Communication apparatus, communication system, communication method, and computer-readable storage medium

Abstract

A communication apparatus includes: a storage unit configured to store information indicating a first basic sequence group including first to Nth basic sequences; a displacement unit that determines a displacement amount from the transmission data, and generates an nth displacement sequence by cyclically displacing an nth basic sequence by the displacement amount, n being an integer from 1 to N, thereby generating first to Nth displacement sequences; a holding unit for holding timing information indicating the transmission timing of the sequence; the sending unit is used for sending each displacement sequence according to the timing information, the first basic sequence to the Nth basic sequence meet a first condition, that is, when the displacement is 0, the sum of correlation values of autocorrelation of the first basic sequence to the Nth basic sequence is not 0, and when the displacement for sending data is not 0, the sum of correlation values of autocorrelation of the first basic sequence to the Nth basic sequence is not 0. The sum of correlation values of autocorrelation of the first basic sequence to the Nth basic sequence is 0.

Description

Technical Field

[0001] The present invention relates to communication technology. Background Art

[0002] For example, IoT (Internet of Things) devices used in smart meters and the like are located in different geographical locations, and one access point (AP) communicates with a plurality of IoT devices. Non-patent document 1 discloses a communication technology called LoRa used in IoT devices and the like.

[0003] Prior Art Literature

[0004] Non-patent literature 1: SEMTECH, “AN1200.22 LoRaTM Modulation Basics,” May 2015 Summary of the invention

[0005] Problem that the invention aims to solve

[0006] In the communication technology disclosed in non-patent document 1, when the number of IoT devices communicating with an AP increases, the number of data packets that the AP can normally receive is limited due to interference, etc. For example, if an AP communicates with 500 IoT devices and one IoT device sends 1,500 data packets per hour, the number of data packets that the AP can successfully receive is approximately 200 data packets per IoT device.

[0007] Therefore, a new communication technology that can suppress the influence of interference and the like is needed.

[0008] Technical means of solving problems

[0009] According to one aspect of the present invention, a communication device includes: a storage unit, which is used to store information representing a first basic sequence group including a first basic sequence to an Nth basic sequence, N is an integer greater than 2, and the first basic sequence to the Nth basic sequence are sequences of L complex numbers, and L is an integer greater than 2; a shift unit, which determines a shift amount according to transmitted data, and cyclically shifts the nth basic sequence by the shift amount to generate an nth shifted sequence, n is an integer from 1 to N, thereby generating the first shifted sequence to the Nth shifted sequence; a storage unit, which is used to store timing information representing the transmission timing of a sequence; and a sending unit, which is used to send the first shifted sequence to the Nth shifted sequence according to the timing information, wherein the first basic sequence to the Nth basic sequence meet a first condition, that is, when the shift amount is 0, the sum of the correlation values ​​of the autocorrelations of the first basic sequence to the Nth basic sequence is not 0, and at the non-zero shift amount used to send data, the sum of the correlation values ​​of the autocorrelations of the first basic sequence to the Nth basic sequence is 0.

[0010] Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In addition, in the accompanying drawings, the same reference numerals are given to the same or identical structures.

[0011] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural diagram of a wireless communication system for illustrating an implementation manner.

[0013] Figure 2 It is a structural diagram of the transmitting side of a wireless device.

[0014] Figure 3 is a diagram showing an example of a basic sequence group.

[0015] Figure 4 This is a diagram showing an example of a shift sequence group.

[0016] Figure 5 It is a diagram showing a transmission example of each shift sequence.

[0017] Figure 6 It is a structural diagram of the receiving side of the access point.

[0018] Figure 7 This is a diagram showing an example of each correlation value of cyclic correlation.

[0019] Figure 8 It is a structural diagram of the sending side of the access point.

[0020] Fig. 9 is a diagram showing another example of a basic sequence group.

[0021] Fig.10 This is a diagram showing an example of an addition sequence group.

[0022] Fig.11 It is a structural diagram of the receiving side of the wireless device.

[0023] Fig.12 This is a diagram showing another example of each correlation value of the cyclic correlation.

[0024] Fig.13 This is a diagram showing still another example of each correlation value of the cyclic correlation.

[0025] Fig.14 is a diagram showing another example of a basic sequence group.

[0026] Fig.15 This is a diagram showing still another example of each correlation value of the cyclic correlation.

[0027] Fig.16 This is a diagram showing an example of mapping information. DETAILED DESCRIPTION

[0028] Below, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the claimed invention, and not all combinations of features described in the embodiments are necessary for the present invention. Two or more of the multiple features described in the embodiments may be combined arbitrarily. In addition, the same or identical structures are given the same reference numerals, and repeated descriptions are omitted.

[0029] <First Embodiment>

[0030] Figure 1 : is a block diagram of a wireless communication system for illustrating the present embodiment. Access point (AP) 2 is a communication device capable of wirelessly communicating with wireless devices (WD) 1-1 to 1-3. WD1-1 to WD1-3 are communication devices capable of wirelessly communicating with AP2. As an example, WD1-1 to WD1-3 are IoT devices. In the following description, WD1-1 to WD1-3 are also collectively referred to as WD1. Figure 1 In the example, AP2 communicates with three WD1s, but this is just an example, and the number of WD1s communicating with AP2 can be one or more. In the following description, the direction from WD1 to AP2 is called the uplink direction, and the direction from AP2 to WD1 is called the downlink direction.

[0031] <Uplink Communication>

[0032] Figure 2 This is a structural diagram of the sending side of WD1. Figure 2 It can also be regarded as the structure of the modulator possessed by WD1. For example, when WD1 initially accesses AP2, WD1 receives basic sequence group information representing a basic sequence group including N basic sequences and uplink timing information associated with the basic sequence group from AP2. Here, any existing communication method (modulation method) can be used to perform initial access. The storage unit 13 stores the basic sequence group information received from AP2. The timing information storage unit 14 stores the uplink timing information received from AP2. The storage unit 13 and the timing information storage unit 14 can be any volatile or non-volatile storage device.

[0033] The basic sequence group includes the first basic sequence to the Nth basic sequence, and each basic sequence is a sequence of L complex numbers. In addition, N and L are integers greater than 2. The conditions that the N basic sequences need to satisfy will be described later. The following is an example of N=4, L=4. Figure 3An example of a basic sequence group represented by the basic sequence group information stored in the storage unit 13 is shown. N=4, so the basic sequence group includes 4 basic sequences from the first basic sequence to the fourth basic sequence. Figure 3 , the first basic sequence is (1, 1, 1, 1), and the second basic sequence is (1, j, -1, -j). The basic sequence group information also indicates the frequency associated with each of the first to fourth basic sequences. Figure 3 , the first basic sequence to the fourth basic sequence are associated with frequencies f1 to f4, respectively.

[0034] The displacement unit 11 performs a displacement operation to cyclically shift each basic sequence of the basic sequence group based on the displacement amount determined by the data to be sent. In the following description, the sequence obtained by the displacement operation of the basic sequence is referred to as a "displacement sequence". A group including N (4 in this example) displacement sequences is referred to as a "displacement sequence group". The displacement operation can be a left cyclic shift or a right cyclic shift. In the following, it is assumed that the displacement operation is a left cyclic shift. Unless it is specifically stated or implied that it is not a left cyclic shift, "displacement" means a left cyclic shift. The displacement unit 11 outputs the displacement sequence group to the sending unit 12.

[0035] In this example, since L=4, there are 4 possible numbers of shifts (shift amounts), namely 0 to 3. Therefore, when L=4, two bits of data (transmission data) can be sent at a time. Generally speaking, when the length of each basic sequence is L, the number of bits that can be sent in one transmission is less than log2L. In the following description, it is assumed that the shift unit 11 performs a shift operation using a value obtained by regarding two bits as a binary number as the shift amount. For example, when the transmission data is "10", the shift unit 11 shifts each of the first basic sequence to the fourth basic sequence by a shift amount of 2. Therefore, the first shift sequence to the fourth shift sequence contained in the shift sequence group are as follows. Figure 4 In addition, in the present embodiment, the value obtained by treating two bits as a binary number is used as the displacement amount, but this is only an example. For example, any correspondence between four modes represented by two bits and four displacement amounts can be predetermined, and the displacement amount can be determined based on the correspondence.

[0036] The uplink timing information stored in the timing information storage unit 14 is information that specifies the transmission timing (transmission start timing) of each shift sequence. The transmission unit 12 transmits each shift sequence at an associated frequency according to the transmission timing indicated by the uplink timing information. Here, the frequency associated with the shift sequence is a frequency associated with the basic sequence that is the basis of the shift sequence. To this end, the transmission unit 12 is configured to access the basic sequence group information stored in the storage unit 13 and obtain frequency information indicating the frequency associated with each basic sequence.

[0037] In this embodiment, a complex number of each shift sequence is sent in one chip, and the period of one chip is called a chip period. In this example, the uplink timing information specifies the sending timing of each shift sequence as a multiple of the chip period. Note that the maximum value T of the timing information is predetermined, and in this example, the maximum value T is 29. When the sending timing of the shift sequence is t (t is any value from 1 to T), it means that the shift sequence is sent from the start timing of the t-th chip period.

[0038] For example, assuming that the uplink timing information indicates that t=9, 2, 29 and 13 are respectively used as the transmission timings of the first shift sequence, the second shift sequence, the third shift sequence and the fourth shift sequence, in this case, Figure 5 As shown, the transmitting unit 12 transmits each shift sequence at an associated frequency.

[0039] The transmitting unit 12 may, for example, map each complex number of the shift sequence to the amplitude and phase of the frequency associated with the shift sequence and transmit the same. Figure 5 Taking the second displacement sequence sent at frequency f2 as an example, at t=2, a sine wave (frequency f2) with an amplitude of a predetermined value A and a phase of 180 degrees is sent, at t=3, a sine wave (frequency f2) with an amplitude of a predetermined value A and a phase of 270 degrees is sent, at t=4, a sine wave (frequency f2) with an amplitude of a predetermined value A and a phase of 0 degrees is sent, and at t=5, a sine wave (frequency f2) with an amplitude of a predetermined value A and a phase of 90 degrees is sent, thereby sending the second displacement sequence.

[0040] Here, WD1 sends a predetermined preamble and the identifier of WD1 before sending data. In this embodiment, the first code chip, that is, the start timing of t=1 is the timing at which the transmission of the predetermined preamble and the identifier is completed. After receiving the predetermined preamble and the identifier of WD1 from WD1, AP2 uses the timing at which the reception is completed as the start timing of t=1 to receive the signal from WD1. Figure 5 In the example, a transmission is completed within a 32-chip period.

[0041] The uplink timing information can be generated by AP2 or pre-stored in AP2. When generated by AP2, AP2 can generate the uplink timing information by, for example, randomly generating the transmission timing t of each displacement sequence within the range of 1 to a maximum value (29 in this example). Here, the uplink timing information can be generated so that the transmission timing t of each displacement sequence is different from each other, or so that no overlapping time period occurs in the transmission of each displacement sequence. In addition, when AP2 communicates with multiple WD1s, uplink timing information for each WD1 can be generated so that the transmission timing of the signal (displacement sequence) sent by each WD1 at the same frequency is different. For example, AP2 can generate uplink timing information for each WD1 separately. Furthermore, when uplink timing information is pre-stored in AP2, multiple different uplink timing information can be stored, and AP2 selects the uplink timing information for communicating with one WD1 from the multiple uplink timing information.

[0042] Figure 6 It shows the structure of the receiving side of AP2. Figure 6 It can also be regarded as the structure of the demodulator included in AP2. The timing information storage unit 24 is, for example, a volatile or non-volatile storage device, and stores the uplink timing information notified to WD1. Note that when the uplink timing information is generated by AP2, AP2 has a generation unit that generates the uplink timing information, which is not shown in the figure. The storage unit 23 is, for example, a volatile or non-volatile storage device, and stores the basic sequence group information notified to WD1. After receiving the preamble code and the identifier of the WD1 from WD1, the receiving unit 25 receives each shift sequence sent by the WD1 according to the uplink timing information notified to the WD1 as a receiving sequence. In this way, the uplink timing information is information indicating the timing of receiving the first shift sequence to the Nth shift sequence sent by WD1 as the first receiving sequence to the Nth receiving sequence for AP2. Here, the receiving unit 25 obtains the frequency of each shift sequence from the basic sequence group information stored in the storage unit 23. The receiving unit 25 outputs the receiving sequence group containing each received receiving sequence to the determination unit 26. For example, it is assumed that there is no interference or noise in the wireless area, and the receiving unit 25 receives the signal sent by WD1 accurately. Figure 4 The shift sequences shown in FIG. 1 are as follows: Figure 4 Each of the shift sequences shown is output to the determination unit 26 as a received sequence.

[0043] The determination unit 26 determines and outputs the data transmitted by the WD1 based on the basic sequence group and the reception sequence group indicated by the basic sequence group information stored in the storage unit 23. The processing in the determination unit 26 will be described below.

[0044] First, the determination unit 26 obtains the cyclic correlation of the nth basic sequence with respect to the nth received sequence. Here, n is an integer from 1 to N, and in this example, N=4. In this example, since L=4, the cyclic correlation includes four correlation values ​​when the shift amount τ is 0 to 3, respectively. Here, when the A sequence is (a0, a1, a2, a3) and the B sequence is (b0, b1, b2, b3), the correlation value when τ=0 is a0×b0*+a1×b1*+a2×b2*+a3×b3*, and the correlation value when τ=1 is a0×b1*+a1×b2*+a2×b3*+a3×b0*. Here, the value b* is the complex conjugate of the value b.

[0045] Figure 7 shows that when the received sequence group is Figure 4 The correlation values ​​when the shift sequence groups are the same are shown. Figure 7 The “first” in the figure represents each correlation value of the cyclic correlation of the first basic sequence with respect to the first received sequence, the “second” represents each correlation value of the cyclic correlation of the second basic sequence with respect to the second received sequence, the “third” represents each correlation value of the cyclic correlation of the third basic sequence with respect to the third received sequence, and the “fourth” represents each correlation value of the cyclic correlation of the fourth basic sequence with respect to the fourth received sequence.

[0046] The determination unit 26 obtains the sum of correlation values ​​having the same offset τ among the cyclic correlations obtained for each sequence. Figure 7 The “sum” in refers to the sum of the correlation values ​​of each sequence with the same offset τ. Figure 7 As shown, when τ=2, the sum of the correlation values ​​is 16, and when τ=0, 1, 3, the sum of the correlation values ​​is 0. Therefore, the determination unit 26 determines that the received sequence group is obtained by cyclically shifting each basic sequence of the basic sequence group to the left by τ=2, and therefore determines that the data (received data) sent by WD1 is "10".

[0047] Next, the conditions that each basic sequence included in a basic sequence group must satisfy are described. In this embodiment, each basic sequence included in the basic sequence group satisfies the following condition 1.

[0048] Condition 1: Regarding the autocorrelation, that is, the cyclic autocorrelation of the nth basic sequence included in the basic sequence group relative to the nth basic sequence, the sum of the cyclic autocorrelations from the first basic sequence to the Nth basic sequence at the same shift amount τ is not 0 when the shift amount τ=0, but is 0 when the shift amount τ≠0.

[0049] Here, for example, when not all L displacements from 0 to (L-1) are used for data transmission, but only Z displacements less than L are used to transmit data (for example, when only displacements from 0 to (Z-1) are used), Condition 1 is modified to the following Condition 1'.

[0050] Condition 1': Regarding the autocorrelation, that is, the cyclic autocorrelation of the nth basic sequence included in the basic sequence group relative to the nth basic sequence, the sum of the cyclic autocorrelations from the first basic sequence to the Nth basic sequence at the same shift amount τ is not 0 when the shift amount τ=0, but is 0 when the shift amount τ is the shift amount for sending (receiving) data and the shift amount τ≠0.

[0051] In the following description, it is assumed that all L displacement amounts are used for data transmission, so condition 1 is used.

[0052] By setting each basic sequence of the basic sequence group in this way, the receiving side can determine the shift amount in the shift operation of the transmitting side based on the cyclic correlation between the receiving sequence group and the basic sequence group. More specifically, the determination unit 26 Figure 7 The shift amount for which the absolute value of the "sum" shown is the largest is determined to be the shift amount of the shift operation in WD1, and the data transmitted by WD1 can be determined.

[0053] here, Figure 7 The correlation values ​​shown are correlation values ​​obtained on the receiving side under ideal conditions where there is no interference in the wireless area. However, in reality, due to interference, noise, etc., the received sequence received by AP2 from WD1 is not the same as the shifted sequence. For example, if the reception conditions on frequencies f1 to f3 are good, but there is interference, noise, etc. on frequency f4, the error of the first received sequence to the third received sequence relative to the first shifted sequence to the third shifted sequence is small, but the error of the fourth received sequence relative to the fourth shifted sequence may be large. In this case, for example, Figure 7 The "sum" shown may not be 0 when τ = 0, 1, 3, and the absolute value of the "sum" may be less than 16 when τ = 2. However, as long as the absolute value of the "sum" when τ = 2 is greater than the absolute value of the "sum" when τ = 0, 1, 3, the data can be correctly determined.

[0054] In this embodiment, when the uplink timing information of each WD1 is set, the transmission timing of the shifted sequences transmitted by each WD1 at the same frequency is different from each other, so the probability that each shifted sequence transmitted by a certain WD1 is interfered by other WD1 is low. Therefore, even if the number of WD1s communicating with one AP2 increases, the influence of interference and the like can be suppressed. Furthermore, in this embodiment, by making the transmission frequencies of each shifted sequence different, the probability that each shifted sequence transmitted by a certain WD1 is interfered by other WD1 is further reduced.

[0055] In addition, in the present embodiment, the first basic sequence to the Nth basic sequence included in the basic sequence group are associated with different frequencies, respectively. Moreover, WD1 uses the frequency associated with the original basic sequence when sending each shifted sequence to AP2. However, the present embodiment is not limited to this method, for example, each shifted sequence can also be sent on the same frequency. In addition, the first frequency can also be associated with some of the first basic sequence to the Nth basic sequence, and the second frequency different from the first frequency can be associated with the remaining basic sequences. In other words, less than N frequencies can be associated with the first basic sequence to the Nth basic sequence. In addition, for multiple shifted sequences associated with the same frequency, when uplink timing information is generated, it is made so that no overlapping time periods appear in the transmission of the multiple shifted sequences. Moreover, even when the first basic sequence to the Nth basic sequence are associated with different frequencies, it is also possible to generate uplink timing information so that no overlapping time periods appear in the transmission of each shifted sequence. By generating uplink timing information in this way, the conditions of filters and the like required on the receiving side can be relaxed.

[0056] <Downlink Communication>

[0057] Figure 8 This is a structural diagram of the sending side of AP2. Figure 8 It can also be regarded as the structure of the modulator included in AP2. Next, an example will be described in which AP2 communicates with two WD1s (WD1-1 and WD1-2) and sends data to each of the two WD1s. Assume that the basic sequence group information stored in the storage unit 13 of WD1-1 represents Figure 3 At the same time, it is assumed that the basic sequence group information stored in the storage unit 13 of WD1-2 represents Fig. 9 The following is the basic sequence group used by WD1-1. Figure 3 The basic sequence group shown is called basic sequence group #1, and the basic sequence group used by WD1-2 Fig. 9 The basic sequence group shown is referred to as basic sequence group #2. The storage unit 23 of AP2 stores basic sequence group information for indicating the basic sequence group #1 and the basic sequence group #2 to be notified to WD1-1 and WD1-2, respectively.

[0058] In this embodiment, basic sequence group #2 is obtained by cyclically shifting each basic sequence of basic sequence group #1. That is, the first basic sequence of basic sequence group #2 is the second basic sequence of basic sequence group #1, the second basic sequence of basic sequence group #2 is the third basic sequence of basic sequence group #1, the third basic sequence of basic sequence group #2 is the fourth basic sequence of basic sequence group #1, and the fourth basic sequence of basic sequence group #2 is the first basic sequence of basic sequence group #1. In addition, the first to fourth basic sequences of basic sequence group #2 are associated with frequencies f1 to f4, respectively.

[0059] The shift unit 21 performs a shift operation on each basic sequence of the basic sequence group #1 using the data #1 (first transmission data) to be transmitted to WD1-1, and outputs the shift sequence group #1 including the first to fourth shift sequences #1 to the adding unit 27. The shift operation in the shift unit 21 is the same as the shift operation performed by the shift unit 11 of WD1. For example, when the bit "10" is to be transmitted to WD1-1, the shift sequence group #1 is as follows: Figure 4 shown.

[0060] Similarly, the shift unit 21 performs a shift operation on each basic sequence of the basic sequence group #2 using the data #2 (second transmission data) to be transmitted to WD1-2, and outputs the shift sequence group #2 including the first shift sequence to the fourth shift sequence #2 to the adding unit 27. For example, when the bit "00" is to be transmitted to WD1-2, the shift sequence group #2 is Fig. 9 Base sequence group #2 itself is shown.

[0061] The adder 27 adds the nth shift sequence of the shift sequence group #1 and the nth shift sequence of the shift sequence group #2 to generate the nth added sequence, thereby generating an added sequence group including the first to fourth added sequences, and outputs it to the transmitter 22 . Fig.10 The individual addition sequences of the addition sequence group are shown.

[0062] The timing information storage unit 24 stores the downlink timing information. The downlink timing information is used for transmission in the downlink direction, and like the uplink timing information, it indicates the transmission timing (transmission start timing) of each addition sequence. Like the uplink timing information, the downlink timing information can be generated by AP2, or it can be pre-generated and stored in AP2. Here, AP2 notifies each WD1 of the uplink timing information and also notifies the downlink timing information. The transmission unit 22 transmits each addition sequence according to the downlink timing information.

[0063] Fig.11 The structure of the receiving side of WD1 is shown. Fig.11 It can also be regarded as the structure of the demodulator included in WD1. The timing information storage unit 14 stores the downlink timing information received from AP2. The receiving unit 15 receives each addition sequence sent by AP2 as a receiving sequence according to the downlink timing information. In this way, the downlink timing information is information for WD1 that indicates the timing of receiving the first addition sequence to the Nth addition sequence sent by AP2 as the first receiving sequence to the Nth receiving sequence. The receiving unit 15 outputs the receiving sequence group containing each received receiving sequence to the determination unit 16. For example, assuming that there is no interference or noise in the wireless area, the receiving unit 15 accurately receives the information sent by AP2 such as Fig.10 The addition sequences shown in FIG. 1 are then received by the receiving unit 15. Fig.10 The respective added sequences shown are output to the determination unit 16 as received sequences.

[0064] The storage unit 13 stores basic sequence group information indicating a basic sequence group. Here, for WD1-1, the basic sequence group information indicates basic sequence group #1, and for WD1-2, the basic sequence group information indicates basic sequence group #2. The processing performed by the determination unit 16 is the same as the processing performed by the determination unit 26.

[0065] Fig.12 Shows when it is received correctly Fig.10 The sum of the correlation values ​​of the cyclic correlation between the nth received sequence of the received sequence group and the nth basic sequence of the basic sequence group #1 when the added sequence group shown is used as the received sequence group, and the sum of the correlation values ​​at the same shift amount τ. Fig.12 The results shown can be used to determine that the data sent by WD1-1 is "10". Fig.13 Shows that when it is received correctly Fig.10 The sum of the correlation values ​​of the cyclic correlation between the nth receiving sequence of the receiving sequence group and the nth basic sequence of the basic sequence group #2 when the added sequence group shown is used as the receiving sequence group, and the sum of the correlation values ​​at the same shift amount τ. Fig.13 The results shown can determine that the transmission data of WD1-2 is "00". In this way, AP2 can use the same downlink timing information to send data to WD1-1 and WD1-2 at the same time.

[0066] Next, the conditions that basic sequence group #1 and basic sequence group #2 must satisfy in order to simultaneously transmit data to WD1-1 and WD1-2 are described. Basic sequence group #1 and basic sequence group #2 are each set to satisfy the following condition 2 in addition to the above condition 1.

[0067] Condition 2: Regarding the cross-correlation, that is, regarding the cyclic cross-correlation between the nth basic sequence included in basic sequence group #1 and the nth basic sequence included in basic sequence group #2, the sum of the correlation values ​​from the first basic sequence to the Nth basic sequence at the same displacement τ is 0 at any displacement τ.

[0068] In addition, for example, when not all L displacements from 0 to (L-1) are used for data transmission, but only Z displacements less than L are used for data transmission (for example, only displacements from 0 to (Z-1) are used), Condition 2 is modified to the following Condition 2'.

[0069] Condition 2': Regarding the cross-correlation, that is, the cyclic cross-correlation between the nth basic sequence included in basic sequence group #1 and the nth basic sequence included in basic sequence group #2, the sum of the correlation values ​​from the first basic sequence to the Nth basic sequence at the same displacement τ is 0 at any one of the (Z) displacements τ used for data transmission (reception).

[0070] In the following description, it is assumed that all L displacement amounts are used to transmit data, so condition 2 is used.

[0071] In this embodiment, basic sequence group #2 is obtained by cyclically shifting basic sequence group #1. Figure 3 The cross-correlation of the shown base sequence group #1 is 0 at any shift amount τ = 0. Therefore, it is obvious that the base sequence group #1 and the base sequence group #2 obtained by cyclically shifting the base sequence group #1 satisfy condition 2.

[0072] Here, more generally, AP2 can use the following M basic sequence groups (M is an integer greater than 2) to communicate with M WD1. That is, the M basic sequence groups respectively meet the above condition 1, and further, any two basic sequence groups in the M basic sequence groups meet the above condition 2. Such M basic sequence groups can be generated in various ways. As an example, use any method to set a Figure 3 The basic sequence group shown includes N basic sequences that satisfy condition 1 and have a mutual correlation value of 0 for all shift amounts τ. Then, M basic sequence groups #1 to basic sequence groups #M (M is an integer from 2 to N) can be generated by cyclically shifting the basic sequences of the basic sequence group.

[0073] Then, AP2 notifies the basic sequence group #1 to the basic sequence group #M to the M WD1s. Furthermore, AP2 notifies the M WD1s of separate uplink timing information and common downlink timing information respectively. The uplink timing information notified to the M WD1s respectively can be set so that the transmission timing of the displacement sequences sent by the M WD1s respectively at the same frequency is different. Each WD1 uses the received basic sequence group to transmit in the uplink direction according to the notified uplink timing information. In addition, each WD1 uses the received basic sequence group to receive in the downlink direction according to the notified downlink timing information. Furthermore, AP2 receives the displacement sequence group from the WD1 according to the uplink timing information notified to the WD1, and uses the basic sequence group notified to the WD1 to determine the data from the WD1. Furthermore, AP2 uses the basic sequence group notified to M WD1s to generate displacement sequence groups for the M WD1s respectively, generates an addition sequence group based on the displacement sequence group for each WD1, and sends the addition sequence group according to the downlink timing information notified to the M WD1s, thereby sending data to the M WD1s respectively.

[0074] Although a separate frequency is allocated to each base sequence of the base sequence group in downlink communication, as described in uplink communication, the same frequency may be allocated to each base sequence of the base sequence group. Furthermore, a frequency less than the number of base sequences may be used.

[0075] In addition, in this embodiment, the same frequencies f1 to f4 are used for uplink and downlink communications, but the frequency used in uplink communication may be different from the frequency used in downlink communication, in other words, frequency division duplex (FDD). In this case, the frequencies f1 to f4 are mapped to different frequencies in the uplink direction and the downlink direction.

[0076] For example, the uplink timing information and the downlink timing information may be encrypted and notified to WD1. By hiding the frequency and transmission timing of each sequence from a third party, it is difficult for the third party to decipher the data transmitted and received between WD1 and AP2.

[0077] <Second Embodiment>

[0078] Next, the second embodiment will be described with emphasis on the differences between the first embodiment. In this embodiment, downlink communication is different from that in the first embodiment. The structure of the transmission side of AP2 in this embodiment corresponds to Figure 8 The structure of the adding unit 27 is omitted. In addition, in this embodiment, the basic sequence group #2 used in the communication with WD1-2 is as follows: Fig.14 The first to fourth basic sequences of basic sequence group #2 are Fig. 9 The same as shown in , but the frequencies associated with the first to fourth basic sequences are Fig. 9 That is, in the first embodiment, the frequency associated with the nth basic sequence of basic sequence group #1 and the frequency associated with the nth basic sequence of basic sequence group #2 are the same, but in the present embodiment, the frequency associated with the nth basic sequence of basic sequence group #1 and the frequency associated with the nth basic sequence of basic sequence group #2 are different.

[0079] Since there is no adding unit 27, the shifting unit 21 outputs the shifted sequence group #1 and the shifted sequence group #2 to the sending unit 22. The sending unit 22 sends each shifted sequence of the shifted sequence group #1 at an associated frequency according to the downlink timing information, and sends each shifted sequence of the shifted sequence group #2 at an associated frequency. Therefore, for example, the first shifted sequence of the shifted sequence group #1 is sent at a frequency f1, and the first shifted sequence of the shifted sequence group #2 is sent at a frequency f2. Here, since the shifted sequence group #1 and the shifted sequence group #2 are sent according to the same downlink timing information, the nth shifted sequence of the shifted sequence group #1 and the nth shifted sequence of the shifted sequence group #2 are sent in the same time period.

[0080] The structure of the receiving side of WD1 in this embodiment is similar to Fig.11 As shown, WD1 receives each shift sequence sent to itself according to the downlink timing information. Specifically, WD1-1 receives the first shift sequence at frequency f1 according to the downlink timing information. In the same period, AP2 sends the first shift sequence to WD1-2 at frequency f2, but due to the different frequencies, WD1-1 will not receive the first shift sequence sent to WD1-2. Moreover, even if the first shift sequence sent to WD1-2 is received due to the filter performance of WD1-1, etc., it will not cause a problem based on condition 2 described in the first embodiment. The situation is the same in WD2-2.

[0081] In addition, in this embodiment, the frequencies of the nth basic sequence of basic sequence group #1 and the nth basic sequence of basic sequence group #2 are different, but they can also be the same. In this case, WD1 will receive the shift sequence sent to other WD1, but according to condition 2, this will not cause a problem.

[0082] <Third Embodiment>

[0083] Next, the differences from the first embodiment and the second embodiment are described in detail. In the first embodiment and the second embodiment, AP2 communicates with a maximum of M WD1s by using M basic sequence groups #1 to basic sequence group #M. In this embodiment, one AP2 communicates with more than M WD1s. In this embodiment, each WD1 is grouped into a cluster containing a maximum of M WD1s. Here, the number of WD1s included in a cluster may also be one. The M or less WD1s included in a cluster are respectively configured with different basic sequence groups among the M basic sequence groups. Moreover, WD1s belonging to multiple different clusters can be configured with the same basic sequence group among the M basic sequence groups.

[0084] Regarding uplink communication, the same uplink timing information is set for WD1 included in the same cluster. On the other hand, different uplink timing information can be set between WD1 included in multiple different clusters. That is, between WD1 included in multiple different clusters, the uplink timing information is set so that the transmission timing of signals sent at the same frequency in the uplink direction is different from each other. A maximum of M WD1 included in the same cluster sends each displacement sequence at the same timing, but according to the above conditions 1 and 2, AP2 is able to demodulate the signals from a maximum of M WD1 in the same cluster. In addition, since the signals of the same frequency are sent at different timings between WD1 included in different clusters, interference can be prevented from becoming too large.

[0085] Here, the downlink communication of a maximum of M WD1s included in the same cluster is the same as in the first embodiment and the second embodiment. Furthermore, when downlink timing information is set for WD1s included in different clusters, the transmission timing of signals transmitted at the same frequency in the downlink direction is different. In other words, different downlink timing information is set for different clusters. Thus, it is possible to prevent the interference of downlink signals between WD1s included in different clusters from becoming too large.

[0086] <Fourth Embodiment>

[0087] In each of the above-mentioned embodiments, one basic sequence group among M basic sequence groups is allocated to one WD1. In the present embodiment, more than two basic sequence groups among M basic sequence groups are allocated to one WD1. In the following description of the present embodiment, the WD1 allocated with more than two basic sequence groups is marked as "WD1" unless it is clearly stated from the context or otherwise stated that it is not the case. Uplink timing information respectively associated with each basic sequence group is allocated to one WD1. For example, when two basic sequence groups, a first basic sequence group and a second basic sequence group, are allocated to one WD1, first uplink timing information associated with the first basic sequence group and second uplink timing information associated with the second basic sequence group are set for WD1. For example, in Figure 5 In the example, WD1 sends two bits of data in a 32-chip period, but by allocating two basic sequence groups to WD1, WD1 can send 4 bits of data in a 32-chip period.

[0088] The multiple uplink timing information corresponding to the multiple different basic sequence groups assigned to WD1 can be the same. Even if the multiple uplink timing information corresponding to the multiple different basic sequence groups are the same, AP2 can demodulate the data from WD1 according to the above-mentioned conditions 1 and 2. Alternatively, when setting the multiple uplink timing information corresponding to the multiple different basic sequence groups, the transmission timing of the displacement sequences of different basic sequence groups sent at the same frequency can also be different. As an example, the multiple uplink timing information corresponding to the multiple different basic sequence groups can be set so that the displacement sequences of different basic sequence groups sent at the same frequency will not be sent overlapping in time.

[0089] In addition, allocating multiple different basic sequence groups and uplink timing information associated with the multiple basic sequence groups to one WD1 is equivalent to performing the same downlink communication as described in the second embodiment in the uplink direction. Unlike the second embodiment, in the second embodiment, AP2 uses each basic sequence group to send data to different WD1s, while WD1 allocated with multiple basic sequence groups uses each basic sequence group to send data to the same AP2. In addition, in the downlink communication described in the second embodiment, each basic sequence group is associated with the same downlink timing information, but in the uplink communication performed by WD1 allocated with multiple basic sequence groups, multiple different uplink timing information associated with each of the multiple basic sequence groups can be allocated as described above.

[0090] Regarding data reception, the AP2 of the second embodiment receives reception sequences based on different basic sequence groups notified to each of the multiple WD1s from the multiple WD1s, respectively, based on the uplink timing information notified to each of the multiple WD1s. Furthermore, the uplink timing information notified to each WD1 is set so that the reception timing (reception start timing) of the reception sequences received from each WD1 at the same frequency is different from each other. In addition, the AP2 of the third embodiment receives reception sequences based on different basic sequence groups from different WD1s in the same cluster, based on the same uplink timing information.

[0091] The AP2 of this embodiment receives reception sequences based on different basic sequence groups from the same WD1 according to the same uplink timing information. Alternatively, the AP2 of this embodiment receives reception sequences based on different basic sequence groups from the same WD1 according to different uplink timing information. Here, different uplink timing information is set so that the reception timing of reception sequences received at the same frequency from each reception sequence received from the same WD1 is different. As an example, different uplink timing information can be set so that the reception periods of different reception sequences at the same frequency from the same WD1 do not overlap in time. In addition, the WD1 of this embodiment receives reception sequences based on different basic sequence groups from the same AP2 according to the same downlink timing information. Alternatively, the WD1 of this embodiment receives reception sequences based on different basic sequence groups from the same AP2 according to different downlink timing information. Different downlink timing information is set so that the reception timing of reception sequences received at the same frequency from each reception sequence received from the same AP2 is different. As an example, the reception periods of different reception sequences at the same frequency can be set so that they do not overlap in time.

[0092] In addition, when multiple basic sequence groups are allocated to the same WD1, the WD1 can also send a summed sequence obtained by adding shifted sequences based on each basic sequence group to AP2, similarly to the downlink communication in the first embodiment. In this case, the uplink timing information indicates the transmission timing of the summed sequence.

[0093] <Fifth Embodiment>

[0094] Next, the fifth embodiment will focus on the differences from the above embodiments. In the above embodiments, the length of each basic sequence in the basic sequence group is L, and in one communication, data less than log2L bits are sent to a communication device of a communication object. In this embodiment, the length of each basic sequence in the basic sequence group is still set to L, but the number of bits that can be sent to a communication device in one communication is greater than log2L bits.

[0095] The following will take the case where WD1 sends 3-bit data "110" and "010" to AP2 in one communication as an example to illustrate this embodiment. Here, it is assumed that the basic sequence group used by WD1 is as follows: Figure 3 As shown. The shift unit 11 of WD1 converts the basic sequence into an intermediate sequence by multiplying the complex number of each basic sequence of the basic sequence group by a value corresponding to the first bit of the three bits. Hereinafter, as an example, when the first bit is "1", it is multiplied by "1", and when the first bit is "0", it is multiplied by "-1". Next, the shift unit 11 uses the last two bits of the three bits as a binary number to determine the shift amount, generates each shifted sequence by shifting each intermediate sequence by the shift amount, and outputs the shifted sequence group containing each shifted sequence to the sending unit 12.

[0096] When the data is "110", the first bit is "1", so each intermediate sequence is the same as the basic sequence. Therefore, the shift unit 11 performs a shift operation on the intermediate sequence (basic sequence) by a shift amount of 2 based on the last two bits "10". Thus, the shift sequence group output to the sending unit 12 is as follows: Figure 4 On the other hand, when the data is "010", since the first bit is "0", the shift unit 11 inverts the sign of each basic sequence and performs a shift operation with a shift amount of 2. Therefore, the shift sequence group output to the transmission unit 12 is Figure 4 In addition, in this example, each basic sequence of the basic sequence group is multiplied by a multiplier corresponding to a bit and then subjected to a shift operation, but after the shift operation, the multiplier corresponding to the bit is multiplied again, and the result is the same.

[0097] The receiving structure of AP2 in this embodiment is the same as that in the first embodiment. Therefore, if the data sent by WD1 is "110", AP2 will receive Figure 7 When the data sent by WD1 is "010", AP2 gets Fig.15 The determination unit 26 determines the last two bits based on the value of the displacement amount τ when the absolute value of the sum of the correlation values ​​is the maximum. In addition, the determination unit 26 can determine whether the first bit is "0" or "1" based on the sign at the displacement amount τ that makes the absolute value the maximum. Note that in this example, when the first bit is "0", it is multiplied by "-1", but if it is multiplied by "2", for example, Fig.15 The sum value when τ=2 is 32. Therefore, more specifically, the determination unit 26 determines whether the first bit is "0" or "1" based on the sum value at the shift amount τ where the absolute value becomes the maximum.

[0098] In addition, although the method of sending 3-bit data from WD1 to AP2 has been described, when sending 4-bit data, for example, "1+j", "-1+j", "-1-j", or "1-j" may be used as a multiplier corresponding to the value of the first two bits. That is, the multiplier may be a complex number. In this case, the determination unit 26 determines the multiplier based on the sum value (complex number) at the displacement amount τ that makes the absolute value the largest, and determines the bit corresponding to the multiplier. Here, the absolute value of the complex number corresponds to the distance from the origin on the complex plane.

[0099] In summary, in the first embodiment, the amount of displacement is determined based on P-bit data (P is an integer greater than 1), and the P-bit data is sent in one communication. Furthermore, P is an integer less than log2L. In contrast, in the present embodiment, (P+Q)-bit (Q is an integer greater than 1) data is sent in one communication. The displacement unit 11 determines the amount of displacement based on the P-bit data in the (P+Q)-bit data. Furthermore, the displacement unit 11 determines the multiplier to be multiplied with each complex number of each basic sequence based on the Q-bit data of the (P+Q)-bit data. Here, the number of multipliers is 2. Q Then, the shift unit 11 generates each shifted sequence by multiplying each basic sequence by a multiplier and performing a shift operation. Furthermore, among the first bit to the (P+Q)th bit constituting the (P+Q) bits, how to select the Q bit for determining the multiplier and the P bit for determining the shift amount is arbitrary, and it is not limited to using the initial Q bit to determine the multiplier.

[0100] In addition, the determination unit 26 of AP2 calculates the cyclic correlation between the received sequence and the corresponding basic sequence for each received sequence, and calculates the sum of the correlation values ​​with the same displacement. Similar to the first embodiment, the determination unit 26 determines the P-bit data based on the displacement when the absolute value of the sum is the maximum. Furthermore, the determination unit 26 determines the multiplier based on the sum value at the displacement when the absolute value is the maximum, and determines the Q-bit data based on the determined multiplier. With such a configuration, the amount of data sent in one communication can be increased compared to the first embodiment. The communication method of this embodiment is applicable not only to the uplink direction, but also to the downlink direction. It can also be applied to the structures of the second to fourth embodiments.

[0101] <Sixth Implementation Method>

[0102] Next, the sixth embodiment will be described, focusing on the differences from the above embodiments. This embodiment is also used to increase the amount of data in one communication, similar to the fifth embodiment. For example, it is assumed that the length L (sequence length) of each basic sequence in the basic sequence group is 5. In the case of the first embodiment, even if L is 5, the number of bits that can be sent in one communication is two bits.

[0103] In the present embodiment, as an example, a combination of selecting three displacement amounts τ from five displacement amounts τ of 0 to 4 is considered. Fig.16 10 combinations of selecting 3 from 5 displacement amounts τ are shown. Fig.16 In the example, "1" indicates that it is selected for combination. Fig.16 As shown, 8 modes represented by 3 bits of data are mapped to one of 10 combinations. Fig.16 For example, "000" corresponds to a combination of shift amounts τ=2, 3, and 4.

[0104] When the transmitted data is "000", the shift unit 11 Fig.16 The mapping represented by the mapping information in the above embodiment is to generate a shifted sequence group #1 by shifting each basic sequence by a shift amount τ=2, to generate a shifted sequence group #2 by shifting each basic sequence by a shift amount τ=3, and to generate a shifted sequence group #3 by shifting each basic sequence by a shift amount τ=4. Then, the shifted sequence group output to the transmitting unit 12 is generated by adding the n-th shifted sequence of the shifted sequence groups #1 to #3. The transmitting unit 12 transmits each shifted sequence according to the uplink timing information in the same manner as in the first embodiment. Here, the mapping information is pre-created and stored in the storage unit 13, or is received from the AP2 together with the uplink timing information, etc.

[0105] The storage unit 23 of AP2 stores Fig.16 The determination unit 26 calculates the cyclic correlation between the received sequence and the corresponding basic sequence through the process described in the first embodiment, and calculates the sum of the correlation values ​​at the same shift amount of each sequence. Then, the determination unit 26 determines the three shift amounts with the largest absolute value of the sum. Fig.12 and Fig.13 As can be seen from the description, when the received sequence is the same as the shift sequence, the sums when the shift amounts are τ=2, 3, and 4 are the same value, and are greater than the sums when the shift amounts are τ=0 and 1. Therefore, the judgment unit 26 Fig.16 From the mapping information shown, it can be determined that the data sent by WD1 is "000".

[0106] In summary, in this embodiment, WD1 and AP2 have the same mapping information. The mapping information represents the relationship between the combination of a predetermined number of displacements and the P-bit data. In addition, the number of combinations is 2 P Again, the predetermined number is greater than 2 and less than L (in Fig.16In the example of , the predetermined number is 3). When sending P-bit data, WD1 determines the predetermined number of shifts based on the data with reference to the mapping information. Then, WD1 generates a shift sequence group corresponding to each shift by performing a shift operation with each shift, and generates a shift sequence group output to the transmitting unit 12 by adding the shift sequence groups corresponding to each shift. On the other hand, AP2 determines the predetermined number of shifts based on the cyclic correlation between the received sequence group and the basic sequence group. Then, AP2 refers to the mapping information based on the determined predetermined number of shifts to determine the data sent by WD1.

[0107] In addition, this embodiment can be combined with the configurations described in the above embodiments. Furthermore, this embodiment is also applicable to downlink communication.

[0108] <Others>

[0109] In the above-mentioned embodiments, a cyclic prefix (CP) may also be added to each shift sequence of the shift sequence group sent by WD1, that is, the CP based on the shift sequence group is sent immediately before or after the shift sequence group. As an example, the CP is the last C (C is an integer less than L) of the shift sequence, and WD1 sends the CP immediately before the shift sequence. In other words, WD1 generates and sends the shift sequence with the CP by adding the CP immediately before the shift sequence. For example, assuming C=2, then Figure 4 The shift sequence with CP added after adding CP to the second shift sequence in is 1, j, -1, -j, 1, j. As another example, CP is the last C of the shift sequence, and WD1 sends CP immediately after the shift sequence. In other words, WD1 generates and sends a shift sequence with CP by adding CP immediately after the shift sequence. The same is true for the downlink direction. By adding CP, information can be demodulated with high accuracy even in a multipath environment.

[0110] Furthermore, in each of the above embodiments, WD1 receives the basic sequence group from AP2, but the basic sequence group information indicating the basic sequence group may also be pre-stored in WD1. In this case, the storage unit 13 may not be a rewritable storage device, but a device that stores the basic sequence group information in hardware. The same applies to the storage unit 23 of AP2.

[0111] In the above embodiments, WD1 and AP2 perform wireless communication, but the present invention is applicable not only to communication using wireless signals in the radio frequency band, but also to communication using sound waves or light. Further, the communication method and communication system described in the above embodiments are also provided.

[0112] In addition, a computer program is provided, which enables a device having one or more processors to perform the functions of WD1 or AP2 described in the above embodiments. The computer program includes instructions, which are stored in one or more storage devices of the device, and when the instructions are executed by one or more processors of the device, the device performs the functions of WD1 or AP2 described in the above embodiments. Further, a computer program is provided, which enables a device having one or more processors to execute the communication method performed by WD1 or AP2 described in the above embodiments. Furthermore, a non-temporary computer-readable storage medium storing these computer programs is also provided.

[0113] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made within the scope of the gist of the present invention.

Claims

1. A communication device, comprising: a storage unit, used to store information indicating a first basic sequence group including a first basic sequence to an N-th basic sequence, where N is an integer greater than or equal to 2, and the first basic sequence to the N-th basic sequence are sequences of L complex numbers, where L is an integer greater than or equal to 2; a shift unit, determining a shift amount according to the transmitted data, and cyclically shifting the nth basic sequence by the shift amount to generate an nth shift sequence, where n is an integer from 1 to N, thereby generating a first shift sequence to an Nth shift sequence; A storage unit, used to store timing information representing the sending timing of the sequence; as well as A sending unit, configured to send the first shift sequence to the Nth shift sequence according to the timing information, wherein: The first basic sequence to the Nth basic sequence satisfies a first condition, that is, when the displacement is 0, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is not 0, and at a non-zero displacement used to send data, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is 0.

2. The communication device according to claim 1, wherein: The transmission timings of the first to Nth shift sequences are different from each other.

3. The communication device according to claim 1 or 2, wherein: The first to Nth shift sequences are respectively associated with frequencies, The sending unit sends the first to Nth shift sequences respectively at the associated frequencies.

4. The communication device according to claim 3, wherein: The frequencies associated with each of the first to Nth shift sequences are different from each other.

5. The communication device according to claim 3, wherein: The frequencies associated with at least two of the first to Nth shift sequences are the same, The transmission timings of the at least two shift sequences indicated by the timing information are set so that the transmission of the at least two shift sequences does not overlap in time.

6. The communication device according to any one of claims 1 to 5, wherein: The transmitted data is P bits of data. The shift unit determines the shift amount according to the P-bit data, The value of P is less than log2L.

7. The communication device according to any one of claims 1 to 5, wherein: The transmitted data is (P+Q) bits of data, The shift unit determines a shift amount according to data of P bits in the (P+Q) bits, and determines a multiplier according to data of Q bits in the (P+Q) bits, and the nth shift sequence is obtained by multiplying L complex numbers of the nth basic sequence by the multiplier and cyclically shifting the shift amount, The value of P is less than log2L.

8. The communication device according to any one of claims 1 to 5, wherein: The displacement unit determines a predetermined number of different displacement amounts according to the transmitted data, The shift unit generates the nth shift sequences for the predetermined number of different shift amounts by cyclically shifting the nth basic sequence respectively using the predetermined number of different shift amounts, and adds the nth shift sequences generated for the predetermined number of different shift amounts, thereby generating the first shift sequence to the Nth shift sequence.

9. The communication device according to any one of claims 1 to 8, wherein: The timing information stored in the storage unit is received from a transmission destination device of the transmission data.

10. The communication device according to any one of claims 1 to 9, wherein: The first to Nth base sequences stored in the storage unit are received from a transmission destination device of the transmission data.

11. The communication device according to any one of claims 1 to 10, wherein: The sending unit sends a cyclic prefix based on the nth shift sequence immediately before or after the nth shift sequence.

12. The communication device according to any one of claims 1 to 8, wherein: The storage unit further stores information indicating a second basic sequence group including the first basic sequence to the Nth basic sequence, wherein the first basic sequence to the Nth basic sequence of the second basic sequence group are sequences of the L complex numbers and satisfy the first condition, The storage unit stores first timing information associated with the first basic sequence group and second timing information associated with the second basic sequence group. When first transmission data and second transmission data are transmitted to the same device, The shift unit cyclically shifts the nth basic sequence of the first basic sequence group by a first shift amount based on the first transmitted data, thereby generating a first shifted sequence group including the first shifted sequence to the Nth shifted sequence, and cyclically shifts the nth basic sequence of the second basic sequence group by a second shift amount based on the second transmitted data, thereby generating a second shifted sequence group including the first shifted sequence to the Nth shifted sequence, The sending unit sends the first shift sequence of the first shift sequence group to the Nth shift sequence according to the first timing information, and sends the first shift sequence of the second shift sequence group to the Nth shift sequence according to the second timing information, The first basic sequence group and the second basic sequence group satisfy a second condition, that is, regarding the cyclic cross-correlation between the nth basic sequence of the first basic sequence group and the nth basic sequence of the second basic sequence group, the sum of correlation values ​​from the first basic sequence to the Nth basic sequence at the same displacement is 0 at any displacement used to send data.

13. The communication device according to claim 12, wherein: The first timing information and the second timing information are set so that the transmission timings of the shift sequences transmitted at the same frequency in the first shift sequence group and the second shift sequence group are different.

14. The communication device according to claim 12, wherein: The first timing information and the second timing information are the same information.

15. The communication device according to any one of claims 1 to 8, wherein: The storage unit further stores information indicating a second basic sequence group including the first basic sequence to the Nth basic sequence, wherein the first basic sequence to the Nth basic sequence of the second basic sequence group are sequences of the L complex numbers and satisfy the first condition, When first transmission data is transmitted to a first communication device and second transmission data is transmitted to a second communication device different from the first communication device, The shift unit cyclically shifts the nth basic sequence of the first basic sequence group by a first shift amount based on the first transmitted data, thereby generating a first shifted sequence group including the first shifted sequence to the Nth shifted sequence, and cyclically shifts the nth basic sequence of the second basic sequence group by a second shift amount based on the second transmitted data, thereby generating a second shifted sequence group including the first shifted sequence to the Nth shifted sequence, The sending unit generates an nth addition sequence by adding the nth shift sequence of the first shift sequence group and the nth shift sequence of the second shift sequence group, and sends the first addition sequence to the Nth addition sequence according to the timing information, The first basic sequence group and the second basic sequence group satisfy a second condition, that is, regarding the cyclic cross-correlation between the nth basic sequence of the first basic sequence group and the nth basic sequence of the second basic sequence group, the sum of correlation values ​​from the first basic sequence to the Nth basic sequence at the same displacement is 0 at any displacement used to send data.

16. The communication device according to any one of claims 1 to 8, wherein: The storage unit further stores information indicating a second basic sequence group including the first basic sequence to the Nth basic sequence, wherein the first basic sequence to the Nth basic sequence of the second basic sequence group are sequences of the L complex numbers and satisfy the first condition, When first transmission data is transmitted to a first communication device and second transmission data is transmitted to a second communication device different from the first communication device, The shift unit cyclically shifts the nth basic sequence of the first basic sequence group by a first shift amount based on the first transmitted data, thereby generating a first shifted sequence group including the first shifted sequence to the Nth shifted sequence, and cyclically shifts the nth basic sequence of the second basic sequence group by a second shift amount based on the second transmitted data, thereby generating a second shifted sequence group including the first shifted sequence to the Nth shifted sequence, The sending unit sends the first shift sequence to the Nth shift sequence of the first shift sequence group and the first shift sequence to the Nth shift sequence of the second shift sequence group according to the same timing information, The first basic sequence group and the second basic sequence group satisfy a second condition, that is, regarding the cyclic cross-correlation between the nth basic sequence of the first basic sequence group and the nth basic sequence of the second basic sequence group, the sum of correlation values ​​from the first basic sequence to the Nth basic sequence at the same displacement is 0 at any displacement used to send data.

17. The communication device according to any one of claims 1 to 8, wherein: It also includes a generating unit for generating the timing information.

18. A communication device, comprising: a storage unit, used to store information indicating a first basic sequence group including a first basic sequence to an N-th basic sequence, where N is an integer greater than or equal to 2, and the first basic sequence to the N-th basic sequence are sequences of L complex numbers, where L is an integer greater than or equal to 2; A storage unit, used to store timing information representing the reception timing of the sequence; A receiving unit, configured to receive a first receiving sequence to an Nth receiving sequence according to the timing information; as well as a determination unit, configured to calculate a cyclic correlation between an nth received sequence and an nth basic sequence, where n is an integer from 1 to N, and sum the correlation values ​​of the cyclic correlation calculated from the first received sequence to the Nth received sequence at the same offset, and determine received data according to the sum value, wherein: The first basic sequence to the Nth basic sequence satisfies a first condition, that is, when the displacement is 0, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is not 0, and at a non-zero displacement used to send data, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is 0.

19. The communication device according to claim 18, wherein: The reception timings of the first to Nth reception sequences are different from each other.

20. The communication device according to claim 18 or 19, wherein: The first to Nth shift sequences are respectively associated with frequencies, The receiving unit receives the first receiving sequence to the Nth receiving sequence at the associated frequencies respectively.

21. The communication device according to claim 20, wherein: The frequencies associated with each of the first to Nth receive sequences are different from each other.

22. The communication device according to claim 20, wherein: The frequencies associated with at least two of the first to Nth received sequences are the same, The reception timings of the at least two reception sequences are set so that reception of the at least two reception sequences does not overlap in time.

23. The communication device according to any one of claims 18 to 22, wherein: The determination unit determines the received data according to the displacement amount when the absolute value of the sum value is maximum.

24. The communication device according to any one of claims 18 to 22, wherein: The determination unit determines the received data based on the displacement amount when the absolute value of the sum value is maximum and the sum value when the absolute value is maximum.

25. The communication device according to any one of claims 18 to 22, wherein: The determination unit determines a predetermined number of displacement amounts according to an absolute value of the sum value, and determines the received data according to the predetermined number of displacement amounts.

26. The communication device according to any one of claims 18 to 25, wherein: The storage unit further stores information indicating a second basic sequence group including the first basic sequence to the Nth basic sequence, wherein the first basic sequence to the Nth basic sequence of the second basic sequence group are sequences of the L complex numbers and satisfy the first condition, The storage unit stores first timing information associated with the first basic sequence group and second timing information associated with the second basic sequence group. The determination unit calculates a first cyclic correlation between the nth received sequence received by the receiving unit according to the first timing information and the nth basic sequence of the first basic sequence group, sums the calculated correlation values ​​of the first cyclic correlation from the first received sequence to the Nth received sequence at the same displacement to obtain a first sum value, determines first received data according to the first sum value, calculates a second cyclic correlation between the nth received sequence received by the receiving unit according to the second timing information and the nth basic sequence of the second basic sequence group, sums the calculated correlation values ​​of the second cyclic correlation from the first received sequence to the Nth received sequence at the same displacement to obtain a second sum value, and determines second received data according to the second sum value, The first basic sequence group and the second basic sequence group satisfy a second condition, that is, regarding the cyclic cross-correlation between the nth basic sequence of the first basic sequence group and the nth basic sequence of the second basic sequence group, the sum of correlation values ​​from the first basic sequence to the Nth basic sequence at the same displacement is 0 at any displacement used to receive data.

27. The communication device according to claim 26, wherein: The first received data and the second received data are data from different devices, The first timing information and the second timing information are the same information.

28. The communication device according to claim 26, wherein: The first received data and the second received data are data from the same device, The first timing information and the second timing information are the same information.

29. The communication device according to claim 26, wherein: The first received data and the second received data are data from different devices, The first timing information and the second timing information are set so that reception timings of reception sequences received at the same frequency are different.

30. The communication device according to claim 26, wherein: The first received data and the second received data are data from the same device, The first timing information and the second timing information are set so that reception timings of reception sequences received at the same frequency are different.

31. A computer-readable storage medium for storing a computer program, which, when executed on one or more processors of a device having more than one processor, enables the device to function as the communication device according to any one of claims 1 to 30.

32. A communication method for a communication device, comprising: Determine the displacement amount according to the sent data; cyclically shifting the first basic sequence to the Nth basic sequence by the shift amount to generate the first shifted sequence to the Nth shifted sequence, N is an integer greater than or equal to 2, the first basic sequence to the Nth basic sequence are sequences of L complex numbers, L is an integer greater than or equal to 2; and The first shift sequence is sent to the Nth shift sequence according to timing information indicating the sending timing of the sequence, wherein: The first basic sequence to the Nth basic sequence satisfies a first condition, that is, when the displacement is 0, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is not 0, and at a non-zero displacement used to send data, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is 0.

33. A communication method for a communication device, comprising: receiving the first to Nth received sequences according to timing information indicating reception timings of the first to Nth received sequences, where N is an integer greater than or equal to 2, the first to Nth received sequences correspond to a first basic sequence to an Nth basic sequence, respectively, and the first to Nth basic sequences are sequences of L complex numbers, where L is an integer greater than or equal to 2; as well as Calculating the cyclic correlation between the nth receiving sequence and the nth basic sequence, where n is an integer from 1 to N, summing the correlation values ​​of the cyclic correlations calculated from the first receiving sequence to the Nth receiving sequence at the same shift amount to obtain a sum value, and determining the received data according to the sum value, wherein: The first basic sequence to the Nth basic sequence satisfies a first condition, that is, when the displacement is 0, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is not 0, and at a non-zero displacement used to send data, the sum of the correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is 0.

34. A communication system comprising an access point and at least two communication devices, wherein: The at least two communication devices respectively include: a storage unit, used to store information indicating a first basic sequence group including a first basic sequence to an N-th basic sequence, where N is an integer greater than or equal to 2, and the first basic sequence to the N-th basic sequence are sequences of L complex numbers, where L is an integer greater than or equal to 2; a shift unit, determining a shift amount according to the transmitted data, and cyclically shifting the nth basic sequence by the shift amount to generate an nth shift sequence, where n is an integer from 1 to N, thereby generating a first shift sequence to an Nth shift sequence; a storage unit, configured to store timing information indicating a transmission timing of a sequence; and A sending unit, configured to send the first shift sequence to the Nth shift sequence according to the timing information, wherein: The first basic sequence to the Nth basic sequence satisfies a first condition, that is, when the displacement is 0, the sum of correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is not 0, and at a displacement that is not 0 and is used to send data, the sum of correlation values ​​of the autocorrelations from the first basic sequence to the Nth basic sequence is 0, A first communication device among the at least two communication devices stores a first basic sequence group as the basic sequence group and stores first timing information as the timing information, A second communication device among the at least two communication devices stores a second basic sequence group as the basic sequence group and stores second timing information as the timing information, The first basic sequence group and the second basic sequence group satisfy a second condition, that is, with respect to a cyclic cross-correlation between the nth basic sequence of the first basic sequence group and the nth basic sequence of the second basic sequence group, a sum of correlation values ​​from the first basic sequence to the Nth basic sequence at the same shift amount is 0 at any shift amount used for sending data, The transmission timing of the first shift sequence to the Nth shift sequence indicated by the first timing information is the same as the transmission timing of the first shift sequence to the Nth shift sequence indicated by the second timing information.

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