CN101383655B - Wireless resource block offset selection method based feedback - Google Patents

Abstract

The invention discloses a feedback-based wireless resource block offset selection method, which is applied to an orthogonal frequency division multiplexing system, and is intended to be used by the sender to change the radio frequency in the wireless resource block according to the offset information fed back by the receiver. Resource configuration, the main feature of which is: after determining the offset set, the receiver obtains channel quality index information based on the channel quality test value of the wireless resource block under all or part of the offset in the offset set; The receiver feeds back part or all of the offset information to the sender according to the channel quality index information; the sender selects an offset according to the part or all of the offset information. The present invention realizes the purpose that the sender changes part or all of the radio resource configuration in the radio resource block according to part or all of the offset information fed back by the receiver.

Description

Feedback-based radio resource block offset selection method

technical field

The invention relates to the access technology in the communication system, in particular to a feedback-based wireless resource block offset selection method.

Background technique

With the evolution of cellular systems, OFDMA (Orthogonal Frequency Division Multiple Access, Orthogonal Frequency Division Multiple Access) systems have gradually become the mainstream technology for future broadband mobile communications. The core idea of OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) system is to use IFFT (Inverse Fast Fourier Transform) to modulate the data stream on multiple sub-carriers (sub-carriers), and divide the frequency response of the channel. , making it parallel, independent and approximately memoryless multiple sub-channels. Therefore, the basic wireless resources of the OFDM system are frequency and time (or time interval). If combined with coding technology and multi-antenna technology, the OFDM system can also obtain additional codeword resources or space resources, using OFDM orthogonal time-frequency resources to obtain Multiple access transmission capability, the system is OFDMA system.

Reducing overhead is an important means for wireless communication systems to obtain higher spectral efficiency. Under the same subcarrier frequency interval, the larger the system bandwidth and the more subcarriers, the greater the overhead of assigning subcarriers for multiple access transmission. At the same time, on the one hand, , transmitting as much data as possible at one time can reduce system overhead. On the other hand, the data length of most services is not fixed, so resource blocks are designed so that they can carry services of smaller lengths, and multiple resource blocks can be combined at the same time. It is very necessary to transmit the business of relatively large length. For example, in the LTE (Long Term Evolution, long-term evolution) system, an RB (ResourceBlock, resource block) is defined to include 12 subcarriers and a time interval of 1 ms, and the subcarrier configuration in the RB is fixed.

In order to improve spectrum utilization, wireless communication systems will adopt adaptive modulation and coding scheme (MCS) according to channel conditions. MCS is usually hierarchical and limited. Base stations and terminals will use multiple RBs to transmit a TB (transport block, data block ), in order to reduce notification overhead, different RBs within a TB use the same MCS. When the subcarrier configuration in the system RB is fixed, since the channel has frequency selection and time selectivity in most cases, and the resources occupied by the TB are only part of the channel resources, the MCS allocated for the TB may not be optimal, so This results in a decrease in spectrum utilization.

Contents of the invention

The technical problem to be solved by the present invention is to provide a feedback-based radio resource block offset selection method for the sender to change the radio resource configuration in the radio resource block according to the offset information fed back by the receiver.

In order to solve the above technical problems, the present invention provides a feedback-based wireless resource block offset selection method, which is applied to an OFDM system, including:

(1) After determining the offset set, the receiver obtains channel quality index information based on the channel quality test value of the wireless resource block under all or part of the offset in the offset set;

(2) The receiver feeds back part or all of the offset information to the sender according to the channel quality index information;

(3) The sender selects an offset according to the part or all of the offset information.

In the above method, the wireless resource block may include: time-frequency resources, a combination of time-frequency resources, codeword resources or space resources, or all of them.

In step (1) of the above method, the determining the offset set may include determining according to the radio resource configuration attributes in the radio resource block.

Further, the radio resource configuration attribute is a radio resource configuration mode in the radio resource block, which may include:

Mode 1, all the radio resource blocks of the OFDM system are configured the same;

In a second manner, the wireless resource block configurations of the OFDM system are different.

Further, according to the radio resource configuration attribute in the radio resource block, determining the offset set may include:

When the wireless resource configuration method in the wireless resource block is the first method, select some or all of the offsets from 0 to A-1 as elements in the offset set, where A is the wireless resource the number of subcarriers in a block; and

When the radio resource configuration mode in the radio resource block is the mode 2, select some or all of the offsets from 0 to B-1 as elements in the offset set, where B is an orthogonal frequency The total number of subcarriers in a division multiplexing system.

In the above method, the step (2) may include:

(21) The receiver counts the channel quality test values of the wireless resource blocks under some or all of the offsets in the offset set;

(22) The receiver calculates the channel quality index information based on the channel quality test value of the radio resource block under the partial or full offset.

Further, the channel quality index information in step (22) may include the quantized value or statistical value of the channel quality test value, and the position information of the radio resource block corresponding to the quantized value or statistical value .

In step (2) of the above method, the receiver may preferably feed back part or all of the offset to the sender according to the offset selection strategy.

In the above method step (2), the offset information can be any of the following:

Offset;

Offset and corresponding channel quality index information;

A set of offsets and a corresponding set of channel quality index information;

Offset and corresponding channel quality test value;

A set of offsets and a corresponding set of channel quality test values.

In step (3) of the above method, the sender may select the one offset according to a predetermined offset selection principle.

In step (3) of the above method, the sender may select the offset periodically or aperiodically.

The above method may further include:

(4) The sender changes the radio resource configuration in part or all of the radio resource blocks according to the selected offset.

Through the above technical solution of the present invention, the sender selects an offset to change the radio resource configuration in part or all of the radio resource blocks according to part or all of the offset information fed back by the receiver, and then The throughput of system transmission is improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is a flowchart of a method for dynamically adjusting wireless resource block configuration based on an offset;

Fig. 2 is a flow chart of an embodiment of a method for selecting a radio resource block offset based on feedback in the present invention;

Figure 3 is a flowchart of an example of the method shown in Figure 2; and

FIG. 4 is a flowchart of Example 2 of the method shown in FIG. 1 .

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The present invention involves radio resource blocks (RBs), and the RBs will first be described in detail below.

(1) RB can be divided into two types according to configuration

The radio resource configuration modes in the radio resource blocks include the following two modes: mode 1, all radio resource blocks in the OFDM system are configured the same; mode 2, radio resource blocks in the OFDM system are configured differently. Correspondingly, RBs can be divided into two types according to the configuration: the radio resource blocks of all OFDM systems in the first type of radio resource blocks have the same configuration, that is, the above-mentioned method 1 is adopted, that is to say, the radio resource blocks of the OFDM system are at least time-frequency There is only one size configuration of resources, the number of subcarriers in different RBs is the same, and the number of OFDM symbols contained in them is also the same; the radio resource block configurations of the OFDM system in the second type of radio resource block are different, that is, the above method two .

(2) RB can be divided into two types according to subcarrier distribution

Centralized RB: If the subcarrier frequencies in the RB are continuous, the RB is called a centralized RB;

Distributed RB: RB other than centralized RB.

(3) RB is divided into two categories according to the mode

Dynamic RB: The subcarrier components contained in the dynamic RB are variable;

Static RB: The subcarrier components included in the static RB are invariable.

(4) RB is classified according to attributes

Logical (or virtual) RB: The subcarriers contained in this RB are virtual, and the logical subcarrier numbers are continuous, and the logical subcarriers in a specific numbered RB are always unchanged;

Physical RB: This RB contains physical subcarriers. The number of physical subcarriers in a specific numbered RB is not necessarily continuous. The physical subcarriers in a specific numbered RB can always remain the same or can be changed.

There is a specific mapping relationship between logical subcarrier numbers and physical subcarriers in a logical (or virtual) RB, and the mapping relationship may be the same or different under different offsets.

In addition, the sender mentioned below may be a BS (Base Station, base station) or AP (AccessPoint, access point), and the receiver may be a UE (User Equipment, terminal).

Based on the above content, as shown in Figure 1, the offset-based RB configuration dynamic adjustment method includes the following processing:

Step 101, determining the offset set according to the radio resource configuration attribute in the RB;

Step 102, periodically or aperiodically select an offset from the offset set, and change the radio resource configuration in some or all RBs according to the selected offset;

Step 103, schedule the data to be transmitted according to the changed RB.

Various details in the above processing will be specifically described below.

First of all, the above-mentioned RB of the OFDM system refers to time-frequency (i.e. time or time interval and frequency or subcarrier) resources, or a combination of time-frequency resources, codeword resources, and space resources. OFDM frequency resources refer to A set of subcarriers in an OFDM system.

In step 101, the radio resource configuration attribute is the radio resource configuration mode in the RB, including: mode 1, all RB configurations in the OFDM system are the same; mode 2, RB configurations in the OFDM system are different.

Correspondingly, in step 101, the process of determining the offset set is specifically: when the radio resource configuration mode in the RB is mode 1, select part or all of the offsets in 0-A-1 as the offset set elements in , where A is the number of subcarriers in the RB; when the radio resource configuration method in the RB is method 2, select some or all of the offsets from 0 to B-1 as the offset set Elements, where B is the total number of subcarriers in the OFDM system.

In step 102, the process of periodically or aperiodically selecting an offset from the offset set is specifically: the sender selects an offset from the offset set periodically or aperiodically or aperiodically according to the feedback information of the receiver. displacement. The method for selecting the offset can be determined according to different principles (eg, minimum block error rate, maximum throughput, etc.), which is not limited in the present invention.

Among them, the above-mentioned process of the sender selecting an offset according to the feedback information of the receiver is specifically: the receiver calculates the channel quality test value of the RB under part or all of the offset; the receiver calculates part or all of the offset. , the channel quality index information based on the channel quality test value of the RB; the receiving direction feeds back part or all of the offset information to the sender; the sender selects an offset according to a predetermined offset selection principle (the following will be combined with Example 1 for specific describe).

The above process of the sender choosing an offset by itself is as follows: the sender counts the data transmission quality under the current offset; the sender adjusts the offset according to the change of the data transmission quality; the sender tries to adjust the offset, and Send data on the RB corresponding to the adjusted offset until the offset trial adjustment ends; after the trial adjustment ends, the sender selects an offset with the best sending quality from the trial results (the following will be combined with Example 2 be described in detail).

In step 102, the process of changing the radio resource configuration in some or all RBs is specifically: the sender changes subcarrier components contained in some or all RBs according to the selected offset and according to a predetermined offset mapping manner.

As mentioned above, the RBs of the OFDM system can be divided into two types, one is called dynamic RB, and the subcarrier components contained in the dynamic RB are variable, and the other is called static RB, and the subcarrier components contained in the static RB are not variable . The RBs in the OFDM system may only have static RBs, may only have dynamic RBs, and may also have both dynamic RBs and static RBs. In addition, the subcarriers of the OFDM system are numbered from small to large in frequency, which is called the physical number, and the subcarrier number in the RB is the subcarrier logical number. For the centralized RB, the logical number and the physical number are the same when the offset is 0. , for a distributed RB, when the offset is 0, there is a definite mapping relationship between the logical number and the physical number.

Based on this, the above-mentioned predetermined offset mapping method is: under a specific offset, the logical numbers of the logically continuous subcarriers (the logical numbers of the subcarriers in the RB are continuous) and the numbers of the physically discrete subcarriers The mapping relationship of the physical number (the physical number corresponds to the actual frequency of the subcarrier).

Wherein, the number of the RB and the logical number of the corresponding subcarrier need to be defined in advance. One way of definition is that the logical number of the subcarriers in the RB with a large number is always greater than the logical number of the subcarriers in an RB with a small number, for example: RB0 includes LSC0~11, VRB1 includes LSC12~23, . . . . In addition, when there is a static RB, the mapping relationship between the logical number and the physical number of the subcarriers in the static RB is the same under different offsets.

In step 103, the process of scheduling the data to be transmitted according to the changed RB is specifically: the sender schedules the data to be transmitted to one or more receivers on the changed RB according to the scheduling policy.

Thus, the flow of the embodiment of the feedback-based radio resource block offset selection method embodiment of the present invention, as shown in FIG. 2 , includes the following steps:

Step 201, determine the offset set according to the radio resource configuration attribute in the RB;

Step 202, the receiver obtains the channel quality index information of the RB-based channel quality test value under all or part of the offsets in the offset set, and feeds back part or all of the offset information to the sender according to the channel quality index information;

Step 203, the sender selects an offset periodically or aperiodically according to part or all of the offset information fed back by the receiver;

Step 204, the sender changes the radio resource configuration in some or all of the RBs according to the selected offset, and sends data to the receiver under the new RB configuration.

The following will use an example to further describe how the present invention changes the radio resource configuration in the radio resource block according to the offset information fed back by the receiver.

Example 1: The sender selects an offset according to the feedback information from the receiver, where the sender is the BS and the receiver is the UE.

As shown in Figure 3, the present invention under this example comprises following processing:

Step 301: Determine an offset set according to radio resource configuration attributes in a radio resource block.

Assuming that the frequency resource bandwidth of the OFDM system carrying data is 9MHz, and the subcarrier spacing is 15KHz, the number of useful subcarriers is 600 except DC (that is, 0Hz subcarrier), which is set from -4.5MHz to 4.5MHz, and the subcarrier number is SC0 ～SC599, 50 resource blocks (RB0～RB49), each RB contains 12 subcarriers, and the set of offsets is {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }, RB is a centralized allocation mode, that is, the subcarriers in each RB are continuous, such as corresponding to an offset of 0, RB0 contains subcarriers SC0, SC1, ..., SC11, RB1 contains SC12, SC13, . .., SC23, and so on, different RBs contain different numbers of subcarriers. RB can also be in a distributed allocation mode, that is, to establish a mapping relationship between logically continuous subcarrier numbers (such as LSC0~LSC599) and physically discrete subcarrier numbers, for example, the m+12×n logical subcarrier and the m×50+n physical subcarriers correspond, where m=0-11, n=0-49. In the distributed allocation mode, corresponding to an offset of 0, RB0 includes subcarriers LSC0, LSC1, ..., LSC11, RB1 includes LSC12, LSC13, ..., LSC23, and so on. OFDM system modulation and coding scheme (MCS) is divided into 6 types, namely 1# is (QPSK, 1/3Turbo code), 2# is (QPSK, 1/2Turbo code), 3# is (16QAM, 1/3Turbo code) , 4# is (16QAM, 1/2Turbo code), 5# is (64QAM, 1/3Turbo code), and 6# is (64QAM, 1/2Turbo code).

Step 302, the UE counts the channel quality test value of the RB under all or part of the offset, such as: signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), signal strength, channel time selectivity parameters, frequency selection Sexual parameters, or any combination of the above parameters.

In step 303, the UE calculates RB-based channel quality index information under all or part of the offset. The RB-based channel quality index information refers to the quantized value or statistical value of the channel quality test value, and the RB position information corresponding to the quantized value or statistical value, such as corresponding to offset 7, RB8, etc. The effective signal-to-interference-plus-noise ratio (SINR) is 10dB or the level is 3 or the modulation coding method (MCS) is 3#.

Step 304, the UE feeds back part or all of the offset information to the BS according to the offset selection strategy, for example: the UE feeds back the channel quality index information of the RB under all 12 offsets to the BS, or the UE feeds back part of the offset information to the BS RB channel quality index information, for example, it is preferred to feed back one or better offsets or offsets that the UE considers the RB channel quality to be the best and all or part of the RB channel quality index information under the corresponding offset , or the offset and further statistical information of all or part of the RB channel quality index information under the corresponding offset. Specifically, in this application example, the UE feeds back 50 RB positions and corresponding CQIs under all offsets from 1 to 12. In other examples, it can also feed back one of the offsets from 1 to 12 amount, such as offset 7.

Step 305: Determine the offset according to the offset selection principle. The BS receives the offset information set fed back by Y UEs, where Y is less than or equal to X, and according to the offset selection principle (for example, to send data to Y UEs, the throughput is the largest, and in other instances, it can also be sent to Y The sum of the Y subchannel capacities sent by UEs is the largest), and the offset is determined.

Step 306, the BS sends data under the new RB configuration. The BS notifies the receiver to refresh the offset, and sends data to all or part of the X UEs on the RB corresponding to the refreshed offset.

Step 307, the UE receives the data sent to itself on the RB corresponding to the refreshed offset according to the resource assignment information. (Step 302-Step 307 is the process of the sender sending data to X receivers at the same time)

Example 2: The sender selects an offset by itself, where the sender is the BS and the receiver is the UE.

As shown in Figure 4, the present invention under this example comprises following processing:

Step 401: Determine an offset set according to radio resource configuration attributes in the radio resource block.

Assuming that the frequency resource bandwidth of the OFDM system carrying data is 9MHz, and the subcarrier spacing is 15KHz, the number of useful subcarriers is 600 except DC (that is, 0Hz subcarrier), which is set from -4.5MHz to 4.5MHz, and the subcarrier number is SC0 ～SC599, 50 resource blocks (RB0～RB49), each RB contains 12 subcarriers, and the set of offsets is {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }, RB is a centralized allocation mode, that is, the subcarriers in each RB are continuous, such as corresponding to an offset of 0, RB0 contains subcarriers SC0, SC1, ..., SC11, RB1 contains SC12, SC13, . .., SC23, and so on, different RBs contain different numbers of subcarriers. RB can also be in a distributed allocation mode, that is, to establish a mapping relationship between logically continuous subcarrier numbers (such as LSC0~LSC599) and physically discrete subcarrier numbers, for example, the m+12×n logical subcarrier and the m×50+n physical subcarriers correspond, where m=0-11, n=0-49. In the distributed allocation mode, corresponding to an offset of 0, RB0 includes subcarriers LSC0, LSC1, ..., LSC11, RB1 includes LSC12, LSC13, ..., LSC23, and so on. OFDM system modulation and coding methods are divided into 6 types, respectively 1# is (QPSK, 1/3Turbo code), 2# is (QPSK, 1/2Turbo code), 3# is (16QAM, 1/3Turbo code), 4# It is (16QAM, 1/2Turbo code), 5# is (64QAM, 1/3Turbo code), and 6# is (64QAM, 1/2Turbo code).

In step 402, the BS sends data to some or all of the X UEs on corresponding RBs with the current offset.

In step 403, the BS counts the data transmission quality under the current offset. Data transmission quality can be measured by reliability indices such as frame error rate and bit error rate. The reliability index can be obtained by counting acknowledgment information (such as: ACK/NACK) or measurement information fed back by one or more receivers, or it can be counted according to the number of retransmission times of the BS.

Step 404, the BS adjusts the offset according to the change of the data transmission quality, for example, setting a transmission quality threshold, when the transmission quality is lower than the threshold, start to adjust the offset until the transmission quality improves or finds in the offset set An optimal integer offset results in the best sending quality. In order to avoid repeated adjustments when the transmission quality is lower than the threshold at all offsets, you can also set the adjustment cycle, find the offset with the best transmission quality within the adjustment cycle, and stop the adjustment until the next adjustment cycle begins, and then repeat adjustment process.

In step 405, the BS tries to adjust the offset, and sends data on the RB corresponding to the adjusted offset until the offset adjustment ends.

Step 406, if the trial adjustment is over, go to step 407, if the trial adjustment is not over, go to step 405.

Step 407 , select the offset with the best transmission quality from the trial results as a new offset, and send data on the RB corresponding to the refreshed offset, and return to step 403 .

In this way, by means of the present invention, by changing the subcarrier configuration in the RB, the channel capacity of the subchannel based on the RB bandwidth in the OFDM system bandwidth is statistically optimized for one or more receivers, thereby improving the transmission efficiency. throughput.

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 (9)

1. the wireless resource block offset selection method based on feedback is applied to ofdm system, it is characterized in that, comprising:

(1) determine side-play amount set after, the recipient obtains in the described side-play amount set under all or part of side-play amount quality index of a channel information based on the channel quality test value of described wireless resource block;

(2) described recipient according to described quality index of a channel information to transmit leg feedback fraction or whole offset information;

(3) described transmit leg is selected a side-play amount according to described part or all of offset information;

Determine described in the step (1) that the side-play amount set comprises:

When the radio-resource-configuration mode in the wireless resource block is that all described wireless resource blocks of ofdm system configure when identical, part or all of side-play amount among selection 0～A-1 is as the element in the described side-play amount set, wherein, A is the sub-carrier number in the described wireless resource block; And

Radio-resource-configuration mode in wireless resource block is that the described wireless resource block of ofdm system configures not simultaneously, part or all of side-play amount among selection 0～B-1 is as the element in the described side-play amount set, wherein, B is the total number of sub-carriers in the ofdm system.

2. the method for claim 1 is characterized in that, described wireless resource block comprises: running time-frequency resource, one or whole combinations in running time-frequency resource and code source or the space resources.

3. the method for claim 1 is characterized in that, described step (2) comprising:

(21) described recipient adds up in the set of described side-play amount partly or entirely under the side-play amount, the channel quality test value of described wireless resource block;

(22) described recipient calculates under the described part or all of side-play amount, based on the described quality index of a channel information of the channel quality test value of described wireless resource block.

4. method as claimed in claim 3, it is characterized in that, quality index of a channel information described in the step (22) comprises quantized value or statistical value to described channel quality test value, and the positional information of the described wireless resource block corresponding with described quantized value or statistical value.

5. the method for claim 1 is characterized in that, recipient described in the step (2) preferably partly or with whole side-play amounts feeds back to described transmit leg according to the side-play amount selection strategy.

6. the method for claim 1 is characterized in that, offset information described in the step (2) be following any:

Side-play amount;

Side-play amount and corresponding quality index of a channel information;

Side-play amount set and corresponding quality index of a channel information aggregate;

Side-play amount and corresponding channel quality test value;

Side-play amount set and corresponding channel quality test value set.

7. the method for claim 1 is characterized in that, transmit leg described in the step (3) is selected a described side-play amount according to predetermined side-play amount selection principle.

8. the method for claim 1 is characterized in that, transmit leg cycle or aperiodic described in the step (3), described side-play amount was selected on ground.

9. the method for claim 1 is characterized in that, described method further comprises:

(4) described transmit leg changes radio-resource-configuration in the part or all of described wireless resource block according to selected described side-play amount.

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