JPWO2008156098A1 - Mapping method, mapping apparatus, mobile station, communication system, and program - Google Patents

Abstract

The present invention provides a technique capable of sufficiently securing the types of step sizes used for reducing other-cell interference and reducing other-cell interference regardless of the number of physical resource blocks transmitted in a distributed manner. Kind Code: A1 An OFDM mapping method in which sub-blocks obtained by dividing, combining, or dividing Physical Resource Blocks into sub-blocks for mapping Virtual Resource Block symbols are used as types of step sizes. Can be secured sufficiently, and a different step size can be set for each cell. By this method, an effect of reducing interference from other cells can be expected, and good communication is possible.

Description

  The present invention relates to a technology of a radio communication system that performs data transmission / reception with a plurality of mobile stations, and more particularly, to a technology of data mapping when performing Distributed transmission to each mobile station.

  OFDM (Orthogonal Frequency Division Multiplexing) has attracted attention as a high-speed transmission technology that is resistant to multipath interference.

  Hereinafter, conventional base station apparatuses and mobile station apparatuses will be described. FIG. 36 is a block diagram showing a configuration of a conventional base station apparatus.

  In FIG. 36, scheduler section 101 uses CQI (Channel Quality Information) from each mobile station apparatus to perform scheduling for determining which user's signal is transmitted in which order using which subcarrier. As this scheduling method, there are algorithms such as MaxC / I and Round Robin. Further, the scheduler unit 101 determines an encoding method (encoding rate) and a modulation method to be used from the CQI. The encoding unit 102 performs encoding such as turbo encoding on user data. The encoding unit 102 also performs processing such as interleaving as necessary.

  The transmission HARQ unit 103 performs processing necessary for HARQ. Details will be described with reference to FIG. FIG. 37 is a block diagram showing a configuration of a transmission HARQ unit of a conventional base station apparatus. As shown in FIG. 37, the transmission HARQ includes a buffer unit 1031 and a rate matching unit 1032. The buffer unit 1031 stores a bit string of transmission data. The rate matching unit 1032 performs rate matching determined by a rate matching parameter (RM parameter) on the transmission data bit string, performs puncturing or repetition on the transmission data as necessary, and inputs the result to the modulation unit 104. To do. The RM parameter may differ depending on the number of transmissions.

  Next, mapping section 105 assigns transmission data and control signals to subcarriers according to a predetermined mapping pattern. Similarly, mapping section 105 maps pilot signals so that they are distributed over the entire frequency band. Mapping section 105 then outputs a transmission signal obtained by mapping the transmission data, control signal, and pilot signal to IFFT section 106.

  The IFFT unit 106 performs IFFT (Inverse Fast Fourier Transform) on the transmission signal. The output signal of IFFT unit 106 is converted from parallel data to serial data by P / S conversion unit 107. CP adding section 108 adds a CP (Cyclic Prefix) for increasing multipath tolerance to the transmission signal. Radio transmission section 109 performs processing such as D / A conversion, up-conversion, and transmission power amplification on the transmission signal, and transmits the signal after execution of the processing from transmission antenna 110 to the mobile station.

  FIG. 38 is a block diagram showing a configuration of a conventional mobile station apparatus.

  In FIG. 38, the wireless reception unit 202 performs processing such as reception power amplification, down-conversion, and A / D conversion on the wireless signal received by the reception antenna 201, and the signal after the processing is subjected to the CP removal unit 203. Output to. CP removing section 203 receives the output signal from radio receiving section 202 and the FFT reference timing, and removes the received signal corresponding to the CP before the FFT timing. The S / P converter 204 performs S / P conversion on the received signal from which the CP has been removed. The FFT unit 205 converts the time domain signal to the frequency domain signal by performing FFT processing. The demapping unit 206 demaps this received signal according to the mapping pattern, and extracts a signal addressed to itself.

  Next, channel separation section 207 separates the received signal into a user signal, a control signal, and a pilot signal. The control signal demodulator 208 demodulates the control signal, and the control signal decoder 209 performs a decoding process after the control signal demodulation process, and outputs a control signal.

  The data demodulator 210 demodulates the user signal. The reception HARQ unit 211 stores a predetermined amount of bits (here, soft decision bits) in the reception HARQ unit 211 after demodulating the user signal. In the case of retransmission, it is combined with the previous received bit stored. The data decoding unit 212 performs decoding such as a turbo code using the bit string to obtain user data. Although not shown here, a channel estimation value calculated using a pilot signal is used during demodulation processing. The Ack / Nack generation unit 215 determines whether or not an error is included from the CRC result of the decoded received data, and generates an Ack signal or a Nack signal.

  Also, CIR measurement section 213 calculates the average received SIR of all subcarriers using the pilot signal. The CQI generation unit 214 generates a CQI from the average reception SIR.

  The Ack signal or Nack signal and the CQI are input to the modulation unit 216, and are encoded, interleaved, and modulated together with the data signal, control signal, and pilot signal transmitted on the uplink, and sent to the mapping unit 217. Is output.

  Mapping section 217 maps the output signal of modulation section 216 for each subcarrier on the frequency axis and outputs the result to IFFT section 218. IFFT section 218 converts the frequency domain signal into a time domain signal and outputs it. The P / S converter 219 performs P / S conversion on the IFFT-time domain signal. CP adding section 220 adds a CP to the P / S converted signal and outputs it. The wireless transmission unit 221 performs processing such as D / A conversion, up-conversion, and transmission power control on the signal, and transmits the signal after the processing is performed from the transmission antenna 222 to the base station.

  Next, a conventional transmission data mapping method will be specifically described.

  In 3GPP LTE, there are Localized transmission and Distributed transmission as downlink data transmission methods, and resource block level distribution is under consideration in Distributed transmission. In the resource block level distribution, it is important not to overlap the mapping patterns in each cell in order to reduce inter-cell interference, and in order to prevent an increase in overhead due to transmitter load reduction and mapping pattern signaling, A simpler mapping method is required. As one solution to this problem, the following method has been proposed at the 3GPP meeting (Non-patent Document 1).

  FIG. 39 shows a data mapping method in each PRB (Physical Resource Block) representing a minimum unit obtained by dividing a transmission resource into a plurality of resource blocks. The PRBs are allocated in a number equal to or greater than the number of DVRBs (Distributed Virtual Resource Blocks) that represent transmission data symbols formed for mapping to the PRBs, and one PRRB data symbol is allocated to each PRB. Mapping is performed sequentially, but for the purpose of reducing inter-cell interference, the DVRB mapped to the head of the PRB is changed in order to avoid overlapping with the PRB mapping pattern of the same number of other cells.

Further, FIG. 40 shows a mapping method for obtaining an inter-cell interference reduction effect. Each transmission symbol the N _D DVRB number N _DVRB, when mapped to N _DVRB number of PRB is the same number as the number of DVRB, whether mapping each data symbol to which PRB, for the intercell interference reduction It is determined by the step size Sn (n is a cell ID) unique to each cell, which represents how many unit step amounts representing the size to be shifted at one time are shifted. Here, Sn = 2 is shown (which means that the PRB size, which is a unit step amount, is shifted by two, and is an operation of shifting the PRB number to be mapped by two), and the DVRB # 0 symbol is , PRB # 0 → PRB # 2 → PRB # 1, and every two PRB numbers are selected for mapping.

The step size Sn is set to a different value in each cell, and the interference of other cells can be reduced by changing the order of PRBs to be mapped.
3GPP TSG RAN WG1 meeting # 49, R1-071014

However, in the conventional method, when DVRB symbols are mapped, symbols are mapped to different PRBs one by one, that is, the unit step amount is set to PRB units, so the step size Sn is a kind larger than the number of PRBs. Cannot be secured. For example, considering the case of 3 PRBs, the order of PRBs to be mapped is: PRB0 → PRB1 → PRB2 (step size Sn = 1)
2. PRB0 → PRB2 → PRB1 (step size Sn = 2)
Only two types can be selected. That is, the number of step sizes that can be secured when the number of PRBs is N is N-1.

  Therefore, in the conventional method, when the number of PRBs transmitted in a distributed manner is small and the number of interfering cells is large, a different mapping pattern cannot be configured for each cell, and the effect of reducing the inter-cell interference is reduced, thereby degrading the characteristics.

  Now, when considering 7-cell repetition of one communication cell and six interfering cells as shown in FIG. 41, there are seven types of step sizes necessary for reducing inter-cell interference, so the number of PRBs is 8 or more. Necessary. Securing the number of transmission PRBs to a certain level or more to reduce inter-cell interference is a major restriction on data transmission.

  An object of the present invention is to provide a data mapping technique capable of transmitting with a different mapping pattern for each cell regardless of the number of transmission PRBs.

  The present invention for solving the above-described problem is an OFDM mapping method, in which sub-blocks obtained by dividing, combining, or combining Physical Resource Blocks are used as shift units when mapping Virtual Resource Block symbols. It is characterized by that.

  The present invention for solving the above-mentioned problems is an OFDM mapping apparatus, and decides to determine that a physical resource block is divided, combined, or a sub-block obtained by dividing and combining is a shift unit for mapping And mapping means for mapping the symbol of the Virtual Resource Block based on the determined shift unit.

  The present invention for solving the above-mentioned problem is a mobile station, and demaps the data in which the symbols of the Virtual Resource Block are mapped using the sub-block obtained by dividing, combining, or dividing the Physical Resource Block as a unit of shift. And means for extracting the symbol.

  The present invention for solving the above-mentioned problems is a communication system, and is a determination means for determining that a sub-block obtained by dividing, combining, or dividing a Physical Resource Block into a unit of shift when mapping is used. And mapping means for mapping a symbol of the Virtual Resource Block based on the determined shift unit, and means for demapping the mapped data.

  The present invention for solving the above-described problem is a program for an information processing apparatus, and the program divides a physical resource block into the information processing apparatus, combines, or divides a sub-block that is combined into a virtual resource block. It is characterized in that a process of mapping as a shift unit when mapping the symbols is executed.

  The present invention for solving the above-described problem is an OFDM mapping method, characterized in that a virtual resource block symbol is mapped to a sub-block obtained by dividing, combining, or dividing a physical resource block.

  According to the present invention, transmission can be performed with different mapping patterns for each cell without being influenced by the number of transmission PRBs and without being influenced by the number of DPRBs to which one DVRB is mapped.

It is a figure which shows the structure of the base station apparatus concerning this invention. It is a figure which shows that three DVRB is mapped by one DPRB. It is a figure which shows the example 1 of a division | segmentation of a subblock. It is a figure which shows the example 2 of a division | segmentation of a subblock. It is a figure which shows the example 3 of a division | segmentation of a subblock. It is a figure which shows the example 4 of a division | segmentation of a subblock. It is a figure which shows the subblock number structure concerning this invention. It is a figure which shows the structure of the mobile station apparatus concerning this invention. It is a figure which shows the detailed method of the transmission data mapping of Example 1. FIG. It is a figure which shows the symbol number structure in a subblock concerning this invention. It is a figure which shows the detailed method of the transmission data mapping of Example 1. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 1. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 1. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 1. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 1. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 1. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 2. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 2. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 2. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 3. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 3. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 3. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 4. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 4. FIG. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the second embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the fifth embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the fifth embodiment. FIG. 10 is a diagram illustrating a detailed method of transmission data mapping according to the fifth embodiment. It is a figure which shows the structure of the conventional base station apparatus. It is a figure which shows the detailed structure of a transmission HARQ part. It is a figure which shows the structure of the conventional mobile station apparatus. It is a figure which shows the detailed method of the conventional transmission data mapping. It is a figure which shows the detailed method of the conventional transmission data mapping. It is a figure which shows generation | occurrence | production of the interference between cells. It is a figure which shows the detailed method of the transmission data mapping of Example 5. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 5. FIG. It is a figure which shows the detailed method of the transmission data mapping of Example 5. FIG.

Explanation of symbols

1, 101 Scheduler unit 2, 102 Encoding unit 3, 103 Transmission HARQ unit 4, 104 Modulation unit 5, 105 Mapping unit 6, 106 IFFT unit 7, 107 P / S conversion unit 8, 108 CP addition unit 9, 109 Radio Transmitter 10, 110 Transmit antenna 11, 201 Receive antenna 12, 202 Radio receiver 13, 203 CP remover 14, 204 S / P converter 15, 205 FFT unit 16, 206 Demapper 17, 207 Channel demultiplexer 18 208 Control signal demodulator 19, 209 Control signal decoder 20, 210 Data demodulator 21, 211 Reception HARQ unit 22, 212 Data decoder 23, 213 CIR measurement unit 24, 214 CQI generator 25, 215 Ack / Nack generation unit 26, 216 Modulation unit 27, 217 Mapping unit 28, 218 IF FT unit 29, 219 P / S conversion unit 30, 220 CP addition unit 31, 221 Radio transmission unit 32, 222 Transmission antenna 33, 51 Mapping pattern determination unit 1031 Buffer unit 1032 Rate matching

(Embodiment 1)
Next, Embodiment 1 of the present invention will be described with reference to the drawings.

As described above, for example, when considering 7-cell repetition of one communication cell and six interference cells as shown in FIG. 41, seven types of step size Sn set for each cell (base station) are required. Therefore, N _DPRB that is the number of Physical Resource Blocks (DPRBs) to be transmitted in a distributed _manner is not 8 or more, and transmission cannot be performed with a different mapping pattern for each cell.

In this embodiment, focusing on the fact that the unit step amount to be shifted in mapping need not be limited to the PRB size, the number of PRBs and Distributed transmission required for Distributed transmission with a different mapping pattern for each cell. comparing the DPRB number N _DPRB allocated when, if there are fewer of DPRB number N _DPRB allocated are mapped as a unit step quantity shifting in mapping sub-block is a block obtained by dividing the PRB . Note that the number of necessary PRBs is set in advance for each base station based on the number of interfering cells.

In the following description, the number of necessary PRBs will be described as a threshold T, and when the number of _DPRBs N _DPRB allocated when transmitting data to the mobile station is smaller than the threshold T, the entire DPRB will be the size of the PRB. A configuration will be described in which division is made into Ns subblocks of size X smaller than a certain xy (number of subcarriers in the frequency axis direction x * number of symbols in the time axis direction).

  FIG. 1 is a configuration diagram of a transmission system of a base station apparatus that performs transmission data mapping in a wireless communication system according to an embodiment of the present invention.

  The base station apparatus of this embodiment includes a scheduler unit 1, an encoding unit 2, a transmission HARQ unit 3, a modulation unit 4, a mapping unit 5, an IFFT unit 6, a P / S conversion unit 7, a CP addition unit 8, and a radio transmission unit. 9, a transmission antenna 10, and a mapping pattern determination unit 51, and includes a mapping pattern determination unit 51 that determines a mapping method according to the number of transmission PRBs.

  Here, since the configuration other than the mapping pattern determination unit 51 is the same as the configuration of the transmission system of the conventional base station apparatus, the description thereof will be omitted here, and the details of the mapping pattern determination unit 51 will be described.

The mapping pattern determination unit 51 receives the DPRB number N _DPRB determined by the scheduler unit 1. The number of _DPRBs N _DPRB is _determined by the scheduler unit 1 so as to be generated with a number equal to or greater than the number of communication users, that is, the number of distributed virtual resource blocks (DVRB). Then, the mapping pattern determination unit 51, the number _{N DPRB} the DPRB is, when the threshold T is smaller than divides the whole DPRB into _{N S} sub-blocks, sub-blocks as a unit step quantity shifting during the mapping Size X is set to a size smaller than PRB size xy. The threshold value T may be held by the mapping pattern determination unit 51 or may be held by a component other than the mapping pattern determination unit 51.

The sub-block size X is expressed by the following formula (Formula 1) according to the number of sub-blocks N _S (N _S > N _DPRB ) included in the transmission signal band.
(Formula 1)
_{X = N DPRB * xy / N} S (X, N DPRB, x, y, N S is a positive integer)

  Here, the determination of the sub-block size performed by the mapping pattern determination unit 51 will be described.

Sub block size, if a DVRB number mapped to one DPRB was _{N MDVRB,}
(1) x = N _{MDVRB xp}
Or
(2) y = N _MDVRB × q
Is established, the sub-block size X is determined as follows, and the number of sub-blocks Ns is determined based on the sub-block size X. Note that p and q are positive integers.

When the relationship (1) is satisfied, the number of carriers in the frequency axis direction of one subblock is the number of _{subcarriers that is} a positive integer multiple of _NMDVRB , or when the relationship (2) is satisfied, one subblock Is divided into sub-blocks as the number of symbols that is a positive integer multiple of _NMDVRB .

This will be described using a simple example. FIG. 2 shows an example in which three DVRBs are mapped to one DPRB of size xy (N _MDVRB = 3).

  Here, when x is a multiple of 3 (in the case of (1) above), the number of subcarriers in the frequency axis direction of one subblock is 3, the number of symbols in the time axis direction is y, and the subblock size X is 3y. The DPRB is divided into x / 3 sub-blocks. This is shown in FIG. This figure shows a state in which one DVRB symbol is mapped with a step size Sn of 1, that is, with a DVRB unit step amount of 1.

  Further, when symbols of the same DVRB are mapped to consecutive subcarriers, the number of subcarriers in the frequency axis direction of one subblock is 6, the number of symbols in the time axis direction is y, and the subblock size X is 6y. The DPRB is divided into x / 6 sub-blocks. This is shown in FIG. This figure shows a situation in which two DVRB symbols are mapped with two step sizes Sn, that is, with DVRB unit step amount set to 1.

  Further, if the number of subblocks does not reach the threshold value T even if the number of subblocks is divided in the frequency axis direction, it is necessary to further divide it into b pieces in the time axis direction to ensure the number of subblocks equal to or greater than the threshold value T. is there. As described above, when the number of subcarriers in the frequency axis direction of one subblock is 6, the subblock size X is 6y / b, and the number of subblocks obtained by dividing DPRB is xb / 6. This is shown in FIG. This figure shows a situation in which two DVRB symbols are mapped with two step sizes Sn, that is, with DVRB unit step amount set to 1.

  On the other hand, when y is a multiple of 3 (in the case of (2) above), the DPRB may be divided into y / 3 sub-blocks with the size in the time axis direction of one sub-block as 3 symbols. I can do it. This is shown in FIG. This figure shows a state in which one DVRB symbol is mapped with a step size Sn of 1, that is, with a DVRB unit step amount of 1.

  Even when the size in the time axis direction is determined and divided into sub-blocks, the size in the time axis direction of one sub-block can be increased in the time axis direction as in the case of FIGS. Needless to say, division in the frequency axis direction can also be performed.

  Here, the case where the relationship of (1) or (2) is established has been described, but the method of determining the subblock size is not necessarily limited to this case, and the number of divided subblocks Ns is the threshold value. It is also possible to determine to be equal to or greater than T, and to determine a sub-block size X satisfying (Equation 1) from its Ns.

  Next, how to attach identification information that uniquely identifies a sub-block will be described. The identification information of the sub-blocks is also the order of sub-blocks necessary for shifting when mapping symbols. The arrangement order of the sub-blocks within the transmission signal band is defined so as to first advance in the frequency axis direction and then in the time axis direction, and identification information is attached. As an example, FIG. 7 shows how identification information is attached when two PRBs are divided into two in the frequency axis direction and two in the time axis direction. As in the case of FIG. 7 (a), it is possible to define and attach identification information so as to first advance in the frequency axis direction and then in the time axis direction over all PRBs, or in FIG. 7 (b). As in the case, in each PRB, the process proceeds first in the frequency axis direction, then proceeds in the time axis direction, and identification information may be attached to one PRB, and then identification information may be attached to the next PRB.

  Note that the above mapping example and the arrangement order (identification information) to be shifted when mapping symbols to sub-blocks are shown as an example, and the arrangement order of sub-blocks is limited to that shown here. Any method may be used as long as the order of arrangement of the sub-blocks is known.

  The sub-block size X determined by the mapping pattern determination unit 51 by the method described above and the step size Sn set in advance in the base station are input to the mapping unit 5, and the mapping unit 15 is based on the input data. Maps transmission data to sub-blocks.

On the other hand, information necessary for demapping in the mobile station must be transmitted from the base station to the mobile station. Therefore, the mapping unit 5 includes the control signal (Downlink L1 / L2 Control Signaling) to map the number of _DPRBs N _DPRB used to calculate the unit step X amount (subblock size) to the PRB, and the mobile station To notify. The number of _DPRBs N _DPRB can also be transmitted by being included in a broadcast signal (BCH: Broadcast Channel) or the like.

_Further , not only the DPRB number N _DPRB but also a configuration in which information necessary for demapping such as the subblock size X, the number of subblocks Ns, the demapping start position, the symbol position, and the like may be notified. Of course, such information may be configured in advance by the mobile station and the base station.

  After mapping is performed by the mapping unit 5, the IFFT unit 6 performs a process for transmitting the mapped data as a unit for transmitting the DRPB.

  Next, processing at the mobile station will be described. FIG. 8 is a configuration diagram of a mobile station apparatus that performs transmission data demapping in a wireless communication system according to an embodiment of the present invention.

  The mobile station includes a reception antenna 11, a radio reception unit 12, a CP removal unit 13, an S / P conversion unit 14, an FFT unit 15, a demapping unit 16, a channel separation unit 17, a control signal demodulation unit 18, and a control signal decoding. 19, data demodulator 20, reception HARQ unit 21, data decoder 22, CIR measurement unit 23, CQI generator 24, Ack / Nack generator 25, modulator 26, mapping unit 27, IFFT unit 28, P / S conversion unit 29, CP addition unit 30, wireless transmission unit 31, transmission antenna 32, and mapping pattern determination unit 33.

  Here, since the configuration other than the mapping pattern determination unit 33 is the same as the configuration of the transmission system of the conventional base station apparatus, the description thereof is omitted here, and the details of the mapping pattern determination unit 33 will be described.

The mapping pattern determination unit 33 extracts the DPRB number N _DPRB information transmitted from the control signal decoding unit 19 and transmitted together with the control signal, and sets a preset PRB size xy, demapping start position, and symbol position. From these, the sub-block size X is calculated. Information necessary for demapping such as the sub-block size X, the demapping start position, and the symbol position may be notified from the base station.

  The sub-block size X and the step size Sn used in the base station that transmitted data to the mobile station are input to the demapping unit 16, the process opposite to the mapping performed in the base station is performed, and the transmission data is sorted in the original order. Return to the channel separation unit 17.

As described above, when the number of PRBs N _DPRB is smaller than the threshold value T, the number of step sizes for reducing the inter-cell interference is sufficient by using a unit for shifting when mapping the sub-blocks obtained by dividing the PRB. Can be secured, and improvement in characteristics can be expected.

<Example 1>
In this embodiment, the shift unit for mapping the sub-blocks obtained by dividing the PRB as described above is used as a shift unit, but it must be mapped so as not to overlap with the PRB mapping pattern of other cells. The specific mapping method will be described below.

  FIG. 9 is a diagram illustrating a transmission data mapping method according to an embodiment of the present invention. Here, a case will be described in which there are three DVRBs with 168 symbols and one symbol is mapped to three DPRBs one by one. The PRB size is 168 with 12 subcarriers in the frequency axis direction and 14 symbols in the time axis direction. The threshold T is 8. At this time, it is divided into 12 sub-blocks so as to be larger than the threshold T, and the sub-block size X is X = 3 × (12 * 14) / 12 = 42 from (Equation 1). For simplicity, the Reference Symbol and Control Symbol in the PRB are not considered.

  When mapping a symbol in a sub-block, the position is determined by defining the sub-block so that it first proceeds in the frequency axis direction and then proceeds in the time axis direction. FIG. 10 shows this definition. The mapping position is determined by defining as described above for all the sub-blocks.

In mapping DVRB symbols to PRBs, it is first necessary to determine from which sub-block to start mapping. For example, when DPRB is divided into k sub-blocks, the relationship between DPRB number N _DPRB and sub-block number Ns is _{expressed by}
Ns = N _DPRB × k (k is an integer of 2 or more)
It is represented by At this time, for each DVRB transmission symbol, when the first sub-block having the DPRB number equal to the DVRB number is used as a mapping start sub-block and one DVRB symbol is mapped to the sub-block, the next DVRB symbol is mapped to the next sub-block. Mapping is performed in order. The mapping position in each sub-block is a position determined according to the DVRB symbol number d (d = 0, 1,..., Nd−1). The DVRB symbol number d may be information other than a number as long as it is information indicating the order of symbols in DVRB.

  Here, the number of symbols in the PRB is 168 (12 * 14), and symbol numbers in the PRB are assigned from 0 to 167. However, in the case of this embodiment, since the number of symbols in the sub-block is 42, only symbol numbers from 0 to 41 can be assigned, and those having a DVRB symbol number of 42 or more cannot be mapped.

  This case will be described with a simple model. FIG. 11 shows a case where two DVRBs are mapped to two DPRBs and six sub-blocks of size 2 are generated.

  In this case, if the first sub-block with the DPRB number equal to each DVRB number is the mapping start sub-block, the data symbol # 0 of DVRB # 0 is mapped to the 0 position of sub-block # 0, and the data of DVRB # 0 Symbol # 1 is mapped to position 1 of sub-block # 1. However, data symbol # 2 of the next DVRB # 0 has no position to be mapped in the sub-block and cannot be mapped.

  Therefore, when the mapping position of the data symbol exceeds the sub block size, it is possible to perform mapping within the sub block by subtracting the value of the sub block size from the numerical value of the mapping position.

  In the case of FIG. 11, data symbol # 2 is mapped to position 2 of sub-block # 2, but exceeds the sub-block size, so sub-block size value 2 is subtracted (2- 2 = 0), mapping to 0 position of sub-block # 2.

  Then, mapping is continued from there again, and data symbol # 3 of DVRB # 0 returns to position 1 of sub-block # 3, and data symbol # 4 of DVRB # 0 returns to position 2 of sub-block # 4. Since the sub-block size is exceeded, the sub-block size value of 2 is subtracted and mapped to the 0 position of sub-block # 4. Then, data symbol # 5 of DVRB # 0 is mapped to 1 position of sub-block # 5. This is shown in FIG. 12 together with the mapping of DVRB # 1 data symbols.

  By the processing as described above, it is possible to map data symbols having numbers exceeding the sub-block size.

Next, problems and countermeasures in the following cases (a) and (b) will be described.
(A) Number of subblocks per 1 DPRB = subblock size × m (m is a positive integer)
(B) Number of subblocks per 1 DPRB × n = subblock size (n is a positive integer)

  When the above relationship is established, a problem as shown in FIG. 13 occurs. FIG. 13 shows a case where two DVRBs are mapped to two DPRBs, and four sub-blocks having a size of 2 are generated, which is the case of (a) above.

  Here, if mapping is performed according to the rules as described above, when mapping data symbol # 2 of DVRB # 0, subblock size value 2 is subtracted because subblock size exceeds subblock size # 2. Even so, at the position 0 of sub-block # 2, it overlaps with the mapping of data symbol # 0 of DVRB # 1. For this reason, when subblock size values are subtracted from the first subblock in each DPRB, a process of adding +1 to the mapping position is added after the subtraction. By this processing, subsequent mapping can be performed without overlapping.

  FIG. 14 shows the mapping of DVRB # 0 and DVRB # 1 in this case. Since data symbol # 2 of DVRB # 0 exceeds the sub block size when mapping to sub block # 2, sub block size value 2 is subtracted, and further, at the head of the sub block in DPRB # 1 Therefore, the mapping position is incremented by 1 and mapped to the 1 position of sub-block # 2. Since the data symbol # 3 of DVRB # 0 exceeds the subblock size again in the subblock # 3, the subblock size value 2 is subtracted and mapped to the 0 position of the subblock # 3.

  Since this problem also occurs in the case of (b) above, mapping is performed by performing the same processing.

  FIG. 15 shows a state where three DVRBs having 168 data symbols are mapped to three DPRBs according to the above rules. Here, since the number of subblocks per 1 DPRB is 4 and the subblock size is 42, the above case (b) is applicable.

  Since the data symbol of DVRB # 0 starts mapping from subblock # 0 and becomes data symbol number 42 exceeding the subblock size in subblock # 6, subblock size value 42 is subtracted and subblock # Data symbol # 42 is mapped to the 0 position of 6. Further, since the data symbol # 84 exceeds the subblock size again in the subblock # 0, the subblock size value 42 is subtracted. Further, since it is the first subblock in DPRB # 0, +1 processing is performed. Data symbol # 84 is mapped to position 1 of subblock # 0. Next, since data symbol # 125 exceeds subblock size again in subblock # 5, subblock size value 42 is subtracted and data symbol # 125 is mapped to the 0 position of subblock # 5. Finally, a sub-block size value 42 is subtracted from the data symbol number 167 exceeding the sub-block size in sub-block # 11 and mapped.

  Actually, depending on the value of the step size Sn, the mapping order is changed for each cell to reduce inter-cell interference. FIG. 16 shows the state of mapping when Sn = 5.

  In this case, first, since the mapping start sub-block is the head sub-block of the DPRB number equal to each DVRB number, the symbol with the symbol number 0 of DVRB # 0 has sub-block # 0 as the mapping start sub-block. Since the mapping position in each sub-block is the symbol number position that matches the symbol number of DVRB, the symbol is mapped to the position of “0” in sub-block # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 5 obtained by shifting the subblock by five, and the mapping position is the symbol number position that matches the symbol number of DVRB. The symbol is mapped at the position of “1” in the sub-block # 5, and this operation is performed until the mapping of all symbols is completed.

  Note that, in the above, when the number of PRBs is less than 8, that is, the threshold T is set to 8, the value of T is not limited to 8, and each radio communication system is adapted to the number of interfering cells. It is possible to set to an optimal value.

<Example 2>
The present embodiment is characterized in that each DVRB symbol is mapped so that multiplexing in each PRB becomes FDM (Frequency Division Multiplexing).

  FIG. 17 is a diagram for explaining the transmission data mapping method according to the second embodiment.

  In the following description, a case where the threshold T is set to 8 and three DVRBs having the number of symbols Nd are mapped to three PRBs as shown in FIG. In the following description, the Reference Symbol and Control Symbol in the PRB are not considered for the sake of simplicity.

  Further, the case where the mapping pattern determination unit 51 generates twelve sub-blocks with the sub-block size being a multiple of the number y of symbols on the time axis of 1 PRB, here the size is 3y, will be described.

  First, in mapping, all DVRB mapping start sub-blocks are head sub-blocks. When one DVRB data is mapped to a sub-block, the next DVRB data is mapped to a sub-block shifted by a predetermined number of steps Sn. In the following description, the case of Sn = 1 will be used.

The mapping pattern indicating the position where the symbol is mapped to the sub-block is defined such that a symbol having a different DVRB number is mapped for each sub-carrier in the frequency axis direction. The number of types of mapping patterns equal to the number of DVRBs is prepared. In this description, three types of mapping patterns, which are the same as the number of DVRBs, are prepared. As shown in the middle sections (a) to (c) of FIG. 17, the mapping patterns are associated with each other so that the mapping pattern can be determined according to the value of (d mod N _DVRB ). That is, each sub-block has a mapping pattern determined according to the value of (d mod N _DVRB ) every time it is shifted by a predetermined number of steps for each cell (a) → (b) → ( c) → (a)... to be repeated.

  The position where the symbol is mapped in the sub-block is mapped to the position of the quotient value of d / Ns in the time axis direction.

  Therefore, since the mapping start sub-block is the first sub-block, sub-block # 0 is used as the mapping start sub-block for the symbol of symbol number 0 of DVRB # 0. The mapping position in the sub-block is such that the symbol is mapped at the 0-th position which is the 0/12 quotient of the subcarrier associated with DVRB # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 1 shifted by one subblock, and the mapping position within the subblock is DVRB # of subblock # 1. Symbols are mapped to the 0th stage position, which is 1 / 12th the quotient of the subcarrier associated with 0, and this operation is performed until mapping of all symbols of each DVRB is completed.

FIG. 18 shows the mapping in the case of Sn = 5.
In this case, first, since the mapping start sub-block is the first sub-block, sub-block # 0 is used as the mapping start sub-block for the symbol of symbol number 0 of DVRB # 0. The mapping position in the sub-block is such that the symbol is mapped at the 0th stage position which is the 0/12 quotient of the subcarrier associated with DVRB # 0 of sub-block # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 5 obtained by shifting the subblock by five, and the mapping position within the subblock is DVRB # of subblock # 5. The symbol is mapped to the 0th stage position which is a quotient of 1/12 of the subcarrier associated with 0, and this operation is performed until the mapping of all symbols of each DRV is completed.

  As described above, when the number of PRBs is smaller than the threshold T (here, 8), by setting the unit step size to be smaller than the PRB size, a sufficient number of step sizes for reducing inter-cell interference can be secured. Improved characteristics can be expected.

  Here, the data multiplexing method in each PRB has been described as FDM, but the multiplexing method is not limited to FDM, and multiplexing by TDM, random, hopping is possible, and further, It is also possible to combine multiple multiplexing methods. As an example, FIG. 19 shows a mapping state at Sn = 5 in the case of TDM multiplexing.

The middle part of FIG. 19 is a mapping pattern.
The mapping pattern indicating the position where the symbol is mapped to the sub-block is defined such that a symbol having a different DVRB number is mapped for each symbol in the time axis direction. Similar to the above, this mapping pattern is prepared for the number of types equal to the number of DVRBs. Here, three types of mapping patterns, which are the same as the number of DVRBs, are prepared. As shown in the middle part of FIG. 19, the mapping pattern is associated so that the mapping pattern can be determined according to the value of (d mod N _DVRB ). That is, each sub-block is set to have a mapping pattern determined according to the value of (Ns mod N _DVRB ) each time it is shifted by a predetermined number of steps for each cell. .

  Therefore, since the mapping start sub-block is the first sub-block, sub-block # 0 is used as the mapping start sub-block for the symbol of symbol number 0 of DVRB # 0. As for the mapping position in the sub-block, the symbol is mapped at the position of the 0th column which is the 0/12 quotient of the subcarrier associated with DVRB # 0 of sub-block # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 5 obtained by shifting the subblock by five, and the mapping position within the subblock is DVRB # of subblock # 5. A symbol is mapped to a position of a 0th column that is a quotient of 1/12 of a subcarrier associated with 0, and this operation is performed until mapping of all symbols is completed.

  In the above description, the mapping start sub-blocks are all head sub-blocks, but they may be from the same sub-block, or may be sub-blocks having the same number as each DVRB number.

  Further, although a description has been given of a configuration in which DVRB symbols are mapped one by one, a configuration in which a predetermined number of symbols are mapped may be used. In this case, when the multiplexing method uses FDM, the number of symbols in the time axis direction of the sub-block is the same as the number of symbols, and when the multiplexing method uses TDM, sub-carriers in the frequency axis direction of the sub-block. It is preferable to perform mapping for each of the same number as the number.

  Furthermore, here, when the number of PRBs is less than 8, that is, the threshold value T is set to 8, the value of T is not limited to 8, and should be set to an optimal value for each wireless communication system. Is possible.

<Example 3>
In the present embodiment, as in the second embodiment, the DPRB is divided so that the number of subblocks is equal to or greater than the threshold T, and each DVRB symbol is multiplexed in each PRB to be FDM. It is a different case.

  FIG. 20 is a diagram for explaining the transmission data mapping method according to the third embodiment.

  In the following description, a case where the threshold T is set to 8 and three DVRBs having the number of symbols Nd are mapped to three PRBs as shown in FIG. In the following description, the Reference Symbol and Control Symbol in the PRB are not considered for the sake of simplicity.

  Further, the case where the mapping pattern determination unit 51 generates twelve sub-blocks with the sub-block size being a multiple of the number y of symbols on the time axis of 1 PRB, here the size is 3y, will be described.

  First, in mapping, the starting sub-block number of each DVRB mapping is the first sub-block of DPRB having the same number as the DVRB number. When one DVRB data is mapped to a subblock, the next DVRB data is mapped to a subblock shifted by a predetermined number of steps. Here, description will be made using Sn = 1.

  The number of types of mapping patterns indicating the positions where symbols are mapped to sub-blocks is equal to the number of DVRBs. In this description, three types of mapping patterns are prepared.

FIG. 21 shows the mapping pattern of each DVRB. This mapping pattern is by _{(d mod N DVRB)} of the value, as the mapping position of the symbol is changed, are associated with the sub-carriers on the value and the frequency axis _{(d mod N DVRB).} The upper part of FIG. 21 shows the state of DVRB # 0 when mapping is performed using the mapping pattern associated with the value of (d mod N _DVRB ). Similarly, the middle part of FIG. 21 shows the state of DVRB # 1 when mapping is performed using the mapping pattern associated with the value of (d mod N _DVRB ). Similarly, the lower part of FIG. 21 shows the state of DVRB # 2 when mapping is performed using the mapping pattern associated with the value of (d mod N _DVRB ).

The first sub-block of each PRB having the same number as the DVRB number is set as the first sub-block to which the mapping pattern is associated, and each sub-block corresponds to the value of (Ns mod N _DVRB ) for each integer multiple of the number of shifts for each DVRB To set the mapping pattern determined in the above. The position where the symbol is mapped in the sub-block is mapped to the position of the quotient value of d / Ns in the time axis direction. This is shown in the lower part of FIG.

  Therefore, first, since the mapping start sub-block is the head sub-block of the DPRB number equal to each DVRB number, the symbol with the symbol number 0 of DVRB # 0 has sub-block # 0 as the mapping start sub-block. The mapping position in the sub-block is such that the symbol is mapped at the 0th stage position which is the 0/12 quotient of the subcarrier associated with DVRB # 0 of sub-block # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 1 shifted by one subblock, and the mapping position within the subblock is DVRB # of subblock # 1. Symbols are mapped to the 0th stage position, which is 1 / 12th the quotient of the subcarrier associated with 0, and this operation is performed until mapping of all symbols of each DVRB is completed.

Actually, depending on the value of the step size Sn, the mapping order is changed for each cell to reduce inter-cell interference. FIG. 22 shows the state of mapping when Sn = 5.
In this case, first, since the mapping start sub-block is the head sub-block of the DPRB number equal to each DVRB number, the symbol with the symbol number 0 of DVRB # 0 has sub-block # 0 as the mapping start sub-block. The mapping position in the sub-block is such that the symbol is mapped at the 0th stage position which is the 0/12 quotient of the subcarrier associated with DVRB # 0 of sub-block # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 5 obtained by shifting the subblock by five, and the mapping position within the subblock is DVRB # of subblock # 5. Symbols are mapped to the 0th stage position, which is 1 / 12th the quotient of the subcarrier associated with 0, and this operation is performed until mapping of all symbols of each DVRB is completed.

  As described above, when the number of PRBs is smaller than the threshold T (here, 8), by setting the unit step size to be smaller than the PRB size, a sufficient number of step sizes for reducing inter-cell interference can be secured. Improved characteristics can be expected.

  Here, the data multiplexing method in each PRB has been described as FDM. However, as in the second embodiment, the multiplexing method is not limited to FDM, and multiplexing by TDM, random, or hopping is also possible. Furthermore, it is possible to combine a plurality of the respective multiplexing methods.

  Further, although a description has been given using a configuration in which DVRB symbols are mapped one by one, a configuration in which a predetermined number is mapped may be used as in the second embodiment. In this case, when the multiplexing method uses FDM, the same number as the number of symbols in the time axis direction of the sub-block, and when the multiplexing method uses TDM, the number of sub-carriers in the frequency axis direction of the sub-block It is preferable to perform mapping for each same number.

  Furthermore, here, when the number of PRBs is less than 8, that is, the threshold value T is set to 8, the value of T is not limited to 8, and should be set to an optimal value for each wireless communication system. Is possible.

<Example 4>
In the present embodiment, as in the second embodiment, the DPRB is divided so that the number of subblocks is equal to or greater than the threshold T, and each DVRB symbol is multiplexed in each PRB to be FDM. A case will be described in which the arrangement method is different from that of the above embodiment.

  FIG. 23 is a diagram illustrating a transmission data mapping method according to the fourth embodiment.

  In the following description, a case where the threshold value T is set to 8 and three DVRBs having the number of symbols Nd are mapped to three PRBs as shown in FIG. Also in this embodiment, for simplicity, Reference Symbol and Control Symbol in PRB are not considered.

  Further, the case where the mapping pattern determination unit 51 generates twelve sub-blocks with the sub-block size being a multiple of the number y of symbols on the time axis of 1 PRB, here the size is 3y, will be described.

  In the present embodiment, as in the second embodiment, the start sub-block of all DVRB symbol mapping is set to 0th, and when one DVRB symbol is mapped to the sub-block, the DV is shifted by a preset number of steps Sn. Map to sub-block. Here, description will be made assuming that Sn = 1.

  As in the second embodiment, the same mapping pattern as the number of DVRBs is prepared for mapping. Then, in order not to overlap with the mapping pattern of the PRB of the same number in another cell, the first subblock of each PRB is set as the first subblock to which the mapping pattern is associated, and the DPRB size / subblock for each integer multiple of the number of shifts Corresponding to the same mapping pattern for the size. Here, the same applies to subblocks # 0, # 1, # 2, and # 3, subblocks # 4, # 5, # 6, and # 7, or subblocks # 8, # 9, # 10, and # 11 They are arranged to be a mapping pattern. Therefore, for each DVRB, the DPRB number to which the sub-block to be mapped belongs is associated with the sub-carrier in the frequency axis direction to be mapped. Each DVRB symbol is mapped to the (d / Ns) stage in the sub-block.

  Therefore, since the mapping start sub-block is the first sub-block, sub-block # 0 is used as the mapping start sub-block for the symbol of symbol number 0 of DVRB # 0. The mapping position in the sub-block is such that the symbol is mapped at the 0-th position which is the 0/12 quotient of the subcarrier associated with DVRB # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 1 shifted by one subblock, and the mapping position within the subblock is DVRB # of subblock # 1. Symbols are mapped to the 0th stage position, which is 1 / 12th the quotient of the subcarrier associated with 0, and this operation is performed until mapping of all symbols of each DVRB is completed.

  FIG. 24 shows the mapping when the step size Sn = 5. As shown in FIG. 24, the number of shifts is an integer multiple of the DPRB size / subblock size. Here, subblocks # 0, # 5, # 10, and # 3, subblocks # 1, # 6, and # 8 , And # 11, or sub-blocks # 2, # 7, # 9, and # 4 are arranged so as to have the same mapping pattern.

  In this case, first, since the mapping start sub-block is the first sub-block, sub-block # 0 is used as the mapping start sub-block for the symbol of symbol number 0 of DVRB # 0. The mapping position in the sub-block is such that the symbol is mapped at the 0th stage position which is the 0/12 quotient of the subcarrier associated with DVRB # 0 of sub-block # 0.

  Next, the symbol with symbol number 1 of DVRB # 0 is mapped to subblock # 5 obtained by shifting the subblock by five, and the mapping position within the subblock is DVRB # of subblock # 5. Symbols are mapped to the 0th stage position, which is 1 / 12th the quotient of the subcarrier associated with 0, and this operation is performed until mapping of all symbols of each DVRB is completed.

  In the above description, the data multiplexing method in each PRB has been described as FDM. However, the multiplexing method is not limited to FDM, and multiplexing by TDM, random, or hopping is possible. It is also possible to combine a plurality of multiplexing methods.

  In the above description, the mapping start sub-blocks are all head sub-blocks, but they may be from the same sub-block, or may be sub-blocks having the same number as each DVRB number.

  In the above description, each DVRB symbol is mapped one by one. However, when the sub-block is divided by a multiple of the number of symbols in the PRB time axis direction, the PRB time is used. Each DVRB symbol may be mapped by the same number as the number of symbols in the axial direction.

  Furthermore, here, when the number of PRBs is less than 8, that is, the threshold value T is set to 8, the value of T is not limited to 8, and should be set to an optimal value for each wireless communication system. Is possible.

  As described above, when the number of PRBs is smaller than the threshold T (here, 8), by setting the unit step size to be smaller than the PRB size, a sufficient number of step sizes for reducing inter-cell interference can be secured. Improved characteristics can be expected. Further, by making all DVRB symbol mapping start sub-blocks the same sub-block, it can be realized by simple processing.

Further, in the first to fourth embodiments described so far, even when the number of PRBs N _{DPRB to} be transmitted is changed, the sub block size is kept constant by changing the number of sub blocks Ns. It is possible to keep the sub-block size X constant.

Conversely, when the number of transmission DPRBs N _DPRB changes, the number of subblocks Ns can be kept constant by changing the subblock size. In this case, although the sub-block size X changes, the number of sub-blocks Ns is kept constant, so that there is an effect that communication can be performed without changing the step size Sn once set.

Further, when the number of transmission DPRBs N _DPRB changes, it is naturally possible to change the subblock size and the number of subblocks. The optimum number of subblocks Ns and the subblock size X according to the environment of each communication cell Can be set flexibly.

<Example 5>
In this embodiment, the DPRB is divided into a plurality of sub-blocks. In order to increase the type (number) of step sizes, the mapping position is shifted in units of sub-blocks.

  When the number of cell repetitions (also referred to as cell reuse factor) is K, all transmission symbols (resources) of Nd DPRBs are divided into K + 1 (threshold T) or more subblocks. Here, the number Ns of subblocks can be expressed as Ns = Nf × Nt using the number of subblocks Nf in the frequency axis direction and the number of subblocks Nt in the time axis direction, and Nt = Ns / Nf.

  In each cell i to which cell repetition is applied, the step size is made different by setting the step size Si = ((i mod K) +1) (i = 0,..., K−1). DPRB transmission symbols are mapped. The first sub-block to be mapped is sub-block # 0. In order to simplify the mapping at the base station, the data symbols extracted from each DVRB are collectively mapped to the sub-block of sub-block # 0.

In addition to the above description, mapping complexity can be reduced by satisfying the following conditions.
(A) For any Nd (regardless of the value of Nd), a fixed value Ns is used.
(B) Nf × NTx is a divisor of 12, that is, the number of subcarriers in DPRB. Here, NTx is the number of transmit diversity antennas.
(C) Let Nt be a divisor of 14, that is, the number of symbols in the DPRB time axis direction. A small value, for example, 2 is preferable.

  The condition (b) will be further described. Regardless of the value of Nd, the size (number of subcarriers) in the frequency axis direction is the same in all subblocks. Then, NTx adjacent subcarriers for SFBC (Space Frequency Block Coding) are mapped to subblocks for Nd users.

Considering together with the condition (a), considering the possible value of Nf for the cases where NTx is 1 and 2, when NTx is 1, it is either 1, 2, 3, 4, 6 or 12, and NTx 2 is one of 1, 2, 3, and 6 because it is necessary to handle symbols in units of 2 subcarriers.
An example of how Ns is determined for a case where the number of cell repetitions is 7 (K = 7). Considering the above conditions (b) and (c), Nt is preferably a small value such as 2 or less from (c). Therefore, the possible value of Ns (= Nf × Nt) for the case where NTx is 1 is become that way.
Ns = 8 (4 × 2), 12 (6 × 2 or 12 × 1)
And for NTx 2 case,
Ns = 12 (6 × 2)
It becomes. Here, it can be said that Ns = 12, particularly (Nf = 6 and Nt = 2) is the most suitable value. The reason is that a common mapping method can be applied regardless of whether NTx = 1 or NTx = 2.

  Here, further examples of mapping will be shown using FIGS. The cell repetition number K is 7, that is, the threshold T is 8, DVRB is mapped to 3 DPRBs (Nd = 3), and the number of transmit diversity antennas is 2 (NTx = 2). Here, the DPRB is divided into 12 sub-blocks (Nf = 6, Nt = 2), and 11 step sizes are prepared. FIG. 42 shows a case where the DPRB is divided into the 12 sub-blocks described above. Here, the subblock numbers are assigned subblocks # 0 to # 5 in the frequency axis direction over the three DPRBs, and then proceed in the time axis direction, and subblocks # 6 to # 11 are added. ing. As the mapping method, the mapping method described in the second embodiment is used. Here, as shown in FIG. 42, the mapping start subblock of each DVRB data symbol is the first subblock # 0, and 14 data symbols (symbol numbers 0 to 13) of 2 subcarriers × 7 OFDM symbols are mapped together. This is the case.

  In FIG. 43, the step size Sn is set to 1.

  First, since the mapping start sub-block is the head sub-block, sub-block # 0 is used as the mapping start sub-block, and DVRB # 0 2 subcarriers × 14 OFDM symbol 14 data symbols are subblock # 0 2 subcarriers. Mapped to

  Next, 14 data symbols (symbol numbers 14 to 27) from symbol number 14 of DVRB # 0 are mapped to subblock # 1 obtained by shifting the subblock by one. The mapping position within the sub-block is the sub-carrier associated with DVRB # 0 of sub-block # 1, here the first sub-carrier of sub-block # 1 is number 1, and is the third, fourth sub-carrier. This operation is performed until symbols are mapped and mapping of all symbols of each DVRB is completed.

  In FIG. 44, the step size Sn is set to 5. Since DVRB mapped to the first subcarrier changes every time the shift is performed, subblocks # 0, # 3, # 6, and # 9, subblocks # 1, # 4, # 7, and # 10, or subblocks The same mapping pattern is used in # 2, # 5, # 8, and # 11.

  In this case, first, since the mapping start sub-block is the first sub-block, 14 data symbols of 2 subcarriers × 7 OFDM symbols of DVRB # 0 are assigned to sub-block # 0. It is mapped to 2 subcarriers.

  Next, 14 data symbols (symbol numbers 14 to 27) from symbol number 14 of DVRB # 0 are mapped to subblock # 5 obtained by shifting the subblock by five. The mapping position within the sub-block is the sub-carrier associated with DVRB # 0 of sub-block # 1, here the first sub-carrier of sub-block # 5 is the first, and is the third, fourth sub-carrier. This operation is performed until symbols are mapped and mapping of all symbols of each DVRB is completed.

As described above, when the number of DPRBs N _MDPRB is smaller than K + 1 (threshold T: 8 here), the entire DPRB to be mapped is divided into Ns subblocks, and the subblock size at the time of mapping is set to the PRB size. By setting to a smaller size, a sufficient number of step sizes for reducing inter-cell interference can be secured, and a characteristic improvement effect can be expected.

  Here, the data multiplexing method in each DPRB has been described as FDM. However, the multiplexing method is not limited to FDM, and multiplexing by TDM, random, or hopping is possible. It is also possible to combine multiple multiplexing methods.

  Even if Nd is larger than the required step size + 1, this method can be applied to a sub-block having a size larger than DPRB. An example in this case is shown in FIGS. 31 and 32. Here, Nd = 15, mapping to 15 × 2 subcarriers in the frequency axis direction and 7 OFDM symbol size in the time axis direction. Is shown. Details will be described in Example 1 of Embodiment 2 described later.

  As in the above embodiment, when the number of PRBs is smaller than the threshold T, the unit step size is set to a size different from the PRB size, that is, the unit step size is set small, thereby reducing the inter-cell interference. A sufficient number of sizes can be secured, and improvement in characteristics can be expected. Further, by making all DVRB symbol mapping start sub-blocks the same sub-block, it can be realized by simple processing.

Further, even when the PRB number _{N DPRB} to Distibuted transmitted is changed, by changing the number of sub-blocks Ns, keep the sub-block size constant, i.e., it is possible to keep the sub-block size X constant.

Conversely, when the number of transmission DPRBs N _DPRB changes, the number of subblocks Ns can be kept constant by changing the subblock size. In this case, although the sub-block size X changes, the number of sub-blocks Ns is kept constant, so that there is an effect that communication can be performed without changing the step size Sn once set.

Further, when the number of transmission DPRBs N _DPRB changes, it is naturally possible to change the subblock size and the number of subblocks. The optimum number of subblocks Ns and the subblock size X according to the environment of each communication cell Can be set flexibly.

(Embodiment 2)
The present embodiment is characterized in that when the number of transmission DPRBs N _DRPB is equal to or greater than a threshold value T, the size X is larger than the PRB size xy.

  Since the configuration of the present embodiment is the same as the configuration of the base station apparatus and mobile station apparatus shown in FIGS. 1 and 8, the description thereof will be omitted and processing different from that of Embodiment 1 will be described.

  In the first embodiment, the block obtained by dividing the PRB is used as a sub-block. However, in this embodiment, a block obtained by combining the PRB is used as a sub-block.

The mapping determination unit 51 according to the present embodiment sets the sub-block size X that is larger than the PRB size xy using Equation 1 so as to satisfy the threshold T ≦ Ns <N _DRPB .

<Example 1>
In the present embodiment, the shift unit for mapping the sub-block combined with the PRB as described above is used as a shift unit, but it must be mapped so as not to overlap with the PRB mapping pattern of other cells. Hereinafter, an example of the mapping method will be described.

  FIG. 25 is a diagram for explaining Example 1 of the second embodiment.

  Here, description will be made using a case where the threshold value T is set to 8 and 15 DVRBs having the number of symbols Nd are mapped to 15 DPRBs as shown in FIG. In the following description, for simplicity, Reference Symbol and Control Symbol in PRB are not considered.

  Further, a case will be described using the case where the mapping pattern determination unit 51 extracts 14 symbols having a subblock size of 14 symbols on the time axis within 1 PRB and generates 12 subblocks having a size of 210.

  For DVRB with DVRB number <subblock number Ns, the subblock number that matches the DVRB number is set as the mapping start position, and if one DVRB symbol is mapped to the subblock, the number of steps is shifted by the preset number of steps Sn. Map to the sub-block. Here, description will be made assuming that Sn = 5.

  The mapping pattern indicating the position where the symbol is mapped to the sub-block is defined such that a symbol having a different DVRB number is mapped for each sub-carrier in the frequency axis direction. This definition is such that the symbol of the DVRB number that matches the sub-block number is mapped to the first sub-carrier of each sub-block number that matches the DVRB number, and is in ascending or descending order from the DVRB number. Define in order. Therefore, for each subblock, the DVRB number is associated with the subcarrier in the frequency axis direction in the subblock. Here, the description has been made using the ascending order or descending order, but the order may be set according to a certain rule.

  As many mapping patterns as the number of sub-blocks are prepared. In this description, twelve types of mapping patterns that are equal to the number of sub-blocks are prepared.

  Each sub-block is mapped with a symbol using a different mapping pattern. Each DVRB symbol is mapped to the (d / Ns) stage in the sub-block.

  Further, sub-blocks shifted based on the step size Sn are extracted and rearranged. Here, assuming the case of Sn = 5, first, subblock # 0, subblock # 5 shifted by step size “5”, subblock # 10 shifted further by step size “5”, and so on. Sub-blocks are extracted and arranged in order. This is shown in the upper part of FIG. Then, the rearranged sub-blocks are extracted with the PRB size. This is shown in the lower part of FIG.

  In this way, by setting the unit step amount to a size larger than the PRB size, the head symbol when mapping from the sub-block to the PRB is different, and the randomness is more random than simply rearranging by the step size Sn. It will become stronger.

  Note that even if all DVRB data mapping start sub-blocks are set to 0th, symbols having the same symbol number of each DVRB are FDM multiplexed, and the symbols are mapped in different order in the sub-blocks in different DPRBs. , 26 mapping results are obtained, and mapping may be performed in this way.

In addition, the number of sub-blocks can be kept constant by changing the sub-block size regardless of the number of transmission DPRBs N _DPRB , and the number of sub-blocks that can secure a sufficient number of step sizes can be set in advance. For example, even when the number of DPRBs changes, mapping can be performed by the same processing, and the burden on the transmission apparatus can be reduced. Further, communication can be performed without changing the step size once set, and the signaling amount due to the change of the step size can be reduced.

Of course, it is possible to fix the subblock size by changing the number of subblocks Ns by changing the number of transmission DPRBs N _DPRB , and it is also possible to make both the number of subblocks Ns and the subblock size variable. The flexible setting according to the environment of each communication cell is possible.

  In the above description, the data multiplexing method in each PRB has been described as FDM. However, the multiplexing method is not limited to FDM, and multiplexing by TDM (Time Division Multiplexing), random, or hopping is also possible. Furthermore, it is possible to combine a plurality of the respective multiplexing methods. As an example, FIGS. 27 and 28 show the state of mapping at Sn = 5 in the case of TDM multiplexing.

  Further, when performing FDM mapping, in the above mapping, the number of subcarriers on the frequency axis to which each DVRB is mapped is 1, but for example, as shown in FIG. It is of course possible to perform mapping with. Here, three subcarrier sequences are grouped into one, DVRB # 0 symbols are mapped to subblocks # 0, # 1, # 2, and # 3, and DVRB # 1 symbols are subsequently subblock # 0. 4, # 5, # 6, and # 7, DVRB # 2 symbols are further sub-block # 8, # 9, # 10, and # 11, and symbols after DVRB # 3 are again subblock # 8. The mapping is performed by the round robin method so that the mapping is returned to 0. Here, FIG. 30 shows a state of mapping when Sn = 5.

  In the above description, each DVRB symbol is mapped one by one. However, when the sub-block is divided by a multiple of the number of symbols in the PRB time axis direction, the PRB time is used. Each DVRB symbol may be mapped by the same number as the number of symbols in the axial direction.

  Furthermore, here, when the number of PRBs is less than 8, that is, the threshold value T is set to 8, the value of T is not limited to 8, and should be set to an optimal value for each wireless communication system. Is possible.

  As described above, when the number of PRBs is larger than the threshold T (here, 8), even if the unit step size is set larger than the PRB size, a sufficient number of step sizes for reducing inter-cell interference can be secured, Improved characteristics can be expected. Further, by making all DVRB symbol mapping start sub-blocks the same sub-block, it can be realized by simple processing. Furthermore, the head symbol at the time of mapping from the sub-block to the PRB is different, and the randomness becomes stronger than the conventional technique in which rearrangement is simply performed by the step size Sn.

<Example 2>
FIG. 31 is a diagram for explaining Example 2 of the second embodiment.

  Here, the threshold T is set to 8, and 15 DVRBs with Nd symbols are mapped to 15 DPRBs as shown in FIG. In the following description, for simplicity, Reference Symbol and Control Symbol in PRB are not considered.

  Also, here, one DVRB data symbol shows an example of mapping two consecutive subcarriers as one set.

  If two consecutive subcarriers for 15 DVRBs are taken as one set, the number of subcarriers in the frequency axis direction in one subblock is determined with 30 subcarriers as a unit. At this time, the total number of subcarriers in the 15 frequency axis directions is 12 × 15 = 180 subcarriers in the frequency axis direction in one DPRB, so that the subblock of 30 subcarriers is in the frequency axis direction. 6 can be generated. However, the threshold value T here is 8, and the condition equal to or higher than the threshold value T cannot be satisfied. Therefore, further division in the time axis direction is required. Here, twelve sub-blocks are generated by dividing into two in the time axis direction.

  The mapping of each DVRB data symbol is started by subblock # 0, and when 14 data symbols of 2 subcarriers × 7 OFDM symbols are collectively mapped to the subblock, the data is shifted by a preset number of steps Sn. Map to sub-block. Here, description will be made assuming that Sn = 1.

  The mapping pattern indicating the position where the symbol is mapped to the sub-block is defined such that a symbol having a different DVRB number is mapped for every two subcarriers in the frequency axis direction. For example, DVRB # 0 data symbols are mapped to the head of sub-block # 0 and are defined in order so that the DVRB number is in ascending or descending order. Therefore, for each sub-block, the DVRB number is associated with the sub-carrier in the frequency axis direction within the sub-block. Here, the description is made using ascending order or descending order, but the order may be set according to a certain rule.

  As many mapping patterns as the number of sub-blocks are prepared. In this description, twelve types of mapping patterns that are equal to the number of sub-blocks are prepared.

  Further, the sub-blocks shifted based on the step size Sn are extracted and rearranged. Here, assuming the case of Sn = 1, first, sub-block # 0, sub-block # 1 shifted by step size “1”, sub-block # 2 further shifted by step size “1”, etc. Sub-blocks are extracted and arranged in order. This is shown in the lower part of FIG. Then, the rearranged sub-blocks are extracted with the PRB size. This is shown in the lower part of FIG.

  In this way, by setting the unit step size to a unit step amount different from the PRB size, that is, a unit step amount larger than the PRB size, the top symbol in mapping from the sub-block to the PRB will be different, and simply the step Randomness becomes stronger than sorting by size Sn.

  Note that for DVRBs with DVRB number <subblock number Ns, the mapping results shown in FIGS. 31 and 32 are obtained even if each DVRB symbol is FDM multiplexed with the subblock number matching the DVRB number as the mapping start position. You may map by such a method.

In addition, the number of sub-blocks can be kept constant by changing the sub-block size regardless of the number of transmission DPRBs N _DPRB , and the number of sub-blocks that can secure a sufficient number of step sizes can be set in advance. For example, even when the number of DPRBs changes, mapping can be performed by the same processing, and the burden on the transmission apparatus can be reduced. Further, communication can be performed without changing the step size once set, and the signaling amount due to the change of the step size can be reduced.

Of course, it is possible to fix the subblock size by changing the number of subblocks Ns by changing the number of transmission DPRBs N _DPRB , and it is also possible to make both the number of subblocks Ns and the subblock size variable. The flexible setting according to the environment of each communication cell is possible.

  In the above description, the data multiplexing method in each PRB has been described as FDM. However, the multiplexing method is not limited to FDM, and multiplexing by TDM (Time Division Multiplexing), random, or hopping is also possible. Furthermore, it is possible to combine a plurality of the respective multiplexing methods.

  In the above description, the case where 14 DVRB symbols are mapped is described. However, each DVRB symbol may be mapped one by one.

  Furthermore, here, when the number of PRBs is less than 8, that is, the threshold value T is set to 8, the value of T is not limited to 8, and should be set to an optimal value for each wireless communication system. Is possible.

(Embodiment 3)
In the present embodiment, when the number of transmission DPRBs N _DRPB is equal to or greater than a threshold value T, the sub-block size X is set to the PRB size xy. Note that the configuration of this embodiment is the same as that of the above embodiment, and thus the description thereof is omitted.

In the first embodiment, since the number of transmission DPRBs N _DPRB is smaller than the threshold value T, the configuration in which the type of step size Sn that can reduce inter-cell interference cannot be secured has been described. In addition to this, when the number of transmission DPRBs N _DPRB is larger than the threshold value and the type of step size Sn can be sufficiently secured, the mapping pattern determination unit 51 sets the sub block size X to the PRB size xy without dividing the PRB. Same as. In the mapping method, the same processing as in the prior art may be performed, or the same processing as in the first embodiment may be performed.

  According to the present embodiment, it is possible to simplify the processes of the base station apparatus and the mobile station apparatus when the state in which the number of transmission PRBs is less than the threshold value T does not occur so much.

(Embodiment 4)
The present embodiment is characterized in that the subblock size X is determined by the same determination method as when the number of transmission DPRBs N _DRPB is equal to or _larger than the threshold T, which is smaller than the threshold T. Note that the configuration of this embodiment is the same as that of the above embodiment, and thus the description thereof is omitted.

The mapping pattern determination unit 51 determines the sub-block size X in the same manner as in the first embodiment when the number of transmission DPRBs N _DPRB is larger than the threshold value T but less than the threshold value T. Also in the mapping method, the same processing as in the first embodiment is performed.

According to this embodiment, transmission regardless DPRB number _{N DPRB,} can mapping the transmission data in the same processing, transmission DPRB number _{N DPRB} and subblock size X, since the notification information of the sub-block number Ns is reduced In addition, the control of the base station apparatus and the mobile station apparatus can be simplified, and a signaling reduction effect can be obtained.

(Embodiment 5)
The present embodiment is characterized in that when the number of DPRBs N _MDPRB allocated to one DVRB is smaller than a threshold T, the DPRB is divided into Ns of sub-blocks of size X smaller than the PRB size xy. Note that the configuration of this embodiment is the same as that of the above embodiment, and thus the description thereof is omitted.

In the first embodiment described above, the case where one DVRB is mapped to all DPRBs has been described. However, even when the number of _DPRBs N _MDPRB to which one DVRB is mapped is small, the type of step size cannot be secured. Happens.

The mapping pattern determination unit 51 determines whether or not the DPRB number N _MDPRB allocated to one DVRB is smaller than the threshold T. When the number of DPRBs N _MDPRB to which one DVRB is mapped is smaller than the threshold T, the entire DPRB to be mapped is divided into Ns sub-blocks, and the sub-block size X at the time of mapping is smaller than the PRB size xy Set to.

Here, the sub-block size X is determined based on Equation 1 so as to satisfy the number of sub-blocks Ns (Ns> N _MDPRB ) included in the transmission signal band.

  FIG. 33 is a diagram showing a transmission data mapping method according to the present embodiment. In the following description, when the threshold T is set to 8 and the DVRB of the number of symbols Nd is 15, one DVRB is mapped to three DPRBs. As an example, DVRB # 0, DVRB # 1, and DVRB # 2 are mapped to DPRB # 0, DPRB # 7, and DPRB # 14. Also, here, one DVRB data symbol shows an example of mapping two consecutive subcarriers as one set.

  In this case, if two consecutive subcarriers for three DVRBs are defined as one set, the number of divisions in the frequency axis direction of one DPRB is 2 with six subcarriers as a unit, and six subcarriers in the frequency axis direction for three DPRBs. Can be divided into blocks. However, the threshold value T here is 8, and the condition equal to or higher than the threshold value T cannot be satisfied, so that further division in the time axis direction is required. Therefore, the DPRB is divided into two in the time axis direction, and one DPRB is divided into four subblocks, and the data symbols of DVRB # 0, DPRB # 1, and DVRB # 2 are mapped to 12 subblocks. Here, the subblock numbers are assigned subblocks # 0 to # 5 in the frequency axis direction over the three DPRBs, and then proceed in the time axis direction, and subblocks # 6 to # 11 are added. ing. Note that the mapping method described in Example 2 of the first embodiment is used. In this case, as shown in FIG. 33, the mapping start sub-block of each DVRB data symbol is the first sub-block # 0, and 14 data symbols of 2 sub-carriers × 7 OFDM symbols are mapped together.

  FIG. 34 shows a mapping result when mapping 14 symbols at a time when the step size Sn = 1.

  Further, FIG. 35 shows the mapping result when the step size Sn = 5.

As described above, when the number of DPRBs N _MDPRB to which one DVRB is mapped is smaller than the threshold T (here, 8), the entire DPRB to be mapped is divided into Ns sub-blocks, By setting the block size X to a size smaller than the PRB size xy, a sufficient number of step sizes for reducing inter-cell interference can be secured, and a characteristic improvement effect can be expected.

  In addition, you may use the mapping method of an Example different from the mapping method described in Example 2 of the said Embodiment 1. FIG. Also, here, the data multiplexing method in each DPRB has been described as FDM, but the multiplexing method is not limited to FDM, and multiplexing by TDM, random, and hopping is possible. It is also possible to combine multiple multiplexing methods.

  Further, although the description has been made using the configuration in which DVRB symbols are mapped every one or every 14 symbols, a configuration may be adopted in which mapping is performed every predetermined number. In this case, when the multiplexing method uses FDM, the number of symbols in the time axis direction of the sub-block is the same as the number of symbols, and when the multiplexing method uses TDM, sub-carriers in the frequency axis direction of the sub-block. It is preferable to perform mapping for each of the same number as the number.

Furthermore, here, the number of DPRBs N _MDPRB to which one DVRB is mapped is less than 8, but the threshold T is not limited to 8, and should be set to an optimum value for each wireless communication system. Is possible.

  In the description of the mapping example of each embodiment of the present invention, for the sake of simplicity, it has been described without considering Reference Symbol or Control Symbol. However, in the actual communication system, when there is Reference Symbol or Control Symbol, Mapping can be performed in the same manner as described in the present embodiment by determining a sub-block size in consideration of the number of each symbol or performing puncturing. Even when mapping is performed by shifting the insertion positions of the Reference Symbol and the Control Symbol, the insertion positions in each cell are the same, so no problem occurs.

  In the above description, various mapping methods have been described. However, other mapping methods may be used as long as mapping can be performed so as not to overlap with PRB mapping patterns of other cells.

  The above-described base station and mobile station of the present invention can be configured by hardware as is apparent from the above description, but can also be realized by a computer program. In this case, functions and operations similar to those of the above-described embodiment are realized by a processor (information processing apparatus) that operates according to a program stored in the program memory. Note that only a part of the functions of the above-described embodiment can be realized by a computer program.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2007-161504 for which it applied on June 19, 2007, and takes in those the indications of all here.

Claims (32)

OFDM mapping method,
A mapping method characterized in that a sub-block obtained by dividing, combining, or dividing a Physical Resource Block is used as a shift unit when mapping a Virtual Resource Block symbol.   The physical resource block is divided, combined, or divided and combined so that the number of subblocks is larger than a threshold set based on the number of interfering cells. Mapping method.   The size of the sub-block is determined based on at least one value among the number of sub-carriers of the Physical Resource Block and the number of symbols mapped on the time axis of the Physical Resource Block. The mapping method according to claim 1 or 2.   The mapping method according to any one of claims 1 to 3, wherein the physical resource block is divided when the number of physical resource blocks is smaller than a threshold set based on the number of interfering cells. .   The physical resource block is divided when the number of physical resource blocks assigned to the mapping of the symbol of the virtual resource block is smaller than a threshold set based on the number of interfering cells. The mapping method according to claim 3.   When the number of Physical Resource Blocks or the number of Physical Resource Blocks assigned to the mapping of Virtual Resource Block symbols is larger than the threshold set based on the number of interfering cells, the Physical Resource Block is not divided. The mapping method according to any one of claims 1 to 5, wherein the mapping method is characterized.   If the number of Physical Resource Blocks or the number of Physical Resource Blocks assigned to the mapping of Virtual Resource Block symbols is larger than the threshold set based on the number of interfering cells, combine the Physical Resource Blocks. The mapping method according to any one of claims 1 to 5, wherein the mapping method is characterized.   The mapping method according to any one of claims 1 to 7, wherein the mapping of the symbol of the Virtual Resource Block is started from a sub-block obtained by dividing the Physical Resource Block associated with the Virtual Resource Block. .   The mapping method according to any one of claims 1 to 7, wherein the mapping of the symbol of the Virtual Resource Block is started from a sub-block associated with the Virtual Resource Block.   8. The mapping method according to claim 1, wherein the mapping of all Virtual Resource Block symbols is started from the same sub-block.   The mapping method according to any one of claims 1 to 10, wherein symbols of Virtual Resource Block are mapped in units of a predetermined number of symbols.   The position in the sub-block to which the symbol of the Virtual Resource Block is mapped is determined based on a mapping pattern set according to the identification information of the symbol of the Virtual Resource Block. Item 12. The mapping method according to any one of Items 11.   12. The mapping method according to claim 1, wherein symbols of the Virtual Resource Block are mapped based on the same number of mapping patterns as the number of Virtual Resource Blocks.   The mapping method according to any one of claims 1 to 11, wherein a mapping pattern to be used for a sub-block is determined according to a number to be shifted when mapping a symbol of a Virtual Resource Block. An OFDM mapping device,
A decision means for deciding to set a sub-block obtained by dividing, combining, or dividing the Physical Resource Block as a shift unit for mapping;
A mapping apparatus comprising mapping means for mapping a symbol of a Virtual Resource Block based on the determined shift unit.   The determination unit determines to divide, combine, or combine Physical Resource Blocks so that the number of subblocks is larger than a threshold set based on the number of interfering cells. The mapping device according to claim 15.   The determining means determines the size of the sub-block based on at least one of the number of sub-carriers of the Physical Resource Block and the number of symbols mapped on the time axis of the Physical Resource Block. The mapping apparatus according to claim 15 or 16, characterized in that   The determination unit according to any one of claims 15 to 17, wherein the determination unit determines to divide the physical resource block when the number of physical resource blocks is smaller than a threshold set based on the number of interfering cells. The mapping device according to any one of the above.   The determining means determines to divide the Physical Resource Block when the number of Physical Resource Blocks assigned to the mapping of the Virtual Resource Block symbol is smaller than a threshold set based on the number of interfering cells. The mapping apparatus according to claim 15, wherein the mapping apparatus is characterized.   The determination means, when the number of Physical Resource Blocks or the number of Physical Resource Blocks assigned to the mapping of Virtual Resource Block symbols is larger than the threshold set based on the number of interfering cells, the Physical Resource Block The mapping apparatus according to claim 15, wherein it is determined that the data is not divided.   The determination means, when the number of Physical Resource Blocks or the number of Physical Resource Blocks assigned to the mapping of Virtual Resource Block symbols is larger than the threshold set based on the number of interfering cells, the Physical Resource Block The mapping device according to claim 15, wherein the mapping device is determined to be combined.   The mapping means starts mapping of a Virtual Resource Block symbol from a sub-block obtained by dividing a Physical Resource Block associated with the Virtual Resource Block. The mapping device described in 1.   The mapping device according to any one of claims 15 to 21, wherein the mapping unit starts mapping of the symbol of the Virtual Resource Block from a sub-block associated with the Virtual Resource Block.   The mapping device according to any one of claims 15 to 21, wherein the mapping unit starts mapping of symbols of all Virtual Resource Blocks from the same sub-block.   The mapping device according to any one of claims 15 to 24, wherein the mapping means maps the symbols of the Virtual Resource Block in units of a predetermined number of symbols.   The mapping unit according to any one of claims 15 to 24, wherein mapping is performed to a position in a sub-block based on a mapping pattern set according to identification information of a symbol of a Virtual Resource Block. The mapping device described.   The mapping device according to any one of claims 15 to 24, wherein the mapping unit maps the symbols of the Virtual Resource Block based on the same number of mapping patterns as the number of Virtual Resource Blocks.   The mapping unit according to any one of claims 15 to 24, wherein mapping is performed based on a mapping pattern used for a sub-block, according to a number to be shifted when mapping a symbol of a Virtual Resource Block. The mapping device described. A mobile station,
A mobile station having means for demapping and extracting data obtained by mapping a virtual resource block symbol using a sub-block obtained by dividing, combining or dividing the physical resource block as a shift unit . A communication system,
A decision means for deciding to set a sub-block obtained by dividing, combining, or dividing the Physical Resource Block as a shift unit for mapping;
Mapping means for mapping a symbol of the Virtual Resource Block based on the determined shift unit;
And means for demapping the mapped data. An information processing apparatus program, the program is stored in the information processing apparatus,
A program that executes a process of mapping a sub-block obtained by dividing, combining, or combining physical resource blocks as a shift unit when mapping symbols of a virtual resource block. OFDM mapping method,
A mapping method characterized by mapping a symbol of a Virtual Resource Block to a sub-block obtained by dividing, combining, or dividing a Physical Resource Block.

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