WO2009021369A1

WO2009021369A1 - A method for adjusting dynamically the wireless resource block allocation based on the offsets

Info

Publication number: WO2009021369A1
Application number: PCT/CN2007/003375
Authority: WO
Inventors: Feng Li; Nan Zhao; Wei Gou; Changqing Zhu; Feng Liang
Original assignee: Zte Corporation
Priority date: 2007-08-15
Filing date: 2007-11-29
Publication date: 2009-02-19
Also published as: CN101111048B; CN101111048A

Abstract

A method for adjusting dynamically the wireless resource block allocation based on the offsets is provided, which includes: step S102, determining the offsets assemble based on the attribute of the wireless resource allocation in the wireless resource blocks; step S104, periodically or nonperiodically selecting an offset from the offsets assemble, and changing the wireless resource allocation in the part or all wireless resource blocks based on the selected offset; step S106, dispatching the data to be transmitted according to the changed wireless resource block. Depending on the above technical solution in the present invention, for one or more receiving sides, the channel capacity of the sub-channel based on RB bandwidth in OFDM system bandwidth is optimized in statistical meaning, so as to improve the transmission throughput, and the solution is particularly applied in the fourth generation mobile communication system.

Description

TECHNICAL FIELD The present invention relates to an access technology in a communication system, and in particular, to a method for dynamically adjusting a radio resource block configuration based on an offset. BACKGROUND OF THE INVENTION With the evolution of cellular systems, the OFDMA (Orthogonal Frequency Division Multiple Access) system has gradually become the mainstream technology for future broadband mobile communications. The core idea of OFDM (Orthogonal Frequency Division Multiplexing) system is to use IFFT (Inverse Fast Fourier Transform) to modulate the data stream on multiple subcarriers, and divide the frequency response of the channel into Parallel, independent approximation of multiple subchannels without memory. Therefore, the basic radio resources of an OFDM system are frequency and time (or time interval). If the coding technique and multi-antenna technology are combined, the OFDM system can obtain additional codeword resources or spatial resources, and obtain the OFDM orthogonal time-frequency resources. Multiple access transmission capability, the system is the OFDMA system. Reducing the overhead is an important means for the wireless communication system to obtain higher potential efficiency. Under the same subcarrier frequency interval, the larger the system bandwidth, the more the number of subcarriers, the greater the overhead of assigning subcarriers for multiple access transmission. The transmission of the largest possible data at a time can reduce the system overhead. On the other hand, the data length of most services is not fixed. Therefore, the resource block can be designed to carry a small-length service, and at the same time, multiple resource block combinations can be combined. It is necessary to pass a large length of business. For example, in an LTE (Long Term Evolution) system, an RB is defined to contain 12 subcarriers and a lms time interval, and the subcarrier configuration in the RB is fixed. In order to improve the spectrum utilization rate, the wireless communication system adopts an adaptive modulation and coding scheme (MCS) according to channel conditions. The MCS is usually hierarchical and limited, and the base station and the terminal use multiple RBs (Resource Blocks) to transmit one. Data block (TB, transport block), in order to reduce the notification overhead, different RBs in 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 is not necessarily optimal, thereby This has led to a decline in spectrum utilization. SUMMARY OF THE INVENTION The present invention has been made in view of the problem of using a fixed RB subcarrier configuration in the prior art, so that the OFDMA channel capacity cannot always be kept large. To this end, the present invention aims to provide an orthogonal A dynamic adjustment method of radio resource block configuration of frequency division multiplexing (OFDM) subcarrier offsets to make the overall throughput or spectrum utilization of a wireless communication system employing orthogonal frequency division multiplexing (OFDM) technology larger. According to the present invention, an offset-based radio resource block configuration dynamic adjustment method is provided. The method includes the following steps: Step S102, determining an offset set according to a radio resource configuration attribute in a radio resource block; Step S104, selecting an offset from the set of offsets periodically or aperiodically, and selecting the offset The offset changes the radio resource configuration in some or all of the radio resource blocks; Step S106, scheduling the data to be transmitted according to the changed radio resource block. In step S102, the radio resource configuration attribute is a radio resource allocation manner in the radio resource block, and includes: mode 1, all radio resource block configurations of the OFDM system are the same; and mode 2, the radio resource block configuration of the OFDM system is different. In step S102, the process of determining the offset set is specifically: when the manner of configuring the radio resources in the radio resource block is mode one, select some or all of the offsets in 0~A-1 as the offset set. In the element, where A is the number of subcarriers in the radio resource block; when the radio resource configuration mode in the radio resource block is mode 2, select some or all of the offsets in 0~B-1 as the offset An element in the set of quantities, where B is the total number of subcarriers in the OFDM system. In step S104, the process of selecting an offset from the set of offsets periodically or aperiodically is specifically: the sender selects a bias from the set of offsets by itself or according to the feedback information of the receiver periodically or aperiodically. Transfer amount. The process of selecting an offset according to the feedback information of the receiver is as follows: the channel quality test value of the radio resource block under the partial or total offset of the receiver; the receiver calculates part or all of the offset The channel quality index information based on the radio resource block; the receiving direction feedbacks part or all of the offset information in the receiving direction; the sender selects an offset according to a predetermined offset selection principle. The above offset information is any one of the following: an offset; an offset and corresponding channel quality index information; an offset set and a corresponding channel quality index information set; an offset and a corresponding channel quality The quantity test value; the set of offsets and the corresponding set of channel quality test values. The above process for the sender to select an offset is specifically as follows: the sender collects the data transmission quality under the current offset; the sender adjusts the offset according to the change of the data transmission shield; the sender attempts to adjust the offset, And transmitting data on the radio resource block corresponding to the adjusted offset until the offset attempting adjustment ends; after the end of the trial adjustment, the sender selects an offset with the best transmission quality from the trial result. In step S104, the process of changing the radio resource configuration in some or all of the radio resource blocks is specifically: the sender changes the subcarriers included in part or all of the radio resource blocks according to the predetermined offset mapping manner according to the selected offset. ingredient. The predetermined offset mapping manner is: a mapping relationship between logical numbers of logically consecutive subcarriers and physical numbers of physically discrete subcarriers at a specific offset; wherein, the number of the radio resource block is predefined and the corresponding The logical number of the subcarrier. In addition, when there is a static radio resource block, the mapping relationship between the logical number and the physical number of the subcarriers in the static radio resource block is the same at different offsets. In step S106, the process of scheduling data to be transmitted according to the changed radio resource block is specifically: the sender sends the data to be transmitted to one or more receivers according to the scheduling policy scheduling on the changed radio resource block. In addition, in step S102, the radio resource block includes: a combination of a time-frequency resource, a time-frequency resource, and a codeword resource or a spatial resource. With the above technical solution of the present invention, by changing the subcarrier configuration in the RB, the channel capacity of the subchannel of the RB-based TB bandwidth in the OFDM system bandwidth is statistically optimized for one or more receivers, thereby improving The throughput of the transmission is especially suitable for the fourth generation mobile communication system. Other features and advantages of the invention will be set forth in the description which follows, and The objectives and other advantages of the invention will be realized and attained by the <RTI The drawings are intended to provide a further understanding of the invention, and are intended to be a part of the description of the invention. In the drawings: FIG. 1 is a flowchart of an offset-based wireless resource block configuration dynamic adjustment method according to an embodiment of the present invention; FIG. 2 is a flowchart of Example 1 of the method illustrated in FIG. 1; A flow chart of Example 2 of the method shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention are described with reference to the accompanying drawings. The present invention relates to a radio resource block (RB), which will be described in detail below.

(1) The RBs can be classified into two types according to the configuration. The radio resource configuration modes in the radio resource blocks include the following two methods: In the first mode, all the radio resource blocks of the OFDM system are configured the same; and in the second mode, the radio resource block configurations of the OFDM system are different. Correspondingly, the RBs can be divided into two types according to the configuration: the radio resource blocks of all the OFDM systems in the first type of radio resource blocks are configured in the same manner, that is, in the foregoing manner 1, that is, the radio resource blocks of the OFDM system are at least time-frequency. The resource has only one size configuration. The number of subcarriers in different RBs is the same, and the number of OFDM symbols included is the same. The OFDM system in the second type of radio resource block has different radio resource block configurations, that is, the above method is used. . (2) The RBs can be divided into two types of centralized RBs according to the subcarrier distribution: if the subcarrier frequencies in the RB are continuous, the RB is called a centralized RB; the distributed RB is an RB other than the centralized RB.

(3) The RB is divided into two types of dynamic RBs according to the mode: the subcarrier components included in the dynamic RB are variable; the static RB: the subcarrier components included in the static RB are not variable. (4) The RB classifies the logical (or virtual) RB according to the attribute: the subcarriers included in the RB are virtual, the logical subcarrier numbers are consecutive, and the logical subcarriers are always unchanged in the specific number RB; Physical RB: The RB The physical subcarriers are included in the RB. The physical subcarrier numbers in the specific numbered RBs are not necessarily continuous. The physical subcarriers in the specific number RB may be always unchanged or may be changed. The logical subcarrier number and the physical subcarrier in the logical (or virtual) RB have a specific mapping relationship. The mapping relationship may be the same or different under different offsets. In addition, the sender mentioned in the following may be a base station (BS) or an access point (AP), and the >1 party may be a User Equipment (UE). Based on the above, as shown in FIG. 1 , the offset-based RB configuration dynamic adjustment method according to the embodiment of the present invention includes the following processing: Step bare S102, determining a set of offsets in a radio resource configuration attribute in the RB; S104. Select an offset from the set of offsets periodically or aperiodically, and change a radio resource configuration in some or all of the RBs according to the selected offset. Step S106: Scheduling data to be transmitted according to the changed RB. Each detail in the above processing will be specifically described below. First, the RB of the OFDM system refers to a time-frequency (ie, time or time interval and frequency or sub-carrier) resource, or a combination of time-frequency resources and one or two of a codeword resource and a spatial resource, and a frequency resource of OFDM A set of subcarriers in an OFDM system. In step S102, the radio resource configuration attribute is a radio resource configuration manner in the RB, including: mode 1, all RB configurations of the OFDM system are the same; and mode 2, the RB configuration of the OFDM system is different. Correspondingly, in step S102, the process of determining the offset set is specifically: when the manner of configuring the radio resources in the RB is mode one, selecting part or all of the offsets in 0~A-1 as the offset set. In the element, where A is the number of subcarriers in the RB; when the mode of configuring the radio resources in the RB is mode 2, some or all of the offsets in 0 to B-1 are selected as the offset set. Element, where B is the total number of subcarriers in the OFDM system. In step S104, the process of selecting an offset from the set of offsets periodically or aperiodically is specifically: the feedback information of the sender or the receiver is selected periodically or aperiodically from the set of offsets. Offset. The method of offset selection may be determined according to different principles (e.g., minimum block error rate, maximum throughput, etc.), which is not limited by the present invention. The process of selecting an offset according to the feedback information of the receiver according to the feedback information of the receiver is specifically: the channel quality test value of the RB under partial or total offset of the receiver; the receiver calculates part or all of the offset RB-based channel quality index information; the receiving direction feedbacks part or all of the offset information; the sender selects an offset according to a predetermined offset selection principle (which will be specifically described below in connection with Example 1). The above-mentioned process for the sender to select an offset is specifically as follows: the sender collects the data transmission quality under the current offset; the sender adjusts the offset according to the change of the data transmission quality; the sender attempts to adjust the offset, and Transmitting data on the RB corresponding to the adjusted offset until the offset attempts to end the adjustment; after the end of the attempted adjustment, the sender selects an offset from the trial result that is the best amount (the following will be combined) Example 2 is described in detail). In step S104, the process of changing the radio resource configuration in some or all of the RBs is specifically: the sender #selects the offset, and changes the subcarrier components included in some or all of the RBs according to a predetermined offset mapping manner. As mentioned above, RBs of an OFDM system can be classified into two types, one is called a dynamic RB, the subcarrier components included in the dynamic RB are variable, and the other is called a static RB. The subcarrier components included in the static RB are not variable. . An RB in an OFDM system may have only static RBs, or only dynamic RBs, and may have both dynamic RBs and static RBs. In addition, the OFDM system subcarriers are numbered from small to large, 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 when the offset is 0. Similarly, for a distributed RB, when the offset is 0, there is a certain mapping relationship between the logical number and the physical number. Based on this, the foregoing predetermined offset mapping manner is: a logical number of logically consecutive subcarriers (the logical numbers of subcarriers in the RB are continuous) and physically discrete subcarriers at a specific offset. The mapping relationship between the physical number (physical number and the actual frequency of the subcarrier). The number of the RB and the logical number of the corresponding subcarrier need to be defined in advance. One way to define is that the logical number of the subcarrier in the RB with a large number is always greater than the logical number of the RB subcarrier with a small number. For example: ^: RB0 includes LSC0~11, and 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 at different offsets. In step S106, the process of scheduling data to be transmitted according to the changed RB is specifically as follows: The sender schedules data to be transmitted to one or more receivers according to the scheduling policy on the changed KB. Embodiments of the present invention will be further described below by way of examples. Instance 1: The sender selects an offset according to the feedback information of the receiver, where the sender is the BS, and the owed party is the UE. As shown in FIG. 2, the present invention in this example includes the following processing: Step S202, Determining the offset set according to the radio resource configuration attribute in the radio resource block; assuming that the frequency resource bandwidth of the OFDM system carrying data is 9 MHz, and the subcarrier spacing is 15 KHz, the number of useful subcarriers except DC (ie, 0 Hz subcarrier) is 600 , set from -4.5MHz to 4.5MHz, sub-carrier number is SC0 SC599, 50 resource blocks (RB0-RB49), each RB contains 12 subcarriers, and the offset set 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, ^^ should be offset from 0 RB0 includes subcarriers SC0, SCI, SC11, RBI includes SC12, SC13, SC23, and so on, and different RBs contain different subcarrier numbers. The RB may also be a distributed allocation mode, that is, establishing a mapping relationship between logically consecutive subcarrier numbers (such as LSC0-LSC599) and physically discrete subcarrier numbers, for example, the m+12xn subcarrier and the mx50. +n physical subcarrier correspondence, where m=0~ll, n=0~49. In the distributed allocation mode, corresponding to the 0 offset, RB0 includes subcarriers LSC0, LSC1, LSC11, and RBI includes LSC12, LSC13, ..., LSC23, and then the class 4隼. The modulation coding scheme (MCS) of OFDM system is divided into six types: 1# for (QPSK, l/3Turbo code;), 2# for (QPSK, l/2Turbo code;), 3# for (16QAM, l/3Turbo code) ), 4# is (16QAM, l/2Turbo code), 5# is (64QAM, l/3Turbo code), and 6# is (64QAM, l/2Turbo code). Step S204, the UE calculates channel quality measurement values of the RB under all or part of the offset, such as: signal to noise ratio (SNR;), signal interference plus noise ratio (SINR), signal strength, time selective parameter of the channel, frequency Optional parameter, or any combination of the above parameters. Step S206, 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 a quantized value or a statistical value of the channel quality measurement value, and RB position information corresponding to the quantized value or the statistical value, such as corresponding to the offset 7, RB8. The equivalent signal interference plus noise ratio (SINR) is 10 dB or level 3 or the modulation coding mode (MCS) is 3# step S208, and the UE feeds back some or all of the offset information to the BS, for example: the UE feeds back all 12 to the BS. The channel quality information of the RB under the offset, or the channel quality information of the RB under the partial offset of the UE to the BS, for example, only feedback one or better multiple offsets that the UE considers the RB channel quality to be the best. Or further statistical information of the offset and all or part of the RB channel quality information, or the offset, and all or part of the RB channel quality information under the corresponding offset. Specifically, in this application example, the UE feeds back 50 RB positions and corresponding CQIs under all offsets of 1-12, or feeds back one of 1 to 12 offsets, such as offset 7 . Step S210, determining an offset according to an offset selection principle. The BS receives the offset information set fed back by the Y UEs, where Y is less than or equal to X, according to the offset selection principle (for example, to send data to Y UEs, the throughput is the largest, or Y sub-sends sent to Y UEs) The sum of the channel capacities is the largest), and the offset is determined. Step S212, the BS sends data in a 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 S214, the offset of the UE according to the resource assignment information after the refresh On the corresponding RB, the data sent to itself is received. (Step S204 - Step S214 is a flow in which the sender simultaneously transmits data to X receivers) Example 2: The sender selects an offset by itself, where the sender is the BS and the receiver is

As shown in FIG. 3, the present invention in this example includes the following processing: Step S302, determining an offset set according to a radio resource configuration attribute in a radio resource block; assuming that a frequency resource bandwidth of an OFDM system carrying data is 9 MHz, a subcarrier The interval is 15KHz, except for DC (that is, 0Hz subcarrier), the number of useful subcarriers is 600, the setting is from -4.5MHz to 4.5MHz, the subcarrier (sub-carrier) number is SC0~SC599, and 50 resource blocks (RB0). -RB49), each RB contains 12 subcarriers, and the offset set is {0, 1 , 2, 3, 4, 5, 6, 7, 8 , 9, 10, 11 } , RB is a centralized allocation mode, that is, subcarriers in each RB are continuous, such as corresponding offset with 0, RB0 includes subcarriers SC0, SCI, SC11, RBI includes SC12, SC13, SC23, and the class 4 is in turn, and different RBs contain different subcarrier numbers. The RB may also be a distributed allocation mode, that is, a mapping relationship between logically consecutive subcarrier numbers (such as LSC0~LSC599) and physically discrete subcarrier numbers, for example, the m+12xn subcarrier and the mx50 are added. +n physical subcarrier correspondence, where m=0~ll, n=0~49. In the distributed allocation mode, ^" should be offset by 0, RB0 contains subcarriers LSC0, LSC1, LSC11, and RBI includes LSC12, LSC13, LSC23, and then class 4. The modulation coding mode (MCS) of OFDM system is divided into six types. 1# is (QPSK, l/3Turbo code), 2# is (QPSK, l/2Turbo code), 3# is (16QAM, l/3Turbo code;), 4# is (16QAM, l/2Turbo code; 5# is (64QAM, l/3Turbo code), 6# is (64QAM, l/2Turbo code); Step S304, the BS uses the current offset to some or all of the X UEs on the corresponding RB The UE sends data; Step S306, the BS collects the data transmission quality under the current offset. The data transmission quality may be measured by a reliability index such as a frame error rate and a bit error rate. The reliability index may be one or more receptions. The acknowledgment information of the party feedback (such as: ACK/NACK) or the statistics of the measurement information is obtained, and may also be counted according to the number of BS retransmissions; Step S308, 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 quality is improved or the best integer offset is found in the offset set to make the transmission quality the best. To avoid repeated adjustments when the transmission quality is below the threshold at all offsets, you can also set the adjustment period. After the period finds the best offset of the transmission quality, the adjustment is stopped until the next adjustment period starts, and the adjustment process is repeated; in step S310, the BS attempts to adjust the offset, and the RB corresponding to the offset after the adjustment is attempted The data is sent up until the offset attempts to end the adjustment; Step S312, if the adjustment is over, the process proceeds to step S314, and if the attempted adjustment is not completed, the process proceeds to step S310; and in step S314, the offset with the best transmission quality is selected from the result of the test. The quantity, the newest offset, and the data is sent on the RB corresponding to the refreshed offset, and the process returns to step S306. Thus, by means of the present invention, the OFDM configuration in the RB can be changed to make the OFDM The channel capacity of the RB bandwidth-based subchannel in the system bandwidth is statistically optimized for one or more receivers, thereby increasing the throughput of the transmission. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

An offset-based radio resource block configuration dynamic adjustment method, comprising: Step S102: #> determining an offset set according to a radio resource configuration attribute in a radio resource block;

Step S104: Select an offset from the set of offsets periodically or aperiodically, and change the radio resource configuration in some or all of the radio resource blocks according to the selected offset; and

Step S106: The data to be transmitted is scheduled according to the changed radio resource block.

The method according to claim 1, wherein in the step 8102, the radio resource configuration attribute is a radio resource allocation manner in a radio resource block, and includes: mode 1, all radio resources of the OFDM system The block configuration is the same; mode 2, the OFDM system has different radio resource block configurations.

The method according to claim 2, wherein in the step bare S102, the process of determining the set of offset amounts is specifically:

When the manner of configuring the radio resource in the radio resource block is the mode one, select some or all of the offsets in 0-A-1 as the elements in the offset set, where A is in the radio resource block. Number of subcarriers; and

When the manner of configuring the radio resources in the radio resource block is the mode 2, select some or all of the offsets in 0-B-1 as the elements in the set of offsets, where B is in the OFDM system. The total number of subcarriers.

The method according to claim 1, wherein in the step S104, the process of selecting an offset from the set of offsets periodically or aperiodically is specifically:

The sender selects an offset from the set of offsets either periodically or aperiodically based on the feedback information of the recipient.

The method according to claim 4, wherein the processing by the sender to select an offset according to the feedback information of the receiver is specifically:

The channel quality test value of the radio resource block under the partial or total offset of the receiver; The receiver calculates channel quality index information based on the radio resource block under part or all of the offset;

The receiving direction returns some or all of the offset information to the sender; and the sender selects an offset according to a predetermined offset selection principle.

The method according to claim 5, wherein the offset information is any one of the following:

Offset;

Offset and corresponding channel quality index information;

An offset set and a corresponding set of channel quality index information;

Offset and corresponding channel quality test values;

A set of offset quality sets of channel offsets and phases.

The method according to claim 4, wherein the processing by the sender to select an offset amount is specifically:

The sender collects data transmission quality under the current offset;

The sender adjusts the offset according to the change of the data transmission quality;

The sender attempts to adjust the offset and transmits data on the radio resource block corresponding to the adjusted offset until the offset attempt adjustment ends;

After the end of the attempted adjustment, the sender selects an offset of the best transmission quality from the result of the attempt.

The method according to claim 1, wherein in step S104, the process of changing the radio resource configuration in part or all of the radio resource blocks is specifically:

The sender changes the subcarrier components included in part or all of the radio resource blocks according to the predetermined offset mapping manner according to the selected offset.

9. The method according to claim 8, wherein the predetermined offset mapping manner is: a logical number of logically consecutive subcarriers and a physical of physically discrete subcarriers at a specific offset. a numbered mapping relationship; wherein, the number of the radio resource block and the logical number of the corresponding subcarrier are predefined.

10. The method according to claim 9, wherein when there is a static radio resource block, the mapping relationship between the logical number and the physical number of the subcarriers in the static radio resource block is the same under different offsets.

The method according to claim 1, wherein in the step S106, the process of scheduling data to be transmitted according to the changed radio resource block is specifically:

The sender sends the data to be transmitted to one or more receivers according to the scheduling policy scheduling on the changed radio resource block.

The method according to any one of claims 1 to 11, wherein in the step S102, the radio resource block comprises: a time-frequency resource, a time-frequency resource and a codeword resource or a space resource. Any one or combination of two.