frame after the current radio frame is (n+k)%10 (% is a remainder symbol); when n+k When >19, the ACK/NACK information is fed back in the subframe whose subframe number is (n+k)%10 in the second radio frame after the current radio frame.

The traditional HARQ timing upstream adopts synchronous HARQ. The transmission and retransmission of a HARQ process have a fixed timing relationship. Since the receiving end knows the time when the transmission occurs in advance, no additional signaling is required to indicate the HARQ process number. The protocol defines two timing relationships for uplink synchronous HARQ, one is the timing relationship from the base station sending the uplink scheduling command on the PDCCH (Physical Downlink Control Channel) to the terminal sending the corresponding uplink data, and the other is from the terminal sending the uplink The timing relationship of ACK/NACK feedback from data to the base station. Among them, Table 3 shows the timing relationship when the terminal sends uplink data to the base station to feed back ACK/NACK:

table 3

As shown in Table 3, the number k in the table represents: if the uplink data is transmitted on the subframe with the subframe number n, the ACK/NACK feedback information in the PHICH (Physical Hybird ARQ Indicator Channel, physical HARQ indicator channel) is in It is transmitted in the subframe whose subframe number is n+k. If the situation of n+k>9 or n+k>19 occurs, it shall be handled according to the processing method for the same situation of downlink HARQ timing.

Since the LTE access system on the licensed frequency band can use channel resources at any time, the timing of the HARQ process shows good continuity. However, due to the introduction of the LBT mechanism in the unlicensed frequency band, the LTE system cannot occupy channel resources all the time. If the HARQ mechanism still uses the timing rules on the licensed frequency band, it may cause the HARQ process to occupy less time at the transmission data time specified in the timing sequence. to the channel resource and cannot transmit data. If such a situation always occurs in a certain HARQ process, the average time delay of the HARQ process will be increased and user experience will be degraded. The specific questions are as follows:

As shown in FIG. 1 , taking TDD mode configuration #1 as an example, the base station successfully transmits data of downlink HARQ process 1 when subframe 0 of radio frame 1 occupies channel resources. However, subframes 4 and 5 of radio frame 1 and subframe 4 of radio frame 2 do not occupy channel resources, so downlink data in processes 3, 4, and 2 cannot be sent.

For the uplink HARQ process, there is also a situation that the uplink data cannot be sent because the channel cannot be occupied at a specified time. As shown in Figure 2, taking TDD configuration #1 as an example, the terminal sends uplink data in subframe 2 of radio frame 1. According to the timing rules, the base station should feed back ACK/NACK information in subframe 6 of radio frame 1. At this moment, the uplink subframe successfully seizes the channel, and the uplink data is successfully sent. However, subframe No. 7 of radio frame 1 and subframe No. 3 of radio frame 2 do not occupy channel resources, so uplink data cannot be sent.

If the above situation always occurs in a certain HARQ process, the delay of the HARQ process will be very large, the fairness of resource allocation of each HARQ process cannot be guaranteed, and data loss may occur, seriously affecting user experience and throughput Quantitative performance.

Therefore, how to prevent the HARQ process from always occupying less than channel resources and unable to send data, reduce the average time delay of the HARQ process, and ensure the fairness of resource utilization by the HARQ process has become an urgent technical problem to be solved.

SUMMARY OF THE INVENTION

Based on at least one of the above-mentioned technical problems, the present invention proposes a new HARQ process transmission scheme on an unlicensed frequency band, which can avoid the problem that the HARQ process cannot send data because the channel is always occupied, and reduces the The average time delay of the HARQ process ensures the fairness of resource utilization among the HARQ processes, which is conducive to improving the throughput of the system.

In view of this, according to the first aspect of the present invention, a HARQ process transmission method on an unlicensed frequency band is proposed, including: the statistical data sender performs a channel detection mechanism on the unlicensed frequency band so that each HARQ process misses a repeat The number of transmission times, and/or statistics of the time elapsed from the establishment of each HARQ process to the receipt of the ACK message by the data sender; according to the number of times each HARQ process misses retransmissions, and/or each HARQ process Determine the transmission priority of each HARQ process during retransmission from the establishment to the time elapsed before the data sender receives the ACK message; each time it is detected that the channel in the unlicensed frequency band can be occupied, according to the Transmission resources are allocated to each HARQ process according to its transmission priority when performing retransmission.

In this technical solution, by counting the number of times that each HARQ process misses retransmission due to the channel detection mechanism performed by the data sending end on the unlicensed frequency band, and/or counting the number of times each HARQ process receives ACK from the establishment to the data sending end The length of time experienced before the message is used to determine the transmission priority of each HARQ process when retransmitting, and to allocate transmission resources to it according to the determined transmission priority, so that for HARQ processes that miss a large number of retransmissions, And/or the HARQ process that takes a long time before the data sender receives the ACK message can be given priority to allocate transmission resources, so as to avoid the problem that the HARQ process cannot send data because the channel is always occupied, The average time delay of the HARQ process is reduced, and the fairness of resource utilization among the HARQ processes is ensured, which is beneficial to improving the throughput of the system.

Wherein, the data sending end may be either a base station or a terminal. When the data sending end is a base station, the HARQ process is a downlink HARQ process; when the data sending end is a terminal, the HARQ process is an uplink HARQ process.

In the above technical solution, preferably, the transmission priority of each HARQ process when performing retransmission and the number of times each HARQ process misses retransmission, and/or each HARQ process from establishment to data The time elapsed before the sender receives the ACK message is positively correlated.

In this technical solution, by making the transmission priority of the HARQ process during retransmission positively correlated with the number of times the HARQ process misses retransmission, the HARQ process with more missed retransmissions can get a higher transmission priority , which can avoid the problem that the HARQ process cannot send data because it always does not occupy the channel, and reduces the average delay of the HARQ process; similarly, by making the transmission priority of the HARQ process when retransmitting The time elapsed from the establishment until the data sender receives the ACK message is positively correlated, so that the HARQ process with a longer delay can obtain a higher transmission priority, thereby reducing the average delay of the HARQ process.

In any of the above technical solutions, preferably, the said In the case of the transmission priority of each HARQ process when performing retransmission, the step of determining the transmission priority of each HARQ process when performing retransmission specifically includes: according to each HARQ process missing retransmission The number of times determines the transmission priority of the HARQ process during retransmission; when multiple HARQ processes miss the same number of retransmissions, according to the length of time elapsed from the establishment of the multiple HARQ processes to the data sender receiving the ACK message Determine transmission priorities of the multiple HARQ processes during retransmission.

In any of the above technical solutions, preferably, the HARQ process transmission method on the unlicensed frequency band further includes: if any HARQ process misses the number of retransmissions reaching a predetermined number of times, and/or any HARQ process from If the time elapsed from the establishment to the time when the data sending end receives the ACK message reaches the first predetermined time length, any HARQ process is discarded.

In any of the above technical solutions, preferably, further comprising: if there are still available transmission resources after allocating transmission resources to each HARQ process, then determining whether there are other HARQ processes that need to be retransmitted; For other HARQ processes that need to be retransmitted, determine the transmission priorities of the other HARQ processes, and allocate transmission resources to the other HARQ processes according to the priorities of the other HARQ processes.

In this technical solution, after allocating transmission resources to each of the above HARQ processes, if there are still available transmission resources, it can be determined whether there are other HARQ processes that need to be retransmitted, and after determining that there are other HARQ processes that need to be retransmitted When , the transmission resources are allocated to other HARQ processes according to their priorities, so that the transmission resources can be fully utilized and the utilization rate of resources can be improved. Wherein, if it is determined that there is no other HARQ process that needs to be retransmitted, a new HARQ process may be established using the remaining transmission resources.

In any of the above technical solutions, preferably, when the HARQ process is a downlink HARQ process, the step of allocating transmission resources to each HARQ process according to its transmission priority when retransmitting, specifically includes : Every time it is detected that the downlink channel of the unlicensed frequency band can be occupied, the transmission resource of the second predetermined duration starting from the current subframe is allocated to a predetermined number of HARQ processes, wherein, if starting from the current subframe to the first The duration before a non-downlink subframe is greater than or equal to the predetermined value T, then use the predetermined value T as the second predetermined duration; if the duration from the current subframe to the first non-downlink subframe is If it is less than the predetermined value T, the time length from the current subframe to the first non-downlink subframe is used as the second predetermined time length, where the predetermined value T is the maximum occupied time of the channel.

In this technical scheme, since the detection of the downlink channel is performed in the downlink subframe, if it is detected that the downlink channel of the unlicensed frequency band can be occupied, the second subframe starting from the current subframe (that is, the downlink subframe) can be Transmission resources of a predetermined duration are allocated to a predetermined number of HARQ processes. Wherein, the determination of the second predetermined duration can be determined according to the maximum occupied duration of the channel and the number of continuous downlink subframes. If the duration of the continuous downlink subframes does not reach the maximum occupied duration of the channel, the duration of the continuous downlink subframes As the second predetermined duration, if the duration of consecutive downlink subframes is greater than the maximum channel occupation duration, then the maximum channel occupation duration is used as the second predetermined duration.

In any of the above technical solutions, preferably, when the HARQ process is an uplink HARQ process, the step of allocating transmission resources to each HARQ process according to its transmission priority when retransmitting, specifically includes : Every time it is detected that the uplink channel of the unlicensed frequency band can be occupied, the transmission resource corresponding to the first uplink subframe after that is allocated to the HARQ process with the highest priority, and continues before the second uplink subframe after that Detecting the channel state of the unlicensed frequency band; or allocating transmission resources corresponding to a predetermined number of uplink subframes starting from the first uplink subframe after each time the channel of the unlicensed frequency band is detected to be occupied by a predetermined The number of HARQ processes.

In this technical solution, since the detection of the uplink channel is performed before the uplink subframe, if it is detected that the uplink channel of the unlicensed frequency band can be occupied each time, only the transmission resources corresponding to the subsequent uplink subframe can be Assigned to the HARQ process with the highest priority, that is, the channel status needs to be detected before occupying the uplink subframe each time; The transmission resource corresponding to the frame is allocated to a predetermined number of HARQ processes. Among them, there are two ways to determine the actual number of the predetermined number: one is the number of continuous uplink subframes after the channel is detected to be idle, that is, the continuous uplink subframes after the channel is detected to be idle are used to carry out For HARQ transmission, for example, if there are 3 uplink subframes after the channel is detected to be idle, then these 3 uplink subframes are used to transmit the HARQ process; the other is part of the continuous uplink subframes after the channel is detected to be idle Uplink subframes, for example, there are 3 uplink subframes after the channel is detected to be idle, if the first 2 uplink subframes are not allocated to other users, and the third uplink subframe is allocated to other users, only the first 2 will be occupied The uplink subframe is used to transmit the HARQ process, and after the occupancy is completed, the channel detection is performed again.

According to the second aspect of the present invention, a HARQ process transmission device on an unlicensed frequency band is also proposed, including: a statistical unit, which is used to count the number of HARQ processes of each HARQ process at the unlicensed frequency band due to the execution of the channel detection mechanism by the data sending end. The number of missed retransmissions, and/or counting the length of time each HARQ process elapses from establishment to data sending end receiving the ACK message; a determining unit, configured to miss the number of retransmissions according to each HARQ process, and/or Or the length of time experienced by each HARQ process from being established to when the data sending end receives the ACK message, and determining the transmission priority of each HARQ process when performing retransmission; the allocation unit is used for each When it is detected that the channel of the unlicensed frequency band can be occupied for the first time, the transmission resource is allocated to each HARQ process according to the transmission priority when performing retransmission.

In this technical solution, by counting the number of times that each HARQ process misses retransmission due to the channel detection mechanism performed by the data sending end on the unlicensed frequency band, and/or counting the number of times each HARQ process receives ACK from the establishment to the data sending end The length of time experienced before the message is used to determine the transmission priority of each HARQ process when retransmitting, and to allocate transmission resources to it according to the determined transmission priority, so that for HARQ processes that miss a large number of retransmissions, And/or the HARQ process that takes a long time before the data sender receives the ACK message can be given priority to allocate transmission resources, so as to avoid the problem that the HARQ process cannot send data because the channel is always occupied, The average time delay of the HARQ process is reduced, and the fairness of resource utilization among the HARQ processes is ensured, which is beneficial to improving the throughput of the system.

Wherein, the data sending end may be either a base station or a terminal. When the data sending end is a base station, the HARQ process is a downlink HARQ process; when the data sending end is a terminal, the HARQ process is an uplink HARQ process.

In the above technical solution, preferably, the transmission priority of each HARQ process when performing retransmission and the number of times each HARQ process misses retransmission, and/or each HARQ process from establishment to data The time elapsed before the sender receives the ACK message is positively correlated.

In this technical solution, by making the transmission priority of the HARQ process during retransmission positively correlated with the number of times the HARQ process misses retransmission, the HARQ process with more missed retransmissions can get a higher transmission priority , which can avoid the problem that the HARQ process cannot send data because it always does not occupy the channel, and reduces the average delay of the HARQ process; similarly, by making the transmission priority of the HARQ process when retransmitting The time elapsed from the establishment until the data sender receives the ACK message is positively correlated, so that the HARQ process with a longer delay can obtain a higher transmission priority, thereby reducing the average delay of the HARQ process.

In any of the above technical solutions, preferably, the said In the case of the transmission priority of each HARQ process during retransmission, the determining unit is specifically configured to: determine the transmission priority of the HARQ process during retransmission according to the number of times each HARQ process misses retransmission ; When multiple HARQ processes miss the same number of retransmissions, determine the transmission priority of the multiple HARQ processes during retransmission according to the time elapsed from the establishment of the multiple HARQ processes to the time the data sender receives the ACK message class.

In any of the above technical solutions, preferably, the HARQ process transmission device on the unlicensed frequency band further includes: a processing unit, which is used to count the number of missed retransmissions of any HARQ process in the statistics unit. The predetermined number of times, and/or when the time period elapsed from the establishment of any HARQ process to the receipt of the ACK message by the data sending end reaches the first predetermined time length, the said any HARQ process is discarded.

In any of the above technical solutions, preferably, the determining unit is further configured to: if there are still available transmission resources after the allocating unit allocates transmission resources to each HARQ process, determine whether there is a need Other HARQ processes for retransmission; if there are other HARQ processes that need to be retransmitted, determine the transmission priorities of the other HARQ processes, and allocate transmission resources to them according to the priorities of the other HARQ processes.

In this technical solution, after allocating transmission resources to each of the above HARQ processes, if there are still available transmission resources, it can be determined whether there are other HARQ processes that need to be retransmitted, and after determining that there are other HARQ processes that need to be retransmitted When , the transmission resources are allocated to other HARQ processes according to their priorities, so that the transmission resources can be fully utilized and the utilization rate of resources can be improved. Wherein, if it is determined that there is no other HARQ process that needs to be retransmitted, a new HARQ process may be established using the remaining transmission resources.

In any of the above technical solutions, preferably, when the HARQ process is a downlink HARQ process, the allocating unit is specifically configured to: detect that the downlink channel of the unlicensed frequency band can be occupied each time at the data sending end , allocate the transmission resources of the second predetermined duration from the current subframe to a predetermined number of HARQ processes, wherein, if the duration from the current subframe to the first non-downlink subframe is greater than or equal to the predetermined value T, the predetermined value T is used as the second predetermined duration; if the duration from the beginning of the current subframe to the first non-downlink subframe is less than the predetermined value T, the current subframe is The duration before the first non-downlink subframe is used as the second predetermined duration, where the predetermined value T is the maximum occupied duration of the channel.

In this technical scheme, since the detection of the downlink channel is performed in the downlink subframe, if it is detected that the downlink channel of the unlicensed frequency band can be occupied, the second subframe starting from the current subframe (that is, the downlink subframe) can be Transmission resources of a predetermined duration are allocated to a predetermined number of HARQ processes. Wherein, the determination of the second predetermined duration can be determined according to the maximum occupied duration of the channel and the number of continuous downlink subframes. If the duration of the continuous downlink subframes does not reach the maximum occupied duration of the channel, the duration of the continuous downlink subframes As the second predetermined duration, if the duration of consecutive downlink subframes is greater than the maximum channel occupation duration, then the maximum channel occupation duration is used as the second predetermined duration.

In any of the above technical solutions, preferably, when the HARQ process is an uplink HARQ process, the allocating unit is specifically configured to detect that the uplink channel of the unlicensed frequency band can be occupied every time at the data sending end , assign the transmission resource corresponding to the first uplink subframe to the HARQ process with the highest priority, and continue to detect the channel state of the unlicensed frequency band before the second uplink subframe; or Each time the data sending end detects that the uplink channel of the unlicensed frequency band can be occupied, it allocates the transmission resources corresponding to the predetermined number of uplink subframes starting from the first subsequent uplink subframe to the predetermined number of HARQ processes.

In this technical solution, since the detection of the uplink channel is performed before the uplink subframe, if it is detected that the uplink channel of the unlicensed frequency band can be occupied each time, only the transmission resources corresponding to the subsequent uplink subframe can be Assigned to the HARQ process with the highest priority, that is, the channel status needs to be detected before occupying the uplink subframe each time; The transmission resource corresponding to the frame is allocated to a predetermined number of HARQ processes. Among them, there are two ways to determine the actual number of the predetermined number: one is the number of continuous uplink subframes after the channel is detected to be idle, that is, the continuous uplink subframes after the channel is detected to be idle are used to carry out For HARQ transmission, for example, if there are 3 uplink subframes after the channel is detected to be idle, then these 3 uplink subframes are used to transmit the HARQ process; the other is part of the continuous uplink subframes after the channel is detected to be idle Uplink subframes, for example, there are 3 uplink subframes after the channel is detected to be idle, if the first 2 uplink subframes are not allocated to other users, and the third uplink subframe is allocated to other users, only the first 2 will be occupied The uplink subframe is used to transmit the HARQ process, and after the occupancy is completed, the channel detection is performed again.

Through the above technical solutions, it is possible to avoid the problem that the HARQ process cannot send data due to the fact that the channel is always occupied, which reduces the average delay of the HARQ process, ensures the fairness of resource utilization among the HARQ processes, and is conducive to improving the system. throughput.

Description of drawings

Figure 1 shows a schematic diagram in which the downlink HARQ process cannot be sent due to the timing rules on the licensed frequency band being used in the unlicensed frequency band;

Fig. 2 shows a schematic diagram in which the uplink HARQ process cannot be sent due to the unlicensed frequency band following the timing rules on the licensed frequency band;

FIG. 3 shows a schematic flowchart of a HARQ process transmission method on an unlicensed frequency band according to a first embodiment of the present invention;

FIG. 4 shows a schematic block diagram of a HARQ process transmission device on an unlicensed frequency band according to a first embodiment of the present invention;

Fig. 5 shows a schematic block diagram of a base station according to an embodiment of the present invention;

FIG. 6 shows a schematic block diagram of a HARQ process transmission device on an unlicensed frequency band according to a second embodiment of the present invention;

Fig. 7 shows a schematic block diagram of a terminal according to an embodiment of the present invention;

FIG. 8 shows a schematic flowchart of a HARQ process transmission method according to a second embodiment of the present invention;

FIG. 9 shows a schematic diagram of consecutive occupation of multiple downlink subframes by a downlink HARQ process according to an embodiment of the present invention;

FIG. 10A shows a schematic diagram of a frame structure in which an uplink subframe exists alone;

FIG. 10B shows a schematic diagram of a frame structure in which uplink subframes exist continuously.

Detailed ways

In order to understand the above-mentioned purpose, features and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described here. Therefore, the protection scope of the present invention is not limited by the specific details disclosed below. EXAMPLE LIMITATIONS.

Fig. 3 shows a schematic flowchart of a HARQ process transmission method on an unlicensed frequency band according to a first embodiment of the present invention.

As shown in FIG. 3, the HARQ process transmission method on the unlicensed frequency band according to the first embodiment of the present invention includes:

Step S30, counting the number of times each HARQ process misses retransmissions due to the channel detection mechanism performed by the data sending end on the unlicensed frequency band, and/or counting the number of times each HARQ process has experienced from the establishment to the data sending end receiving the ACK message duration.

Step S32, according to the number of times each HARQ process misses retransmissions, and/or the duration of each HARQ process from being established to when the data sender receives an ACK message, determine that each HARQ process is in progress Transmission priority when retransmitting.

Wherein, the transmission priority of each HARQ process during retransmission and the number of times each HARQ process misses retransmissions, and/or the experience of each HARQ process from being established to when the data sender receives the ACK message The duration is positively correlated.

Specifically, by making the transmission priority of the HARQ process when retransmission is positively correlated with the number of times the HARQ process misses retransmissions, the HARQ process with more missed retransmissions can obtain a higher transmission priority, and then can Avoiding the problem that the HARQ process cannot send data due to the fact that the channel is not always occupied, and reduces the average delay of the HARQ process; similarly, by making the transmission priority of the HARQ process when retransmitting The time elapsed before the data sender receives the ACK message is positively correlated, so that the HARQ process with a large delay can obtain a higher transmission priority, thereby reducing the average delay of the HARQ process.

Step S34, each time it is detected that the channel in the unlicensed frequency band can be occupied, allocate transmission resources to each HARQ process according to the transmission priority when performing retransmission.

In this technical solution, by counting the number of times that each HARQ process misses retransmission due to the channel detection mechanism performed by the data sending end on the unlicensed frequency band, and/or counting the number of times each HARQ process receives ACK from the establishment to the data sending end The length of time experienced before the message is used to determine the transmission priority of each HARQ process when retransmitting, and to allocate transmission resources to it according to the determined transmission priority, so that for HARQ processes that miss a large number of retransmissions, And/or the HARQ process that takes a long time before the data sender receives the ACK message can be given priority to allocate transmission resources, so as to avoid the problem that the HARQ process cannot send data because the channel is always occupied, The average time delay of the HARQ process is reduced, and the fairness of resource utilization among the HARQ processes is ensured, which is beneficial to improving the throughput of the system.

In any of the above technical solutions, preferably, the said In the case of the transmission priority of each HARQ process when performing retransmission, the step of determining the transmission priority of each HARQ process when performing retransmission specifically includes: according to each HARQ process missing retransmission The number of times determines the transmission priority of the HARQ process during retransmission; when multiple HARQ processes miss the same number of retransmissions, according to the length of time elapsed from the establishment of the multiple HARQ processes to the data sender receiving the ACK message Determine transmission priorities of the multiple HARQ processes during retransmission.

In any of the above technical solutions, preferably, the HARQ process transmission method on the unlicensed frequency band further includes: if any HARQ process misses the number of retransmissions reaching a predetermined number of times, and/or any HARQ process from If the time elapsed from the establishment to the time when the data sending end receives the ACK message reaches the first predetermined time length, any HARQ process is discarded.

In any of the above technical solutions, preferably, further comprising: if there are still available transmission resources after allocating transmission resources to each HARQ process, then determining whether there are other HARQ processes that need to be retransmitted; For other HARQ processes that need to be retransmitted, determine the transmission priorities of the other HARQ processes, and allocate transmission resources to the other HARQ processes according to the priorities of the other HARQ processes.

In this technical solution, after allocating transmission resources to each of the above HARQ processes, if there are still available transmission resources, it can be determined whether there are other HARQ processes that need to be retransmitted, and after determining that there are other HARQ processes that need to be retransmitted When , the transmission resources are allocated to other HARQ processes according to their priorities, so that the transmission resources can be fully utilized and the utilization rate of resources can be improved. Wherein, if it is determined that there is no other HARQ process that needs to be retransmitted, a new HARQ process may be established using the remaining transmission resources.

Wherein, the data sending end mentioned in the above scheme can be either a base station or a terminal. When the data sending end is a base station, the HARQ process is a downlink HARQ process; when the data sending end is a terminal, the HARQ process is an uplink HARQ process. The following describes the specific resource allocation process for the uplink HARQ process and the downlink HARQ process:

1. For the downlink HARQ process.

When the HARQ process is a downlink HARQ process, the step of allocating transmission resources to each HARQ process according to the transmission priority of each HARQ process during retransmission in the above step S34 specifically includes: When the channel is available, allocate the transmission resources of the second predetermined duration starting from the current subframe to a predetermined number of HARQ processes, wherein, if the duration from the current subframe to the first non-downlink subframe is greater than or equal to a predetermined value T, then use the predetermined value T as the second predetermined duration; if the duration from the beginning of the current subframe to the first non-downlink subframe is less than the predetermined value T, then use the The duration from the current subframe to the first non-downlink subframe is used as the second predetermined duration, where the predetermined value T is the maximum occupied duration of the channel.

In this technical scheme, since the detection of the downlink channel is performed in the downlink subframe, if it is detected that the downlink channel of the unlicensed frequency band can be occupied, the second subframe starting from the current subframe (that is, the downlink subframe) can be Transmission resources of a predetermined duration are allocated to a predetermined number of HARQ processes. Wherein, the determination of the second predetermined duration can be determined according to the maximum occupied duration of the channel and the number of continuous downlink subframes. If the duration of the continuous downlink subframes does not reach the maximum occupied duration of the channel, the duration of the continuous downlink subframes As the second predetermined duration, if the duration of consecutive downlink subframes is greater than the maximum channel occupation duration, then the maximum channel occupation duration is used as the second predetermined duration.

2. For the uplink HARQ process.

When the HARQ process is an uplink HARQ process, the step of allocating transmission resources to each HARQ process according to the transmission priority of each HARQ process during retransmission in the above step S34 specifically includes: When the channel is available, allocate the transmission resource corresponding to the first uplink subframe after that to the HARQ process with the highest priority, and continue to detect the channel status of the unlicensed frequency band before the second uplink subframe thereafter; or When it is detected that the channel in the unlicensed frequency band can be occupied, the transmission resources corresponding to the predetermined number of uplink subframes starting from the first subsequent uplink subframe are allocated to the predetermined number of HARQ processes.

In this technical solution, since the detection of the uplink channel is performed before the uplink subframe, if it is detected that the uplink channel of the unlicensed frequency band can be occupied each time, only the transmission resources corresponding to the subsequent uplink subframe can be Assigned to the HARQ process with the highest priority, that is, the channel status needs to be detected before occupying the uplink subframe each time; The transmission resource corresponding to the frame is allocated to a predetermined number of HARQ processes. Among them, there are two ways to determine the actual number of the predetermined number: one is the number of continuous uplink subframes after the channel is detected to be idle, that is, the continuous uplink subframes after the channel is detected to be idle are used to carry out For HARQ transmission, for example, if there are 3 uplink subframes after the channel is detected to be idle, then these 3 uplink subframes are used to transmit the HARQ process; the other is part of the continuous uplink subframes after the channel is detected to be idle Uplink subframes, for example, there are 3 uplink subframes after the channel is detected to be idle, if the first 2 uplink subframes are not allocated to other users, and the third uplink subframe is allocated to other users, only the first 2 will be occupied The uplink subframe is used to transmit the HARQ process, and after the occupancy is completed, the channel detection is performed again.

Fig. 4 shows a schematic block diagram of an apparatus for transmitting a HARQ process on an unlicensed frequency band according to a first embodiment of the present invention.

As shown in FIG. 4 , the apparatus 400 for HARQ process transmission on an unlicensed frequency band according to the first embodiment of the present invention includes: a statistics unit 402 , a determination unit 404 and an allocation unit 406 .

Among them, the statistical unit 402 is used to count the number of times that each downlink HARQ process misses retransmissions due to the channel detection mechanism performed by the base station on the unlicensed frequency band, and/or count each downlink HARQ process from establishment to before the base station receives the ACK message The elapsed duration; the determining unit 404 is configured to determine the elapsed time according to the number of times each downlink HARQ process misses retransmissions, and/or the elapsed time of each downlink HARQ process from being established to when the base station receives an ACK message The transmission priority of each downlink HARQ process during retransmission; the allocation unit 406 is configured to, when the base station detects that the channel of the unlicensed frequency band can be occupied, according to the priority of each downlink HARQ process during retransmission The transmission priority assigns transmission resources to it.

In this technical solution, by counting the number of times that each downlink HARQ process misses retransmissions due to the channel detection mechanism performed by the base station on the unlicensed frequency band, and/or counting the number of times each downlink HARQ process is set up to before the base station receives the ACK message to determine the transmission priority of each downlink HARQ process during retransmission, and allocate transmission resources to it according to the determined transmission priority, so that for the downlink HARQ process with a large number of missed retransmissions, And/or the downlink HARQ process with a long time elapsed from the establishment until the base station receives the ACK message can be given priority to allocate transmission resources, thereby avoiding the problem that the downlink HARQ process cannot send data because the channel is always occupied, The average time delay of the downlink HARQ process is reduced, and the fairness of resource utilization between the downlink HARQ processes is ensured, which is conducive to improving the throughput of the system.

In the above technical solution, preferably, the transmission priority of each downlink HARQ process when performing retransmission and the number of times each downlink HARQ process misses retransmission, and/or each downlink HARQ process The time length elapsed until the base station receives the ACK message is positively correlated.

In this technical solution, the transmission priority of the downlink HARQ process during retransmission is positively correlated with the number of missed retransmissions of the downlink HARQ process, so that the downlink HARQ process with more missed retransmissions can get a higher transmission priority, thereby avoiding the problem that the downlink HARQ process cannot send data due to the fact that the channel is not always occupied, and reduces the average delay of the downlink HARQ process; similarly, by making the downlink HARQ process retransmit The transmission priority is positively correlated with the time elapsed from the establishment of the downlink HARQ process until the base station receives the ACK message, so that the downlink HARQ process with a large delay can obtain a higher transmission priority, thereby reducing the downlink HARQ process. average latency.

In any of the above technical solutions, preferably, according to the number of times each downlink HARQ process misses retransmissions and the duration of each downlink HARQ process from being established to when the base station receives an ACK message, determine the In the case of the transmission priority of each downlink HARQ process during retransmission, the determining unit 404 is specifically configured to: determine the retransmission of the downlink HARQ process according to the number of times each downlink HARQ process misses retransmission when multiple downlink HARQ processes miss retransmissions for the same number of times, determine that the multiple downlink HARQ processes are retransmitted according to the length of time elapsed from the establishment of the multiple downlink HARQ processes until the base station receives the ACK message The transmission priority of the transmission time.

In any of the above technical solutions, preferably, the device 400 for transmitting the downlink HARQ process on the unlicensed frequency band further includes: a processing unit 408, configured to count any downlink HARQ process missed by the statistics unit 402 When the number of times of transmission reaches the predetermined number, and/or the time length of any downlink HARQ process from establishment to the time when the base station receives the ACK message reaches the first predetermined time length, the said any downlink HARQ process is discarded.

In any of the above technical solutions, preferably, the determining unit 404 is further configured to: if there are still available transmission resources after the allocating unit 406 allocates transmission resources to each downlink HARQ process, determine Whether there are other downlink HARQ processes that need to be retransmitted; if there are other downlink HARQ processes that need to be retransmitted, determine the transmission priority of the other downlink HARQ processes, and allocate them to them according to the priorities of the other downlink HARQ processes transfer resources.

In this technical solution, after allocating transmission resources to each of the above-mentioned downlink HARQ processes, if there are still available transmission resources, it can be determined whether there are other downlink HARQ processes that need to be retransmitted. After determining that there are other downlink HARQ processes that need to be retransmitted During the downlink HARQ process, transmission resources are allocated to other downlink HARQ processes according to their priorities, so as to ensure that the transmission resources are fully utilized and improve resource utilization. Wherein, if it is determined that there is no other downlink HARQ process that needs to be retransmitted, the remaining transmission resources may be used to establish a new HARQ process.

In any of the above-mentioned technical solutions, preferably, the allocating unit 406 is specifically configured to: each time the base station detects that the downlink channel of the unlicensed frequency band can be occupied, assign the second predetermined duration starting from the current subframe to The transmission resources are allocated to a predetermined number of downlink HARQ processes, wherein, if the duration from the current subframe to the first non-downlink subframe is greater than or equal to a predetermined value T, the predetermined value T is used as the first Two predetermined durations; if the duration from the current subframe to the first non-downlink subframe is less than the predetermined value T, the duration from the current subframe to the first non-downlink subframe As the second predetermined duration, the predetermined value T is the maximum occupied duration of the channel.

In this technical scheme, since the detection of the downlink channel is performed in the downlink subframe, if it is detected that the downlink channel of the unlicensed frequency band can be occupied, the second subframe starting from the current subframe (that is, the downlink subframe) can be Transmission resources of a predetermined duration are allocated to a predetermined number of downlink HARQ processes. Wherein, the determination of the second predetermined duration can be determined according to the maximum occupied duration of the channel and the number of continuous downlink subframes. If the duration of the continuous downlink subframes does not reach the maximum occupied duration of the channel, the duration of the continuous downlink subframes As the second predetermined duration, if the duration of consecutive downlink subframes is greater than the maximum channel occupation duration, then the maximum channel occupation duration is used as the second predetermined duration.

Fig. 5 shows a schematic block diagram of a base station according to an embodiment of the present invention.

As shown in FIG. 5 , a base station 500 according to an embodiment of the present invention includes: an apparatus 400 for transmitting a HARQ process on an unlicensed frequency band as shown in FIG. 4 .

Fig. 6 shows a schematic block diagram of an apparatus for transmitting a HARQ process on an unlicensed frequency band according to a second embodiment of the present invention.

As shown in FIG. 6 , an apparatus 600 for transmitting a HARQ process on an unlicensed frequency band according to a second embodiment of the present invention includes: a statistics unit 602 , a determination unit 604 and an allocation unit 606 .

Among them, the statistical unit 602 is used to count the number of times that each uplink HARQ process misses retransmission due to the channel detection mechanism performed by the terminal on the unlicensed frequency band, and/or count each uplink HARQ process from establishment to before the terminal receives the ACK message The elapsed duration; the determining unit 604 is configured to determine the elapsed time according to the number of times each uplink HARQ process misses retransmissions, and/or the elapsed time of each uplink HARQ process from being established to when the terminal receives an ACK message The transmission priority of each uplink HARQ process during retransmission; the allocation unit 606 is configured to, when the terminal detects that the channel of the unlicensed frequency band can be occupied, according to the transmission priority of each uplink HARQ process during retransmission The transmission priority assigns transmission resources to it.

In this technical solution, by counting the number of times that each uplink HARQ process misses retransmission due to the channel detection mechanism performed by the terminal on the unlicensed frequency band, and/or counting the number of times each uplink HARQ process is established to before the terminal receives the ACK message The elapsed time is used to determine the transmission priority of each uplink HARQ process during retransmission, and allocate transmission resources to it according to the determined transmission priority, so that for the uplink HARQ process that misses a large number of retransmissions, And/or the uplink HARQ process that takes a long time before the terminal receives the ACK message can be given priority to allocate transmission resources, so as to avoid the problem that the uplink HARQ process cannot send data because the channel is always occupied, The average time delay of the uplink HARQ process is reduced, and the resource utilization fairness between the uplink HARQ processes is ensured, which is beneficial to improving the throughput of the system.

In the above technical solution, preferably, the transmission priority of each uplink HARQ process when performing retransmission and the number of times each uplink HARQ process misses retransmission, and/or each uplink HARQ process The time length elapsed until the terminal receives the ACK message is positively correlated.

In this technical solution, by making the transmission priority of the uplink HARQ process when retransmission is positively correlated with the number of times the uplink HARQ process misses retransmission, the uplink HARQ process with more missed retransmissions can get a higher Transmission priority, thereby avoiding the problem that the uplink HARQ process cannot send data due to the fact that the uplink HARQ process cannot always occupy the channel, and reduces the average delay of the uplink HARQ process; similarly, by making the uplink HARQ process retransmit The transmission priority is positively correlated with the time elapsed from the establishment of the uplink HARQ process until the terminal receives the ACK message, so that the uplink HARQ process with a large delay can obtain a higher transmission priority, thereby reducing the overhead of the uplink HARQ process. average latency.

In any of the above technical solutions, preferably, according to the number of times each uplink HARQ process misses retransmissions and the time elapsed before each uplink HARQ process is established until the terminal receives an ACK message, determine the In the case of the transmission priority of each uplink HARQ process during retransmission, the determining unit 604 is specifically configured to: determine the retransmission of the uplink HARQ process according to the number of times each uplink HARQ process misses retransmission when multiple uplink HARQ processes miss retransmissions for the same number of times, determine the number of times that the multiple uplink HARQ processes are retransmitted according to the time elapsed from the establishment of the multiple uplink HARQ processes until the terminal receives the ACK message The transmission priority of the transmission time.

In any of the above technical solutions, preferably, the device 600 for transmitting the uplink HARQ process on the unlicensed frequency band further includes: a processing unit 608, configured to make statistics in the statistics unit 602 that any uplink HARQ process misses When the number of times of transmission reaches a predetermined number of times, and/or the time length of any uplink HARQ process from establishment to the terminal receiving the ACK message reaches the first predetermined time length, the any uplink HARQ process is discarded.

In any of the above technical solutions, preferably, the determining unit 604 is further configured to: if there are still available transmission resources after the allocation unit 606 allocates transmission resources to each uplink HARQ process, determine Whether there are other uplink HARQ processes that need to be retransmitted; if there are other uplink HARQ processes that need to be retransmitted, determine the transmission priority of the other uplink HARQ processes, and assign them to the other according to the priorities of the other uplink HARQ processes transfer resources.

In this technical solution, after allocating transmission resources to each of the above-mentioned uplink HARQ processes, if there are still available transmission resources, it can be determined whether there are other uplink HARQ processes that need to be retransmitted, and after determining that there are other uplink HARQ processes that need to be retransmitted During the uplink HARQ process, transmission resources are allocated to other uplink HARQ processes according to their priorities, so that the transmission resources can be fully utilized and the utilization rate of resources can be improved. Wherein, if it is determined that there is no other uplink HARQ process that needs to be retransmitted, the remaining transmission resources may be used to establish a new HARQ process.

In any of the above-mentioned technical solutions, preferably, the allocating unit 606 is specifically configured to: each time the terminal detects that the uplink channel of the unlicensed frequency band can be occupied, the transmission corresponding to the next first uplink subframe Resources are allocated to the uplink HARQ process with the highest priority, and the channel status of the unlicensed frequency band is continuously detected before the second uplink subframe; or the uplink channel of the unlicensed frequency band is detected by the terminal every time it can be occupied , allocate the transmission resources corresponding to the predetermined number of uplink subframes starting from the first subsequent uplink subframe to the predetermined number of uplink HARQ processes.

In this technical solution, since the detection of the uplink channel is performed before the uplink subframe, if it is detected that the uplink channel of the unlicensed frequency band can be occupied each time, only the transmission resources corresponding to the subsequent uplink subframe can be Assigned to the uplink HARQ process with the highest priority, that is, the channel status needs to be detected before each uplink subframe is occupied; The transmission resource corresponding to the subframe is allocated to a predetermined number of uplink HARQ processes. Among them, there are two ways to determine the actual number of the predetermined number: one is the number of continuous uplink subframes after the channel is detected to be idle, that is, the continuous uplink subframes after the channel is detected to be idle are used to carry out For uplink HARQ transmission, for example, if there are 3 uplink subframes after the channel is detected to be idle, then these 3 uplink subframes are used to transmit the uplink HARQ process; the other is to detect that the channel is idle in the continuous uplink subframes For example, there are 3 uplink subframes after the channel is detected to be idle, if the first 2 uplink subframes are not allocated to other users, and the third uplink subframe is allocated to other users, only the first 2 uplink subframes are occupied. Two uplink subframes are used to transmit the HARQ process, and after the occupancy is completed, the channel detection is performed again.

Fig. 7 shows a schematic block diagram of a terminal according to an embodiment of the present invention.

As shown in FIG. 7 , a terminal 700 according to an embodiment of the present invention includes: an apparatus 600 for transmitting a HARQ process in an unlicensed frequency band as shown in FIG. 6 .

In summary, the technical solution of the present invention is mainly aimed at when the unlicensed frequency band is used by the LTE system, and proposes a channel resource allocation method based on the priority of the HARQ process, so as to avoid the problem that some HARQ processes cannot send data because they always do not occupy the channel , which reduces the average time delay of the HARQ process and ensures the fairness of resource utilization among the HARQ processes. Among them, the technical solution of the present invention is not only applicable to the scene where the unlicensed frequency band is used by the LTE system in TDD mode, but also applicable to the scene where the unlicensed frequency band is used by the LTE system in the way of SDL or dynamic uplink and downlink.

As specifically shown in FIG. 8, the HARQ process transmission method according to the second embodiment of the present invention includes:

Step 802, the data sending end determines the HARQ process to be retransmitted. Wherein, the data sending end may be a base station or a terminal.

Step 804, the data sender competes for the channel.

Step 806, judging whether the channel preemption is successful, if yes, execute step 808; otherwise, continue to compete for the channel.

Step 808, counting the time delay T{i} of each HARQ process and the number of missed transmissions N{i} due to the LBT mechanism.

Step 810, judge whether there are elements with the same size in N{i}, if yes, execute step 812; otherwise, execute step 816.

Step 812, compare elements in T{i} corresponding to elements of the same size in N{i}, that is, compare the time delays of these HARQ processes when there are HARQ processes with the same number of missed transmissions.

Step 814, sort the corresponding processes in descending order according to the size of the elements in T{i}.

Step 816, arrange the corresponding processes in descending order according to the size of elements in N{i}.

Step 818, determine the priority of the HARQ process according to the result of the descending order, wherein the higher the order, the higher the priority.

Step 820, allocate channel resources to the HARQ process according to the determined order of priority.

Step 822, occupying the channel to transmit the HARQ process. After the channel occupation ends, return to step 804 .

In the HARQ process transmission method shown in Figure 8, in order to ensure the communication quality, the data sender must perform channel detection before sending data on the unlicensed frequency band, and only when it is detected that the frequency band is not used by other different systems or the noise is low use. When the sender detects that the channel is available, the sender performs priority sorting according to the delay of the HARQ process and the number of transmissions missed due to the LBT mechanism. After the sorting is completed, the channel resources are allocated in order of priority from high to low.

Among them, the delay refers to the time elapsed by the sender after the establishment of the HARQ process and before receiving the ACK message; the number of missed transmissions refers to the failure of the HARQ process due to the LBT mechanism not preempting the channel resources at the time specified in the sequence. The number of times to send retransmission data.

When determining the priority of the HARQ process based on the statistical delay of the HARQ process and the number of transmissions missed due to the LBT mechanism, first compare the number of transmissions the HARQ process misses due to the LBT mechanism. The greater the number, the higher the priority; if For HARQ processes with the same number of missed transmissions, compare their HARQ process delays, and the greater the delay, the higher the priority. Finally, the results of the two comparisons are integrated to obtain the prioritization of each HARQ process. In other embodiments of the present invention, the priority of the HARQ process may also be determined only according to the time delay of the HARQ process or the number of missed transmissions due to the LBT mechanism.

The following describes the downlink HARQ process and the uplink HARQ process respectively:

1. Downlink HARQ process.

1. When downlink data needs to be transmitted, the base station performs channel detection, and the channel can be occupied within Tms after the channel resources are competed for. Among them, counting the delay of the HARQ process refers to counting the delay of the downlink HARQ process that the base station has sent but has not received ACK feedback; counting the number of transmissions missed by the HARQ process refers to counting the missed retransmission of the downlink HARQ process that has received NACK feedback times.

2. When allocating resources, resources are allocated to HARQ processes with higher priority in units of subframes. Wherein, when the channel is detected to be idle, multiple downlink subframes can be continuously occupied to transmit the HARQ process. For example, for the frame structure shown in FIG. HARQ process 3, HARQ process 6, HARQ process 1, HARQ process 5, HARQ process 2, and HARQ process 4 are transmitted in the 6 downlink subframes. Among them, the multiple subframes occupied continuously are determined according to the maximum occupation time of the channel and the number of continuous downlink subframes. Subframes, if the duration of consecutive downlink subframes is greater than the maximum channel occupation duration, the channel occupation duration is the maximum channel occupation duration.

3. If the channel duration occupied by the counted HARQ process is less than the maximum channel occupation time T, after allocating resources to the qualified HARQ process, you can make another HARQ process priority statistics to allocate the remaining downlink channel resources distributed, and so on. If there is no matching HARQ process after the statistics and there are remaining downlink channel resources, the resources will not be allocated.

4. If there are still some HARQ processes that have not been allocated channel resources at the end of a channel occupancy time, these processes will not get any resources, and they will participate in the resource allocation after the next channel occupancy.

5. Each HARQ process priority determination after the base station occupies the channel is independent of each other and does not affect each other. The result of each priority determination is only used for the current channel resource allocation.

6. When the feedback information of a certain downlink HARQ process received by the base station is ACK confirmation information, the time delay and the number of missed transmissions of the process are cleared.

7. If the direction of the current subframe is uplink, but the downlink occupied time has not ended, the downlink data transmission is ended, and the occupied time T is cleared.

8. When the number of missed transmissions of a downlink HARQ process reaches a predetermined number (for example, 4 times), the data of the HARQ process is discarded, and the time delay and the number of missed transmissions of the downlink HARQ process are reset to zero.

9. The feedback timing rules of the HARQ process The downlink HARQ timing rules in the TD-LTE system on the licensed frequency band can still be used in the licensed frequency band.

2. Uplink HARQ process.

1. When it is necessary to transmit uplink data, the terminal performs channel detection, and sends uplink data to the base station when the channel is detected to be idle. Since the maximum occupancy time of the uplink channel is 1ms, and according to the continuity and detection method of the uplink subframe, resource allocation methods are mainly divided into the following two types:

Mode 1: As shown in FIG. 10A , when the uplink subframe exists alone, and the front and rear subframes are non-uplink subframes, channel resources are allocated to the uplink HARQ process with the highest priority according to the priority of the HARQ process.

Method 2: As shown in Figure 10B, when the uplink subframes exist continuously, there are two ways to detect the uplink channel: one is to detect before each uplink subframe, and determine whether it is on the uplink subframe according to the detection result Transmission HARQ process; the other is that after preempting the channel resources before any of the uplink subframes, if the subframe is still an uplink subframe after the subframe, then the subsequent channel detection can no longer be performed, and the channel can be directly occupied until encountering The downlink subframe or the base station allocates subsequent uplink subframes to other users for use.

Wherein, when channel detection is performed before each uplink subframe, if it is determined that the uplink channel can be occupied, the channel resource is allocated to the uplink HARQ process with the highest priority; when any channel detection process before any uplink subframe preempts When channel resources are available and the channel is directly occupied in the next n consecutive uplink subframes, the n+1 uplink subframes may be allocated to multiple HARQ processes with higher priorities.

2. In the HARQ timing rules of TD-LTE, uplink HARQ is synchronous, that is, the timing of transmission and retransmission is fixed, but in the present invention, since resources are allocated according to priority, uplink data transmission and retransmission The timing of the HARQ is not fixed, that is, in the technical solution of the present invention, the uplink HARQ is asynchronous transmission.

3. The statistical uplink HARQ process delay refers to the statistics of the delay of the uplink HARQ process that the terminal has sent but has not received ACK feedback; the statistics of the number of HARQ missed transmissions refers to the statistics of the uplink HARQ process that has received NACK feedback. The number of transmissions.

4. If the number of HARQ processes for priority sorting is less than the total number of consecutive uplink subframes, after allocating resources to eligible HARQ processes, do another HARQ process priority statistics, and allocate the remaining uplink channel resources. and so on. If there is no matching HARQ process after the statistics and channel resources remain, these resources will not be allocated.

5. If there are still some uplink HARQ processes that have not been allocated channel resources at the end of a channel occupancy time, these processes will not get any resources. They will participate in resource allocation after occupying the channel next time.

6. Each HARQ process priority determination after the terminal occupies the channel is independent of each other and does not affect each other. The result of each priority determination is only used for the current channel resource allocation.

7. When the feedback information of a certain uplink HARQ process received by the terminal is ACK confirmation information, the time delay and the number of missed transmissions of the process are cleared.

8. When the number of missed transmissions of an uplink HARQ process reaches a predetermined number (for example, 4 times), the data of the HARQ process is discarded, and the time delay and the number of missed transmissions of the uplink HARQ process are reset to zero.

9. The feedback timing rules of the HARQ process The uplink HARQ timing rules in the TD-LTE system on the licensed frequency band can still be used in the licensed frequency band.

The above describes the technical solution of the present invention in detail in conjunction with the accompanying drawings. The present invention proposes a new HARQ process transmission scheme on the unlicensed frequency band, which can avoid the problem that the HARQ process cannot send data because the channel is always occupied. The average time delay of the HARQ process is reduced, and the fairness of resource utilization among the HARQ processes is ensured, which is beneficial to improving the throughput of the system.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (14)

1. A HARQ process transmission method on an unlicensed frequency band, characterized in that, comprising: Count the number of times each HARQ process misses retransmissions due to the implementation of the channel detection mechanism on the unlicensed frequency band by the data sender, and/or count the time elapsed from the establishment of each HARQ process to the receipt of the ACK message by the data sender; According to the number of times each HARQ process misses retransmissions, and/or the time period that each HARQ process elapses from being established to when the data sender receives an ACK message, determine when each HARQ process is retransmitting transmission priority; When it is detected that the channel of the unlicensed frequency band can be occupied each time, according to the transmission priority of each HARQ process when it is retransmitted, allocate transmission resources to it; The transmission priority of each HARQ process during retransmission and the number of times each HARQ process misses retransmissions, and/or the experience of each HARQ process from being established to when the data sender receives an ACK message The duration is positively correlated. 2. The HARQ process transmission method on the unlicensed frequency band according to claim 1, characterized in that, according to the number of times that each HARQ process misses retransmission and each HARQ process is received from the establishment to the data sending end In the case of determining the transmission priority of each HARQ process when retransmitting the time elapsed until the ACK message, the step of determining the transmission priority of each HARQ process when retransmitting specifically includes : determining the transmission priority of the HARQ process during retransmission according to the number of times each HARQ process misses retransmission; When multiple HARQ processes miss retransmissions for the same number of times, determine the transmission priority of the multiple HARQ processes during retransmission according to the length of time elapsed from the establishment of the multiple HARQ processes until the data sender receives the ACK message . 3. the HARQ process transmission method on the unlicensed frequency band according to claim 1, is characterized in that, also comprises: If the number of times that any HARQ process misses the retransmission reaches the predetermined number of times, and/or the time length experienced by any HARQ process from the establishment to the data sending end before receiving the ACK message reaches the first predetermined time length, then discard the any HARQ process. process. 4. the HARQ process transmission method on the unlicensed frequency band according to claim 1, is characterized in that, also comprises: If there are still available transmission resources after the transmission resources are allocated to each HARQ process, then determine whether there are other HARQ processes that need to be retransmitted; If there are other HARQ processes that need to be retransmitted, the transmission priorities of the other HARQ processes are determined, and transmission resources are allocated to the other HARQ processes according to the priorities of the other HARQ processes. 5. The HARQ process transmission method on the unlicensed frequency band according to any one of claims 1 to 4, characterized in that, when the HARQ process is a downlink HARQ process, according to each HARQ process in the The steps of allocating transmission resources to the transmission priority during retransmission include: When it is detected that the downlink channel of the unlicensed frequency band can be occupied, the transmission resource of the second predetermined duration starting from the current subframe is allocated to a predetermined number of HARQ processes, wherein, If the duration from the current subframe to the first non-downlink subframe is greater than or equal to a predetermined value T, then use the predetermined value T as the second predetermined duration; If the duration from the current subframe to the first non-downlink subframe is less than the predetermined value T, then use the duration from the current subframe to the first non-downlink subframe as the first 2. Predetermined duration, wherein the predetermined value T is the maximum occupied duration of the channel. 6. The HARQ process transmission method on the unlicensed frequency band according to any one of claims 1 to 4, wherein, when the HARQ process is an uplink HARQ process, according to each HARQ process in The steps of allocating transmission resources to the transmission priority during retransmission include: Every time it is detected that the uplink channel of the unlicensed frequency band can be occupied, the transmission resource corresponding to the first uplink subframe after that will be allocated to the HARQ process with the highest priority, and the detection will continue before the second uplink subframe the channel state of the unlicensed frequency band; or When it is detected that the channel in the unlicensed frequency band can be occupied, the transmission resources corresponding to the predetermined number of uplink subframes starting from the first subsequent uplink subframe are allocated to the predetermined number of HARQ processes. 7. A HARQ process transmission device on an unlicensed frequency band, characterized in that it comprises: The statistical unit is used to count the number of retransmissions that each HARQ process misses due to the channel detection mechanism performed by the data sender on the unlicensed frequency band, and/or count each HARQ process from establishment to before the data sender receives the ACK message the length of time elapsed; A determining unit, configured to determine each HARQ process according to the number of times each HARQ process misses retransmissions, and/or the time period that each HARQ process elapses from being established to when the data sending end receives an ACK message Transmission priority when retransmitting; An allocation unit, configured to allocate transmission resources to each HARQ process according to the transmission priority of each HARQ process when it detects that the channel of the unlicensed frequency band can be occupied each time; The transmission priority of each HARQ process during retransmission and the number of times each HARQ process misses retransmissions, and/or the experience of each HARQ process from being established to when the data sender receives an ACK message The duration is positively correlated. 8. The HARQ process transmission device on the unlicensed frequency band according to claim 7, characterized in that, according to the number of times each HARQ process misses retransmission and each HARQ process is received from the establishment to the data sending end The length of time elapsed before the ACK message, in the case of determining the transmission priority of each HARQ process when performing retransmission, the determination unit is specifically used for: determining the transmission priority of the HARQ process during retransmission according to the number of times each HARQ process misses retransmission; When multiple HARQ processes miss retransmissions for the same number of times, determine the transmission priority of the multiple HARQ processes during retransmission according to the length of time elapsed from the establishment of the multiple HARQ processes until the data sender receives the ACK message . 9. The HARQ process transmission device on the unlicensed frequency band according to claim 7, further comprising: The processing unit is configured to count the number of missed retransmissions of any HARQ process by the statistical unit reaching a predetermined number of times, and/or the time elapsed by any HARQ process from being established to when the data sending end receives the ACK message reaches the first time When a predetermined period of time is reached, any HARQ process is discarded. 10. The HARQ process transmission device on the unlicensed frequency band according to claim 7, wherein the determining unit is further used for: If there are still available transmission resources after the allocation unit allocates transmission resources to each HARQ process, then determine whether there are other HARQ processes that need to be retransmitted; If there are other HARQ processes that need to be retransmitted, the transmission priorities of the other HARQ processes are determined, and transmission resources are allocated to the other HARQ processes according to the priorities of the other HARQ processes. 11. The HARQ process transmission device on the unlicensed frequency band according to any one of claims 7 to 10, wherein when the HARQ process is a downlink HARQ process, the allocation unit is specifically used for: When the data sending end detects that the downlink channel of the unlicensed frequency band can be occupied, the transmission resource of the second predetermined duration starting from the current subframe is allocated to a predetermined number of HARQ processes, wherein, If the duration from the current subframe to the first non-downlink subframe is greater than or equal to a predetermined value T, then use the predetermined value T as the second predetermined duration; If the duration from the current subframe to the first non-downlink subframe is less than the predetermined value T, then use the duration from the current subframe to the first non-downlink subframe as the first 2. Predetermined duration, wherein the predetermined value T is the maximum occupied duration of the channel. 12. The HARQ process transmission device on the unlicensed frequency band according to any one of claims 7 to 10, wherein when the HARQ process is an uplink HARQ process, the allocation unit is specifically used for: When the data sending end detects that the uplink channel of the unlicensed frequency band can be occupied, the transmission resource corresponding to the first uplink subframe after that is allocated to the HARQ process with the highest priority, and the second uplink subframe after that Continue to detect the channel state of the unlicensed frequency band before the subframe; or When the data sending end detects that the uplink channel of the unlicensed frequency band can be occupied, the transmission resources corresponding to the predetermined number of uplink subframes starting from the first subsequent uplink subframe are allocated to the predetermined number of HARQ processes. 13. A base station, characterized by comprising: the HARQ process transmission device on the unlicensed frequency band according to any one of claims 7 to 11. 14. A terminal, characterized by comprising: the HARQ process transmission device on the unlicensed frequency band according to any one of claims 7, 8, 9, 10 and 12.