Terminal, base station, communication method and integrated circuit

Abstract

The present invention relates to a terminal, a base station, a communication method and an integrated circuit. The terminal comprises: a circuit for generating a signal based on a plurality of cyclic shift amounts respectively corresponding to a plurality of frequency resources; and a transmitting unit for transmitting the generated signal in the plurality of frequency resources.

Description

[0001] This application is a divisional application of the invention patent with application date of October 5, 2017, application number 201780055539.9, and invention name “Terminal, base station and communication method”. Technical Field

[0002] The invention relates to a terminal, a base station, a communication method and an integrated circuit. Background Art

[0003] In the standardization of the fifth generation mobile communication system (5G), 3GPP is discussing a new radio access technology (NR (New RAT)) that does not necessarily have backward compatibility with the existing system, namely LTE / LTE-Advanced.

[0004] In LTE / LTE-Advanced, a terminal (sometimes also referred to as "UE (User Equipment)") transmits a sounding reference signal (SRS) (hereinafter referred to as "SRS") using wireless resources allocated from a base station (sometimes also referred to as "eNB" or "gNB"). The base station can estimate the uplink quality in the transmission band of the SRS by measuring the reception quality of the SRS. In addition, in LTE / LTE-Advanced, in order to suppress the increase of CM (Cubic Metric) / PAPR (Peak-to-Average Power Ratio), it is stipulated that the SRS is transmitted in a continuous frequency band.

[0005] In NR, such as Fig.14 As shown, it is studied to transmit SRS simultaneously in a plurality of partial frequency bands (hereinafter referred to as "partial frequency bands") 100 (ie, to transmit SRS in non-contiguous frequency bands) (for example, refer to Non-Patent Document 1).

[0006] In NR, a wider system band is being studied compared to LTE / LTE-Advanced. When the SRS transmission bandwidth is wide, the transmission power of the terminal near the cell edge will be insufficient. Therefore, the SRS is transmitted discontinuously by using part of the system band, suppressing the transmission power of the terminal while transmitting the SRS in the broadband. As a result, the base station can perform broadband uplink quality estimation in a short time.

[0007] In the transmission of non-continuous frequency band SRS, a SRS based on multiple short sequences using sequence data of shorter sequence lengths equivalent to multiple partial frequency bands is being studied (for example, refer to non-patent document 2). The SRS code sequence is used for Zadoff-Chu (ZC) sequence data used in the SRS of LTE / Advanced LTE. It is assumed that the sequence length of the ZC sequence data is equivalent to the length of 1 partial frequency band 100. When multiple partial frequency bands are transmitted simultaneously, the SRS is transmitted using multiple ZC sequence data.

[0008] Based on the SRS of the plurality of short sequences, different cyclic shift (CS) amounts (or phase shift amounts) are set between the terminals in each sub-band 100. Thus, when the size of the sub-band 100 is the same, the SRSs of the plurality of terminals whose transmission bands are not consistent can be orthogonally coded in units of the sub-band 100 (see Fig.14 ). Therefore, the SRS based on multiple short sequences has the advantage that the degree of freedom in frequency scheduling of the SRS is higher.

[0009] Prior art literature

[0010] Non-patent literature

[0011] Non-patent document 1: R1-1613470, CATT et al., “WF on SRS transmission for NR”, RAN1#87, November 2016

[0012] Non-patent document 2: R1-1611808, LG et al., “Considerations on NR SRS design”, RAN1#87, November 2016 Summary of the invention

[0013] In order to enable multiple terminals to flexibly use CS for orthogonal coding in SRS based on multiple short sequences, it is necessary to notify the terminal of the CS amount for each sub-band 100 (see Fig.15 ). Therefore, there is a problem that the overhead caused by the notification of the CS amount is large.

[0014] The non-limiting embodiments of the present invention contribute to providing a terminal, a base station, and a communication method that can reduce the signaling overhead for notifying the CS amount in an SRS based on multiple short sequences.

[0015] A terminal of one embodiment of the present invention includes: a circuit that specifies a frequency domain for sending a reference signal containing specified sequence data, and applies a phase shift corresponding to the specified frequency domain to the reference signal; and a sending unit that sends the reference signal to which the phase shift is applied in the specified frequency domain.

[0016] A base station according to one embodiment of the present invention includes: a receiving unit that receives a reference signal including specified sequence data in a specified frequency domain; and a circuit that compares a reference signal to which a phase shift amount corresponding to the specified frequency domain is applied with the received reference signal.

[0017] A communication method according to one aspect of the present invention comprises the following steps: specifying a frequency domain for sending a reference signal including specified sequence data, applying a phase shift corresponding to the specified frequency domain to the reference signal, and sending the reference signal to which the phase shift is applied in the specified frequency domain.

[0018] A communication method according to one aspect of the present invention includes the steps of receiving a reference signal including predetermined sequence data in a designated frequency domain, and comparing a reference signal to which a phase shift amount corresponding to the designated frequency domain is applied with the received reference signal.

[0019] A terminal according to one embodiment of the present invention includes: a circuit that generates a signal based on a plurality of cyclic shift amounts corresponding to a plurality of frequency resources, respectively; and a transmitting unit that transmits the generated signal in the plurality of frequency resources.

[0020] A base station of one embodiment of the present invention comprises: a circuit that allocates a frequency domain including multiple frequency resources to a terminal; and a receiving unit that receives a signal from the terminal, wherein the signal is generated based on multiple cyclic shift amounts corresponding to the multiple frequency resources respectively and is sent from the terminal.

[0021] A communication method according to one aspect of the present invention includes: generating a signal based on a plurality of cyclic shift amounts corresponding to a plurality of frequency resources respectively; and transmitting the generated signal in the plurality of frequency resources.

[0022] A communication method according to one embodiment of the present invention comprises: allocating a frequency domain including a plurality of frequency resources to a terminal; and receiving a signal from the terminal, the signal being generated based on a plurality of cyclic shift amounts respectively corresponding to the plurality of frequency resources and being transmitted from the terminal.

[0023] An integrated circuit according to one aspect of the present invention controls the following processes: a process of generating a signal based on a plurality of cyclic shift amounts corresponding to a plurality of frequency resources, respectively; and a process of transmitting the generated signal in the plurality of frequency resources.

[0024] An integrated circuit of one embodiment of the present invention controls the following processing: a process of allocating a frequency domain including a plurality of frequency resources to a terminal; and a process of receiving a signal from the terminal, the signal being generated based on a plurality of cyclic shift amounts respectively corresponding to the plurality of frequency resources and being sent from the terminal.

[0025] Furthermore, these general or specific methods may be implemented as systems, devices, methods, integrated circuits, computer programs, or storage media, or may be implemented by any combination of systems, devices, methods, integrated circuits, computer programs, and storage media.

[0026] According to one aspect of the present invention, in SRS based on a plurality of short sequences, it is possible to reduce the signaling overhead for notifying the CS amount.

[0027] It will be clear from the description and drawings that more advantages and effects of one embodiment of the present invention can be provided by several embodiments and the features described in the description and drawings, respectively, without providing all the features in order to obtain one or more of the same features. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The structure of a terminal according to an embodiment of the present invention is shown.

[0029] Figure 2 The structure of a base station according to an embodiment of the present invention is shown.

[0030] Figure 3 The definition of partial frequency band and RU is explained.

[0031] Figure 4 The structure of the base station according to the first embodiment is shown.

[0032] Figure 5 The structure of the terminal according to the first embodiment is shown.

[0033] Figure 6 This section shows the operation of the terminal in the first embodiment.

[0034] Figure 7 The operation of the base station in implementation mode 1 is shown.

[0035] Figure 8 Explanation of CS calculation method 1.

[0036] Fig. 9 An example of SRS allocation for CM evaluation is shown.

[0037] Fig.10 It shows the simulation results of evaluating CM.

[0038] Fig.11 Indicates that CM is a combination with a higher CS amount.

[0039] Fig.12 The correspondence of the CS amount in the CS amount calculation method 3 is shown.

[0040] Fig.13 The correspondence of the CS amount in the CS amount calculation method 4 is shown.

[0041] Fig.14 An SRS based on multiple short sequences is described.

[0042] Fig.15 The code orthogonalization in partial frequency band units by CS is described. DETAILED DESCRIPTION

[0043] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, when describing the same elements in a differentiated manner, such as "CS group 342A" and "CS group 342B", reference numerals are used, and when describing the same elements in a differentiated manner, such as "CS group 342", only the common numerals among the reference numerals are sometimes used. In addition, the numerals may be represented by "#".

[0044] In the present invention, in the SRS based on multiple short sequences, the frequency resource unit equivalent to the sequence length of one code sequence (ZC sequence, etc.) data is called a resource unit (RU). One RU is composed of one or more resource blocks (RBs). In addition, the continuous frequency band containing one or more RUs for sending SRS is called a partial frequency band. The partial frequency band size and the RU size may also be changed according to the cell, the service category of the NR (eMBB, URLLC, mMTC) or the carrier frequency. Furthermore, in this embodiment, the case where the RU size and the partial frequency band size are equal is described as an example. However, if Figure 3 As shown, the size of the partial frequency band 120 may also be larger than the size of the RU 110 .

[0045] In addition, in the present invention, as an example, the RU number is assumed to be a number assigned in frequency order in a grid of RU units in the case where the system bandwidth is divided by the RU size.

[0046] <Overview of communication system>

[0047] The communication system according to each embodiment of the present invention includes a base station 10 and a terminal 12 .

[0048] Figure 1 1 is a block diagram showing the structure of the terminal 12 according to the embodiment of the present invention. Figure 1 In the terminal 12 shown, the circuit 13 specifies the frequency domain for sending the reference signal including the specified sequence data, applies the phase shift corresponding to the specified frequency domain to the reference signal, and the sending unit 72 sends the reference signal with the phase shift applied in the specified frequency domain.

[0049] Figure 2 1 is a block diagram showing the structure of the base station 10 according to the embodiment of the present invention. Figure 2In the base station 10 shown, the receiving unit 20 receives a reference signal including prescribed sequence data in a designated frequency domain, and the circuit 11 applies a phase shift corresponding to the designated frequency domain to the reference signal.

[0050] <Implementation method 1>

[0051] Next, the configurations of the base station 10 and the terminal 12 in the SRS based on a plurality of short sequences are shown respectively.

[0052] <Base station structure>

[0053] Figure 4 is a block diagram showing the configuration of the base station 10 in the SRS based on multiple short sequences according to the present embodiment. Figure 4 In the present invention, the base station 10 includes an antenna 21, a receiving unit 20, a demodulation and decoding unit 22, an SRS extraction unit 24, a quality estimation unit 26, a scheduling unit 28, a replica generation unit 30, a CS amount calculation unit 32, an SRS resource holding unit 34, an SRS control signal generation unit 36, a modulation and coding unit 38, and a transmission unit 40. The functions of the SRS extraction unit 24, the quality estimation unit 26, and the replica generation unit 30 may also be included in Figure 2 In the circuit 11.

[0054] The receiving unit 20 performs receiving processing such as down-conversion and A / D conversion on the wireless signal received from the terminal 12 via the antenna 21. The receiving unit 20 outputs the signal subjected to the receiving processing to the demodulation and decoding unit 22.

[0055] The demodulation and decoding unit 22 demodulates and decodes the signal received from the reception unit 20. The demodulation and decoding unit 22 outputs the demodulated and decoded signal to the SRS extraction unit 24.

[0056] The SRS extracting unit 24 extracts the SRS from the signal received from the demodulating and decoding unit 22 based on the SRS resource information received from the SRS resource holding unit 34. The SRS extracting unit 24 outputs the extracted SRS to the quality estimating unit 26.

[0057] The SRS resource information includes information required by the terminal 12 to send the SRS. For example, the SRS resource information includes information about the code sequence data such as the RU number, the RU size, and the CS offset. Furthermore, the base station 10 does not have to always notify all the information included in the SRS resource information. The base station 10 may also notify the terminal 12 in advance of part of the information such as the RU size as information on a cell unit.

[0058] The SRS resource holding unit 34 stores the SRS resource information notified to the terminal 12. The SRS resource information notified to the terminal 12 is output from the scheduling unit 28.

[0059] The CS amount calculation unit 32 calculates the CS amount of each RU in the SRS allocation band based on the RU number and the CS offset included in the SRS resource information received from the SRS resource holding unit 34. The CS amount calculation unit 32 outputs the calculated CS amount of each RU to the replica generation unit 30. The details of the calculation method of the CS amount using the RU number will be described later.

[0060] The replica generation unit 30 determines the RU size based on the SRS resource information received from the SRS resource holding unit 34, and generates a replica signal of the RU size using the SRS code sequence data such as the ZC sequence data. The replica generation unit 30 applies CS (i.e., phase shift) to the generated replica signal based on the CS amount of each RU received from the CS amount calculation unit 32, and generates a replica signal to which CS is applied. The replica generation unit 30 outputs the replica signal to which the generated CS is applied to the quality estimation unit 26. In addition, the replica signal can also be called a reference signal.

[0061] The quality estimation unit 26 performs a correlation operation to compare the SRS extracted by the SRS extraction unit 24 with the replica signal to which the CS is applied output from the replica generation unit 30, and estimates the channel quality in the uplink from the terminal 12 to the base station 10. This estimation result is referred to as a quality estimation result. This correlation operation is performed for each RU, that is, for each code sequence length. The quality estimation unit 26 outputs the quality estimation result to the scheduling unit 28.

[0062] The scheduling unit 28 performs data scheduling (MCS setting, frequency resource allocation, transmission power control, etc.) based on the quality estimation result received from the quality estimation unit 26. The scheduling unit 28 determines the SRS resource information of each terminal 12 in consideration of the frequency allocated to the data. The scheduling unit 28 outputs the determined SRS resource information to the SRS control signal generation unit 36 ​​and the SRS resource holding unit 34.

[0063] The SRS control signal generating unit 36 ​​generates a control signal for notifying the terminal 12 of the SRS resource information received from the scheduling unit 28. The SRS control signal generating unit 36 ​​outputs the generated control signal to the modulation and coding unit 38.

[0064] The modulation and coding unit 38 modulates and codes the control signal received from the SRS control signal generating unit 36 ​​, and outputs the modulated and coded control signal to the transmitting unit 40 .

[0065] The transmission unit 40 performs transmission processing such as D / A conversion, up-conversion, and amplification on the signal received from the modulation and coding unit 38. The transmission unit 40 transmits the wireless signal subjected to the transmission processing to the terminal 12 via the antenna 21.

[0066] <Terminal structure>

[0067] Figure 5 1 is a block diagram showing the structure of the terminal 12 in the SRS based on multiple short sequences according to the present embodiment. Figure 5 In the embodiment, the terminal 12 includes an antenna 61, a receiving unit 60, a demodulation and decoding unit 62, a CS amount calculation unit 64, an SRS generation unit 66, an SRS frequency band setting unit 68, a modulation and coding unit 70, and a transmission unit 72. The function of the SRS frequency band setting unit 68 may also be included in Figure 1 In the circuit 13.

[0068] The receiving unit 60 performs receiving processing such as down-conversion and A / D conversion on the reception signal received by the antenna 61. The receiving unit 60 outputs the signal subjected to the receiving processing to the demodulation and decoding unit 62.

[0069] Demodulation and decoding section 62 demodulates and decodes the signal received from reception section 60, and extracts SRS resource information transmitted from base station 10 from the decoded and demodulated signal. Demodulation and decoding section 62 outputs the extracted SRS resource information to CS amount calculation section 64 and SRS frequency band setting section 68.

[0070] SRS band setting section 68 maps the SRS received from SRS generating section 66 to the RU number included in the SRS resource information. SRS band setting section 68 outputs the obtained signal to modulation and coding section 70.

[0071] The CS amount calculation unit 64 performs the same processing as the CS amount calculation unit 32 of the base station 10. That is, the CS amount calculation unit 64 calculates the CS amount of each RU based on the RU number and the CS offset included in the SRS resource information. The CS amount calculation unit 64 outputs the calculated CS amount to the SRS generation unit 66.

[0072] The SRS generation unit 66 generates an SRS using code sequence (ZC sequence) data having a sequence length equivalent to the RU size based on the RU size included in the SRS resource information. The SRS generation unit 66 applies a cyclic shift (phase shift) based on the CS amount per RU received from the CS amount calculation unit 64 to the generated SRS. The SRS generation unit 66 outputs the SRS to which the cyclic shift is applied to the SRS band setting unit 68.

[0073] The modulation and coding unit 70 modulates and codes the signal received from the SRS band setting unit 68. The modulation and coding unit 70 outputs the modulated and coded signal to the transmission unit 72.

[0074] The transmission unit 72 performs transmission processing such as D / A conversion, up-conversion, and amplification on the signal received from the modulation and coding unit 70. The transmission unit 72 transmits the wireless signal obtained by the transmission processing to the base station 10 via the antenna 61.

[0075] <Base station and terminal operations>

[0076] The operations in the base station 10 and the terminal 12 having the above configurations will be described in detail.

[0077] Figure 6 is a flowchart showing the operation of the terminal 12, Figure 7 It is a flowchart showing the operation of the base station 10 .

[0078] Terminal 12 specifies the RU (i.e., frequency domain) for sending a reference signal (ST100), applies the phase shift corresponding to the specified RU to the reference signal (i.e., the signal containing SRS) (ST102), and sends the reference signal to which the phase shift is applied in the specified RU to base station 10 (ST104).

[0079] When the base station 10 receives the reference signal from the terminal 12 in the designated RU (ST120), it applies the phase shift corresponding to the designated RU to the reference signal (ST122), and compares the reference signal received from the terminal 12 with the reference signal to which the phase shift is applied (ST124). Through this comparison, the base station 10 estimates the channel quality in the uplink from the terminal 12 to the base station 10.

[0080] <CS amount calculation method>

[0081] Next, the details of the CS calculation method using the RU number, which is performed in the CS amount calculation unit of the terminal 12 and the base station 10, will be described.

[0082] <CS amount calculation method 1>

[0083] Figure 8 This is an explanatory diagram of CS calculation method 1.

[0084] In CS calculation method 1, the RU number of the frequency resource and the CS amount are uniquely associated, and the CS offset amount that differs between the terminals 12 for multiplexing SRS is notified to each terminal 12 regardless of the number of sub-bands for each terminal 12 .

[0085] The base station 10 and the terminal 12 calculate the CS amount of the RU based on the RU number and the CS offset of each sub-band. The CS offset may be notified dynamically using DCI (Downlink Control Information) or semi-statically.

[0086] exist Figure 8 In row 202 of Table 200, a CS amount "0" uniquely corresponds to RU#0, a CS amount "1" uniquely corresponds to RU#1, ..., and a CS amount "4" uniquely corresponds to RU#4. UE#0 is notified of a CS offset "1". UE#1 is notified of a CS offset "3". When SRS is transmitted in RU#4, UE#0 will add the notified CS offset "1" to the CS amount "4" corresponding to RU#4, and calculate a cyclic shift amount (phase shift amount) "5" for the SRS. When SRS is transmitted in RU#4, UE#1 will add the notified CS offset "3" to the CS amount "4" corresponding to RU#4, and calculate a cyclic shift amount (phase shift amount) "7" for the SRS. As a result, different cyclic shift amounts are applied to the SRS of UE#0 and UE#1 transmitted in the same RU#4, so the base station 10 can distinguish the SRS of UE#0 and UE#1.

[0087] Thus, by uniquely associating the RU number of the frequency resource with the CS amount, the base station 10 only needs to notify the terminal 12 of the CS offset, without having to notify the CS amount for each sub-band. Therefore, the signaling overhead from the base station 10 to the terminal 12 can be reduced.

[0088] Furthermore, the CS offset may be calculated from the ID of the terminal 12 itself (eg, RNTI (Radio Network Temporary ID)) instead of being notified by the base station 10 .

[0089] In this way, by calculating the CS offset from the ID of the terminal 12 itself, the base station 10 does not need to notify the terminal 12 of the CS offset. Therefore, the signaling overhead from the base station 10 to the terminal 12 can be further reduced. In this case, the base station 10 performs scheduling so that the terminals 12 with different CS offsets are allocated to the same RU.

[0090] As described above, according to the present embodiment, by uniquely associating the RU number of the frequency resource and the CS amount, it is possible to reduce the signaling overhead of the CS amount in the SRS based on a plurality of short sequences.

[0091] <Implementation method 2>

[0092] As mentioned above, by using CS calculation method 1, the signaling overhead of the CS amount can be reduced.

[0093] However, the SRS based on multiple short sequences may increase the CM or PAPR depending on the combination of the CS amounts used in each RU.

[0094] Fig. 9 This is a diagram showing an example of SRS allocation for CM evaluation.

[0095] exist Fig. 9 In the figure, the number of partial frequency bands is "4", the ZC sequence number is "1", the RU size is 4RB (1RB=12 subcarriers), the partial frequency band interval is 4RB, and the RUs sending SRS are RU#0, #2, #4, and #6.

[0096] Fig.10 Yes means Fig. 9 Curve 300 is a graph showing simulation results for evaluating CM in all combinations of CS amounts in .

[0097] The CM of OFDM data is 4.0 dB, so according to the curve 300, it can be seen that there are about 5% of combinations in which the CM of the SRS is larger than the CS amount of the CM of the OFDM data.

[0098] Fig.11 Table 320 is a table showing an example of a combination of CS amounts in which CM has a particularly high CS amount among all combinations of CS amounts for each RU.

[0099] In the allocation mode of CS amount to each RU, Fig.11 In the following cases A to D as shown in the example of table 320, CM becomes larger.

[0100] Case A: All RUs (or part of the frequency band) have the same CS amount

[0101] Case B: The CS amount of the adjacent RU (or partial band) changes monotonically

[0102] Case C: The CS amount in the first half (lower frequency side) and the second half (higher frequency side) of the RU (or partial band) is the same

[0103] Case D: The CS amount is the same in most (3 / 4 or more in this evaluation condition) of all RUs (or partial bands)

[0104] Therefore, in Embodiment 2, CS amount calculation methods 2 to 4 for suppressing the above situation are described. In addition, the configuration of the base station 10 and the terminal 12 in Embodiment 2, the configuration in which the CS amount and the RU number of the frequency resource are uniquely associated, the configuration in which different CS offsets are notified to the terminal 12 that multiplexes the SRS in the same frequency band regardless of the number of partial frequency bands for each terminal 12, etc., are assumed to be the same as those in Embodiment 1.

[0105] CS amount calculation methods 2, 3, and 4 each have a different method for corresponding RU numbers and CS amounts. This will be described below.

[0106] <CS amount calculation method 2>

[0107] CS amount calculation method 2 is a method of randomly assigning a CS amount to each RU number.

[0108] The setting of the random CS amount for each RU number may also be defined in a cell unit or system specification according to a predetermined pattern table. Alternatively, the setting of the random CS amount for each RU number may also be calculated using a predetermined pseudo-random number according to the following formula 1.

[0109] CS(m,n)=mod(PN(m)+Δ(n),N CS )…(Formula 1)

[0110] Where m is the RU number, n is the terminal number, and N CS is the maximum number of CSs (for LTE / LTE-Advanced, N CS = 12), CS(m,n) represents the CS amount in terminal #n and RU number #m, PN(m) represents the pseudo-random number (0 to N) in RU number #m CS -1), Δ(n) represents the CS offset of terminal #n.

[0111] According to CS amount calculation method 2, by randomly setting the CS amount for each RU using a pattern table and a pseudo-random number, the probability of CM increase can be reduced in SRS based on multiple short sequences. In addition, similar to CS amount calculation method 1, the effect of reducing signaling overhead can also be achieved.

[0112] <CS amount calculation method 3>

[0113] CS quantity calculation method 3 is to calculate the maximum CS number (N CS A method of assigning different CS amounts to each RU in a CS group consisting of continuous (or adjacent) RUs.

[0114] Fig.12 This is a table 340 showing the correspondence of CS amounts in CS amount calculation method 3.

[0115] Fig.12 Table 340 is an example in which the maximum CS number is "3", RU#0 to RU#2 belong to CS group 342A, RU#3 to RU#5 belong to CS group 342B, and different CS amounts are uniquely associated with each RU in each CS group 342.

[0116] Furthermore, when the CS groups 342 are different, the same CS amount may be used. Alternatively, different CS amounts may be used for each CS group 342. For example, different offsets (Δ group ).

[0117] According to CS amount calculation method 3, different CS amounts correspond to each RU in the CS group, so in the continuous (or adjacent) N CS When SRS is allocated to each RU, the probability of the CS amount being the same in the allocated frequency band decreases. That is, the probability of occurrence of situations A, C, and D can be reduced. Therefore, the probability of increasing CM can be suppressed. In addition, as with CS amount calculation method 1, the signaling overhead can be reduced.

[0118] <CS amount calculation method 4>

[0119] Similar to CS calculation method 3, CS amount calculation method 4 also corresponds different CS amounts to each RU in a CS group. However, in CS amount calculation method 4, a CS group is not composed of consecutive RUs, but of N RUs. comb The maximum number of CSs in a RU interval (N CS ) RUs.

[0120] Assume N comb is a predetermined partial frequency band interval applicable to the terminal 12. For example, when the partial frequency band interval is limited to an even number of RUs for the purpose of signaling reduction, N comb =2.

[0121] Fig.13 This is a table 360 ​​showing an example of CS amount distribution according to CS amount calculation method 4.

[0122] Fig.13 The table 360 ​​is, N comb =2, N CS =3, RU#0, #2, #4, ... belong to CS group 362A, RU#1, #3, #5, ... belong to CS group 362B, and in each CS group 362, different CS amounts are uniquely associated with each RU.

[0123] Furthermore, when different CS groups 362 are used, the same CS amount may be used. Alternatively, different CS amounts may be used for each CS group 362. For example, different offset amounts (Δ group ).

[0124] According to CS calculation method 4, for N comb Each RU in the CS group formed by the interval of RUs corresponds to a different CS amount, so in N comb When SRS is allocated to RUs with an interval of RUs, the probability of the same CS amount in the allocated frequency band decreases. That is, the probability of occurrence of situations A, C, and D can be reduced. Therefore, the probability of increasing CM can be suppressed. In addition, as with CS amount calculation method 1, signaling overhead can be reduced.

[0125] Furthermore, in the case of the CS calculation method in Embodiment 2, there may be a combination in which CM has a higher CS amount according to the RU allocation pattern of SRS. Therefore, in the scheduling of the base station 10, the transmission band may be allocated to avoid a combination in which CM has a higher CS amount (the above-mentioned cases A to D).

[0126] In addition, the notification method of the CS offset in the second embodiment can be dynamically notified using DCI, or can be semi-statically notified.

[0127] Alternatively, the CS offset may be calculated based on the ID (RNTI) of the terminal 12 itself instead of being notified by the base station 10 .

[0128] Furthermore, each of the above-mentioned embodiments may have the following structures.

[0129] In the SRS based on multiple short sequences, when the transmission power of the terminal 12 reaches the maximum transmission power, a part of the partial frequency band may be discarded (not transmitted). In the SRS based on multiple short sequences, the required transmission power can be reduced by reducing the number of partial frequency bands, and the CM can be reduced, so the SRS can be transmitted with the required uplink transmission power.

[0130] Furthermore, by using SRS based on a plurality of short sequences, although uplink quality estimation cannot be performed in a partially discarded partial frequency band, orthogonality due to CS in the partial frequency band to be transmitted can be maintained, so uplink quality estimation can be performed.

[0131] When a sequence having a sequence length equivalent to the entire transmission band is divided for each sub-band to generate SRS, if a part of the sub-band is dropped, orthogonality due to CS is distorted in all the sub-bands, making it difficult to estimate uplink quality.

[0132] In addition, in the above-mentioned embodiments, SRS is cited as an example of information to be transmitted, but the present invention is not limited to this, and a reference signal of an orthogonal sequence such as DM-RS (demodulation reference signal) or CSI-RS (Channel state information reference signal) may also be used.

[0133] Furthermore, the SRS sequence data is not limited to a ZC sequence, and may be a GCL (Generalized Chirp Like) sequence, an M sequence, or a computer-generated CAZAC sequence used in 1 and 2 RB transmission of LTE / LTE-Advanced.

[0134] The above has described the various embodiments of the present invention. The above embodiments may be combined in any manner.

[0135] The present invention can be implemented by software, hardware or software in cooperation with hardware. Each functional block described in the above embodiment can be partially or entirely implemented as an integrated circuit, i.e., LSI, and each process described in the above embodiment can also be partially or entirely controlled by an LSI or a combination of LSIs. LSI can be composed of individual chips, or can be partially or entirely composed of one chip. LSI can also include data input and output. Depending on the degree of integration, LSI is sometimes also referred to as IC, system LSI, super LSI, and ultra LSI. The method of integrated circuit is not limited to LSI, and can also be implemented with a dedicated circuit, a general-purpose processor or a dedicated processor. In addition, an FPGA (Field Programmable Gate Array) that can be programmed after LSI manufacturing can also be used, or a reconfigurable processor (Reconfigurable Processor) that can reconfigure the connection and setting of the circuit unit inside the LSI can be used. The present invention can also be implemented as digital processing or analog processing. Moreover, with the technological progress of semiconductors or other technologies derived therefrom, if there is a technology that can replace LSI for integrated circuitization, of course, the technology can be used to integrate the functional blocks. For example, there is also the possibility of applying biotechnology, etc.

[0136] The terminal of the present invention includes: a circuit that specifies a frequency domain for sending a reference signal containing specified sequence data, and applies a phase shift amount corresponding to the specified frequency domain to the reference signal; and a sending unit that sends a reference signal to which the phase shift amount is applied in the specified frequency domain.

[0137] In the terminal of the present invention, the random phase shift amounts correspond to a plurality of frequency domains respectively.

[0138] In the terminal of the present invention, the random phase shift amount is an amount calculated based on a predetermined pseudo-random number.

[0139] In the terminal of the present invention, different phase shift amounts correspond to a plurality of continuous frequency domains respectively.

[0140] In the terminal of the present invention, the phase shift amount is an amount calculated based on an ID that is different for each terminal.

[0141] In the terminal of the present invention, the phase shift amount is an amount calculated based on an offset amount different for each terminal and transmitted from the base station.

[0142] The base station of the present invention includes: a receiving unit for receiving a reference signal including specified sequence data in a specified frequency domain; and a circuit for comparing a reference signal to which a phase shift amount corresponding to the specified frequency domain is applied with the received reference signal.

[0143] The communication method of the present invention includes the following steps: specifying a frequency domain for sending a reference signal containing specified sequence data, applying a phase shift amount corresponding to the specified frequency domain to the reference signal, and sending a reference signal to which the phase shift amount is applied in the specified frequency domain.

[0144] The communication method of the present invention comprises the following steps: receiving a reference signal including specified sequence data in a specified frequency domain, and comparing a reference signal to which a phase shift amount corresponding to the specified frequency domain is applied with the received reference signal.

[0145] The above-mentioned embodiments are examples for explaining the present invention, and the scope of the present invention is not limited to the embodiments. A person skilled in the art can implement the present invention in other forms without departing from the spirit of the present invention.

[0146] One aspect of the present invention is useful for a mobile communication system.

[0147] Description of symbols

[0148] 10 Base Station

[0149] 11 Circuit

[0150] 12 Terminal

[0151] 13 Circuit

[0152] 20 Receiving Unit

[0153] 21 Antenna

[0154] 22 Demodulation and decoding unit

[0155] 24SRS Extraction Unit

[0156] 26 Quality Estimation Unit

[0157] 28 Scheduling Unit

[0158] 30 replica generation units

[0159] 32CS Quantity Computing Unit

[0160] 34SRS Resource Retention Unit

[0161] 36SRS control signal generation unit

[0162] 38 Modulation and Coding Unit

[0163] 40 Sending Unit

[0164] 60 receiving unit

[0165] 61 Antenna

[0166] 62 Demodulation and decoding unit

[0167] 64CS Quantity Computing Unit

[0168] 66SRS Generation Unit

[0169] 68SRS Band Setting Unit

[0170] 70 Modulation and coding unit

[0171] 72 Sending Unit

Claims

1. Terminal, including: A circuit that generates a signal based on a plurality of cyclic shift amounts corresponding to a plurality of frequency resources respectively and a cyclic shift amount of each terminal; as well as A sending unit sends the generated signal in the multiple frequency resources.

2. The terminal according to claim 1, The signal is composed of a plurality of sequences respectively mapped to the plurality of frequency resources, and the circuit generates the signal using the plurality of cyclic shift amounts for each of the plurality of sequences.

3. The terminal according to claim 2, Each of the plurality of sequences has a sequence length corresponding to one of the plurality of frequency resources.

4. The terminal according to claim 1, The different cyclic shift amounts correspond to the multiple frequency resources respectively.

5. The terminal according to claim 1, The circuit generates the signal based on a cyclic shift amount obtained by adding a cyclic shift amount for each terminal to the plurality of cyclic shift amounts respectively corresponding to the plurality of frequency resources.

6. The terminal according to claim 5, The cyclic shift amount for each terminal is notified from the base station.

7. The terminal according to claim 1, The multiple frequency resources are not continuous in the frequency domain.

8. The terminal according to claim 1, The multiple frequency resources are spaced apart at prescribed intervals in the frequency domain.

9. The terminal according to claim 1, The multiple cyclic shift amounts uniquely correspond to the multiple frequency resources respectively.

10. Base station, including: circuit, allocating a frequency domain including a plurality of frequency resources to a terminal; as well as The receiving unit receives a signal from the terminal, the signal being generated based on a plurality of cyclic shift amounts corresponding to the plurality of frequency resources and a cyclic shift amount for each terminal and being transmitted from the terminal.

11. The base station according to claim 10, The signal is composed of a plurality of sequences respectively mapped to the plurality of frequency resources, and the receiving unit receives the signal generated by using the plurality of cyclic shift amounts for the plurality of sequences respectively.

12. The base station according to claim 11, Each of the plurality of sequences has a sequence length corresponding to one of the plurality of frequency resources.

13. The base station according to claim 10, The different cyclic shift amounts correspond to the multiple frequency resources respectively.

14. The base station according to claim 10, The receiving unit receives the signal generated based on a cyclic shift amount obtained by adding a cyclic shift amount for each terminal to the plurality of cyclic shift amounts respectively corresponding to the plurality of frequency resources.

15. The base station of claim 14, further comprising: A sending unit sends the cyclic shift amount of each terminal to the terminal.

16. The base station according to claim 10, The multiple frequency resources are not continuous in the frequency domain.

17. The base station according to claim 10, The multiple frequency resources are spaced apart at prescribed intervals in the frequency domain.

18. The base station according to claim 10, The multiple cyclic shift amounts uniquely correspond to the multiple frequency resources respectively.

19. Communication methods, including: generating a signal based on a plurality of cyclic shift amounts respectively corresponding to a plurality of frequency resources and a cyclic shift amount of each terminal; as well as The generated signal is transmitted in the plurality of frequency resources.

20. Communication methods, including: Allocating a frequency domain including a plurality of frequency resources to a terminal; as well as A signal is received from the terminal, the signal being generated based on a plurality of cyclic shift amounts respectively corresponding to the plurality of frequency resources and a cyclic shift amount for each terminal and being transmitted from the terminal.

21. Integrated circuits that control the following processes: A process of generating a signal based on a plurality of cyclic shift amounts respectively corresponding to a plurality of frequency resources and a cyclic shift amount for each terminal; and and transmitting the generated signal in the plurality of frequency resources.

22. Integrated circuits that control the following processes: A process of allocating a frequency domain including a plurality of frequency resources to a terminal; and A process of receiving a signal from the terminal, the signal being generated based on a plurality of cyclic shift amounts respectively corresponding to the plurality of frequency resources and a cyclic shift amount for each terminal and being transmitted from the terminal.

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