CN100571113C - A Realization Method of HSDPA in Time Division Synchronous Code Division Multiple Access System - Google Patents

Abstract

The invention discloses a kind of in TDS-CDMA system the implementation method of HSDPA, be applied to form in the communication system by base station and user terminal, the base station includes medium access control-high speed downlink packet and inserts entity, adopt a plurality of carrier waves to carry out transfer of data between base station and the user terminal, comprise the steps: that medium access control-high speed downlink packet in the base station inserts entity the data block of a Transmission Time Interval is divided into the plurality of sub data block, respectively the plurality of sub data block is encoded and modulate; Then respectively with each sub-block by relevant code track, time slot and carrier wave send to user terminal separately; User terminal receives sub-block on relevant code track, time slot and carrier wave, and each sub-block is separated mediation decoding, and all sub-blocks in the Transmission Time Interval that receives are merged.Adopt this method, can effectively improve descending peak rate and cell data throughput, and can be compatible mutually with existing HSDPA technology.

Description

A Realization Method of HSDPA in Time Division Synchronous Code Division Multiple Access System

technical field

The invention relates to the third generation mobile communication field, in particular to a method for realizing HSDPA in a time division synchronous code division multiple access system.

Background technique

With the increase of mobile communication multimedia services, the 2Mb/s data transmission rate of the third-generation mobile communication system cannot meet the demand. Therefore, it has become inevitable to develop a mobile communication system with larger capacity and higher bit transmission rate. At present, Wideband Code Division Multiple Access (WCDMA) mobile communication system, CDMA2000 mobile communication system and Time Division Synchronous Code Division Multiple Access (Time Division-Synchronous Code Division Multiple Access, TD-SCDMA) mobile communication system are all in progress Enhanced technology to develop higher service rates and provide more B3G application services. Among them, the main enhanced technologies of TD-SCDMA and WCDMA systems are adaptive modulation and coding (Adaptive Modulation and Coding, AMC) technology, hybrid automatic repeat request (Hybrid Automatic Repeatre-Quest, HARQ) technology and fast cell selection (Fast Cell Selection, FCS) technology-based high-speed downlink packet access (High Speed Downlink Packet Access, HSDPA) technology.

At present, HSDPA technology adopts single-carrier mode. Single-carrier HSDPA technology introduces medium access control-high-speed downlink packet access entity (MAC-hs) in the medium access control layer (MAC) to complete related scheduling, feedback and retransmission, etc. Function, the MAC-hs entity is located in the base station (Node B). After the single-carrier HSDPA technology is adopted, the control of information retransmission originally required on the network side can be directly carried out in the Node B. In addition, the single-carrier HSDPA technology introduces a high-speed downlink shared channel (High Speed Downlink Shared Channel, which transmits user data, HS-DSCH), which introduces HSDPA-specific high-speed shared control channel (High Speed Shared Control Channel for HS-DSCH, HS-SCCH) and HSDPA-specific high-speed shared information channel (High Speed Shared Information Channel for HS-DSCH, HS-DSCH) at the physical layer -SICH), directly and quickly complete the information exchange between the user terminal (UE) and Node B.

For TD-SCDMA, due to the relatively narrow-band time division duplex (TDD) mode, the theoretical peak rate on a single carrier can reach 2.8Mbps, which is basically equivalent to the spectral efficiency of HSDPA in the frequency division duplex (FDD) mode, but on a single carrier The downlink peak rate that can be provided is relatively low, and it is difficult to directly meet the needs of operators for high-speed packet data services. Therefore, it is necessary to improve the existing solutions to meet the requirements of operators for high-speed packet data services.

Contents of the invention

The technical problem to be solved in the present invention is to provide a method for realizing HSDPA in a time-division synchronous code division multiple access system. The method can effectively improve the downlink peak rate and cell data throughput rate, and can be compatible with the existing HSDPA technology at the same time.

In order to solve the above technical problems, the present invention provides a method for implementing HSDPA in a Time Division Synchronous Code Division Multiple Access system, which is applied to a mobile communication system composed of a base station and a user terminal. The base station includes a medium access control-high-speed downlink packet The access entity uses multiple carriers for data transmission between the base station and the user terminal, including the following implementation steps:

(a1) Medium access control in the base station - the high-speed downlink packet access entity divides a data block of a transmission time interval into several sub-data blocks according to the user terminal capability and system radio resources, and then encodes and modulates several sub-data blocks respectively , and determine their respective code channels, time slots and carriers;

(a2) Send the radio resource configuration information of each sub-data block to the user terminal, each sub-data block waits for a period of time, and then sends it to the user terminal through the corresponding code channel, time slot and carrier;

(a3) The user terminal receives the sub-data blocks on the corresponding code channel, time slot and carrier according to the received radio resource configuration information, demodulates and decodes each sub-data block, and then sends each sub-data block to the base station respectively. A response message for the data block;

(a4) Media access control in the base station - the high-speed downlink packet access entity judges the received response message, if the response message indicates that the sub-data block is received correctly, release the corresponding sub-data block space, otherwise retransmit the corresponding sub-data block ;

(a5) After receiving all sub-data blocks of a transmission time interval, the user terminal performs data combination on them.

Further, the present invention also has the following characteristics: the transmission time interval is 5ms.

Further, the present invention also has the following characteristics: the time length in step (a2) is at least 2 time slots.

Furthermore, the present invention also has the following characteristics: the technology of transmitting the sub-data block to the user terminal adopts the hybrid automatic retransmission technology.

Further, the present invention also has the following features: the response message in step (a3) includes the channel quality measurement indication information of the sub-data block and the confirmation information of hybrid automatic retransmission, and the confirmation message is used to indicate whether the sub-data block is received correctly .

Further, the present invention also has the following characteristics: the retransmission of the sub-data block described in step (a4) can reduce the code rate, reduce punching, and adopt a low-rate modulation method in the newly designated code channel, time slot and carrier on the transmission.

Furthermore, the present invention also has the following features: different carriers among the plurality of carriers adopt interleaving technology.

Further, the present invention also has the following features: the wireless resource configuration information includes configuration information of carriers, time slots and code channels, and the configuration information of time slots and code channels is sent to the user through a high-speed shared control channel dedicated to HSDPA For the terminal, the carrier configuration information is sent to the user terminal through the HSDPA dedicated high-speed shared control channel, broadcast channel or downlink dedicated data channel.

Further, the present invention also has the following features: the response message of the user terminal is sent to the base station through a high-speed shared information channel dedicated to HSDPA.

Further, the present invention also has the following features: the HSDPA-dedicated high-speed shared control channel, broadcast channel or downlink dedicated data channel is sent on a single carrier; the HSDPA-dedicated high-speed shared information channel is sent on a single or multiple carriers .

Compared with the prior art, the present invention has the following advantages:

A, the present invention adopts multi-carrier HSDPA to realize the data interaction between the user terminal and the base station, which can effectively improve the downlink peak rate and cell data throughput;

B. The multi-carrier HSDPA adopted in the present invention can divide a larger data block into several sub-data blocks according to the code channel, time slot, carrier resource and user terminal capability, and each sub-data block independently performs HARQ, encoding and decoding, and modulation and transmission , making data scheduling fast and flexible;

C. The present invention uses interleaving technology between different carriers, which can reduce the bit error rate caused by carrier fading differences;

D, the multi-carrier HSDPA that the present invention adopts is little to physical layer channel as HS-SCCH, HS-SICH change, even can not change; Also less for the change of MAC-hs, this makes the present invention and existing HSDPA Technology can be well compatible.

Description of drawings

Fig. 1 is a schematic diagram of the timing relationship of HS-DSCH, HS-SCCH and HS-SICH channels in multi-carrier HSDPA;

Fig. 2 is a schematic diagram of the MAC layer scheduling process in multi-carrier HSDPA when data segmentation is adopted;

Fig. 3 is a schematic diagram of a MAC layer scheduling process in single carrier HSDPA;

Fig. 4 is a schematic diagram of MAC scheduling in multi-carrier HSDPA without sub-data segmentation and direct transmission;

Fig. 5 is the data flow schematic diagram of the HS-DSCH channel in the multi-carrier HSDPA implementation method;

6 is a schematic diagram of information interaction between a user terminal and a base station in a multi-carrier HSDPA implementation method;

Fig. 7 is a schematic flowchart of a method for implementing multi-carrier HSDPA.

Detailed ways

In order to deeply understand the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

In the TD-SCDMA mobile communication system, this embodiment adopts the multi-carrier HSDPA technology to meet the user's demand for capacity and speed. Compared with the single-carrier HSDPA technology, the multi-carrier HSDPA technology has the following changes in the physical layer, physical channel expansion For three-dimensional, including carrier, time slot and code channel, the mapping of HS-DSCH channel to physical channel has increased the mapping to multiple carriers; single carrier HSDPA has specified the code channel for UE to upload HS-SICH in HS-SCCH and time slot resources. Therefore, for HS-SCCH, it is only necessary to add carrier configuration information, such as the frequency points where multiple carriers are located, so that the UE can receive HSDPA downlink services on these carriers. If the HS-SCCH is not changed, the carrier configuration information The UE may be notified over a Broadcast Channel (BCH) or a Dedicated Data Channel (DCH); for HS-SICH there may be no change. Among them, the timing relationship of HS-DSCH, HS-SCCH, and HS-SICH channels is shown in Figure 1. After the HS-SICH transmits the response message of each data block in the last transmission time Transmission of the radio resource configuration information of each sub-block of the current TTI, for example, the aforementioned specified UE uploads the code channel and time slot resources of the HS-SICH, and the carrier configuration information, after at least 2 time slots, The HS-DSCH starts to transmit each sub-data block of the current TTI. Specifically, after sending the radio resource configuration information of sub-data block 1, at least two time slots pass before sending sub-data block 1. For each sub-data block All the same.

In addition, the MAC layer has the following changes. The MAC-hs entity located in the MAC layer in single-carrier HSDPA has been improved. The improved MAC-hs entity can divide the data block into suitable transmission according to the channel environment, UE capability and wireless resources. independent sub-data blocks, and then combine the sub-data blocks at the UE side. Since the large data block is divided into small sub-data blocks, the base station can release or update the storage space after obtaining the ACK confirmation information of the sub-data blocks; on the UE side, since the independent sub-data blocks are small, it is convenient for HARQ , which can effectively utilize limited storage resources.

The following compares the MAC layer scheduling process in the multi-carrier HSDPA technology that uses data segmentation before data transmission, the single-carrier HSDPA technology, and the multi-carrier HSDPA technology that does not use data segmentation before data transmission. As shown in Figure 2, Figure 3, and Figure 4, the scheduling complexity of the MAC layer in the multi-carrier HSDPA technology using data block segmentation is close to that of single carrier, that is, there is no excessive scheduling, and the data block is directly processed without segmentation. Although the complexity of MAC scheduling in multi-carrier HSDPA is reduced during transmission, under the same throughput index, if an error occurs, the required storage space will be doubled due to the large base number, and the amount of information that needs to be retransmitted will also increase. Much larger than the sub-block approach, which is not conducive to fast and flexible scheduling.

In the multi-carrier HSDPA technology, the HS-DSCH channel data flow is shown in Figure 5. The data in a TTI of 5ms is divided into several sub-data blocks. The size of each sub-data block can be the same or different. The improved The MAC-hs entity is allocated. Each sub-data block can independently perform code block segmentation, physical layer HARQ, bit scrambling, HS-DSCH interleaving, 16QAM (16 quadrature amplitude modulation) constellation rearrangement and physical channel mapping. Since the physical channel is extended to three dimensions, including carrier , time slot and code channel, so each sub-data block is mapped to the corresponding carrier, time slot and code channel respectively.

The information interaction between the user terminal and the base station is shown in Figure 6. The UE first sends the user terminal capabilities to the base station through the uplink DCH, including whether it supports multi-carriers. If it does not support multi-carriers, the base station uses single-carrier HSDPA. If it supports multi-carriers, the base station The carrier is configured according to the capabilities of the user terminal, and the configured carrier information is sent to the UE through the downlink DCH, BCH or HS-SCCH. In addition, the code channel and time slot resources are still sent to the UE through the HS-SCCH. HS-SCCH will not increase with the number of carriers. After at least two time slots have elapsed after sending the control information of each data block, the base station correspondingly sends each data block to the UE in sequence. In addition, for HS-SICH, since it is necessary to report the response message including the channel quality indicator (CQI) corresponding to each sub-data block and the confirmation information of HARQ, in the case of multi-carrier, with the increase of sub-data blocks, corresponding Increase the number of HS-SICHs.

As shown in Fig. 7, according to the specific embodiment of the present invention, adopt the method for realizing HSDPA of a plurality of carriers in TD-SCDMA system, its flow process comprises the following steps:

Step 701, the UE sends the user terminal capability to the base station through the uplink DCH, the user terminal capability includes whether it supports multi-carriers and the buffer capacity of the user terminal;

Step 702, the MAC-hs entity of the base station judges whether the user terminal supports multi-carrier according to the received user terminal capability, if so, execute step 703, otherwise adopt single-carrier HSDPA;

Step 703, the MAC-hs entity configures the number of carriers according to the user terminal capabilities, and divides a data block in a 5ms TTI into several blocks according to the code channel, time slot and carrier resources, channel environment and user terminal capabilities Sub-data blocks, wherein the lengths of the sub-data blocks can be the same or different;

Step 704, respectively encode and modulate several sub-data blocks, and simultaneously map each sub-data block to corresponding code channels, time slots and carriers;

Step 705: Send the radio resource configuration information of each sub-data block to the UE, wherein the frequency resource configuration information (ie, carrier information) in the radio resource configuration information, such as the frequency points where multiple carriers are located, is transmitted through HS-SCCH, The DCH or BCH is sent to the UE, the code channel and time slot resource information in the radio resource configuration information is sent to the UE through the HS-SCCH, and the HS-SCCH, DCH or BCH is sent on a single carrier;

Step 706, each sub-data block is sent on the corresponding carrier, time slot and code channel at least after the respective radio resource configuration information is sent out for 2 time slots;

Step 707, the UE receives independent sub-data blocks on corresponding code channels, time slots and carriers, and performs demodulation and decoding;

In step 708, the UE verifies the receiving performance of each sub-data block through a cyclic redundancy check (CRC), and obtains the CIR value of a single carrier or the comprehensive performance of multiple carriers by measuring the comprehensive performance of multiple carriers in the entire band. CIR value, and then send the CQI and HARQ confirmation information of each sub-data block to the base station respectively through HS-SICH, where the HARQ confirmation information is ACK or NACK; if the CRC of the sub-data block is correct, it indicates that the corresponding sub-data block is received correctly , the acknowledgment information of HARQ sent by the corresponding sub-data block is ACK, otherwise it indicates that the corresponding sub-data block is received incorrectly, and the acknowledgment information of HARQ sent by the corresponding sub-data block is NACK; HS-SICH is sent on a single or multiple carriers;

Step 709, the UE hands over the correct sub-data blocks verified by the CRC to the MAC layer, waits for merging, and releases the physical layer buffer space of the corresponding sub-data blocks;

Step 710, if the sub-data block confirmation message received by the base station is ACK, then release or update the corresponding sub-data block space to prepare for the next TTI or retransmission; if the sub-data block confirmation message received by the base station is NACK, Then retransmit the corresponding sub-data block;

Step 711, after a complete data transmission of one TTI is completed, the user terminal performs data combination at the MAC layer.

In addition, retransmission can be performed on the newly designated code channel, time slot, and carrier. The amount of retransmitted data can be changed according to the release of resources. For example, if a sub-data block needs to be retransmitted, in order to ensure correct transmission, the code rate can be reduced , reduce punching, and use low-rate modulation.

It can be seen from the above analysis that the use of multi-carrier HSDPA can not only effectively improve the HSDPA peak rate and cell data throughput of TD-SCDMA, but also fully consider the maximum consistency with single-carrier HSDPA.

Claims (10)

1. A method for implementing high-speed downlink packet access to HSDPA in a time-division synchronous code division multiple access system, which is applied to a mobile communication system composed of a base station and a user terminal. The base station includes a medium access control-high-speed downlink packet access entity , using multiple carriers for data transmission between the base station and the user terminal, the method includes the following implementation steps: (a1) Medium access control in the base station - the high-speed downlink packet access entity divides a data block of a transmission time interval into several sub-data blocks according to the user terminal capability and system radio resources, and then encodes and modulates several sub-data blocks respectively , and determine their respective code channels, time slots and carriers; (a2) Send the radio resource configuration information of each sub-data block to the user terminal, each sub-data block waits for a period of time, and then sends it to the user terminal through the corresponding code channel, time slot and carrier; (a3) The user terminal receives the sub-data blocks on the corresponding code channel, time slot and carrier according to the received radio resource configuration information, demodulates and decodes each sub-data block, and then sends each sub-data block to the base station respectively. A response message for the data block; (a4) Media access control in the base station - the high-speed downlink packet access entity judges the received response message, if the response message indicates that the sub-data block is received correctly, release the corresponding sub-data block space, otherwise retransmit the corresponding sub-data block ; (a5) After receiving all sub-data blocks of a transmission time interval, the user terminal performs data combination on them. 2. A method for implementing high-speed downlink packet access to HSDPA in a time-division synchronous code division multiple access system according to claim 1, wherein the transmission time interval is 5 ms. 3. A method for realizing high-speed downlink packet access to HSDPA in a time-division synchronous code division multiple access system according to claim 2, characterized in that: the time length in step (a2) is at least 2 time slots. 4. A method for realizing high-speed downlink packet access to HSDPA in a time-division synchronous code division multiple access system according to claim 3, characterized in that: the technology of transmitting sub-data blocks to user terminals adopts hybrid automatic retransmission technology. 5. A method for realizing high-speed downlink packet access HSDPA in a time-division synchronous code division multiple access system according to claim 4, characterized in that: the response message described in step (a3) includes the channel quality of the sub-data block The measurement indication information and the confirmation information of the hybrid automatic repeat transmission are used to indicate whether the sub-data block is received correctly. 6. A method for realizing high-speed downlink packet access HSDPA in a time-division synchronous code division multiple access system according to claim 5, characterized in that: when retransmitting the sub-data block in the step (a4), the code is reduced Rate, reduce punching, and use low-rate modulation to transmit on the newly designated code channel, time slot and carrier. 7. A method for realizing high-speed downlink packet access to HSDPA in a time-division synchronous code division multiple access system according to claim 6, characterized in that: different carriers among the plurality of carriers adopt interleaving technology. 8. A method for realizing high-speed downlink packet access (HSDPA) in a time-division synchronous code division multiple access system according to claim 7, characterized in that: said wireless resource configuration information includes carrier, time slot and code channel Configuration information, the configuration information of time slots and code channels is sent to the user terminal through the high-speed downlink packet access HSDPA dedicated high-speed shared control channel, and the carrier configuration information is accessed through the high-speed downlink packet access HSDPA dedicated high-speed shared control channel, broadcast channel or downlink dedicated data channel to the user terminal. 9. A method for realizing high-speed downlink packet access to HSDPA in a time-division synchronous code division multiple access system according to claim 8, characterized in that: the response message of the user terminal is through the high-speed downlink packet access HSDPA dedicated The high-speed shared information channel is sent to the base station. 10. A method for realizing high-speed downlink packet access to HSDPA in a time-division synchronous code division multiple access system according to claim 9, characterized in that: the high-speed downlink packet access to HSDPA dedicated high-speed shared control channel, broadcast The channel or the downlink dedicated data channel is sent on a single carrier; the high-speed downlink packet access HSDPA dedicated high-speed shared information channel is sent on a single or multiple carriers.

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