Communication device, communication method, and program

Abstract

Provided is a communication technology that can increase the accommodation number of communication devices. 【Solution means】The communication device includes means for mapping transmission data to an N-dimensional first vector, means for converting the first vector into a second vector by multiplying it with a first regular matrix of size N, and processing means for generating an M-dimensional (M≧N) third vector corresponding to each of N time instants based on the second vector according to element information, where the value of the element corresponding to the n-th time instant (n is an integer from 1 to N) of the third vector corresponding to the n-th time instant is the same as the value of the element corresponding to the n-th time instant of the second vector, and the values of the other elements are 0; means for converting the third vector corresponding to the n-th time instant into a fourth vector corresponding to the n-th time instant by multiplying it with a second regular matrix; and transmission means for transmitting M numerical sequences indicated by the fourth vector corresponding to the n-th time instant starting from the n-th time instant.

Description

Technical Field

[0001] The present disclosure relates to communication technology.

Background Art

[0002] An IoT (Internet of Things) device, which is a wireless device (WD) used in a smart meter or the like, communicates with a server device or the like arranged in a communication network via an access point (AP). The AP is a communication device that accommodates one or more WDs and provides wireless access to the communication network for the WDs, and is also called a base station (BS). Non-Patent Document 1 discloses a communication technology called LoRa used for wireless communication between an IoT device and an AP that accommodates the IoT device.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the communication technology disclosed in Non-Patent Document 1, when the number of IoT devices communicating with the AP increases, the number of packets that the AP can normally receive is limited due to the influence of interference or the like. For example, when one AP communicates with 500 IoT devices and one IoT device transmits 1500 packets per hour, the number of packets that the AP can normally receive is about 200 packets per IoT device. Therefore, in the communication technology disclosed in Non-Patent Document 1, the number of IoT devices (accommodation number) that can be accommodated in the AP is limited.

[0005] The present disclosure provides a communication technology that can increase the accommodation number of communication devices.

Means for Solving the Problem

[0006] According to one aspect of the present disclosure, a communication device includes storage means for storing processing information including time information indicating N time instants from a first time instant to an N-th time instant, frequency information indicating a frequency at each of the N time instants indicated by the time information, a one-to-one correspondence between the N time instants indicated by the time information and N elements of an N-dimensional vector, and element information indicating a one-to-one correspondence between the N time instants indicated by the time information and N elements of M elements of an M-dimensional vector, where N is an integer of 2 or more and M is an integer of N or more; mapping means for mapping transmission data to a first vector of N dimensions; first conversion means for converting the first vector into a second vector of N dimensions by multiplying the first vector and a first regular matrix of size N; processing means for performing a process of generating, based on the second vector, an M-dimensional third vector corresponding to each of the N time instants according to the element information, where a value of an element of the third vector corresponding to the n-th time instant (n is an integer from 1 to N) is the same as a value of an element of the second vector corresponding to the n-th time instant, and a value of an element different from the element of the third vector corresponding to the n-th time instant is 0; second conversion means for converting the third vector corresponding to the n-th time instant into a fourth vector of M dimensions corresponding to the n-th time instant by multiplying the third vector corresponding to the n-th time instant and a second regular matrix of size M; and transmission means for transmitting, as signals of the frequencies at the n-th time instant indicated by the frequency information, M numerical sequences indicated by the fourth vector corresponding to the n-th time instant starting from the n-th time instant. In the element information among the M elements corresponding to the n-th time instant and the corresponding shown The value of the element is In the element information among the N elements corresponding to the n-th time instant shown as the same as the value of the element of the second vector corresponding to the n-th time instant, and a value of an element different from the element of the third vector corresponding to the n-th time instant is 0 corresponding the processing means; second conversion means for converting the third vector corresponding to the n-th time instant into a fourth vector of M dimensions corresponding to the n-th time instant by multiplying the third vector corresponding to the n-th time instant and a second regular matrix of size M; and transmission means for transmitting, as signals of the frequencies at the n-th time instant indicated by the frequency information, M numerical sequences indicated by the fourth vector corresponding to the n-th time instant starting from the n-th time instant.

Advantages of the Invention

[0007] According to the present disclosure, the accommodation number of the communication device can be increased.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of the features described in the embodiments are essential for the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Also, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] <First Embodiment> FIG. 1 is a configuration diagram of a wireless communication system used in the description of the embodiment. The access point (AP) 2 is a communication device capable of wireless communication with the wireless devices (WDs) 1-1 to 1-4 and is also called a base station (BS). The WDs 1-1 to 1-4 are communication devices capable of wireless communication with the AP 2. As an example, the WDs 1-1 to 1-4 are IoT devices. In the following description, the WDs 1-1 to 1-4 are also collectively referred to as WD1. In the example shown in FIG. 1, the AP 2 accommodates four WDs 1. In the following description, the direction from WD1 to AP2 is denoted as the upward direction, and the direction from AP2 to WD1 is denoted as the downward direction. The AP 2 is connected to a communication network (not shown), and the AP 2 has a function of relaying communication between the WD1 and a server of the communication network (not shown).

[0011] FIG. 2 is a diagram showing a configuration example of the WD1 and the AP2. The WD1 and the AP2 include a modulator 3, a demodulator 4, a storage unit 5, and a wireless unit 6. The modulator 3 includes a mapping unit 31, a conversion unit 32, a processing unit 33, and a conversion unit 34. The demodulator 4 includes a conversion unit 44, a processing unit 43, a conversion unit 42, and a determination unit 41. The transmission information and the reception information are stored in the storage unit 5. The transmission information is information used on the transmission side of the modulator 3 and the wireless unit 6, and the reception information is information used on the reception side of the demodulator 4 and the wireless unit 6. Although the details of the transmission information and the reception information will be described later, they include time information indicating N (N is an integer of 2 or more) different times t1 to t N and frequency information indicating the frequencies at the N times t1 to t N respectively.

[0012] U1, U2, V1, and V2 shown in FIG. 2 are all numerical sequences of N complex numbers. Also, W1, W2, S, and R shown in FIG. 2 are all numerical sequences of M complex numbers. Note that N is an integer of 2 or more, and M is an integer of N or more. In the following description, the N numerical sequences are made to correspond to N-dimensional vectors. Also, the N elements e1 to e of the N-dimensional vector {e1, e2, e3, ···, e N} NWhen distinguishing, the left - hand element is denoted as the "first element". Thus, e2 is the second element, and e N is the Nth element. Further, in the following description, it is assumed that an "N - dimensional vector" is also an "N - row and 1 - column matrix". Note that the first element of an N - dimensional vector corresponds to the element in the first row (the uppermost element) of an N - row and 1 - column matrix, and the Nth element of an N - dimensional vector corresponds to the element in the Nth row (the lowermost element) of an N - row and 1 - column matrix. The same applies to M numerical sequences.

[0013] The mapping unit 31 outputs an N - dimensional vector U1 based on the data to be transmitted (transmission data). The conversion unit 32 outputs an N - dimensional vector V1 which is the product of a regular matrix A of size N (N rows and N columns) and the vector U1. The regular matrix A is a complex square matrix, and there exists an inverse matrix A -1 such that the product with matrix A is the identity matrix. Note that the inverse matrix A -1 is also a regular matrix. For example, when matrix A is a unitary matrix, the product of matrix A and its adjoint matrix A * is the identity matrix. The adjoint matrix A * of matrix A is a matrix obtained by taking the complex conjugate of each element (component) of matrix A and then transposing it. Naturally, the adjoint matrix A * of matrix A is also a unitary matrix.

[0014] The processing unit 33 outputs an M - dimensional vector W1(t n (where n is an integer from 1 to N)) corresponding to each of the times t n ) indicated by the transmission information. Details of the processing in the processing unit 33 will be described later. The conversion unit 34 outputs an M - dimensional vector S(t n ) corresponding to the time t n , which is the product of a regular matrix B of size M (M rows and M columns) and the vector W1(t n ). The wireless unit 6 converts the M numerical sequences of the vector S(t n ) into a radio signal (transmission signal) at the frequency at the time t n indicated by the transmission information and transmits them in order from the time t n .

[0015] Also, the wireless unit 6 receives the signal at time t n A radio signal (received signal) with a frequency of n t n M-dimensional vector R(t n The conversion unit 44 outputs the inverse matrix B of the regular matrix B used by the conversion unit 34 on the transmission side. -1 and vector R(t n ) at time t n M-dimensional vector W2(t n ) according to the received information. N ) to generate and output an N-dimensional vector V2. The conversion unit 42 converts the inverse matrix A of the regular matrix A used by the conversion unit 32 on the transmission side. -1 and vector V2, and outputs an N-dimensional vector U2. A determination unit 41 determines the transmitted data based on vector U2.

[0016] Any regular matrix can be used as the regular matrices A and B used in the transform unit 32 and the transform unit 34. In the following, as a specific example, the regular matrix A used in the transform unit 32 is a discrete Fourier transform (DFT) matrix M DFT The regular matrix B used in the transform unit 34 is defined as an inverse discrete Fourier transform (IDFT) matrix M IDFT Therefore, the inverse matrix B used in the conversion unit 44 is -1 is the discrete Fourier transform (DFT) matrix M DFT The inverse matrix A used in the conversion unit 42 is -1 is the inverse discrete Fourier transform (IDFT) matrix M IDFTThis is the case. In this case, the processes performed by the conversion unit 32 and the conversion unit 44 are discrete Fourier transform processes, and the processes performed by the conversion unit 34 and the conversion unit 42 are inverse discrete Fourier transform processes. Further, the modulator 3 has a configuration in which the mapping unit 31 and the processing unit 33 are provided with respect to a configuration that performs an IDFT after a DFT, which is used in a modulator of normal DFT spread - orthogonal frequency - division multiplexing (OFDM). Similarly, the demodulator 4 has a configuration in which the processing unit 43 and the determination unit 41 are provided with respect to a configuration that performs an IDFT after a DFT, which is used in a demodulator of normal DFT spread - OFDM.

[0017] [When M = N] Hereinafter, for the ease of understanding of the embodiments, the description will be made assuming M = N.

[0018] DFT matrix M of size N DFT and IDFT matrix M IDFT are, when ω = e -j2π / N as follows. Note that the coefficients commonly multiplied to each element are omitted.

[0019] [Equation]

[0020] Hereinafter, for the sake of simplicity of explanation, when exemplifying specific numerical values, N = 4 (therefore, in this example, M = 4 as well) is used. However, the value of N can be any value of 2 or more, and the value of M can be any value of N or more. When N = 4, the DFT matrix M DFT and IDFT matrix M IDFT are as follows.

[0021] [Equation]

[0022] The mapping unit 31 of the modulator 3 and the determination unit 41 of the demodulator 4 have mapping information. The mapping information is information indicating the correspondence between data and N-dimensional reference vectors. In the present embodiment, the reference vector is a complex value "α" in which one value among N elements is different from 0, and the values of the other (N - 1) elements are "0". Therefore, the total number of reference vectors is N. In the following description, the reference vector in which the n-th (n is an integer from 1 to N) element has the value α is denoted as the "n-th reference vector". Since the total number of reference vectors is N, the number of bits P of the data mapped to one reference vector is less than or equal to log2N.

[0023] FIG. 3 shows an example of mapping information in the case of N = 4. According to the mapping information in FIG. 3, the data "00" is mapped to the first reference vector, that is, {α, 0, 0, 0}. Note that the mapping information shown in FIG. 3 is an example, and a reference vector different from the first reference vector can be associated with the data "00". In the present embodiment, the non-zero element position of the reference vector indicates the data.

[0024] <Upward communication> First, the upward communication will be described. In the following description, it is assumed that the transmission information shown in FIG. 4(A) is stored in the storage unit 5 of WD1-1, the transmission information shown in FIG. 4(B) is stored in the storage unit 5 of WD1-2, the transmission information shown in FIG. 4(C) is stored in the storage unit 5 of WD1-3, and the transmission information shown in FIG. 4(D) is stored in the storage unit 5 of WD1-4. On the other hand, in the storage unit 5 of AP2, it is assumed that the reception information shown in FIG. 4(A) is stored in association with WD1-1, the reception information shown in FIG. 4(B) is stored in association with WD1-2, the reception information shown in FIG. 4(C) is stored in association with WD1-3, and the reception information shown in FIG. 4(D) is stored in association with WD1-4. Since the transmission information used on the transmission side and the reception information used on the reception side are the same information, in the following description, "transmission information" and "reception information" are collectively referred to as "processing information".

[0025] The processing information is from the first time t1 to the N-th time tN It includes time information indicating a time, frequency information indicating the frequency at each of the N times indicated by the time information, and element information indicating a one-to-one correspondence between the N times indicated by the time information and the N elements of the N-dimensional vector. Since the processing information shown in FIGS. 4(A) to 4(D) is for the case of N = 4, the time information indicates four times, i.e., the first time t1 to the fourth time t4, the frequency information indicates the frequency at each of the four times, and the element information indicates a one-to-one correspondence between each of the first time t1 to the fourth time t4 and the four elements of the four-dimensional vector.

[0026] Each time indicated by the time information is the elapsed time from a periodic reference time. That is, the first time t1 to the fourth time t4 are periodic times. In this example, it is assumed that the first time t1 is earlier than the second time t2, the second time t2 is earlier than the third time t3, and the third time t3 is earlier than the fourth time t4. However, the relationship among the first time t1 to the fourth time t4 is not limited to the above-described relationship. For example, the first time t1 may be the second earliest time, the third earliest time, or the latest time among the four times. The same applies to other times. More generally speaking, the "first" to "Nth" of the first time t1 to the Nth time t N in the time information are for distinguishing the N times and do not indicate the order on the time axis.

[0027] Also, in the frequency information of the processing information shown in FIGS. 4(A) to 4(D), although the frequencies at each of the four times are different, a configuration may be adopted in which the frequencies at at least two of the four times are the same.

[0028] When N = 4, the element information is obtained by circularly shifting the order of the "first" to "fourth" elements in the range from shift amount 0 to shift amount 3. Specifically, for the element information in Fig. 4(A), in the order of the first time t1 to the fourth time t4, the elements corresponding to the times are in the order of the first element to the fourth element. And the element information in Figs. 4(B), 4(C), and 4(D) is obtained by circularly shifting the order of the element positions shown by the element information in Fig. 4(A) to the right by shift amounts of "1", "2", and "3".

[0029] In the following description, the element information in which the element corresponding to the first time is the first element is also referred to as the first element information, the element information in which the element corresponding to the second time is the first element is also referred to as the second element information, the element information in which the element corresponding to the third time is the first element is also referred to as the third element information, and the element information in which the element corresponding to the fourth time is the first element is also referred to as the fourth element information. Also, as shown in Figs. 4(A) to 4(D), the processing information including the first element information is also referred to as the first processing information, the processing information including the second element information is also referred to as the second processing information, the processing information including the third element information is also referred to as the third processing information, and the processing information including the fourth element information is also referred to as the fourth processing information.

[0030] Generally speaking, N different processing information including the same time information and frequency information but different element information can be created, that is, the first processing information to the Nth processing information. The kth processing information (k is an integer from 1 to N) includes the kth element information, and the kth element information indicates the xth element of the N-dimensional vector as an element of the N-dimensional vector corresponding to the nth time, where x is the value obtained by adding 1 to the remainder of dividing (N + n - k) by N. That is, x = {(N + n - k) mod N} + 1. Note that "mod" indicates the remainder operation.

[0031] <Upward communication by WD1-1> The following describes the case where WD1-1 transmits data "10" to AP2. In the following description, for the sake of simplicity of notation, it is assumed that "α" in the mapping information of FIG. 3 is 1. In this embodiment, the mapping unit 31 outputs the reference vector corresponding to the data as vector U1. That is, in this example, since the data is "10", the mapping unit 31 of WD1-1 outputs {0, 0, 1, 0}, which is the third reference vector, as vector U1. The conversion unit 32 of WD1-1 performs a discrete Fourier transform on this vector U1 and outputs vector V1. Vector V1 is as follows.

[0032]

Number

[0033] The processing unit 33 of WD1-1 refers to the first processing information (FIG. 4(A)) stored in the storage unit 5 of WD1-1, and based on vector V1, at time t n outputs the vector W1(t n ) corresponding thereto. According to the processing information shown in FIG. 4(A), at time t1, the first element corresponds. In this case, the processing unit 33 of WD1-1 extracts only the first element among the four elements of vector V1, and outputs vector W1(t1) with the remaining elements set to 0. The same applies to vectors W1(t2) to W1(t4). Therefore, W1(t1) = {1, 0, 0, 0}, W1(t2) = {0, -1, 0, 0}, W1(t3) = {0, 0, 1, 0}, and W1(t4) = {0, 0, 0, -1}.

[0034] The conversion unit 34 of WD1-1 performs an inverse discrete Fourier transform on vector W1(t n ) and outputs the vector S(t n ) corresponding to time t n . Vectors S(t1) to S(t4) are shown below.

[0035]

Number

[0036] The wireless section 6 of WD1-1 converts the vectors S(t1) to S(t4) output by the conversion section 34 into wireless signals of the corresponding frequencies at the times indicated by the frequency information and transmits them to AP2 at times t1 to t4. In FIG. 4(A), the frequencies at times t1 to t4 are frequencies f1 to f4. Therefore, the wireless section 6 transmits a wireless signal corresponding to the numerical series indicated by the vector S(t1) at frequency f1 from time t1 to time t1 + 3 in accordance with the first processing information, and transmits a wireless signal corresponding to the numerical series indicated by the vector S(t2) at frequency f2 from time t2 to time t2 + 3, and transmits a wireless signal corresponding to the numerical series indicated by the vector S(t3) at frequency f3 from time t3 to time t3 + 3, and transmits a wireless signal corresponding to the numerical series indicated by the vector S(t4) at frequency f4 from time t4 to time t4 + 3. Note that the period for transmitting one complex value of the vector S is defined as "1". The wireless signal corresponding to the vector S can be obtained by associating the complex values indicated by the respective elements of the vector S with the constellation of quadrature amplitude modulation (QAM). FIG. 5 shows the signal transmitted by WD1-1. In this embodiment, the numerical series indicated by the vector S is transmitted in ascending order of the element numbers, but it can also be transmitted in descending order.

[0037] The wireless section 6 of AP2 receives the wireless signal corresponding to the vector S(t n ~t n +3) during the time from time t n in accordance with the first processing information shown in FIG. 4(A), and outputs the vector R(t n ) corresponding to time t n . The conversion section 44 of AP2 performs a discrete Fourier transform on the input vector R(t n ) and outputs the vector W2(t n ) corresponding to time t n . Assuming that there is no influence of interference, noise, etc. in the wireless section, R(t n ) = S(t n ). Also, the matrix B used by the conversion section 44 *is the inverse matrix of matrix B used by the conversion unit 34. Therefore, the vectors W2(t1) to W2(t4) output by the conversion unit 44 are the same as W1(t1) to W1(t4). That is, W2(t1) = {1, 0, 0, 0}, W2(t2) = {0, -1, 0, 0}, W2(t3) = {0, 0, 1, 0}, and W2(t4) = {0, 0, 0, -1}.

[0038] The processing unit 43 of AP2 outputs the vector V2 based on the vectors W2(t1) to W2(t4) according to the first processing information. Specifically, since the element corresponding to time t1 is the first element, the processing unit 43 of AP2 extracts the first element of the vector W2(t1) corresponding to time t1 and uses it as the first element of the vector V2. Similarly, since the elements corresponding to times t2, t3, and t4 are the "second element", "third element", and "fourth element", respectively, the processing unit 43 of AP2 extracts the second element of the vector W2(t2) corresponding to time t2, the third element of the vector W2(t3) corresponding to time t3, and the fourth element of the vector W2(t4) corresponding to time t4 and uses them as the second element, third element, and fourth element of the vector V2. Therefore, the processing unit 43 of AP2 outputs the same {1, -1, 1, -1} as the vector V1 as the vector V2.

[0039] The conversion unit 42 of AP2 performs an inverse discrete Fourier transform on the vector V2 and outputs the vector U2. Therefore, the vector U2 output by the conversion unit 42 is as follows.

[0040]

Number

[0041] The determination unit 41 of AP2 determines which reference vector was used on the transmission side based on the element position with the largest absolute value among the four elements of vector U2 and the mapping information shown in FIG. 3, and determines the data transmitted by WD1-1 based on the determined reference vector. Since the element with the largest absolute value among the four elements of vector U2 is the third element, the determination unit 41 of AP2 determines that the third reference vector was used on the transmission side based on the mapping information. Therefore, it can be determined that WD1-1 transmitted the data "10".

[0042] <Upward communication by WD1-2> Subsequently, the case where WD1-2 transmits the data "11" to AP2 will be described. Since the data is "11", the mapping unit 31 of WD1-2 outputs the fourth reference vector as vector U1. That is, the vector U1 output by the mapping unit 31 of WD1-2 is {0, 0, 0, 1}. The conversion unit 32 of WD1-2 performs a discrete Fourier transform on this vector U1 to output vector V1. Vector V1 is as follows.

[0043]

Number

[0044] According to the second processing information (FIG. 4(B)) that WD1-2 has, the fourth element corresponds to time t1. In this case, the processing unit 33 of WD1-2 extracts only the fourth element among the four elements of vector V1 and outputs a vector W1(t1) with the remaining elements set to 0. The same applies to vectors W1(t2), W1(t3), and W1(t4). Therefore, W1(t1) = {0, 0, 0, -j}, W1(t2) = {1, 0, 0, 0}, W1(t3) = {0, j, 0, 0}, and W1(t4) = {0, 0, -1, 0}.

[0045] The conversion unit 34 of WD1-2 performs an inverse discrete Fourier transform on vector W1(t n ) to obtain vector S(t n) is output. Vectors S(t1) to S(t4) are shown below.

[0046]

Number

[0047] Therefore, the signal transmitted by the wireless unit 6 of WD1-2 is as shown in FIG. 5.

[0048] The wireless unit 6 of AP2 receives the wireless signal corresponding to the vector S(t n ) and outputs the vector R(t n ). Assuming that there is no influence of interference, noise, etc. in the wireless section, R(t n ) = S(t n ). Therefore, the vectors W2(t1) to W2(t4) output by the conversion unit 44 are the same as W1(t1) to W1(t4). That is, W2(t1) = {0, 0, 0, -j}, W2(t2) = {1, 0, 0, 0}, W2(t3) = {0, j, 0, 0}, and W2(t4) = {0, 0, -1, 0}.

[0049] The processing unit 43 of AP2 outputs the vector V2 based on the vectors W2(t1) to W2(t4) according to the second processing information. Specifically, since the fourth element corresponds at time t1, the processing unit 43 of AP2 extracts the fourth element of the vector W2(t1) and uses it as the fourth element of the vector V2. Similarly, since the "first element", "second element", and "third element" correspond to times t2, t3, and t4, respectively, the processing unit 43 of AP2 extracts the first element of the vector W2(t2), the second element of the vector W2(t3), and the third element of the vector W2(t4) and uses them as the first element, second element, and third element of the vector V2. Therefore, the processing unit 43 outputs the same {1, j, -1, -j} as the vector V1 as the vector V2.

[0050] The conversion unit 42 of AP2 performs an inverse discrete Fourier transform on the vector V2 and outputs the vector U2. Therefore, the vector U2 output by the conversion unit 42 is as follows.

[0051]

Number

[0052] Since the absolute value of the fourth element among the four elements of the vector U2 is the largest, the determination unit 41 of AP2 determines that WD1-2 has transmitted the data "11" based on the mapping information.

[0053] <Upward communication by WD1-3 and WD1-4> The upward communication by WD1-3 and WD1-4 is the same as the upward communication by WD1-1 and WD1-2. For example, although the calculation formula is omitted, assuming that both WD1-3 and WD1-4 transmit the data "00", the signals transmitted by WD1-3 and WD1-4 to AP2 are as shown in FIG. 5. Note that the processing in AP2 is also the same as that described in the upward communication by WD1-1 and WD1-2, so it is omitted.

[0054] <Downward communication> Next, the downlink communication by AP2 will be described. Similar to the uplink communication, in the storage unit 5 of AP2, the processing information shown in FIGS. 4(A) to 4(D) is stored in association with WD1-1 to WD1-4 as transmission information. In the storage unit 5 of WD1-1, the processing information shown in FIG. 4(A) is stored as reception information. In the storage unit 5 of WD1-2, the processing information shown in FIG. 4(B) is stored as reception information. In the storage unit 5 of WD1-3, the processing information shown in FIG. 4(C) is stored as reception information. In the storage unit 5 of WD1-4, the processing information shown in FIG. 4(D) is stored as reception information. Also, similar to the uplink communication, it is assumed that data "10" is transmitted to WD1-1, data "11" is transmitted to WD1-2, data "00" is transmitted to WD1-3, and data "00" is transmitted to WD1-4. That is, the following description will be given by taking as an example the case where AP2 transmits the same data as the data transmitted by each WD1 to AP2 in the description of the uplink communication.

[0055] Furthermore, in the following description, the vectors U1, V1, and W1 generated in AP2 based on the data transmitted to WD1-1 are denoted as U 1-1 , V 1-1 , and W 1-1 . The vectors U1, V1, and W1 generated in AP2 based on the data transmitted to WD1-2 are denoted as U 1-2 , V 1-2 , and W 1-2 . The vectors U1, V1, and W1 generated in AP2 based on the data transmitted to WD1-3 are denoted as U 1-3 , V 1-3 , and W 1-3 . The vectors U1, V1, and W1 generated in AP2 based on the data transmitted to WD1-4 are denoted as U 1-4 , V 1-4 , and W 1-4 .

[0056] From the mapping information shown in FIG. 3, the vector U 1-1 = {0, 0, 1, 0}, the vector U 1-2 = {0, 0, 0, 1}, the vector U 1-3={1, 0, 0, 0}, and vector U 1-4 ={1, 0, 0, 0}. Vector U 1-1 = {0, 0, 1, 0} to vector V 1-1 The calculation formula for obtaining is as shown in Equation 1, and vector U 1-2 = {0, 0, 0, 1} to vector V 1-2 The calculation formula for obtaining is as shown in Equation 7. Vector U 1-3 = {1, 0, 0, 0} to vector V 1-3 The calculation formula for obtaining, and vector U 1-4 = {1, 0, 0, 0} to vector V 1-4 The calculation formula for obtaining is omitted, but vector V 1-1 ~V 1-4 will be as shown in Figure 6.

[0057] The processing unit 33 of AP2 processes vector V 1-1 based on the first processing information (Figure 4(A)) associated with WD1-1 to generate W 1-1 (t1)~W 1-1 (t4). W 1-1 (t n ) is a vector corresponding to the time t n based on the data to be transmitted to WD1-1. W 1-1 (t n ) is, as shown in Figure 6, the same as the vector W1(t n ) generated when WD1-1 transmits the data "10" in the upward direction. Similarly, the processing unit 33 of AP2 processes vector V 1-2 based on the second processing information (Figure 4(B)) associated with WD1-2 to generate W 1-2 (t1)~W 1-2 (t4). W 1-2 (t n ) is, as shown in Figure 6, the same as the vector W1(t n ) generated when WD1-2 transmits the data "11" in the upward direction.

[0058] Similarly, the processing unit 33 of AP2 processes vector V 1-3 based on the third processing information (Figure 4(C)) associated with WD1-3 to generate W 1-3(t n ) is generated. As is clear from the third processing information shown in FIG. 4(C) and the vector V shown in FIG. 6, the vector W 1-3 is as shown in FIG. 6. Note that the vector W 1-3 (t n ) is the same as the vector W1(t 1-3 ) generated when WD1-3 transmits the data "00" in the upward direction. Further, the processing unit 33 of AP2 processes the vector V n based on the fourth processing information (FIG. 4(D)) associated with WD1-4 to generate W n (t 1-4 ). As is clear from the fourth processing information shown in FIG. 4(D) and the vector V shown in FIG. 6, the vector W 1-4 (t n ) is as shown in FIG. 6. Note that the vector W 1-4 (t 1-4 ) is the same as the vector W1(t n ) generated when WD1-4 transmits the data "00" in the upward direction. 1-4 (t n ) is the same as the vector W1(t n ) generated when WD1-4 transmits the data "00" in the upward direction.

[0059] The processing unit 33 of AP2 further outputs the vector obtained by adding W 1-1 (t1) to W 1-4 (t1) as the vector W1(t1), outputs the vector obtained by adding W 1-1 (t2) to W 1-4 (t2) as the vector W1(t2), outputs the vector obtained by adding W 1-1 (t3) to W 1-4 (t3) as the vector W1(t3), and outputs the vector obtained by adding W 1-1 (t4) to W 1-4 (t4) as the vector W1(t4). FIG. 6 also shows W1(t1) to W1(t4).

[0060] The conversion unit 34 of AP2 performs an inverse discrete Fourier transform on the vector W1(t n ) to output the vector S(t n ). Vectors S(t1) to S(t4) are shown below.

[0061] [Number]

[0062] The vectors S(t1) to S(t4) transmitted by AP2 from each of the times t1 to t4 correspond to the signals transmitted by WD1-1 to WD1-4 from S(t1) to S(t4) as described in the uplink communication, that is, the signals shown in FIG. 5 added together.

[0063] Assuming that there is no influence of interference, noise, etc. in the wireless section, the vector R(t n ) = S(t n ) output by the wireless sections 6 of WD1-1 to WD1-4. Therefore, the vectors W2(t1) to W2(t4) output by the conversion sections 44 of each WD1 are the same as W1(t1) to W1(t4) shown in FIG. 6.

[0064] The processing section 43 of WD1-1 outputs a vector V2 based on the vectors W2(t1) to W2(t4) according to the first processing information shown in FIG. 4(A). Specifically, since the first element corresponds to the time t1 in the processing section 43 of WD1-1, the first element of the vector W2(t1) is taken out and used as the first element of the vector V2. Similarly, since the second element, the third element, and the fourth element correspond to the times t2, t3, and t4, respectively, the processing section 43 of WD1-1 takes out the second element of the vector W2(t2), the third element of the vector W2(t3), and the fourth element of the vector W2(t4) and uses them as the second element, the third element, and the fourth element of the vector V2. That is, the processing section 43 of WD1-1 outputs the same {1, -1, 1, -1} as the vector V 1-1 for the vector V2.

[0065] The conversion unit 42 of WD1-1 performs an inverse discrete Fourier transform on the vector V2 and outputs the vector U2. The vector U2 output by the conversion unit 42 of WD1-1 is as shown in Equation 6. Therefore, the determination unit 41 of WD1-1 determines that the third reference vector is used on the transmission side based on the mapping information, and thus can determine that AP2 has transmitted the data "10".

[0066] The processing unit 43 of WD1-2 outputs the vector V2 based on the vectors W2(t1) to W2(t4) according to the second processing information shown in FIG. 4(B). Specifically, since the fourth, first, second, and third elements correspond to the times t1, t2, t3, and t4 respectively in the processing unit 43 of WD1-2, the fourth element of the vector W2(t1), the first element of the vector W2(t2), the second element of the vector W2(t3), and the third element of the vector W2(t4) are taken out and used as the fourth, first, second, and third elements of the vector V2. That is, the processing unit 43 of WD1-2 outputs the same {1, j, -1, j} as the vector V 1-2 for the vector V2.

[0067] The conversion unit 42 of WD1-2 performs an inverse discrete Fourier transform on the vector V2 and outputs the vector U2. The vector U2 output by the conversion unit 42 of WD1-2 is as shown in Equation 12. Therefore, the determination unit 41 of WD1-2 determines that the fourth reference vector is used on the transmission side based on the mapping information, and thus can determine that AP2 has transmitted the data "11".

[0068] The processing unit 43 of WD1-3 outputs the vector V2 based on the vectors W2(t1) to W2(t4) according to the third processing information shown in FIG. 4(C). Although detailed description is omitted, the vector V2 output by the processing unit 43 of WD1-3 is the vector V 1-3It becomes the same {1, 1, 1, 1}. The conversion unit 42 of WD1-3 performs an inverse discrete Fourier transform on the vector V2 and outputs the vector U2. Although the calculation formula is omitted, the vector U2 output by the conversion unit 42 of WD1-3 becomes {4, 0, 0, 0}. Therefore, the determination unit 41 of WD1-3 determines that the first reference vector is used on the transmission side based on the mapping information, and thus can determine that AP2 has transmitted the data "00".

[0069] The processing unit 43 of WD1-4 outputs the vector V2 based on the vectors W2(t1) to W2(t4) according to the fourth processing information shown in FIG. 4(D). Although detailed description is omitted, the vector V2 output by the processing unit 43 of WD1-4 is the vector V 1-4 It becomes the same {1, 1, 1, 1}. The conversion unit 42 of WD1-4 performs an inverse discrete Fourier transform on the vector V2 and outputs the vector U2. Although the calculation formula is omitted, the vector U2 output by the conversion unit 42 of WD1-4 becomes {4, 0, 0, 0}. Therefore, the determination unit 41 of WD1-4 determines that the first reference vector is used on the transmission side based on the mapping information, and thus can determine that AP2 has transmitted the data "00".

[0070] <Summary when M = N> As shown in FIG. 5, the vector S(t1) transmitted by WD1-1 from time t1, the vector S(t2) transmitted from time t2, the vector S(t3) transmitted from time t3, and the vector S(t4) transmitted from time t4 are the first column, the second column, the third column, and the fourth column vectors of the IDFT matrix M IDFT correspond to those obtained by circularly shifting the vectors in the right direction (downward when regarded as an N-row 1-column matrix) by 2. The reason for corresponding to those circularly shifted by 2 in the right direction is that in the mapping information, the position of the value "α" in the third reference vector corresponding to the data "10" is the third element shifted 2 positions to the right from the first element. Also, the vectors S(t1), S(t2), S(t3), and S(t4) are the IDFT matrix M IDFTThe correspondence to the first column, second column, third column, and fourth column is due to the fact that in the first processing information used by WD1-1, the "first element", "second element", "third element", and "fourth element" correspond to times t1, t2, t3, and t4 respectively.

[0071] Similarly, as shown in FIG. 5, the vectors S(t1), S(t2), S(t3), and S(t4) transmitted by WD1-2 from times t1, t2, t3, and t4 respectively are the vectors of the fourth column, first column, second column, and third column of the IDFT matrix M IDFT shifted to the right (downward when regarded as an N-row 1-column matrix) by 3. The reason for the right shift by 3 corresponds to the fact that in the mapping information, the position of the value "α" in the fourth reference vector corresponding to the data "11" is the fourth element shifted 3 positions to the right from the first element. Also, the vectors S(t1), S(t2), S(t3), and S(t4) are IDFT corresponding to the fourth column, first column, second column, and third column of the IDFT matrix M because in the second processing information used by WD1-2, the "fourth element", "first element", "second element", and "third element" correspond to times t1, t2, t3, and t4 respectively.

[0072] Similarly, as shown in FIG. 5, the vectors S(t1), S(t2), S(t3), and S(t4) transmitted by WD1-3 from times t1, t2, t3, and t4 respectively are the vectors of the third column, fourth column, first column, and second column of the IDFT matrix M IDFT shifted to the right (downward when regarded as an N-row 1-column matrix) by 0. The reason for the right shift by 0 corresponds to the fact that in the mapping information, the position of the value "α" in the first reference vector corresponding to the data "00" is the first position, that is, the right shift amount is 0. Also, the vectors S(t1), S(t2), S(t3), and S(t4) are IDFTThe fact that it corresponds to the third column, fourth column, first column, and second column is because in the third processing information used by WD1-3, the "third element", "fourth element", "first element", and "second element" correspond to times t1, t2, t3, and t4 respectively. The same applies to the vectors S(t1), S(t2), S(t3), and S(t4) transmitted by WD1-4.

[0073] Here, in FIG. 5, WD1-1 to WD1-4 transmit the vector S(t1) at the same frequency f1 from time t1 to time t1 + 3, transmit the vector S(t2) at the same frequency f2 from time t2 to time t2 + 3, transmit the vector S(t3) at the same frequency f3 from time t3 to time t3 + 3, and transmit the vector S(t4) at the same frequency f4 from time t4 to time t4 + 3. Therefore, AP2 will receive a signal obtained by synthesizing the wireless signals from each of WD1-1 to WD1-4. This signal corresponds to the signal transmitted by AP2 in the description of the downlink direction. As described in the downlink communication, WD1-1 can determine the data value transmitted by AP2 to WD1-1 from the signal obtained by synthesizing the signals addressed to other WD1s by using the first processing information shown in FIG. 4(A). Similarly, WD1-2 can determine the data value transmitted by AP2 to WD1-2 from the signal obtained by synthesizing the signals addressed to other WD1s by using the second processing information shown in FIG. 4(B). The same applies to WD1-3 and WD1-4. Therefore, in the uplink communication, AP2 also receives a wireless signal obtained by synthesizing the signals from each of WD1-1 to WD1-4, and can correctly determine the data transmitted by each WD1 by using the processing information associated with each WD1.

[0074] In this way, AP2 can communicate with N WD1s in the uplink and downlink using the same time and frequency resources. In the above description, for the sake of simplicity, the processing information used by WD1 and AP2 in the uplink communication and the processing information used by WD1 and AP2 in the downlink communication are assumed to be the same. However, the processing information used by WD1 and AP2 in the uplink communication is different from the processing information used by WD1 and AP2 in the downlink communication. That is, the processing information used in the uplink communication and the processing information used in the downlink communication are configured such that a frequency division duplexing (FDD) configuration in which the frequencies used in the uplink communication and the frequencies used in the downlink communication are different, or a time division duplexing (TDD) configuration in which the time slots of the uplink communication and the time slots of the downlink communication are alternately provided.

[0075] In the above description, it is assumed that there is no influence of interference, noise, etc. in the radio section. Considering the influence of interference, noise, etc. in the radio section, the vectors R(t1)=S(t1), R(t2)=S(t2), R(t3)=S(t3), and R(t4)=S(t4) do not hold. In this case, the vector V2 and the vector U2 also deviate from the numerical values used in the above description. For example, in the case of uplink communication by WD1-1, the vector U2 shown in Equation 6 is {0,0,4,0}, but due to interference, noise, etc., the first, second, and fourth elements become values different from "0", and the third element may become a value different from "4".

[0076] Note that the amount of change of the values of the first, second, and fourth elements from "0", and the amount of change of the value of the third element from "4" increase as the interference and noise increase. However, as long as the absolute value of the third element is larger than the absolute values of the other elements, the receiving side can correctly determine the data transmitted by the transmitting side. For example, in the processing information of FIG. 4, the transmission start times of each vector S and the frequencies used for transmitting each vector S were made different. Therefore, the probability that all four vectors S are strongly affected by interference and noise is low. Thus, in vector U2, the probability that the absolute value of the element position corresponding to the data becomes smaller than the absolute values of the other element positions can be reduced, and the occurrence probability of bit errors can be reduced.

[0077] Note that in the processing information shown in FIG. 4, each vector S was transmitted at a different frequency, but it is also possible to adopt a configuration in which two or more vectors S are transmitted at the same frequency. For example, it is also possible to transmit all of the vectors S at the same frequency. However, the time information is set so that the transmission periods of two or more vectors S transmitted at the same frequency do not overlap. Conversely, the transmission periods of two or more vectors transmitted at different frequencies may overlap. In other words, the N vectors S are transmitted using different resources. Different resources mean that at least one of time and frequency is different.

[0078] As described above, by using N pieces of processing information including the same time information and frequency information, AP2 can communicate with N WD1s, but one WD1 can also use two or more pieces of the N pieces of processing information. In this case, the processing performed by the WD1 that uses two or more pieces of processing information is the same as the processing performed by AP2 described above. However, in the processing performed by AP2 described above, AP2 communicates with a plurality of WD1s using a plurality of pieces of processing information, while the WD1 that uses two or more pieces of processing information communicates with the same AP2 using two or more pieces of processing information.

[0079] Furthermore, one AP2 can also communicate with more than N WD1s. For example, a set of N WD1s that use N pieces of processing information with the same time information and frequency information is defined as a "cluster". Here, the nth (n is an integer from 1 to N) WD1 in the cluster is assumed to use the nth processing information. Then, more than N WD1s are classified into multiple clusters. For example, if two clusters, cluster #1 and cluster #2, are provided, AP2 can communicate with up to 2×N WD1s. Here, the time information and frequency information of the processing information used by the WD1s belonging to cluster #1 are the same, and the time information and frequency information of the processing information used by the WD1s belonging to cluster #2 are the same. However, at least one of the time information and frequency information included in the processing information used by the WD1s belonging to cluster #1 is made different from that included in the processing information used by the WD1s belonging to cluster #2. Specifically, the processing information used by the WD1s in cluster #1 and the processing information used by the WD1s in cluster #2 are set so that the WD1s in cluster #1 and the WD1s in cluster #2 do not transmit vector S from the same time using the same frequency.

[0080] As an example, the cluster can be configured as shown in FIG. 7. In FIG. 7, a total of G×H clusters from cluster #1-1 to cluster #G-H are configured. Here, G and H are each integers of 1 or more. The H clusters from cluster #g-1 to cluster #g-H use only frequency f g Here, g is an integer from 1 to G. Also, the G clusters from cluster #1-h to #G-h use the same time information #h. Here, h is an integer from 1 to H. The sets of N times (transmission and reception start timings) indicated by time information #1 to #H are all different. Note that different time information means that at least one of the N times indicated by the time information is different. The value of H is determined based on the amount of interference caused by signals transmitted at the same frequency by multiple WD1s belonging to different clusters. Note that the same WD1 can also belong to different clusters simultaneously using the processing information of each cluster.

[0081] Note that the processing information is pre-stored in the storage units 5 of AP2 and WD1 by any method. For example, the processing information can be stored in the storage unit 5 of WD1 when WD1 is sold or when WD1, which is an IoT device, is installed. Then, the operator who operates AP2 can be configured to store the processing information used in communication with the newly installed or sold WD1 in the storage unit 5 of the AP2 via a control interface (not shown). Alternatively, all the processing information that AP2 will use in the future can be pre-stored in the storage unit 5 of AP2, and when WD1 is installed or sold, the operator who operates AP2 can be configured to notify AP2 via the control interface of the processing information used in communication with the installed or sold WD1.

[0082] Also, in the case of a configuration where all the processing information that AP2 will use in the future is pre-stored in the storage unit 5 of AP2, WD1 can obtain the processing information used by WD1 from AP2. Specifically, WD1 and AP2 are configured to be able to communicate with each other via control signaling (not shown). Note that any existing communication method can be used for communication via control signaling. And WD1 in which the processing information is not stored in the storage unit 5 accesses AP2 via control signaling and requests the processing information when powered on. AP2 can select the processing information used by WD1 from the unused processing information and transmit the selected processing information to WD1 via control signaling.

[0083] [When M is greater than N] Hereinafter, the case where M is greater than N will be described. When M is greater than N, the processing unit 33 outputs an M-dimensional vector W1(t n ) based on the N-dimensional vector V1, and the processing unit 43 outputs an N-dimensional vector V2 based on the M-dimensional vector W2(t n ). In the following description, N = 4 and M = 8, and the 4-dimensional vectors W1(t n ) and W2(t n ) described in the case of N = M = 4 are denoted as vectors W1´(t n ) and W2´(t n) is denoted as

[0084] When M is greater than N, the conversion information is stored in the storage unit 5. FIG. 10(A) shows an example of the conversion information. The conversion information is information indicating a one-to-one correspondence between four elements of a 4D vector and four elements out of eight elements of an 8D vector. The processing unit 33 converts the 4D vector W1´(t n ) into an 8D vector W1(t n ) and outputs it to the conversion unit 34. Note that for the four elements not shown in the conversion information among the eight elements of the 8D vector W1(t n ), the processing unit 33 outputs their values as 0 to the conversion unit 34. Similarly, the processing unit 43 converts the 8D vector W2(t n ) into a 4D vector W2´(t n ), and generates a vector V2 based on the vector W2´(t n ) and outputs it to the conversion unit 42.

[0085] According to FIG. 10(A), it is shown that the first to fourth elements of the 4D vector W1´(t n ) correspond to the first to fourth elements of the 8D vector W1(t n ). As described in the communication in the upward direction, when WD1-1 transmits the data "10" to AP2, W1´(t1) = {1, 0, 0, 0}. Therefore, in the case of the conversion information in FIG. 10(A), the processing unit 33 of WD1-1 outputs W1(t1) = {1, 0, 0, 0, 0, 0, 0, 0} to the conversion unit 34.

[0086] Since the product of the matrix B used by the conversion unit 34 of WD1-1 and the matrix B * used by the conversion unit 44 of AP2 is the identity matrix, ignoring the influence in the radio interval, the vector W2(t n ) output by the conversion unit 44 of AP2 is equal to the vector W1(t n ). The processing unit 43 of AP2 extracts the first to fourth elements of the vector W2(t n ) based on the conversion information shown in FIG. 10(A), and the vector W2´(t nTake the first to fourth elements of (). That is, W2´(t1) = {1, 0, 0, 0}. The subsequent processing is the same as that described in the case of N = M = 4.

[0087] The same applies to the downward direction. For example, as described in the explanation of the downward direction in the case of N = M = 4, assume that AP2 transmits data "10" to WD1-1, data "11" to WD1-2, and data "00" to WD1-3 and WD1-4. In this case, as shown in FIG. 6, W1´(t1) = {1, 1, 1, -j}. When AP2 uses the conversion information in FIG. 10(A), the processing unit 33 of AP2 outputs W1(t1) = {1, 1, 1, -j, 0, 0, 0, 0} to the conversion unit 34.

[0088] Ignoring the influence in the wireless section, the vector W2(t n ) output by the conversion unit 44 of each WD1 is equal to the vector W1(t n ). The processing unit 43 of each WD1 extracts the first to fourth elements of the vector W2(t n ) based on the conversion information shown in FIG. 10(A) and makes them the first to fourth elements of the vector W2´(t n ). That is, W2´(t1) = {1, 1, 1, -j}. The subsequent processing is the same as that described in the case of N = M = 4.

[0089] FIG. 10(B) shows another example of the conversion information. According to FIG. 10(B), it is shown that the 1st, 2nd, 3rd, and 4th elements of the 4-dimensional vector W1´(t n ) correspond to the 1st, 3rd, 5th, and 7th elements of the 8-dimensional vector W1(t n ). Therefore, when W1´(t1) = {1, 1, 1, -j}, the processing unit 33 outputs W1(t1) = {1, 0, 1, 0, 1, 0, -j, 0} to the conversion unit 34.

[0090] When M = N, the maximum number of WD1s in one cluster was N. On the other hand, when M is greater than N and the value obtained by dividing M by N is 2 or more, the maximum number of WD1s in one cluster can be made greater than N. Specifically, if the value obtained by truncating the decimal part of the value of M divided by N is Z, the maximum number of WD1s in one cluster can be set to Z × N. In this example, since M = 8 and N = 4, Z is 2. Therefore, in this example, the maximum number of WD1s in one cluster can be set to 8.

[0091] In this case, one cluster will include two sub - clusters, sub - cluster #1 and sub - cluster #2. More generally speaking, one cluster includes Z sub - clusters from sub - cluster #1 to sub - cluster #Z. When M = N, since Z = 1, one cluster consists of only one sub - cluster, and the cluster and the sub - cluster are the same. Therefore, the cluster described when M = N is actually an explanation of a sub - cluster.

[0092] Both sub - cluster #1 and sub - cluster #2 can include a maximum of 4 WD1s. The 4 WD1s in sub - cluster #1 use one of the first processing information to the fourth processing information shown in FIG. 4. Note that the processing information used by the 4 WD1s in sub - cluster #1 is different from the processing information used by other WD1s in sub - cluster #1. The same applies to sub - cluster #2. However, the 4 WD1s in sub - cluster #1 use the conversion information shown in FIG. 10(B), and the 4 WD1s in sub - cluster #2 use the conversion information shown in FIG. 10(C).

[0093] The conversion information shown in FIG. 10(B) associates the 4 elements of the 4 - dimensional vector with the odd - numbered elements among the 8 elements of the 8 - dimensional vector. On the other hand, the conversion information shown in FIG. 10(C) associates the 4 elements of the 4 - dimensional vector with the even - numbered elements of the 8 - dimensional vector that are not used in the conversion information shown in FIG. 10(B).

[0094] The processing unit 33 of the WD1 belonging to sub - cluster #1 is the 4 - dimensional vector W1´(tn ) is converted into an 8 - dimensional vector W1(t n ) based on the conversion information in FIG. 10(B). The processing unit 33 of WD1 belonging to sub - cluster #2 converts a 4 - dimensional vector W1´(t n ) into an 8 - dimensional vector W1(t n ) based on the conversion information in FIG. 10(C). The processing unit 42 of AP2 uses the conversion information in FIG. 10(B) to receive data from WD1 belonging to sub - cluster #1 and converts an 8 - dimensional vector W2(t n ) into a 4 - dimensional vector W2´(t n ). Also, the processing unit 42 of AP2 uses the conversion information in FIG. 10(C) to receive data from WD1 belonging to sub - cluster #2 and converts an 8 - dimensional vector W2(t n ) into a 4 - dimensional vector W2´(t n ).

[0095] Further, the processing unit 33 of AP2 converts a 4 - dimensional vector W1´(t n ) generated based on data to be transmitted to one or more WD1 belonging to sub - cluster #1 into an 8 - dimensional vector W 11 (t n ) based on the conversion information in FIG. 10(B). Also, the processing unit 33 of AP2 converts a 4 - dimensional vector W1´(t n ) generated based on data to be transmitted to one or more WD1 belonging to sub - cluster #2 into an 8 - dimensional vector W 12 (t n ) based on the conversion information in FIG. 10(C). Then, the processing unit 33 of AP2 outputs a vector obtained by adding the 8 - dimensional vector W 11 (t n ) and the 8 - dimensional vector W 12 (t n ) as an 8 - dimensional vector W1(t n ) to the conversion unit 34.

[0096] For example, assume that the processing unit 33 of AP2 generates W1´(t1) = {1, 1, 1, -j} based on the data to be transmitted to the four WD1s in sub-cluster #1, and generates W1´(t1) = {1, 1, 1, 1} based on the data to be transmitted to the four WD1s in sub-cluster #2. In this case, the vector W 11 (t1) = {1, 0, 1, 0, 1, 0, -j, 0}, and the vector W 12 (t1) = {0, 1, 0, 1, 0, 1, 0, 1}. Therefore, the vector W1(t1) = {1, 1, 1, 1, 1, 1, -j, 1}.

[0097] Ignoring the noise in the wireless section etc., the vector W1(t1) = the vector W2(t1). The processing unit 43 of the WD1 belonging to sub-cluster #1 generates a vector W2´(t1) = {1, 1, 1, -j} whose first, third, fifth, and seventh elements of the vector W2(t1) are the first, second, third, and fourth elements based on the conversion information shown in Fig. 10(B). Also, the processing unit 43 of the WD1 belonging to sub-cluster #2 generates a vector W2´(t1) = {1, 1, 1, 1} whose second, fourth, sixth, and eighth elements of the vector W2(t1) are the first, second, third, and fourth elements based on the conversion information shown in Fig. 10(C). The subsequent processing is as already described, and the signals of sub-cluster #1 and sub-cluster #2 do not interfere with each other.

[0098] Note that although the description has been given assuming that the processing unit 33 generates an N-dimensional vector W1´(t n ) from an N-dimensional vector V1 based on the element information, and then converts the N-dimensional vector W1´(t n ) to an M-dimensional vector W1(t n ) based on the conversion information, by using the element information considering the conversion information, the processing unit 33 can generate an M-dimensional vector W1(t n ) from the N-dimensional vector V1. Similarly, the processing unit 43 can generate an N-dimensional vector V1 from the M-dimensional vector W2(t n ) by using the element information considering the conversion information.

[0099] FIG. 11 shows the corrected element information obtained by correcting the element information of the first to fourth processing information shown in FIG. 4 in consideration of the conversion information shown in FIG. 10(B). According to FIG. 11, the element information indicates a one-to-one correspondence between N time points indicated by the time information and N elements of the N-dimensional vector, and a one-to-one correspondence between N time points indicated by the time information and N elements out of M elements of the M-dimensional vector. In this example, since M = 8 and N = 4, the "4" in the element information of FIG. 11 indicates an element of a 4-dimensional vector, and the "8" indicates an element of an 8-dimensional vector. The element information is also information indicating a one-to-one correspondence between the elements of the N-dimensional vector and the elements of the M-dimensional vector. The correspondence between the elements of the N-dimensional vector and the elements of the M-dimensional vector corresponding to the same time point indicated by the time information is the same as the correspondence indicated by the conversion information shown in FIG. 10(B).

[0100] FIG. 12 shows the corrected element information obtained by correcting the element information of the first to fourth processing information shown in FIG. 4 in consideration of the conversion information shown in FIG. 10(C). The difference from the element information shown in FIG. 11 is only the correspondence between the elements of the N-dimensional vector and the elements of the M-dimensional vector. The N elements of the M-dimensional vector indicated by the element information shown in FIG. 12 are all different from the N elements of the M-dimensional vector indicated by the element information shown in FIG. 11.

[0101] The time information and frequency information of the total eight pieces of processing information shown in FIGS. 11 and 12 are the same. On the other hand, the eight pieces of element information of each of the total eight pieces of processing information shown in FIGS. 11 and 12 are different. More specifically, the elements of the 4-dimensional vector corresponding to each of the N time points indicated by the element information in FIGS. 11(A) and 12(A) are the same, but the elements of the 8-dimensional vector corresponding to each of the N time points are different. The same applies to the element information in FIGS. 11(B) and 12(B), the element information in FIGS. 11(C) and 12(C), and the element information in FIGS. 11(D) and 12(D).

[0102] In FIGS. 11 and 12, the k-th processing information is a name based on the elements of an N-dimensional vector corresponding to each of N times. That is, when x = {(N + n - k) mod N} + 1, the processing information having the element information indicating the x-th element of the N-dimensional vector as the element corresponding to the n-th time is defined as the k-th processing information. As shown in FIGS. 11 and 12, each sub-cluster has the 1st to N-th processing information, but the N elements of the M-dimensional vectors corresponding to each of the N times indicated by the element information are different for each sub-cluster.

[0103] For example, when the 1st processing information in FIG. 11(A) is used for WD1-1 of sub-cluster #1, in the downward direction, the processing unit 33 of AP2 outputs a vector W 1-1 (t1) in which the first element is the first element of vector V1 and the rest are 0, and outputs a vector W 1-1 (t2) in which the third element is the second element of vector V1 and the rest are 0, and outputs a vector W 1-1 (t3) in which the fifth element is the third element of vector V1 and the rest are 0, and outputs a vector W 1-1 (t4) in which the seventh element is the first element of vector V1 and the rest are 0.

[0104] Also, when the 1st processing information in FIG. 12(A) is used for WD1-1 of sub-cluster #2, in the downward direction, the processing unit 33 of AP2 outputs a vector W 1-1 (t1) in which the second element is the first element of vector V1 and the rest are 0, and outputs a vector W 1-1 (t2) in which the fourth element is the second element of vector V1 and the rest are 0, and outputs a vector W 1-1 (t3) in which the sixth element is the third element of vector V1 and the rest are 0, and outputs a vector W 1-1 (t4) in which the eighth element is the first element of vector V1 and the rest are 0.

[0105] Then, the processing unit 33 of AP2 generates a total of eight vectors W for WD1-1 to WD1-4 of sub-cluster #1 and WD1-1 to WD1-4 of sub-cluster #2 1-n (t n ) and adds them to generate a vector W1(t n ) and outputs it to the conversion unit 34.

[0106] The processing unit 43 of WD1-1 in sub-cluster #1 that uses the first processing information in Fig. 11(A) outputs a vector V2 with the first element of vector W2(t1) as the first element, the third element of vector W2(t2) as the second element, the fifth element of vector W2(t3) as the third element, and the seventh element of vector W2(t4) as the fourth element. Also, the processing unit 43 of WD1-1 in sub-cluster #2 that uses the first processing information in Fig. 12(A) outputs a vector V2 with the second element of vector W2(t1) as the first element, the fourth element of vector W2(t2) as the second element, the sixth element of vector W2(t3) as the third element, and the eighth element of vector W2(t4) as the fourth element. Although only the downward direction has been described, a person skilled in the art can understand the upward direction processing based on the above description, so the description thereof is omitted.

[0107] Note that the element information shown in Fig. 4 was such that the n-th element of vector V1 was the same as the n-th element in vector W1. However, as is clear from the above description, the n-th element of vector V1 can also be an element different from the n-th element of vector W1. Also, in the above specific example, the conversion units 32 and 44 use the discrete Fourier transform (DFT) matrix M DFT and the conversion units 34 and 42 use the inverse discrete Fourier transform (IDFT) matrix M IDFT . However, the inverse matrix A of the regular matrix A used by the conversion unit 32 on the transmission side is used by the conversion unit 42 on the reception side, and the inverse matrix B of the regular matrix B used by the conversion unit 34 on the transmission side is ―1 used by the conversion unit 42 on the reception side, and the inverse matrix B of the regular matrix B used by the conversion unit 34 on the transmission side is ―1As long as the receiving-side conversion unit 44 uses them, the matrix A and the matrix B are independent, and any type of regular matrix can be used as the matrix A and the matrix B.

[0108] As described above, according to this embodiment, the number of wireless devices that can be accommodated in the AP can be increased.

[0109] <Second Embodiment> Subsequently, regarding the second embodiment, the differences from the first embodiment will be mainly described. In the first embodiment, the data was mapped to one of the N reference vectors, and the mapped reference vector was taken as the vector U1. Therefore, the number of bits P carried by the vector U1 was equal to or less than log2N. In this embodiment, the number of bits carried by the vector U1 is made more than log2N bits.

[0110] FIG. 8 shows an example of the mapping information when N = 4. In FIG. 8, the correspondence between the combinations of the second and third bits among the 3-bit data and one reference vector is the same as the mapping information of the first embodiment shown in FIG. 3. In this embodiment, the value of the first bit among the 3-bit data is associated with a "multiplier". The mapping unit 31 generates the vector U1 by multiplying the reference vector determined based on the combination of the second and third bits by the multiplier determined based on the value of the first bit. In FIG. 8, as an example, when the first bit is "0", the multiplier is "1", and when the first bit is "1", the multiplier is "2".

[0111] For example, when α = 1 as in the first embodiment and WD1-1 transmits the data "010", since the multiplier is 1, the vector U2 at AP2 is {0, 0, 4, 0}, which is the same as in Equation 6. On the other hand, when WD1-1 transmits the data "110", since the multiplier is 2, the vector U2 at AP2 is {0, 0, 8, 0}. The determination unit 41 of AP2 determines the reference vector based on the position of the element with the largest absolute value among the elements of the vector U2, and determines the multiplier based on the actual value of the element with the largest absolute value. Then, the determination unit 41 determines the first bit among the 3-bit data based on the determined multiplier, and determines the second and third bits among the 3-bit data based on the determined reference vector.

[0112] Note that the multiplier may be a negative value as long as it is a non-zero value, and may even be a complex value. For example, in FIG. 8, the multiplier when the first bit is 1 was set to 2, but the multiplier when the first bit is 1 can also be set to -1. In this case, the vector U2 corresponding to the data "110" is {0, 0, -4, 0}. Therefore, the determination unit 41 can determine whether the multiplier is 1 or -1. Also, in FIG. 8, the multiplier was determined based on one bit, but a configuration can be adopted in which the multiplier is determined based on a plurality of bits. For example, based on the combination of the values of 2 bits, "1 + j", "-1 + j", "-1 - j", "1 - j" can be used as the multiplier.

[0113] To summarize, in the first embodiment, the reference vector was determined based on P-bit (P is an integer of 1 or more) data, and the reference vector was directly used as the vector U1, so that P-bit data was transmitted in one communication. Note that P is an integer less than or equal to log2N. On the other hand, in this embodiment, (P + Q)-bit (Q is an integer of 1 or more) data is transmitted in one communication. The mapping unit 31 determines the reference vector based on the P-bit data among the (P + Q)-bit data. Also, the mapping unit 31 determines the non-zero multiplier β based on the Q-bit data among the (P + Q)-bit data. Note that the number of multipliers β is 2 QThat is, the mapping unit 31 generates a vector U1 by multiplying a reference vector determined based on the P bits by a multiplier β determined based on the Q bits. Therefore, the number of possible values of the non-zero elements of the vector U1 is 2 Q That is, among the first to (P + Q) bits constituting the (P + Q) bits, how to select the Q bits used to determine the multiplier and the P bits used to determine the reference vector is arbitrary and is not limited to the configuration in which the multiplier is determined by the first Q bits.

[0114] On the other hand, the determination unit 41 determines the P-bit data based on the element position of the vector U2 having the largest absolute value. Further, the determination unit 41 determines the multiplier based on the actual value of the element position of the vector U2 having the largest absolute value, and determines the Q-bit data based on the determined multiplier. With this configuration, the amount of data transmitted in one communication can be made larger than that in the first embodiment.

[0115] <Third Embodiment> Subsequently, the third embodiment will be described focusing on the differences from the above embodiments. In the first and second embodiments, the reference vector is α in which only one of the N elements is different from 0, and the remaining (N - 1) elements are 0. In this embodiment, a reference vector is used in which the values of γ (γ is an integer from 2 to (N - 1)) of the N elements are α different from 0, and the values of the remaining elements are 0.

[0116] Figure 9 shows an example of mapping information when γ = 2. For example, similar to the first embodiment, assuming α = 1 and vector U1 is the same as the reference vector, when WD1-1 transmits data "10", vector U1 becomes {0, 0, 1, 1}. As is clear from the description in the first embodiment, assuming there is no noise or interference in the wireless section, vector U2 generated by AP2 becomes {0, 0, 4, 4}. The determination unit 41 of AP2 can determine that WD1-1 has transmitted data "10" because the top two elements in terms of the magnitude of the absolute value are the third and fourth elements. That is, in the first embodiment, data is mapped to one non-zero element of the reference vector, but in this embodiment, data is mapped to a combination of γ non-zero elements out of N elements of the reference vector.

[0117] When N = 4, if γ = 2, the maximum number of reference vectors is 4C2 = 6, and if γ = 3, the maximum number of reference vectors is 4C3 = 4. Therefore, the number of bits that can be mapped to one reference vector is 2 or less as in the first embodiment. However, when N is greater than 4, the number of bits that can be mapped to one reference vector can be made larger than log2N. As an example, when N = 6, if γ = 3, the maximum number of reference vectors can be 6C3 = 20. Therefore, in the case of the first embodiment, even when N = 6, the number of bits that can be mapped to one reference vector is 2, but in this embodiment, by setting γ = 3, the number of bits that can be mapped to one reference vector can be made 4.

[0118] Thus, in this embodiment, the reference vector is a vector in which γ of the N elements are α and the remaining (N - γ) elements are 0. The mapping unit 31 determines the reference vector based on P-bit data and outputs the reference vector as vector U1. Therefore, the combination of the positions of the elements in vector U1 whose values are different from 0 indicates P-bit data. Here, the value of P is log2( N C γ)It is as follows. And the determination unit 41 determines P-bit data based on combinations of positions of γ elements in descending order of absolute value in vector U2.

[0119] Note that this embodiment can also be combined with the second embodiment. In this case, the mapping unit 31 determines a reference vector based on P-bit data among (P + Q)-bit data, and determines a non-zero multiplier β based on Q-bit data. Note that the number of multipliers β is 2 Q It is. And the mapping unit 31 generates vector U1 by multiplying the reference vector determined based on P bits by the multiplier β determined based on Q bits. Therefore, the combination of positions of elements in vector U1 that are different from 0 indicates P-bit data, and the values of elements in vector U1 that are different from 0 indicate Q-bit data. Here, the value of P is log2( N C γ )It is as follows. And the determination unit 41 determines P-bit data based on combinations of positions of γ elements in descending order of absolute value in vector U2, determines a multiplier based on the values of γ elements in descending order of absolute value in vector U2, and determines Q-bit data based on the determined multiplier. Note that for the determination of the multiplier, a value obtained by a predetermined operation based on the actual values of γ elements, such as the average value of the values of the upper γ elements in absolute value, can be used. Thereby, more bits than log2N can be transmitted using an N-dimensional vector.

[0120] <Others> In each of the above embodiments, a configuration may be adopted in which a cyclic prefix (CP) is added to the vector S transmitted by WD1 or AP2, that is, a configuration in which the CP based on the vector S is transmitted immediately before or after the vector S. As an example, the CP is the last C numerical sequences (C is an integer not exceeding N) of the M numerical sequences of the vector S. In this case, the CP is added immediately before the vector S. In other words, WD1 and AP2 generate and transmit the vector S with CP by adding the CP immediately before the vector S. For example, if the vector S is {-1, -j, 1, j} and C = 2, the vector S with CP is {1, j, -1, -j, 1, j}. As another example, the CP is the first C numerical sequences of the M numerical sequences of the vector S. In this case, WD1 transmits the CP immediately after the vector S. In other words, WD1 and AP2 generate and transmit the vector S with CP by adding the CP immediately after the vector S. For example, if the vector S is {-1, -j, 1, j} and C = 2, the vector S with CP is {-1, -j, 1, j, -1, -j}. By adding the CP, information can be demodulated accurately even in a multipath environment.

[0121] Furthermore, in each of the above embodiments, it is assumed that WD1 and AP2 communicate wirelessly. However, the present invention is applicable not only to communication using radio signals in the radio frequency band but also to communication using, for example, sound waves or light. Furthermore, the communication methods and communication systems described in each of the above embodiments are provided.

[0122] Furthermore, there is provided a computer program that causes a device having one or more processors to function as the WD1 or AP2 described in each of the above embodiments. The computer program is stored in one or more memory devices of the device, and when executed by one or more processors of the device, includes program instructions that cause the device to function as the WD1 or AP2 described in each of the above embodiments. Further, there is provided a computer program that causes a device having one or more processors to execute the communication method performed by the WD1 or AP2 described in each of the above embodiments. Further, there is provided a non-transitory computer-readable storage medium storing these computer programs.

[0123] The invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the gist of the invention.

Description of Reference Numerals

[0124] 31: Mapping unit, 32, 33, 43, 44: Conversion units, 33, 43: Processing units, 5: Storage unit, 6: Wireless unit

Claims

1. A communication device, storage means for storing processing information including time information indicating N time instants from a first time instant to an Nth time instant, frequency information indicating the frequency at each of the N time instants indicated by the time information, a one-to-one correspondence between the N time instants indicated by the time information and N elements of an N-dimensional vector, and element information indicating a one-to-one correspondence between the N time instants indicated by the time information and N elements out of M elements of an M-dimensional vector, where N is an integer of 2 or more, and M is an integer of N or more, said storage means; mapping means for mapping transmission data to a first vector of N dimensions; first conversion means for converting the first vector into a second vector of N dimensions by multiplying the first vector and a first regular matrix of size N; processing means for performing a process of generating, based on the second vector, a third vector of M dimensions corresponding to each of the N time instants according to the element information, wherein, for an element corresponding to the nth time instant (n is an integer from 1 to N) among the M elements of the third vector corresponding to the nth time instant, the value of the corresponding element indicated as corresponding to the nth time instant in the element information is the same as the value of the element indicated as corresponding to the nth time instant in the N elements of the second vector, and the values of elements different from the corresponding element of the third vector corresponding to the nth time instant are 0, said processing means; second conversion means for converting the third vector corresponding to the nth time instant into a fourth vector of M dimensions corresponding to the nth time instant by multiplying the third vector corresponding to the nth time instant and a second regular matrix of size M; transmission means for transmitting, as signals of the frequency at the nth time instant indicated by the frequency information, M numerical sequences indicated by the fourth vector corresponding to the nth time instant from the nth time instant; A communication device comprising the above.

2. The communication device according to claim 1, wherein the time information and the frequency information are set such that the transmission periods of a plurality of fourth vectors transmitted at the same frequency among the fourth vectors transmitted from the nth time instant do not overlap.

3. The communication device according to claim 1, wherein the first vector is a vector in which the values of γ (γ is an integer of 1 or more and (N−1) or less) elements out of the N elements are different from 0 and the values of (N−γ) elements are 0.

4. The value of γ is 1, and the transmission data is data of P bits. The positions of the non-zero elements of the first vector indicate the P-bit data. The value of P is log ２ The communication device according to claim 3, wherein it is N or less.

5. The value of γ is 1. The transmission data is (P + Q)-bit data. The positions of the non-zero elements of the first vector indicate the P-bit data within the (P + Q) bits. The values of the non-zero elements of the first vector indicate the Q-bit data within the (P + Q) bits. The value of P is log ２ The communication device according to claim 3, wherein it is N or less.

6. The value of γ is 2 or more. The transmission data is P-bit data. The combination of the positions of the non-zero elements of the first vector indicates the P-bit data. The value of P is log ２ ( Ｎ C γ ) or less, the communication device according to claim 3.

7. The value of γ is 2 or more. The transmission data is (P + Q)-bit data. The combination of the positions of the non-zero elements of the first vector indicates the P-bit data within the (P + Q) bits. The values of the non-zero elements of the first vector indicate the Q-bit data within the (P + Q) bits. The value of P is log ２ ( Ｎ C γ ) and is as follows. The communication device according to claim 3.

8. The transmission means transmits a cyclic prefix based on the M numerical sequences indicated by the fourth vector immediately before or after the M numerical sequences. The communication device according to claim 1.

9. The storage means stores a plurality of pieces of processing information in which at least one of the time information and the frequency information is different. Among the plurality of pieces of processing information, the first processing information is used for transmitting the first transmission data. Among the plurality of pieces of processing information, the second processing information is used for transmitting the second transmission data. The communication device according to claim 1.

10. The storage means stores a plurality of pieces of processing information in which the time information and the frequency information are the same but the element information is different. Among the plurality of pieces of processing information, the first processing information is used for transmitting the first transmission data. Among the plurality of pieces of processing information, the second processing information is used for transmitting the second transmission data. The communication device according to claim 1.

11. The N elements of the M-dimensional vector indicated by the first processing information and the N elements of the M-dimensional vector indicated by the second processing information are the same. The communication device according to claim 10.

12. The N elements of the M-dimensional vector indicated by the first processing information do not include the N elements of the M-dimensional vector indicated by the second processing information. The communication device according to claim 10.

13. When transmitting the first transmission data and the second transmission data. The mapping means generates the first vector based on the first transmission data and the first vector based on the second transmission data. The first conversion means converts the first vector based on the first transmission data into the second vector based on the first transmission data, and converts the first vector based on the second transmission data into the second vector based on the second transmission data. The processing means generates the third vector corresponding to the n-th time based on the first transmission data from the second vector based on the first transmission data according to the element information included in the first processing information, and generates the third vector corresponding to the n-th time based on the second transmission data from the second vector based on the second transmission data according to the element information included in the second processing information. The second conversion means multiplies the fifth vector corresponding to the n-th time, which is obtained by adding the third vector corresponding to the n-th time based on the first transmission data and the third vector corresponding to the n-th time based on the second transmission data, and the second regular matrix, to convert the fifth vector corresponding to the n-th time into the fourth vector corresponding to the n-th time. The communication device according to claim 10.

14. The communication device according to claim 13, wherein the devices to which the first transmission data and the second transmission data are transmitted are different.

15. The communication device according to claim 13, wherein the devices to which the first transmission data and the second transmission data are transmitted are the same.

16. A communication device, a storage means for storing processing information including time information indicating N times from the first time to the N-th time, frequency information indicating the frequencies at the N times indicated by the time information, a one-to-one correspondence between the N times indicated by the time information and the N elements of the N-dimensional vector, and a one-to-one correspondence between the N times indicated by the time information and N elements of the M elements of the M-dimensional vector, where N is an integer of 2 or more, and M is an integer of N or more, the storage means; a receiving means for receiving a signal having a frequency at the n-th time indicated by the frequency information from the n-th time (n is an integer from 1 to N) indicated by the time information and outputting an M-dimensional fourth vector corresponding to the n-th time including M numerical sequences. First conversion means for converting the fourth vector corresponding to the n-th moment into an M-dimensional third vector corresponding to the n-th moment by multiplying the fourth vector corresponding to the n-th moment by a first regular matrix of size M; Processing means for performing a process of generating an N-dimensional second vector from the third vectors corresponding to each of the N moments according to the element information, wherein the value of the element indicated as corresponding to the n-th moment among the N elements of the second vector is the same as the value of the element indicated as corresponding to the n-th moment among the M elements of the third vector corresponding to the n-th moment in the element information; the processing means; Second conversion means for converting the second vector into a first vector by multiplying the second vector by a second regular matrix of size N; Determination means for determining received data based on the first vector; A communication device comprising the above.

17. The communication device according to claim 16, wherein the time information and the frequency information are set such that the reception periods of signals received at the same frequency from each of the first time to the N-th time do not overlap.

18. The received data is P-bit data, The determination means determines the received data based on the position of the element having the largest absolute value among the N elements of the first vector. The value of P is log ２ The communication device according to claim 16, wherein it is N or less.

19. The received data is (P + Q)-bit data, The determination means determines the P-bit data among the (P + Q) bits based on the position of the element having the largest absolute value among the N elements of the first vector, and determines the Q-bit data among the (P + Q) bits based on the value of the element having the largest absolute value. The value of P is log ２ The communication device according to claim 16, wherein it is N or less.

20. The received data is P-bit data, The determination means determines the P-bit data based on the combination of the positions of the top γ elements in descending order of the absolute values of the N elements of the first vector, The value of γ is 2 or more. The value of P is log ２ ( Ｎ C γ ) and is as follows. The communication device according to claim 16

21. The received data is (P + Q)-bit data, The determination means determines the P-bit data among the (P + Q) bits based on the combination of the positions of the top γ elements in descending order of the absolute values of the N elements of the first vector, and determines the Q-bit data among the (P + Q) bits based on the values of the top γ elements. The value of γ is 2 or more. The value of P is log ２ ( Ｎ C γ ) and below. The communication device according to claim 16.

22. The storage means stores a plurality of pieces of processing information in which at least one of the time information and the frequency information is different. Among the plurality of pieces of processing information, the first processing information is used for receiving the first received data. The communication device according to claim 16, wherein among the plurality of pieces of processing information, the second processing information is used for receiving the second received data.

23. The storage means stores a plurality of pieces of processing information in which the time information and the frequency information are the same but the element information is different. Among the plurality of pieces of processing information, the first processing information is used for receiving the first received data. The communication device according to claim 16, wherein among the plurality of pieces of processing information, the second processing information is used for receiving the second received data.

24. When receiving the first received data and the second received data, the processing means generates the second vector corresponding to the first received data from the third vectors corresponding to the N times according to the element information included in the first processing information, and generates the second vector corresponding to the second received data from the third vectors corresponding to the N times according to the element information included in the second processing information. The second conversion means uses the second regular matrix to convert the second vector corresponding to the first received data into the first vector corresponding to the first received data, and converts the second vector corresponding to the second received data into the first vector corresponding to the second received data. The determination means determines the first received data based on the first vector corresponding to the first received data, and determines the second received data based on the second vector corresponding to the second received data. The communication device according to claim 23.

25. The communication device according to claim 24, wherein the devices that are the transmission sources of the first received data and the second received data are different.

26. The communication device according to claim 24, wherein the devices that are the transmission sources of the first received data and the second received data are the same.

27. A computer program that, when executed by the one or more processors of a device having one or more processors, causes the device to function as the communication device according to any one of claims 1 to 26.

28. A communication method by a communication device having processing information including time information indicating N time instants from a first time instant to an N-th time instant, frequency information indicating frequencies at each of the N time instants indicated by the time information, a one-to-one correspondence between the N time instants indicated by the time information and N elements of an N-dimensional vector, and element information indicating a one-to-one correspondence between the N time instants indicated by the time information and N elements out of M elements of an M-dimensional vector, where N is an integer of 2 or more, and M is an integer of N or more, and the communication method includes: mapping transmission data to a first vector of N dimensions; converting the first vector into a second vector of N dimensions by multiplying the first vector by a first regular matrix of size N; generating, based on the second vector, a third vector of M dimensions corresponding to each of the N time instants according to the element information, wherein, for the corresponding element whose value is indicated to correspond to the n-th time instant (n is an integer from 1 to N) among the M elements of the third vector corresponding to the n-th time instant, the value of the corresponding element is the same as the value of the element indicated to correspond to the n-th time instant among the N elements of the second vector, and the values of the elements different from the corresponding element of the third vector corresponding to the n-th time instant are 0; converting the third vector corresponding to the n-th time instant into a fourth vector of M dimensions corresponding to the n-th time instant by multiplying the third vector corresponding to the n-th time instant by a second regular matrix of size M; transmitting, from the n-th time instant, M numerical sequences indicated by the fourth vector corresponding to the n-th time instant as a signal of the frequency at the n-th time instant indicated by the frequency information; A communication method comprising the above steps.

29. A communication method by a communication device having processing information including time information indicating N time instants from a first time instant to an N-th time instant, frequency information indicating frequencies at each of the N time instants indicated by the time information, a one-to-one correspondence between the N time instants indicated by the time information and N elements of an N-dimensional vector, and element information indicating a one-to-one correspondence between the N time instants indicated by the time information and N elements out of M elements of an M-dimensional vector, where N is an integer of 2 or more, and M is an integer of N or more, and the communication method includes: Receiving a signal of the frequency at the n-th time indicated by the frequency information from the n-th time (n is an integer from 1 to N) indicated by the time information, and outputting a 4th vector of M dimensions corresponding to the n-th time including M numerical sequences; Converting the 4th vector corresponding to the n-th time into a 3rd vector of M dimensions corresponding to the n-th time by multiplying the 4th vector corresponding to the n-th time by a 1st regular matrix of size M; Generating a 2nd vector of N dimensions from the 3rd vectors corresponding to the N times according to the element information, wherein the value of the element indicated as corresponding to the n-th time in the element information among the N elements of the 2nd vector is the same as the value of the element indicated as corresponding to the n-th time in the element information among the M elements of the 3rd vector corresponding to the n-th time; Converting the 2nd vector into a 1st vector by multiplying the 2nd vector by a 2nd regular matrix of size N; Determining received data based on the 1st vector; A communication method including the above.

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