CN101291171B - Feedback method of indication of communication channel quality - Google Patents

Abstract

The present invention provides a CQI feedback method, including: step S102, the receiver constructs channel quality index information, wherein the channel quality index information includes channel quality parameters of some or all unavailable resource blocks; step S104, the receiver transmits The receiver feeds back the channel quality index information of available resource blocks; step S106, the receiver feeds back the channel quality index information of unavailable resource blocks to the transmitter; step S108, the transmitter restores the channel quality index information of each resource block according to the received channel quality index information value. Through the technical solution of the invention, the average throughput of the sector can be significantly improved without significantly increasing the uplink overhead of the receiver, thereby improving system performance.

Description

Channel Quality Index Feedback Method

technical field

The present invention relates to a channel quality index in the communication field, and more specifically, relates to a channel quality index feedback method in a communication system.

Background technique

Channel Quality Indication (CQI for short) is the channel condition information that the receiver feeds back to the transmitter in the communication system.

The transmitter corresponds the CQI information fed back by the receiver to a certain transport block size, coding mode, and modulation mode, and on this basis, the transmitter performs resource allocation and scheduling for the receiver according to the CQI information. Therefore, the authenticity of the channel that can be reflected by the CQI information and the uplink overhead consumed by feedback will have a greater impact on system performance. However, in fact, the authenticity of the channel reflected by the CQI information and the resources consumed by feedback are a pair of contradictions. If it is necessary to reflect the channel as realistically as possible, a full feedback strategy can be adopted, that is, to feed back every scheduling channel on the entire working frequency band. The channel quality information of the unit, but this will generate huge overhead. For example, for a 10M bandwidth communication system, the Orthogonal Frequency Division Multiplexing (OFDM) technology adopted divides the entire frequency band into 600 subcarriers, and each 24 subcarriers are used as a resource block, a total of 25 resource blocks; each resource block is used as a scheduling unit, then 25 CQI values are needed to reflect the channel quality of each resource block on the entire frequency band.

At present, a variety of methods have been proposed for CQI feedback, mainly as follows:

1. Average CQI feedback: feed back an average CQI value within the entire transmission bandwidth;

2. Complete CQI feedback: Feedback the CQI values of all resource blocks in the entire bandwidth;

3. The CQI feedback of the strongest M resource blocks: feedback the M largest CQI values, the location information of the resource blocks where they are located, and the average CQI values on other resource blocks;

4. The CQI mean value feedback of the strongest M resource blocks: feedback the mean value of the M largest CQI values, the location information of the resource blocks where they are located, and the average CQI values on other resource blocks;

5. CQI feedback of the strongest M resource blocks in a group: grouping adopts a cyclic method, and reports the CQI of the strongest M resource blocks in a group each time;

6. Threshold-based CQI feedback: Based on the CQI value measured by each receiver in the full frequency band, calculate the average value of the CQI value contained in the highest CQI value and the CQI threshold, and compare the average CQI value with the position of these CQI values The information is fed back to the transmitter;

7. Differential CQI feedback: Feedback an absolute CQI value and differential CQI values (1-bit) of other resource blocks each time; where, the calculation of differential CQI bits can be divided into calculating the differential information in the frequency domain and calculating the time domain Differential information in two ways;

8. Hierarchical continuous resource block CQI feedback: the entire transmission bandwidth is divided into several levels, and the CQI feedback information includes level information, resource block information, and CQI value information;

9. Hierarchical non-contiguous resource block CQI feedback: CQI feedback information includes resource block bitmap and CQI value, wherein the bitmap shows the position of the resource block corresponding to the CQI value.

Among the various methods mentioned above, although method 1 causes the least overhead to the uplink, it does not have the advantage of frequency selection; although method 2 can more accurately reflect the channel quality status on each resource block, it will affect the uplink The link brings huge overhead; methods 3, 4, 5, and 6 can compensate for the shortcomings of methods 1 and 2, but for channels with strong frequency domain selectivity, the quality of the channel may be in each resource block There is a large difference, so using the same CQI value to represent several resource blocks with large channel quality differences will cause large errors, causing unreasonable resource allocation, and thus leading to system performance degradation; while methods 7, 8, and 9 The computational complexity is high.

Contents of the invention

The present invention is made aiming at the problems of large system overhead, high computational complexity, and low system performance in the related art. Therefore, the present invention aims to provide a channel quality index feedback method in a communication system, which can Overcome at least one of the above problems.

According to an embodiment of the present invention, a channel quality index feedback method is provided.

The method includes: step S102, the receiver constructs channel quality index information, wherein the channel quality index information includes channel quality parameters of some or all unavailable resource blocks; step S104, the receiver feeds back the channel quality of available resource blocks to the transmitter Index information; step S106, the receiver feeds back channel quality index information of unavailable resource blocks to the transmitter; step S108, the transmitter restores the channel quality index value of each resource block according to the received channel quality index information.

The above-mentioned available resource blocks are resource blocks that the transmitter can use as scheduling units; unavailable resource blocks are resource blocks that the transmitter cannot use as resource allocation objects. Wherein, the available resource block may be a resource block whose CQI is non-zero according to the statistics of the receiver, and correspondingly, the unusable resource block may be a resource block whose CQI is zero according to the receiver's statistics.

Specifically, the channel quality parameters of the unavailable resource blocks include at least one of the following: location information of the unavailable resource blocks, and number information of the unavailable resource blocks. At the same time, the channel quality index information fed back in step S106 includes channel quality parameters of unavailable resource blocks, so that the channel quality index information fed back in step S106 includes at least one of the following: position information of unavailable resource blocks, unavailable Information about the number of resource blocks.

In addition, in step S102, the channel quality index information may be constructed through the following processes: the receiver obtains the signal-to-interference-plus-noise power ratio of each resource block; the receiver corresponds the signal-to-interference-plus-noise power ratio to the channel quality index.

In step S104, the receiver may feed back the channel quality index information of the available resource blocks in any of the following ways: average channel quality index feedback, complete channel quality index feedback, channel quality index feedback of the strongest M resource blocks, Channel quality index mean feedback of the strongest M resource blocks, channel quality index feedback of grouped strongest M resource blocks, threshold-based channel quality index feedback, differential channel quality index feedback, hierarchical continuous resource block channel quality index Feedback, hierarchical discontinuous resource block channel quality index feedback.

In addition, it should be noted that the channel quality index information mentioned above is the channel condition information fed back by the receiver to the transmitter.

Through the technical solution of the invention, the average throughput of the sector can be significantly improved without significantly increasing the uplink overhead of the receiver, thereby improving system performance.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is the flowchart of the CQI feedback method according to the embodiment of the present invention; And

Fig. 2 is a detailed processing flowchart of a processing example of a CQI feedback method according to an embodiment of the present invention.

Detailed ways

An embodiment of the present invention provides a CQI feedback method. In this method, the CQI information fed back by the receiver not only includes CQI information of available resource blocks, but also includes location information and/or number information of unavailable resource blocks, In this way, the scheduler of the transmitter does not consider these unavailable resource blocks as the object of resource allocation, otherwise, the scheduler of the transmitter allocates an unavailable resource block to the receiver and tries to retransmit it many times, which may reduce the throughput .

In addition, related concepts mentioned in the embodiments provided below are as follows:

1. CQI information: the channel status information fed back by the receiver in the communication system to the transmitter;

2. Available resource block: the transmitter can use it as the resource block of the scheduling unit;

3. Unavailable resource block: a resource block that the transmitter cannot use as a target of resource allocation.

Based on the foregoing, preferred embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, the CQI feedback method according to the embodiment of the present invention includes the following steps: step S102, the receiver constructs CQI information, wherein the CQI information includes channel quality parameters of some or all unavailable resource blocks; step S104, receiving The receiver feeds back CQI information of available resource blocks to the transmitter; step S106, the receiver feeds back CQI information of unavailable resource blocks to the transmitter; step S108, the transmitter recovers the CQI values of each resource block according to the received CQI information.

Among them, there are many ways to select the available resource blocks, and the most accurate one is the resource blocks whose CQI values are not zero at the receiver (for example, the user terminal). Correspondingly, the unavailable resource blocks are A resource block whose CQI value is zero according to the statistics of the computer. Preferably, combined with the CQI feedback of the strongest M resource blocks, the CQI average feedback of the strongest M resource blocks, the CQI feedback of grouping the strongest M resource blocks, or the threshold-based CQI feedback method, multiple reductions can be achieved. An overhead CQI information feedback method.

In addition, the channel quality parameters of the unavailable resource blocks include at least one of the following: location information of the unavailable resource blocks, and number information of the unavailable resource blocks. And the CQI information fed back in step S106 includes the channel quality parameters of unavailable resource blocks, so, on the one hand, the CQI information fed back in step S106 can include the position information of unavailable resource blocks and the number of unavailable resource blocks On the other hand, when the receiver feeds back the location information and number information of unavailable resource blocks at adjacent times, the CQI information fed back in step S106 may not include the location information and unavailable resource blocks at the same time. information about the number of resource blocks, but include one of them.

It should be noted that in step S104, the CQI information of the available resource blocks can be fed back in any of the following ways: average CQI feedback, complete CQI feedback, CQI feedback of the strongest M resource blocks, strongest M resource blocks CQI average value feedback of resource blocks, CQI feedback of M resource blocks with the strongest grouping, threshold-based CQI feedback, differential CQI feedback, hierarchical continuous resource block CQI feedback, hierarchical non-consecutive resource block CQI feedback (details of the above methods A description has been given in the background of this application).

The above steps given in this embodiment are only exemplary, and the present invention is not limited thereto. For example, the feedback of CQI information of available resource blocks and unavailable resource blocks can be implemented in any suitable manner, for example, the CQI information of available resource blocks and unavailable resource blocks can be fed back at the same time, or only part of them can be fed back each time Or CQI information of all unavailable resource blocks.

The CQI feedback method according to the embodiment of the present invention will be described in detail below in combination with specific examples.

Example 1

Taking the downlink of a 10M bandwidth communication system as an example, using OFDM technology, using OFDM technology, the entire frequency band is divided into 600 subcarriers, and each 24 subcarriers are used as a resource block, that is, a scheduling unit, with a total of 25 resource blocks; CQI The feedback cycle takes one Transmission Time Interval (TTI), where TTI=1 ms, assuming 100 feedback cycles.

In addition, in this example, the CQI information of the available resource blocks is realized by using the CQI feedback mode of the strongest M resource blocks; the receiver is a user terminal (UE), and the transmitter is a base station.

As shown in Figure 2, the specific implementation of this instance includes the following processing:

Step S202: the user terminal (UE) calculates the SINR (Interference+Noise ratio, signal to interference plus noise power ratio) on each resource block;

Step S204: The UE corresponds the SINR of the resource block to the CQI (the CQI information is the basis for the UE to perform feedback);

Step S206-1: In each CQI feedback period, the UE uses the strongest M resource block CQI feedback method to feed back the CQI information of the available resource blocks to the base station, that is, feeds back the M largest CQI values, the resource blocks where they are located The location information of , and the average CQI value on other resource blocks;

Step S206-2: UE feeds back CQI information of unavailable resource blocks to the base station, including location information of resource blocks with a CQI value of 0 (that is, unavailable resource blocks) counted at the UE;

Step S208: The base station restores the CQI value of each resource block according to the received CQI feedback information (specifically, the transmitter receives the CQI feedback information, fills the largest M CQI values into the corresponding resource block positions, and fills 0 into its The corresponding resource block position, the remaining positions are filled with the average CQI value except the largest M CQI values), which is used as the basis for resource allocation and scheduling (step S210).

It should be noted that in step S206-1, other feedback methods can also be used, for example, CQI average value feedback of the strongest M resource blocks, CQI feedback of grouped strongest M resource blocks, threshold-based CQI Feedback is threshold-based CQI feedback, which is obvious to those skilled in the art.

In addition, in step S206-2, the fed back CQI information of unavailable resource blocks may also include the number information of resource blocks with a CQI value of 0 (that is, unavailable resource blocks); based on channel changes within a CQI feedback interval For the slow characteristic, the position of the resource block with the CQI value of 0 can be obtained according to the position of the resource block with the CQI value of 0 at the previous feedback moment and the number of resource blocks with the CQI value of 0 fed back this time.

If the information on the number of unavailable resource blocks is fed back in step S206-2, then in step S208, after recovering the CQI values of each resource block, the base station also needs to count the positions of resource blocks with a CQI value of 0, It serves as a reference for determining the position of the unavailable resource block at the next CQI feedback moment.

Afterwards, when it is judged that the preset number of feedback loops has not been reached (100 times), the above-mentioned processing is repeatedly executed.

It can be seen from the above embodiments and examples that the technical solution of the present invention can consider that when a certain resource block is unavailable, keep its CQI value 0 instead of setting it to a smaller but greater than 0 value. Therefore, at this time, the scheduler will not consider it as an object of resource allocation, otherwise, the scheduler will allocate an originally unavailable resource block to the UE and try to retransmit it multiple times, which may reduce the throughput. Therefore, the method can significantly improve the average throughput of the sector without significantly increasing the uplink overhead of the UE, thereby improving the performance 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 modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. a channel quality index feedback method is characterized in that, comprising:

Step S102; Receiver structure quality index of a channel information; Wherein, comprise the channel quality parameter of part or all of unavailable Resource Block in the said quality index of a channel information, wherein; Said unavailable Resource Block is that transmitter can not be with its Resource Block as the object of resource allocation, and said quality index of a channel information is the channel condition information of said receiver to said transmitter feedback;

Step S104, said receiver is to the said quality index of a channel information of transmitter feedback available resource block, and wherein, said available resource block is that said transmitter can be with its Resource Block as scheduling unit;

Step S106, said receiver feed back the said quality index of a channel information of said unavailable Resource Block to said transmitter; And

Step S108, said transmitter recover the quality index of a channel value of each Resource Block according to the said quality index of a channel information that receives.

2. channel quality index feedback method according to claim 1 is characterized in that,

The channel quality parameter of said unavailable Resource Block comprise following one of at least: the number information of the positional information of said unavailable Resource Block, said unavailable Resource Block.

3. channel quality index feedback method according to claim 2 is characterized in that,

The said quality index of a channel information of in said step S106, feeding back comprises the channel quality parameter of said unavailable Resource Block.

4. channel quality index feedback method according to claim 3 is characterized in that,

The said quality index of a channel information of in said step S106, feeding back comprise following one of at least: the number information of the positional information of said unavailable Resource Block, said unavailable Resource Block.

5. channel quality index feedback method according to claim 1 is characterized in that,

Said available resource block is that the quality index of a channel of said receiver statistics is the Resource Block of non-zero.

6. channel quality index feedback method according to claim 1 is characterized in that,

Said unavailable Resource Block is that the quality index of a channel of said receiver statistics is zero Resource Block.

7. channel quality index feedback method according to claim 1 is characterized in that,

In said step S102, construct said quality index of a channel information through following processing:

Said receiver obtains the signal and interference plus noise power ratio of each Resource Block;

Said receiver corresponds to quality index of a channel with said signal and interference plus noise power ratio.

8. channel quality index feedback method according to claim 1; It is characterized in that; In said step S104, said receiver feeds back the said quality index of a channel information of said available resource block through following any one mode: quality index of a channel average feedback, the quality index of a channel feedback of M the strongest Resource Block that divide into groups, the quality index of a channel feedback based on thresholding, differential channel quality index feedback, the graduation continuous resource piece quality index of a channel of the quality index of a channel feedback of average channel quality index feedback, complete channel performance figure feedback, the strongest M Resource Block, M the strongest Resource Block discontinuous Resource Block quality index of a channel of feeding back, classify is fed back.

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