CN105517171B - A method and base station for scheduling LTE terminals in LTE-A network - Google Patents

Abstract

The method that the invention discloses a kind of in LTE-A network dispatches LTE terminal, this method comprises: base station used MCS index value when determining to terminal distribution transfer resource, and the MCS index value is compared with preset threshold value；When judging that the MCS index value is greater than preset first threshold value, the terminal is dispatched in the subframe for be not configured CSI-RS；When judging that the MCS index value is less than preset second threshold value, the dispatch terminal in CSI-RS subframe；When judging that the MCS index value is more than or equal to second threshold value and is less than or equal to first threshold value, the dispatch terminal in CSI-RS subframe, while optimizing hybrid automatic repeat-request (HARQ) process flow.The present invention further simultaneously discloses a kind of base station that LTE terminal is dispatched in LTE-A network.

Description

A method and base station for scheduling LTE terminals in LTE-A network

technical field

The present invention relates to the technical field of mobile communication, and in particular, to a method and a base station for scheduling LTE terminals in an LTE-A network.

Background technique

At present, in the standard of the evolved LTE (LTE-A) network, that is, in the Release 10 standard (R10 for short) and subsequent standards, an important reference signal is introduced, that is, the Channel State Indication Reference Signal (Channel State Indication RS) , CSI-RS) for the terminal to measure the channel information. The location of the CSI-RS in the frequency domain is shown in FIG. 1 ; in the time domain, the CSI-RS can be configured with different periods, such as 5ms, 10ms, 40ms, etc. as required. A subframe configured with CSI-RS is called a CSI-RS subframe.

When the LTE-A network is configured with CSI-RS, the LTE terminal on the CSI-RS subframe, that is, the R8/R9 terminal (terminal that conforms to the R8 and/or R9 standard) does not know the existence of CSI-RS, so R8/R9 The terminal mistakenly receives the CSI-RS as data, which leads to an increase in the bit error rate and a decrease in the data transmission rate. From the simulation results of the impact of CSI-RS on R8/R9 terminal performance, it can be seen that when the modulation and coding strategy (MCS) index value = 10, the signal-to-noise ratio (SNR) of 10% block error rate (BLER) is increased by 1.5 dB, when the MCS index value = 14, the SNR of 10% BLER is increased by 4dB.

In order to solve the above-mentioned problem of terminal data transmission damage, a staggered scheduling method can be adopted, that is, the R8/R9 terminal is scheduled on the subframe where the CSI-RS is not configured. However, this method will waste downlink subframes, especially when the ratio of R10 terminals in the network is not high, the wasted downlink subframes are very large. In addition, a method of reducing the order of the MCS index value may also be adopted, that is, scheduling the R8/R9 terminal on the CSI-RS subframe while reducing the MCS index value. However, due to the large fluctuation of the wireless channel, the degree of influence of CSI-RS on the R8/R9 terminal is difficult to predict, so the order of decreasing the MCS index value is also difficult to determine, so the actual use effect of this method is poor.

SUMMARY OF THE INVENTION

To solve the existing technical problems, embodiments of the present invention provide a method and a base station for scheduling LTE terminals in an LTE-A network.

An embodiment of the present invention provides a method for scheduling an LTE terminal in an evolved LTE network, the method comprising:

The base station determines the MCS index value used when allocating transmission resources to the terminal, and compares the MCS index value with a preset threshold value;

When judging that the MCS index value is greater than a preset first threshold value, schedule the terminal on a subframe where CSI-RS is not configured; when judging that the MCS index value is less than a preset second threshold value, in Scheduling the terminal on the CSI-RS subframe; when judging that the MCS index value is greater than or equal to the second threshold value and less than or equal to the first threshold value, schedule the terminal on the CSI-RS subframe , while optimizing the hybrid automatic repeat request (HARQ) processing flow.

Wherein, the base station determines the MCS index value used when allocating transmission resources to the terminal, including:

The base station estimates the MCS index value that will be used if transmission resources are allocated to the terminal according to the channel quality indicator (CQI) message reported by the terminal, combined with the BER information and/or transmission rate information of link adaptation .

Wherein, scheduling the terminal on the CSI-RS subframe includes:

The scheduling of the terminal by the base station shares the time slot with the CSI-RS subframe.

Wherein, the optimized HARQ processing flow includes:

The initial transmission of HARQ of the terminal is scheduled on the CSI-RS subframe, and in the retransmission process of the same HARQ process of the terminal, the subframe in which the CSI-RS is not configured is selected to schedule the terminal.

Preferably, the method further includes:

According to the influence degree of CSI-RS on terminal performance, the base station correspondingly sets two MCS index value thresholds: a first threshold value and a second threshold value, the first threshold value corresponding to terminal performance not affected by CSI-RS , the second threshold value corresponds to that the terminal performance cannot work normally due to the influence of CSI-RS, and the first threshold value is greater than the second threshold value.

Wherein, the terminal is: a terminal conforming to the R8 and/or R9 standard in LTE.

The embodiment of the present invention also provides a base station for scheduling LTE terminals in an evolved LTE network, the base station includes: a determination module, a judgment module and a processing module; wherein,

The determining module is used to determine the MCS index value used when allocating transmission resources to the terminal;

The judging module is configured to compare the determined MCS index value with a preset threshold value, and trigger the processing module to perform corresponding operations according to different comparison results;

The processing module is configured to schedule the terminal on a subframe without CSI-RS when it is determined that the MCS index value is greater than a preset first threshold value; determine that the MCS index value is less than a preset first threshold value When there are two thresholds, the terminal is scheduled on the CSI-RS subframe; when it is determined that the MCS index value is greater than or equal to the second threshold and less than or equal to the first threshold, the CSI-RS The terminal is scheduled on the subframe, and the HARQ processing flow is optimized at the same time.

Preferably, the base station further includes: a setting module, configured to correspondingly set two MCS index value thresholds according to the degree of influence of the CSI-RS on the terminal performance: a first threshold value and a second threshold value, the first threshold value The threshold value corresponds to terminal performance that is not affected by CSI-RS, the second threshold value corresponds to terminal performance that cannot work normally due to the influence of CSI-RS, and the first threshold value is greater than the second threshold value.

Wherein, the determining module determines the MCS index value used when allocating transmission resources to the terminal, including:

The determining module estimates, according to the CQI message reported by the terminal, combined with the BER information and/or the transmission rate information of the link adaptation, the MCS index value that will be used if the terminal is allocated transmission resources.

Wherein, the processing module optimizes the HARQ processing flow, including:

The processing module schedules the initial transmission of HARQ of the terminal on the CSI-RS subframe, and during the retransmission process of the same HARQ process of the terminal, selects the subframe in which the CSI-RS is not configured to schedule the terminal.

The method and base station for scheduling an LTE terminal in an LTE-A network provided by the embodiment of the present invention, the base station determines the MCS index value used when allocating transmission resources to the terminal, and compares the MCS index value with a preset threshold value comparison; when judging that the MCS index value is greater than a preset first threshold value, schedule the terminal on a subframe where CSI-RS is not configured; when judging that the MCS index value is less than a preset second threshold value , schedule the terminal on the CSI-RS subframe; when judging that the MCS index value is greater than or equal to the second threshold value and less than or equal to the first threshold value, schedule the terminal on the CSI-RS subframe At the same time, the hybrid automatic repeat request (HARQ) processing flow is optimized. In the embodiment of the present invention, by considering that the performance of R8/R9 terminals with different MCS index values is affected by CSI-RS differently, the terminal is reasonably scheduled, so that the CSI-RS subframe can be used by the threshold with lower MCS index value, that is, the second gate R8/R9 terminals below the limit are fully utilized to make full use of air interface resources and ensure system performance. At the same time, for the terminal whose MCS index value is between the two thresholds, it is not easy to be easily defined due to the influence of CSI-RS, so it is also scheduled on the CSI-RS subframe, and the optimized HARQ processing flow is adopted to ensure the utilization of air interface resources. On the basis of the rate, the data transmission performance is improved.

Description of drawings

In the drawings, which are not necessarily to scale, like reference numerals may describe like parts in the different views. Similar reference numbers with different letter suffixes may denote different instances of similar components. The accompanying drawings generally illustrate, by way of example and not limitation, the various embodiments discussed herein.

FIG. 1 is a schematic diagram of the location distribution of CSI-RS in the frequency domain;

FIG. 2 is a schematic flowchart of the implementation of a method for scheduling an LTE terminal in an LTE-A network according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a base station for scheduling an LTE terminal in an LTE-A network according to an embodiment of the present invention.

Detailed ways

In the embodiment of the present invention, the base station determines the MCS index value used when allocating transmission resources to the terminal, and compares the MCS index value with a preset threshold value; judging that the MCS index value is greater than the preset th When there is a threshold value, the terminal is scheduled on the subframe where the CSI-RS is not configured; when it is judged that the MCS index value is less than the preset second threshold value, the terminal is scheduled on the CSI-RS subframe; When it is determined that the MCS index value is greater than or equal to the second threshold value and less than or equal to the first threshold value, the terminal is scheduled on the CSI-RS subframe, and the HARQ processing flow is optimized at the same time.

In the embodiment of the present invention, the terminal is a terminal conforming to the R8 and/or R9 standard in LTE.

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

FIG. 2 is a schematic diagram of an implementation flowchart of a method for scheduling an LTE terminal in an LTE-A network according to an embodiment of the present invention. As shown in FIG. 2 , the method includes:

Step 201: the base station determines the MCS index value used when allocating transmission resources to the terminal;

Specifically, the base station estimates, according to the channel quality indicator (CQI) message reported by the terminal, combined with the information such as the BER information and/or the transmission rate of link adaptation, if it allocates transmission resources to the terminal, it will use The MCS index value.

Here, the estimation method is in the prior art and will not be described in detail here.

Step 202: Compare the MCS index value with a preset threshold value, and if the MCS index value is greater than the preset first threshold value, perform step 203; if the MCS index value is less than the preset first threshold value If the MCS index value is greater than or equal to the second threshold value and less than or equal to the first threshold value, then execute step 205;

Here, the base station determines whether to schedule the terminal on the CSI-RS subframe according to the determined MCS index value: specifically, if the MCS index value is greater than the preset first threshold value, perform step 203; if If the MCS index value is less than the preset second threshold value, go to step 204; if the MCS index value is greater than or equal to the second threshold value and less than or equal to the first threshold value, go to step 205 .

Step 203: Schedule the terminal on a subframe where CSI-RS is not configured;

Step 204: schedule the terminal on the CSI-RS subframe, that is, the scheduling of the terminal by the base station can share the time slot with the CSI-RS subframe;

Step 205: Schedule the terminal on the CSI-RS subframe while optimizing the HARQ processing flow;

Specifically, the base station can schedule the terminal on the CSI-RS subframe, and at the same time, the base station needs to optimize the HARQ processing flow, that is, the base station schedules the above-mentioned value greater than or equal to the second threshold on the CSI-RS subframe while the When the terminal is less than or equal to the first threshold value, only the initial transmission of HARQ is scheduled on the CSI-RS subframe, and during the retransmission process of the same HARQ process of the terminal, the subframe without CSI-RS is selected to schedule the terminal , to ensure the success rate of retransmission.

In the embodiment of the present invention, by considering that the performance of R8/R9 terminals with different MCS index values is affected by CSI-RS differently, the terminal is reasonably scheduled, so that the CSI-RS subframe can be used by the threshold with lower MCS index value, that is, the second gate R8/R9 terminals below the limit are fully utilized to make full use of air interface resources and ensure system performance. At the same time, for the terminal whose MCS index value is between the two thresholds, it is not easy to be easily defined due to the influence of CSI-RS, so it is also scheduled on the CSI-RS subframe, and the optimized HARQ processing flow is adopted to ensure the utilization of air interface resources. On the basis of the rate, the data transmission performance is improved.

It can be known from the prior art that the influence of CSI-RS on the performance of the R8/R9 terminal has the following rules, that is, the influence is larger under the high MCS index value, and the influence is smaller under the low MCS index value.

Therefore, in an embodiment of the present invention, the method further includes: the base station correspondingly sets two MCS index value thresholds according to the degree of influence of the CSI-RS on the terminal performance: the first threshold value, corresponding to the terminal performance not affected by the CSI -RS influence and a second threshold value, the corresponding terminal performance cannot work normally due to the influence of CSI-RS, and the first threshold value is greater than the second threshold value. In this way, when the base station schedules the terminal, it adopts different scheduling methods according to the set three MCS index value interval ranges.

Here, the first threshold value and the second threshold value can be set according to the empirical value, for example: the first threshold value and the second threshold value can be set according to the simulation result of the impact of the CSI-RS on the terminal performance, and the first threshold value of the MCS index value can be set to 15, The second threshold value of the MCS index value is 9.

An embodiment of the present invention further provides a base station for scheduling LTE terminals in an evolved LTE network. As shown in FIG. 3 , the base station 30 includes: a determination module 301, a determination module 302, and a processing module 303; wherein,

The determining module 301 is configured to determine the MCS index value used when allocating transmission resources to the terminal;

The judging module 302 is configured to compare the determined MCS index value with a preset threshold value, and trigger the processing module 303 to perform corresponding operations according to different comparison results;

Here, the judgment module 302 judges whether to schedule the terminal on the CSI-RS subframe according to the determined MCS index value.

The processing module 303 can be implemented by a base station scheduler, and is configured to schedule the terminal on a subframe where CSI-RS is not configured when the MCS index value is greater than a preset first threshold value; determine the MCS index When the value is less than a preset second threshold value, schedule the terminal on the CSI-RS subframe; determine that the MCS index value is greater than or equal to the second threshold value and less than or equal to the first threshold value When , the terminal is scheduled on the CSI-RS subframe, and the HARQ processing flow is optimized at the same time.

Specifically, if the processing module 303 determines that the MCS index value is greater than the preset first threshold, the terminal is scheduled on the subframe without CSI-RS; if the processing module 303 determines that the MCS index value is less than The preset second threshold value, the terminal is scheduled on the CSI-RS subframe, that is, the scheduling of the terminal can share the time slot with the CSI-RS subframe; if the processing module 303 determines the MCS index If the value is greater than or equal to the second threshold value and less than or equal to the first threshold value, the terminal is scheduled on the CSI-RS subframe. At the same time, the HARQ processing flow needs to be optimized, that is: the HARQ The initial transmission process uses CSI-RS subframes, and the retransmission process of HARQ selects subframes without CSI-RS configuration to ensure the success rate of retransmission.

Wherein, the determining module 301 and the determining module 302 may be a central processing unit (Central Processing Unit, CPU), a digital signal processor (Digital Signal Processor, DSP) or a programmable logic array (Field-Programmable Gate Array, FPGA) in the base station 30 )accomplish.

Preferably, in an embodiment of the present invention, the base station 30 further includes: a setting module 304, configured to correspondingly set two MCS index value thresholds according to the degree of influence of the CSI-RS on the terminal performance: the first threshold value and the The second threshold value, the first threshold value corresponds to the terminal performance that is not affected by CSI-RS, the second threshold value corresponds to the terminal performance that cannot work normally due to the influence of CSI-RS, the first threshold value greater than the second threshold value.

Wherein, the determining module determines the MCS index value used when allocating transmission resources to the terminal, including:

The determination module estimates the MCS index value that will be used if transmission resources are allocated to the terminal according to the CQI message reported by the terminal and in combination with information such as the BER and/or transmission rate of link adaptation.

Wherein, the processing module optimizes the HARQ processing flow, including:

The processing module schedules the initial transmission of HARQ of the terminal on the CSI-RS subframe, and selects the subframe without CSI-RS to schedule the terminal during the retransmission process of the same HARQ process of the terminal.

In the embodiment of the present invention, the base station performs reasonable scheduling on the terminal by considering that the performance of R8/R9 terminals with different MCS index values is affected by CSI-RS differently, so that the CSI-RS subframe can be used by a threshold with a lower MCS index value, that is, the second R8/R9 terminals below the threshold are fully utilized to make full use of air interface resources and ensure system performance. At the same time, for the terminal whose MCS index value is between the two thresholds, it is not easy to be easily defined due to the influence of CSI-RS, so it is also scheduled on the CSI-RS subframe, and the optimized HARQ processing flow is adopted to ensure the utilization of air interface resources. On the basis of the rate, the data transmission performance is improved.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media having computer-usable program code embodied therein, including but not limited to disk storage, optical storage, and the like.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (8)

1. A method for scheduling an LTE terminal in an evolved LTE network, characterized in that the method comprises: The base station determines the MCS index value of the modulation and coding strategy used when allocating transmission resources to the terminal, and compares the MCS index value with a preset threshold value; When judging that the MCS index value is greater than a preset first threshold value, schedule the terminal on a subframe where the channel state indication reference signal CSI-RS is not configured; judging that the MCS index value is less than a preset second threshold value When the limit is set, the terminal is scheduled on the CSI-RS subframe; when it is judged that the MCS index value is greater than or equal to the second threshold value and less than or equal to the first threshold value, the terminal is scheduled on the CSI-RS subframe The terminal is scheduled on the CSI-RS subframe, and the HARQ initial transmission of the terminal's hybrid automatic retransmission request is scheduled on the CSI-RS subframe. During the retransmission process of the same HARQ process of the terminal, the subframe scheduling without CSI-RS is selected. the terminal. 2. The method according to claim 1, wherein the base station determines the MCS index value used when allocating transmission resources to the terminal, comprising: The base station estimates the MCS index value that will be used if transmission resources are allocated to the terminal according to the channel quality indication CQI message reported by the terminal, combined with the BER information and/or transmission rate information of link adaptation. 3. The method according to claim 1, wherein the scheduling the terminal on the CSI-RS subframe comprises: The scheduling of the terminal by the base station shares the time slot with the CSI-RS subframe. 4. The method according to any one of claims 1-3, wherein the method further comprises: According to the influence degree of CSI-RS on terminal performance, the base station correspondingly sets two MCS index value thresholds: a first threshold value and a second threshold value, the first threshold value corresponding to terminal performance not affected by CSI-RS , the second threshold value corresponds to that the terminal performance cannot work normally due to the influence of CSI-RS, and the first threshold value is greater than the second threshold value. 5. The method according to any one of claims 1-3, wherein the terminal is a terminal conforming to the R8 and/or R9 standard in LTE. 6. A base station for scheduling LTE terminals in an evolved LTE network, wherein the base station comprises: a determination module, a judgment module and a processing module; wherein, The determining module is used to determine the MCS index value used when allocating transmission resources to the terminal; The judging module is configured to compare the determined MCS index value with a preset threshold value, and trigger the processing module to perform corresponding operations according to different comparison results; The processing module is configured to schedule the terminal on a subframe without CSI-RS when it is determined that the MCS index value is greater than a preset first threshold value; determine that the MCS index value is less than a preset first threshold value When there are two thresholds, the terminal is scheduled on the CSI-RS subframe; when it is determined that the MCS index value is greater than or equal to the second threshold and less than or equal to the first threshold, the CSI-RS The terminal is scheduled on the subframe, and the initial transmission of the terminal's hybrid automatic retransmission request HARQ is scheduled on the CSI-RS subframe. During the retransmission process of the same HARQ process of the terminal, the subframe without CSI-RS is selected. frame schedule the terminal. 7. The base station according to claim 6, characterized in that, the base station further comprises: a setting module, configured to correspondingly set two MCS index value thresholds according to the influence degree of CSI-RS on terminal performance: the first threshold value and a second threshold value, the first threshold value corresponds to terminal performance that is not affected by CSI-RS, the second threshold value corresponds to terminal performance that cannot work normally due to the influence of CSI-RS, and the first threshold value corresponds to The limit value is greater than the second threshold value. 8. The base station according to claim 6 or 7, wherein the determining module determines the MCS index value used when allocating transmission resources to the terminal, comprising: The determining module estimates, according to the CQI message reported by the terminal, combined with the BER information and/or the transmission rate information of the link adaptation, the MCS index value that will be used if the terminal is allocated transmission resources.