Receiving device, and receiving method

Abstract

To provide a receiving device capable of correcting phase variation.SOLUTION: The receiving device includes: a receiving circuit that receives signals transmitted in a MIMO (Multiple-Input Multiple-Output) manner; and a control circuit configured to control the correction of signal phase variation using information regarding transmission precoding of signals in a transmitting device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a receiving device and a receiving method. [Background technology]

[0002] In cellular wireless communications including 5G NR (New Radio access technology), multiple-input multiple-output (MIMO) transmission is used to improve throughput (see, for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 38.300, V15.14.0 “NR; NR and NG-RAN Overall Description; Stage 2 (Release 15)”, 2023-03 [Non-Patent Document 2] “PROPOSAL FOR A USER-CENTRIC RAN ARCHITECTURE TOWARDS BEYOND 5G”, IEICE Technical Report, vol. 121, no. 189, SAT2021-43, pp. 4-10, October 2021. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is room for improvement in the method of correcting the phase fluctuation.

[0005] A non-limiting embodiment of the present disclosure contributes to providing a receiving device and a receiving method capable of correcting phase fluctuations. [Means for solving the problem]

[0006] A receiving device according to one embodiment of the present disclosure includes a receiving circuit that receives a signal transmitted via MIMO (Multiple-Input Multiple-Output) and a control circuit that controls correction of phase fluctuations of the signal using information regarding transmission precoding of the signal in a transmitting device.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0008] According to an embodiment of the present disclosure, phase variations can be corrected.

[0009] Further advantages and benefits of certain aspects of the present disclosure will become apparent from the specification and drawings, in which such advantages and / or benefits are provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of which are provided to obtain one or more identical features. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a portion of a transmitting device; [Diagram 2] FIG. 1 is a block diagram showing an example of the configuration of a portion of a receiving device. [Diagram 3] FIG. 1 is a block diagram showing a configuration example of a transmission device. [Figure 4] FIG. 1 is a block diagram showing a configuration example of a receiving device. [Diagram 5] Diagram showing an example of signal mapping [Figure 6] FIG. 1 is a block diagram showing a configuration example of a transmission device. [Figure 7] FIG. 1 is a block diagram showing a configuration example of a receiving device. [Figure 8] FIG. 1 is a block diagram showing a configuration example of a transmission device. [Figure 9]FIG. 1 is a block diagram showing a configuration example of a receiving device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] For the 6G system (sixth generation mobile communication system), system virtualization such as "virtualized terminals" or "virtualized base stations" that use multiple relay devices or wireless antennas that are distributed are being considered (see, for example, Non-Patent Document 2). Such virtualized systems are sometimes called "virtualized terminal systems" or "distributed antenna systems."

[0013] In addition to the millimeter wave band, 6G is considering the use of high-frequency radio waves such as the terahertz band (or sub-terahertz band) of 100 GHz or more. For example, Non-Patent Document 2 proposes a system that uses terahertz waves for communication in the vicinity of a terminal.

[0014] In MIMO transmission, the base station (e.g., also called gNB or gNodeB) and the terminal (e.g., also called UE: User Equipment) each transmit and receive multiple data streams using multiple antennas, thereby improving throughput. Since MIMO transmission is a transmission that uses the same time-frequency resources, the receiving device performs data stream separation processing (hereinafter referred to as "MIMO separation processing"). For example, the transmitting device can improve throughput by performing precoding transmission using a transmission weight suitable for the MIMO channel (or propagation path) conditions.

[0015] When using high frequency bands such as millimeter waves and terahertz waves, the signals are susceptible to the effects of phase noise or frequency offsets that occur in local oscillators. The effects of phase noise or frequency offsets appear as, for example, common phase error (CPE) or inter-carrier interference (ICI), and can lead to degradation of error rates. For this reason, the receiving device performs phase variation correction processing such as CPE correction or ICI removal to reduce the effects of phase noise or frequency offsets.

[0016] In preparation for 6G, virtualized systems using high frequency bands are being considered; however, the impact of phase noise or phase fluctuations due to frequency offsets occurring in each of multiple wireless antennas on communication performance, and countermeasures to this impact, have not been fully considered.

[0017] For example, when independent (e.g., different) phase fluctuations occur in each of a plurality of radio antennas on the transmitting side and the receiving side, characteristics may deteriorate if phase fluctuation correction is not performed appropriately. Furthermore, in the case where different phase fluctuations occur in a plurality of radio antennas after precoding during precoding transmission, a method for appropriately correcting the phase fluctuations in a receiving device has not been fully considered.

[0018] In a non-limiting embodiment of the present disclosure, for example, a method for performing phase noise correction in a case where different phase fluctuations occur in each of a plurality of radio antennas after precoding in MIMO transmission will be described.

[0019] (Embodiment 1) In this embodiment, the receiving device includes a first channel estimator and a second channel estimator, and performs MIMO separation processing using a channel estimation value by either of the channel estimators according to a predetermined timing.

[0020] [Communication system overview] A communication system according to an embodiment of the present disclosure includes at least one transmitting device 100 and at least one receiving device 200. For example, in a downlink, the transmitting device 100 may be a base station, and the receiving device 200 may be a terminal. Also, for example, in an uplink, the transmitting device 100 may be a terminal, and the receiving device 200 may be a base station. Also, for example, in a sidelink, the transmitting device 100 and the receiving device 200 may be terminals.

[0021] The transmitting device 100 and the receiving device 200 perform communication using, for example, a plurality of antennas.

[0022] Fig. 1 is a block diagram showing a configuration example of a part of a transmitting device 100. In the transmitting device 100 shown in Fig. 1, a control unit (e.g., corresponding to a control circuit) applies transmission precoding to a signal, a demodulation reference signal (e.g., DMRS), and a phase tracking reference signal (e.g., PT-RS). A transmitting unit (e.g., corresponding to a transmitting circuit) transmits the signal, the demodulation reference signal, and the phase tracking reference signal.

[0023] Fig. 2 is a block diagram showing a configuration example of a part of the receiving device 200. In the receiving device 200 shown in Fig. 2, a receiving unit (e.g., corresponding to a receiving circuit) receives a signal transmitted by MIMO. A control unit (e.g., corresponding to a control circuit) performs MIMO separation processing of a signal in a channel of MIMO transmission using a demodulation reference signal in a first time resource (e.g., symbol) in which a demodulation reference signal (e.g., DMRS) to which transmission precoding is applied to a signal in the transmitting device 100 is arranged, and performs MIMO separation processing using a phase tracking reference signal in a second time resource (e.g., symbol) in which a phase tracking reference signal (e.g., PT-RS) to which transmission precoding is applied is arranged.

[0024] [Example of transmitter configuration] Fig. 3 is a block diagram showing an example of a configuration of a transmitting device 100 according to this embodiment. The transmitting device 100 shown in Fig. 3 may include, for example, an encoding unit 101, a modulating unit 102, a multiplexing unit 103, a precoding unit 104, an Orthogonal Frequency Division Multiplexing (OFDM) modulating unit 105, a radio transmitting unit 106, and an antenna 107.

[0025] At least one of the encoding unit 101, the modulation unit 102, the multiplexing unit 103, the precoding unit 104, and the OFDM modulation unit 105 shown in Fig. 3 may be included in the control unit shown in Fig. 1. Also, at least one of the radio transmission unit 106 and the antenna 107 shown in Fig. 3 may be included in the transmission unit shown in Fig. 1.

[0026] The encoding unit 101 performs error correction encoding on a signal (for example, transmission data) using an encoding method such as turbo encoding, low density parity check (LDPC) encoding, or polar encoding.

[0027] The modulation unit 102 maps the encoded bit string to an IQ constellation such as quadrature phase shift keying (QPSK) or 16-quadrature amplitude modulation (16QAM), for example, and generates modulation symbols.

[0028] The multiplexing unit 103 multiplexes, for example, the modulation symbols and the reference signals. The modulation symbols and the reference signals may be allocated to time and frequency resources assigned thereto. For example, the reference signals may include a demodulation reference signal (DMRS: Demodulation Reference Signal) used in reception processing and a reference signal (PT-RS: Phase Tracking Reference Signal) used for phase tracking.

[0029] The precoding unit 104 performs, for example, a precoding process for MIMO transmission (for example, a weighting process for modulation symbols) on the signal input from the multiplexing unit 103. Note that when a unit matrix is ​​used as the precoding matrix, this is equivalent to not performing precoding.

[0030] The OFDM modulation unit 105, for example, maps the transmission signal input from the precoding unit 104 to subcarriers, and converts the frequency domain signal into a time domain signal by IFFT (Inverse Fast Fourier Transform) processing to generate an OFDM signal. The OFDM modulation unit 105 also adds a CP (Cyclic Prefix) by copying some samples after the OFDM symbol of the signal after IFFT to the beginning. At this time, the OFDM modulation unit 105 may perform windowing processing to reduce out-of-band radiation power due to discontinuity between OFDM symbols. Note that instead of windowing processing, filtering processing may be performed, or other waveform shaping processing for limiting the frequency band may be used.

[0031] The wireless transmitting unit 106 performs wireless transmission processing such as digital-to-analog conversion, up-conversion to a transmission frequency using a local oscillator, and signal amplification processing, and transmits the signal after the wireless transmission processing from an antenna 107.

[0032] The processing in each unit that performs the transmission process may be performed for each of a plurality of antenna systems. Also, each antenna system may process a transmission signal to a different relay terminal (for example, in the case of a virtualized terminal system) or an AP (Access Point) (for example, in the case of a distributed antenna system). Also, processing units such as a wireless transmission unit that processes each antenna system may be located in the same housing, or may be distributed and arranged in different housings.

[0033] [Example of receiving device configuration] Fig. 4 is a block diagram showing an example of the configuration of receiving apparatus 200 according to this embodiment. Receiving apparatus 200 shown in Fig. 4 may include, for example, antenna 201, radio receiving section 202, OFDM demodulating section 203, first channel estimating section 204, second channel estimating section 205, MIMO receiving processing section 206, demodulating section 207, and decoding section 208.

[0034] At least one of the antenna 201 and the radio receiving unit 202 shown in Fig. 4 may be included in the receiving unit shown in Fig. 2. Also, at least one of the OFDM demodulating unit 203, the first channel estimating unit 204, the second channel estimating unit 205, the MIMO receiving processing unit 206, the demodulating unit 207, and the decoding unit 208 shown in Fig. 4 may be included in the control unit shown in Fig. 2.

[0035] The radio receiving unit 202 performs radio receiving processes such as down-conversion, analog-to-digital conversion, and band-limiting filtering on a signal received by the antenna 201 to obtain a baseband signal.

[0036] The OFDM demodulation unit 203, for example, removes the CP added to the signal input from the radio receiving unit 202, and performs FFT (Fast Fourier Transform) processing on the signal from which the CP has been removed, thereby converting the signal from a time domain signal to a frequency domain signal.

[0037] For example, in a symbol in which a DMRS is transmitted (hereinafter also referred to as a DMRS symbol), the first channel estimation unit 204 extracts a received signal of the DMRS from the OFDM demodulated signal input from the OFDM demodulation unit 203, and estimates a MIMO channel. For example, the first channel estimation unit 204 estimates a MIMO channel for the received DMRS signal by using a replica of the DMRS.

[0038] For example, in a symbol in which the PT-RS is transmitted (hereinafter also referred to as a PT-RS symbol), the second channel estimation unit 205 extracts a PT-RS reception signal from the OFDM demodulated signal input from the OFDM demodulation unit 203, and performs MIMO channel estimation. For example, the second channel estimation unit 205 performs MIMO channel estimation for the PT-RS reception signal using a replica of the PT-RS. Here, for example, since the PT-RS is transmitted sparsely in the frequency direction compared to the DMRS, the channel estimation of the PT-RS may involve frequency direction interpolation using an adaptive filter or the like. At that time, a channel estimation value estimated using the DMRS, which is estimated in the first channel estimation unit 204, may be used.

[0039] The MIMO reception processing unit 206 performs MIMO reception processing including channel equalization (or MIMO separation processing) on ​​the OFDM demodulated signal input from the OFDM demodulation unit 203 using the channel estimation values ​​estimated in the first channel estimation unit 204 and the second channel estimation unit 205, and separates (or detects) each multiplexed stream signal. For example, for a symbol in which a DMRS is transmitted, the MIMO reception processing unit 206 performs MIMO reception processing using the MIMO channel estimation value estimated in the first channel estimation unit 204 (for example, the MIMO channel estimation value based on the DMRS), and for a symbol in which a PT-RS is transmitted, performs MIMO reception processing using the MIMO channel estimation value estimated in the second channel estimation unit 205 (for example, the MIMO channel estimation value based on the PT-RS).

[0040] In addition, examples of the MIMO reception processing include a separation method based on the MMSE (Minimum Mean Square Error) standard, a separation method by zero forcing, etc. In addition, when MIMO transmission is not performed, the MIMO reception processing unit 206 performs channel equalization and does not need to detect stream signals.

[0041] The demodulator 207 converts the modulation symbols modulated by a modulation method such as QPSK or 16QAM into a bit string.

[0042] The decoding unit 208 performs a decoding process on a bit string that has been coded using a coding method such as an LDPC code.

[0043] The processing in each unit that performs reception processing may be performed for each of a plurality of antenna systems. Also, each antenna system may process reception signals from different relay terminals or APs. Also, processing units such as wireless reception units that perform processing for each antenna system may be located in the same housing, or may be distributed in different housings.

[0044] [Example of Operation of the Transmitting Device 100 and the Receiving Device 200] Next, an example of the operation of the transmitting device 100 and the receiving device 200 will be described.

[0045] In this embodiment, on the transmitting side of MIMO transmission (for example, transmitting apparatus 100), stronger phase fluctuations are applied to the MIMO transmitting antenna systems individually than on the receiving side (for example, receiving apparatus 200).

[0046] FIG. 5 shows an example of mapping of a transmission signal.

[0047] In the example of Fig. 5, the vertical direction indicates subcarriers (frequency) and the horizontal direction indicates symbols (time). A DMRS used during demodulation in receiver 200 (receiving side) is allocated to the third symbol shown in Fig. 5.

[0048] The DMRS is densely arranged in the subcarrier direction to follow the frequency response of the channel. On the other hand, the DMRS may be sparsely arranged in the symbol direction when the time response of the channel is slow. In the example of FIG. 5, the DMRS is arranged in the third symbol, and the DMRS is not arranged in the other symbols.

[0049] The PT-RS is densely arranged in the symbol direction to track the phase fluctuation that differs for each symbol. On the other hand, since the phase fluctuation is less likely to vary in the frequency direction, the PT-RS may be sparsely arranged in the frequency direction. In the example of Fig. 5, the PT-RS is arranged every few subcarriers.

[0050] Also, as shown in FIG. 5, in addition to the DMRS and PT-RS, a control channel or a data channel may be placed in the first two symbols, and a data channel may be placed in the area from the fourth symbol onwards where no PT-RS is placed.

[0051] Next, the channel estimation process and the MIMO reception process for the DMRS symbol will be described.

[0052] In the DMRS symbol, the first channel estimation unit 204 extracts a DMRS received signal from the OFDM demodulated signal, and estimates the MIMO channel using a DMRS replica. When data is transmitted in this DMRS symbol, the MIMO reception processing unit 206 performs MIMO reception processing using the MIMO channel estimation value estimated in the first channel estimation unit 204. For example, the MIMO reception processing unit 206 calculates an MMSE receiving weight using the channel estimation value, and multiplies the received signal by the MMSE receiving weight to perform stream separation.

[0053] Next, the channel estimation process and MIMO reception process for each symbol after the DMRS symbol (for example, a symbol in which no DMRS is assigned, or a PT-RS symbol) will be described.

[0054] In this symbol, the second channel estimation unit 205 extracts the received signal of the PT-RS from the OFDM demodulated signal, and estimates the MIMO channel using a replica of the PT-RS. For example, as shown in FIG. 5, since the PT-RS is sparsely arranged in the subcarrier direction, the second channel estimation unit 205 may perform an interpolation process using an adaptive filter or the like to improve the tracking ability of the channel estimation value in the frequency direction. In addition, in this interpolation process, it is also possible to use a channel estimation value estimated by the DMRS symbol. Then, the MIMO reception processing unit 206 performs MIMO reception processing using the MIMO channel estimation value estimated by the second channel estimation unit 205 in each symbol of the PT-RS. For example, the MIMO reception processing unit 206 calculates an MMSE reception weight using the channel estimation value, and multiplies the received signal by the MIMO reception weight to perform stream separation.

[0055] The phase fluctuation during precoding transmission in the above operation will be explained using mathematical expressions.

[0056] Here, as an example, a MIMO transmission in which the number of transmitting antennas is m=2 and the number of receiving antennas is n=2 will be described. n (t) is expressed as equation (1).

number

[0057] In formula (1), h nm denotes the MIMO channel between transmit antenna m and receive antenna n, and w ms is the sending stream s s The transmit precoding weight for the transmit antenna m is shown. m (t) denotes the phase variation at transmitting antenna m, which varies with time t. In equation (1), the phase variations (e.g., φ1(t) and φ2(t)) for each transmitting antenna are independent (different).

[0058] In equation (1), the phase variations φ1(t) and φ2(t) at each transmitting antenna are expressed as the MIMO channel h nm and the transmit precoding weight w ms Since it is sandwiched between and, the received signal r n In (t), these components are mixed together, so it is difficult to separate the phase fluctuation components and perform phase fluctuation correction on the receiving side.

[0059] Next, the received signal in the DMRS symbol will be described. Here, the phase variation φ in equation (1) is m (t), and the phase variation in the DMRS symbol is φ m (t d ), then the received signal r n (t) is expressed as equation (2).

number

[0060] In this case, the MIMO channel h nm and the phase variation φ in the DMRS symbol m (t d ) and the transmit precoding weight w ms These can be collectively considered as an “aggregate MIMO channel.” Receiving apparatus 200 can estimate this aggregate MIMO channel using the DMRS to which transmit precoding is applied in the DMRS symbol.

[0061] Thereby, in the DMRS symbol, the receiving device 200 estimates the aggregated MIMO channel using the DMRS to which the transmission precoding is applied, and performs MIMO receiving processing using the estimated value of the aggregated MIMO channel to separate the transmission stream. In this way, the receiving device 200 performs MIMO separation based on the aggregated MIMO channel including the phase fluctuation in the DMRS symbol, and can simultaneously perform correction of the phase fluctuation in the DMRS symbol and MIMO separation.

[0062] Next, a description will be given of the received signal in the symbols following the DMRS symbol (for example, the PT-RS symbol). Here, the phase variation φ m (t) is the phase variation φ m (t d ), and the relative phase variation Δ m (t p ), then the received signal r n (t) is expressed as equation (3). Here, Δ m (t d )=0.

number

[0063] In this case, as in equation (2), the MIMO channel h nm and the phase variation Δ m (t p ) and transmit precoding weight w ms These can be collectively considered as an “aggregate MIMO channel.” The receiving device 200 can estimate this aggregate MIMO channel using the PT-RS to which transmit precoding is applied in the PT-RS symbol.

[0064] In this case, since the PT-RSs are sparsely arranged in the frequency direction, the channel estimation value may be estimated sparsely in the frequency direction. Therefore, the receiving device 200 may perform interpolation in the frequency direction on the channel estimation value using an adaptive filter or the like. In addition, in this interpolation process, the receiving device 200 may use the channel estimation value estimated in the DMRS symbol.

[0065] Thereby, in the PT-RS symbol, the receiving device 200 estimates the aggregated MIMO channel using the PT-RS to which the transmission precoding is applied, and performs MIMO receiving processing using the channel estimation value of the aggregated MIMO channel to separate the transmission stream. In this way, the receiving device 200 performs MIMO separation based on the aggregated MIMO channel including the phase fluctuation in the PT-RS symbol, and can simultaneously perform correction of the phase fluctuation in the PT-RS symbol and MIMO separation.

[0066] Next, as an operation example of a communication system using the above-described transmitting device 100 and receiving device 200, an example of application to a virtualized terminal system and a distributed antenna system being considered for 6G will be described.

[0067] In a virtualized terminal system, a user terminal and a relay terminal are connected by a link using a high frequency (e.g., terahertz waves), so that the user terminal and the relay terminal behave as if they were one terminal device. For example, the relay terminal is used as a remote antenna connected to the user terminal by a link using a high frequency (e.g., terahertz waves, etc.).

[0068] Here, when each relay terminal serves as a transmitting antenna system of a user terminal, each relay terminal is located at a physically separate location and therefore uses an independent local oscillator. For this reason, in a virtualized terminal system, communication is performed using an independent (not shared) local oscillator between the transmitting antenna systems on the user terminal (e.g., transmitting device 100) side. On the other hand, a base station (e.g., receiving device 200) may use a local oscillator shared by multiple (e.g., two) antennas, for example. In this way, in the uplink in the virtualized terminal system, independent phase fluctuations may occur for each transmitting antenna system in the transmitting device 100 (e.g., user terminal).

[0069] In a distributed antenna system, a plurality of APs (Access Points) or RUs (Radio Units) are connected to a base station (e.g., a transmitting device 100), and each AP serves as a transmitting antenna system of the base station. Each of the distributed APs uses an independent local oscillator. For this reason, in the distributed antenna system, the base station (e.g., a transmitting device 100) communicates using an independent (not shared) local oscillator between the transmitting antenna systems. On the other hand, a user terminal (e.g., a receiving device 200) may use a common local oscillator for multiple (e.g., two) antennas. In this way, in the downlink in the distributed antenna system, independent phase fluctuations may occur for each transmitting antenna system in the transmitting device 100 (e.g., a base station).

[0070] In this case, transmission preceding is applied to the DMRS and PT-RS in addition to the transmission signal, and after phase noise is added in each of the transmission antenna systems, the signal passes through a MIMO channel and is received by the receiving device 200. For this reason, the receiving device 200 obtains a transmission signal (stream) by performing MIMO reception processing for the DMRS symbol based on a channel estimation value using the DMRS to which transmission preceding is applied, and performing MIMO reception processing for the PT-RS symbol based on a channel estimation value using the PT-RS to which transmission preceding is applied.

[0071] Thus, in this embodiment, receiving apparatus 200 receives a signal transmitted by MIMO, and in a symbol in which a DMRS to which transmission preceding is applied to the transmission signal in transmitting apparatus 100 is placed, performs MIMO separation processing using the DMRS, and in a symbol in which a PT-RS to which transmission preceding is applied is placed, performs MIMO separation processing using the PT-RS.

[0072] By performing MIMO separation processing using a channel estimation value using either DMRS or PT-RS according to a predetermined timing (for example, either DMRS symbol or PT-RS symbol), receiving apparatus 200 can perform stream separation with phase fluctuation corrected even when transmission precoding is applied. Therefore, according to this embodiment, receiving apparatus 400 can appropriately correct phase fluctuation.

[0073] Note that the mapping of transmission signals (including, for example, DMRS and PT-RS) shown in FIG. 5 is an example and is not limiting. For example, the DMRS may be arranged contiguously or non-contiguously in multiple symbols, and may be arranged contiguously or non-contiguously in the subcarrier direction. Also, for example, the PT-RS may be arranged contiguously or non-contiguously in the symbol direction, and may be arranged contiguously or non-contiguously in multiple subcarriers. Also, for example, the PT-RS is not limited to being arranged in a symbol after the DMRS, and may be arranged in a symbol prior to the DMRS. Also, the DMRS and PT-RS are not limited to being arranged in the third symbol or later, and may be arranged in the first or second symbol or later.

[0074] (Embodiment 2) In this embodiment, the receiving device performs MIMO separation processing and phase fluctuation correction using a channel estimation value based on a DMRS to which no preceding is applied and a phase fluctuation estimation value based on a PT-RS to which no preceding is applied, and then performs stream separation by removing the preceding component.

[0075] A communication system according to an embodiment of the present disclosure includes at least one transmitting device 300 and at least one receiving device 400. The transmitting device 300 and the receiving device 400 perform communication using, for example, a plurality of antennas.

[0076] Fig. 6 is a block diagram showing an example of the configuration of a transmitting apparatus 300 according to the present embodiment. Note that in transmitting apparatus 300 shown in Fig. 6, the operations of encoding section 301 and multiplexing section 302 differ from those in the first embodiment.

[0077] The encoding unit 301 performs error correction encoding on the transmission data and information related to transmission precoding in the transmitting device 300 (hereinafter, referred to as transmission precoding information). The transmission precoding information may be transmitted by, for example, a control channel and at least one of control information of a higher layer.

[0078] The multiplexing unit 302 multiplexes the modulation symbols to which the preceding has been applied and reference signals to which no preceding has been applied (for example, DMRS and PT-RS). That is, in the transmitting device 300, the transmission preceding is not applied to the DMRS and the PT-RS.

[0079] Fig. 7 is a block diagram showing a configuration example of a receiving apparatus 400 according to the present embodiment. Note that in the receiving apparatus 400 shown in Fig. 7, the operations of a channel estimation unit 401, a phase fluctuation estimation unit 402, a precoding information holding unit 403, a MIMO reception processing unit 404, a phase fluctuation correction unit 405, and a precoding removal unit 406 are different from those in the first embodiment.

[0080] Channel estimation section 401 estimates a MIMO channel by extracting a DMRS received signal from, for example, the OFDM demodulated signal input from OFDM demodulation section 203. For example, channel estimation section 401 estimates a MIMO channel by using a DMRS replica for the DMRS received signal.

[0081] The phase fluctuation estimation unit 402 extracts, for example, a PT-RS reception signal from the OFDM demodulated signal input from the OFDM demodulation unit 203, and estimates the amount of phase fluctuation of each symbol. For example, the phase fluctuation estimation unit 402 performs channel estimation on the PT-RS reception signal using a PT-RS replica. Then, the phase fluctuation estimation unit 402 compares, for example, a channel estimation value estimated using the PT-RS symbol with a channel estimation value estimated in the channel estimation unit 401 using the DMRS symbol, and estimates the relative amount of phase fluctuation in each symbol from the phase in the DMRS symbol. For example, the phase fluctuation estimation unit 402 estimates a different phase fluctuation for each transmission antenna (for example, antenna 107) of the transmission device 300.

[0082] The precoding information holding unit 403 holds the transmission precoding information transmitted from the transmitting device 300 from among the OFDM demodulated signals input from the OFDM demodulation unit 203. For example, the precoding information holding unit 403 receives the transmission precoding information notified from the transmitting device 300 by the control channel or the control information of the higher layer using a predetermined receiving method, and holds the extracted transmission precoding information.

[0083] The MIMO reception processing unit 404 performs MIMO reception processing including channel equalization on the OFDM demodulated signal input from the OFDM demodulation unit 203, for example, using the channel estimation value estimated in the channel estimation unit 401, and separates the signals multiplexed in the MIMO channel.

[0084] cormorant The phase variation correcting unit 405 performs phase variation correction on the signals separated in the MIMO receiving processing unit 404, for example, by using the phase variation estimated in the phase variation estimating unit 402. The phase variation correcting unit 405 performs individual correction for phase variations that differ for each transmitting antenna of the transmitting device 300, for example.

[0085] The precoding removal unit 406, for example, based on the transmission precoding information held by the precoding information holding unit 403, separates (or detects) the transmission stream by multiplying the signal that has been subjected to phase fluctuation correction in the phase fluctuation correction unit 405 by the inverse matrix of the transmission precoding matrix.

[0086] [Example of Operation of the Transmitting Device 300 and the Receiving Device 400] Next, an example of the operation of the transmitting device 300 and the receiving device 400 will be described.

[0087] In this embodiment, similarly to the first embodiment, stronger phase fluctuations are applied individually to each MIMO transmission antenna system on the transmitting side (eg, transmitting apparatus 300) of MIMO transmission than on the receiving side (eg, receiving apparatus 400).

[0088] In this embodiment, as the signal mapping, for example, the same signal mapping as in the first embodiment (eg, FIG. 5) may be used.

[0089] In this embodiment, in receiving apparatus 400, transmit precoding information regarding transmit precoding applied to a transmit signal in transmitting apparatus 300 is already known.

[0090] The transmission precoding information may be notified from the transmitting device 300 to the receiving device 400 by, for example, at least one of a control channel and control information of a higher layer.

[0091] Alternatively, the receiving apparatus 400 may identify (or estimate) the transmit precoding information using a reference signal transmitted from the transmitting apparatus 300. For example, a reference signal to which transmit precoding is applied and a reference signal to which transmit precoding is not applied may be arranged in locations with similar channel conditions (for example, adjacent subcarriers). In this case, the receiving apparatus 400 can estimate the transmit precoding by comparing channel estimation values ​​using the reference signal to which transmit precoding is applied and the reference signal to which transmit precoding is not applied.

[0092] The transmission process in the transmitting device 300 and the reception process in the receiving device 400 will be described below.

[0093] In this embodiment, transmitting apparatus 300 transmits the DMRS and the PT-RS without applying transmit precoding, and transmits the transmission data by applying transmit precoding.

[0094] The receiving apparatus 400 (eg, channel estimator 401) estimates a MIMO channel using a received signal of a DMRS to which no transmit preceding is applied.

[0095] Furthermore, the receiving device 400 (for example, the phase fluctuation estimation unit 402) performs channel estimation using a received signal of a PT-RS to which no transmission preceding is applied. The receiving device 400 then compares a channel estimation value estimated using the PT-RS with a channel estimation value estimated using a DMRS in the same subcarrier as the subcarrier to which the PT-RS is transmitted, and estimates the amount of phase fluctuation from the DMRS symbol in the symbol to which the PT-RS is transmitted. The receiving device 400 may perform this phase fluctuation estimation process for each PT-RS symbol.

[0096] The receiving device 400 (for example, the MIMO receiving processing unit 404) performs MIMO separation of the received signal in each symbol using a MIMO channel estimation value estimated using the DMRS. Furthermore, the receiving device 400 (for example, the phase fluctuation correcting unit 405) performs phase fluctuation correction on the MIMO separated signal using the estimated phase fluctuation amount in each symbol. Furthermore, the receiving device 400 (for example, the precoding removing unit 406) performs separation into transmission streams by multiplying the phase fluctuation corrected signal by an inverse matrix of the transmission precoding using the transmission precoding information held by the receiving device 400.

[0097] The above process will be explained using mathematical expressions.

[0098] As in the first embodiment, as an example, a MIMO transmission in which the number of transmitting antennas m=2 and the number of receiving antennas n=2 will be described. n (t) is expressed as equation (3).

[0099] In equation (3), the phase variation φ in the DMRS symbol m (t d ) and the phase variation Δ m (t p ) is separated as shown in equation (4).

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[0100] Here, the matrix (A) in equation (4) is the MIMO channel h nm and the phase variation φ in the DMRS symbol m (t d ) is a matrix representing an aggregate MIMO channel including the matrix (A) and the matrix (B). The matrix (A) can be estimated by performing channel estimation using DMRS to which no transmit precoding is applied.

[0101] Matrix (B) in equation (4) represents the relative phase variation Δ m (t p ) is a matrix representing

[0102] For example, MIMO channel h nm and the phase variation φ in the DMRS symbol m (t d ) and the relative phase variation Δ m (t pAn aggregate MIMO channel including the matrix (A) and the matrix (B) (e.g., a matrix obtained by combining the matrix (A) and the matrix (B)) can be estimated by performing channel estimation using a PT-RS to which no transmit precoding is applied. Then, the matrix (B) can be estimated by comparing the aggregate MIMO channel obtained by combining the matrix (A) and the matrix (B) with the matrix (A).

[0103] In this way, the receiving device 400 estimates the matrix (A) using the DMRS to which the transmit preceding is not applied, estimates the matrix (B) using the PT-RS to which the transmit preceding is not applied, performs MIMO demultiplexing processing on the received signal using the matrix (A), and corrects the phase fluctuation of the signal after the MIMO demultiplexing processing using the matrix (B). As a result, the matrix (C) remains in the equation (4). The receiving device 400 (for example, the precoding removal unit 406) removes the precoding component by multiplying the inverse matrix of the transmit preceding (matrix (C)) based on the transmit preceding information, and obtains the transmit stream s s Separate.

[0104] As described above, in this embodiment, the receiving apparatus 400 receives a signal transmitted by MIMO, and controls correction of phase fluctuation of the signal by using transmission precoding information for the signal in the transmitting apparatus 300. For example, the receiving apparatus 400 performs a signal separation process in a MIMO transmission channel by using a DMRS to which transmission precoding is not applied, corrects phase fluctuation of the signal after separation process by using a PT-RS to which transmission precoding is not applied, and performs stream separation of the signal after phase fluctuation correction based on the transmission precoding information.

[0105] As a result, even when transmission precoding is applied, the receiving device 400 can perform stream separation with phase variation corrected. Also, in this embodiment, even when different phase variations occur in each of the multiple transmitting antennas after transmission precoding in the transmitting device 300 in MIMO transmission, the receiving device 400 can separate the phase variation component from the received signal and perform phase variation correction. Therefore, according to this embodiment, the receiving device 400 can appropriately correct the phase variation.

[0106] (Embodiment 3) In this embodiment, the receiving device estimates channel estimation values ​​and phase fluctuations from which the preceding components have been removed using channel estimation values ​​from DMRS and PT-RS to which preceding is applied, and performs MIMO separation processing and phase fluctuation correction based on the channel estimation values ​​and phase fluctuations from which the preceding components have been removed, and then performs stream separation by removing the preceding components.

[0107] A communication system according to an embodiment of the present disclosure includes at least one transmitting device 500 and at least one receiving device 600. The transmitting device 500 and the receiving device 600 perform communication using, for example, a plurality of antennas.

[0108] Fig. 8 is a block diagram showing an example of the configuration of a transmitting apparatus 500 according to the present embodiment. Note that in transmitting apparatus 500 shown in Fig. 8, the operations of encoding section 501 and multiplexing section 502 differ from those in the first embodiment.

[0109] Encoding section 501 performs error correction coding on transmission data and information related to transmission precoding in transmitting device 500 (hereinafter referred to as transmission precoding information). The transmission precoding information may be transmitted by, for example, a control channel and at least one of control information of a higher layer.

[0110] The multiplexing unit 502 multiplexes the pre-precoded modulation symbols and reference signals (for example, DMRS and PT-RS). That is, in the transmitting device 500, transmission precoding is applied to the DMRS and PT-RS.

[0111] Fig. 9 is a block diagram showing an example of the configuration of a receiving apparatus 600 according to the present embodiment. Note that in the receiving apparatus 600 shown in Fig. 9, the operations of a channel matrix correcting section 601 and a MIMO receiving processing section 602 are different from those in the second embodiment.

[0112] The channel matrix correction unit 601 corrects a channel estimation value (e.g., a channel matrix) by, for example, multiplying a channel estimation value estimated in the channel estimation unit 401 (e.g., a channel estimation value estimated using DMRS) by an inverse matrix of a transmission precoding matrix based on the transmission precoding information stored in the precoding information storage unit 403.

[0113] The MIMO reception processing unit 602 performs MIMO reception processing including channel equalization on the OFDM demodulated signal input from the OFDM demodulation unit 203, for example, using the channel estimation value corrected in the channel matrix correction unit 601, and separates the signals multiplexed in the MIMO channel.

[0114] [Example of operation of transmitting device 500 and receiving device 600] Next, an example of the operation of the transmitting device 500 and the receiving device 600 will be described.

[0115] In this embodiment, similarly to the first and second embodiments, stronger phase fluctuations are applied individually to each MIMO transmission antenna system on the transmitting side (e.g., transmitting device 500) of MIMO transmission than on the receiving side (e.g., receiving device 600).

[0116] In this embodiment, the same signal mapping as in the first embodiment (eg, FIG. 5) may be used as the signal mapping.

[0117] In this embodiment, information on the transmit precoding applied to a transmit signal in the transmit device 300 is known in the receive device 600, similar to the second embodiment. For example, the transmit precoding information may be notified from the transmit device 300 to the receive device 400 by at least one control information of a control channel and an upper layer, similar to the second embodiment, or may be specified (or estimated) by the receive device 600 based on a reference signal transmitted from the transmit device 500.

[0118] The transmission process in the transmitting device 500 and the reception process in the receiving device 600 will be described below.

[0119] In this embodiment, transmitting apparatus 500 transmits the DMRS and PT-RS by applying transmission precoding, similar to the transmission data.

[0120] The receiving device 600 (eg, the channel estimating unit 401) estimates a MIMO channel using a received signal of a DMRS to which transmit preceding is applied.

[0121] Furthermore, the receiving device 600 (for example, the phase fluctuation estimation unit 402) performs channel estimation using the received signal of the PT-RS to which transmission precoding is applied. Then, the receiving device 600 estimates the amount of phase fluctuation from the DMRS symbol in the PT-RS symbol, as in the second embodiment. The receiving device 600 may perform this phase fluctuation estimation process for each PT-RS symbol.

[0122] The receiving device 600 (e.g., the channel matrix correction unit 601) corrects a channel estimation value (e.g., a channel matrix) of a MIMO channel by multiplying a channel estimation value estimated using a DMRS by an inverse matrix of a transmission preceding matrix, for example, based on the transmission preceding information held by the preceding information holding unit 403.

[0123] The receiving device 600 (for example, the MIMO receiving processing unit 602) performs MIMO separation of the received signal in each symbol using the channel estimation value of the corrected MIMO channel. Furthermore, the receiving device 400 (for example, the phase fluctuation correcting unit 405) performs phase fluctuation correction on the MIMO separated signal using the estimated phase fluctuation amount in each symbol. Furthermore, the receiving device 400 (for example, the precoding removing unit 406) performs separation into transmission streams by multiplying the phase fluctuation corrected signal by the inverse matrix of the transmission precoding using the transmission precoding information held by the receiving device 400.

[0124] The above process will be explained using mathematical expressions.

[0125] As in the first and second embodiments, an example of MIMO transmission in which the number of transmitting antennas m=2 and the number of receiving antennas n=2 will be described. n (t) is expressed as equation (3).

[0126] As in the second embodiment, for the received signal shown in equation (3), the phase variation φ m (t d ) and the phase variation Δ m (t p ) is separated into Equation (4), which is shown in Equation (4). Here, in the case where matrix (D) and matrix (E) are further added to the matrix arrangement shown in Equation (4), Equation (5) is shown.

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[0127] The matrix (A), the matrix (B), and the matrix (C) in the equation (5) are the same as those in the equation (4).

[0128] Matrix (D) in equation (5) is a combination of matrix (A) and matrix (B), and is the MIMO channel hnm and the phase variation φ in the DMRS symbol m (t d ) and the relative phase variation Δ m (t p ) is a matrix that represents the joint MIMO channel including

[0129] The matrix (E) in equation (5) is a combination of matrices (D) and (C), and is the MIMO channel h nm and the phase variation φ in the DMRS symbol m (t d ) and the relative phase variation Δ m (t p ), and transmit precoding (transmit weights). The matrix (E) is the entire MIMO channel between the transmit antenna end of the transmitter 500 and the receive antenna end of the receiver 600.

[0130] The matrix (E), which is the entire MIMO channel, can be estimated by performing channel estimation using DMRS or PT-RS to which transmit precoding is applied.

[0131] In addition, the components of the matrix (C) corresponding to the transmission precoding known to the receiving device 600 are removed from the matrix (E), so that the MIMO channel h nm and the phase variation φ in the DMRS symbol m (t d ) and the relative phase variation Δ m (t p ) can be derived. For example, the matrix (D) can be derived by multiplying the matrix (E) from the right side by the inverse matrix of the matrix (C) which is the transmit precoding.

[0132] An example of the operation of MIMO separation in the receiving device 600 (for example, the channel matrix correction unit 601 and the MIMO receiving processing unit 602) will be described.

[0133] In the DMRS symbol, the relative phase variation Δ m (t d )=0. Thus, for a DMRS symbol, matrix (B) becomes the identity matrix, and matrix (E) is actually the joint MIMO channel consisting of matrices (A) and (C).

[0134] Therefore, in the DMRS symbol, the receiving device 600 (e.g., the channel matrix correction unit 601) multiplies the aggregated MIMO channel consisting of matrices (A) and (C) by the inverse matrix of the transmit precoding (e.g., matrix (C)). For example, the receiving device 600 derives the matrix (A) by multiplying the aggregated MIMO channel (e.g., the combined matrix of matrices (A) and (C)) by the inverse matrix of the matrix (C) from the right. This process is performed to obtain the MIMO channel h obtained by removing the transmit precoding component (e.g., matrix (C)) from the entire MIMO channel (e.g., matrix (E)). nm and the phase variation φ in the DMRS symbol m (t d ) (or a process of correcting the channel matrix).

[0135] The MIMO reception processing unit 602 performs MIMO demultiplexing processing on the received signal input from the OFDM demodulation unit 203 using the aggregate MIMO channel (for example, matrix (A)) derived in the channel matrix correction unit 601 .

[0136] Next, an example of the operation of phase fluctuation estimation in the receiving device 600 (for example, the phase fluctuation estimating section 402 and the phase fluctuation correcting section 405) will be described.

[0137] In symbols after the DMRS (e.g., PT-RS symbols), the receiving device 600 estimates a matrix (E) using the PT-RS to which the transmit precoding is applied, and multiplies the matrix (E) by the inverse matrix of the transmit precoding (e.g., matrix (C)). For example, the receiving device 600 multiplies the inverse matrix of the matrix (C) from the right of the matrix (E) to derive a matrix (D) that is an aggregate MIMO channel including the matrices (A) and (B) by removing the transmit precoding components from the entire MIMO channel.

[0138] Then, the receiving apparatus 600 compares the matrix (A) estimated in the DMRS symbol with the derived matrix (D) to obtain a relative phase variation amount Δ m (t p Receiver 600 estimates a matrix (B) representing the relative phase fluctuation. For example, receiver 600 performs this relative phase fluctuation estimation process for each symbol after the DMRS symbol.

[0139] For example, the receiving device 600 corrects the phase fluctuation of a signal that has been subjected to MIMO receiving processing for each symbol, using the estimated amount of phase fluctuation for each symbol (for example, matrix (B)).

[0140] In this way, the receiving device 600 estimates the matrix (A) using the DMRS to which the transmit precoding is applied and the transmit precoding information, estimates the matrix (B) using the PT-RS to which the transmit precoding is applied and the transmit precoding information, performs MIMO separation processing on the received signal using the matrix (A), and corrects the phase fluctuation of the signal after the MIMO separation processing using the matrix (B). As a result, the matrix (C) remains in the equation (5). The receiving device 600 (for example, the precoding removal unit 406) can remove the precoding component by multiplying the inverse matrix of the transmit precoding (matrix (C)) based on the transmit precoding information, and the transmit stream s s Separate.

[0141] As described above, in this embodiment, the receiving apparatus 600 receives a signal transmitted by MIMO, and controls correction of phase fluctuation of the signal by using transmission precoding information for the signal in the transmitting apparatus 500. For example, the receiving apparatus 600 performs a separation process of a signal in a channel of MIMO transmission by using a DMRS to which transmission precoding is applied and the transmission precoding information, corrects phase fluctuation of the signal after separation process by using a PT-RS to which transmission precoding is applied and the transmission precoding information, and performs stream separation of the signal after phase fluctuation correction based on the transmission precoding information.

[0142] As a result, even when transmission precoding is applied, the receiving device 600 can perform stream separation with phase variation corrected. Also, in this embodiment, in MIMO transmission, even when different phase variations occur in each of the multiple transmitting antennas after transmission precoding in the transmitting device 500 and transmission precoding is applied to the DMRS and PT-RS, the receiving device 600 can separate the phase variation component from the received signal and perform phase variation correction. Therefore, according to this embodiment, the receiving device 600 can appropriately correct the phase variation.

[0143] The embodiments of the present disclosure have been described above.

[0144] In the above embodiment, an example using terahertz waves or millimeter waves has been described, but the present invention can also be applied to other frequency bands.

[0145] Furthermore, in the above embodiment, the case of a virtualized terminal or a distributed antenna system using a relay terminal has been described, but the present invention can also be applied to a normal terminal (for example, where antennas are not distributed) or base station.

[0146] In addition, although a method for correcting phase fluctuations due to phase noise and frequency offset has been described, the method for correcting phase fluctuations may be applied to phase fluctuations due to both phase noise and frequency offset, or may be applied to phase fluctuations due to either phase noise or frequency offset.

[0147] The millimeter wave band may be read as the frequency of "Frequency range 2 (FR2)", and the sub-6 GHz band may be read as the frequency of "Frequency range 1 (FR1)".

[0148] In addition, the reference signal is not limited to DMRS and PT-RS, and may be other signals. For example, the reference signal may be any of CSI-RS (Channel State Information - Reference Signal), TRS (Tracking Reference Signal), CRS (Cell-specific Reference Signal), and SRS (Sounding Reference Signal). In addition, DMRS and PT-RS may be treated as the same type of reference signal without being distinguished.

[0149] Furthermore, the unit of time resource is not limited to symbols and may be other units of time resources, and the unit of frequency resource is not limited to subcarriers and may be other units of frequency resources.

[0150] In addition, the notation "... part" in the above-mentioned embodiments may be replaced with other notations such as "... circuitry," "... device," "... unit," or "... module."

[0151] The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of the above embodiment may be realized partially or entirely as an LSI, which is an integrated circuit, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip that includes some or all of the functional blocks. The LSI may have input and output of data. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI.

[0152] The method of integration is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, after LSI manufacturing, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing.

[0153] Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0154] The present disclosure may be implemented in any type of apparatus, device, or system having a communication function (collectively referred to as a communication apparatus). The communication apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both as functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones, etc.), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks, etc.), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices, etc.), game consoles, digital book readers, telehealth and telemedicine devices, communication-enabled vehicles or mobile conveyances (e.g., cars, airplanes, boats, etc.), and combinations of the above devices.

[0155] Communications Equipment includes, but is not limited to portable or mobile equipment, non-portable or fixed equipment, devices and systems of any kind, such as smart home devices (appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines and any other "Things" that may exist on an Internet of Things (IoT) network.

[0156] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0157] A communications apparatus also includes devices, such as controllers and sensors, connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0158] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0159] A receiving device according to one embodiment of the present disclosure includes a receiving circuit that receives a signal transmitted via MIMO (Multiple-Input Multiple-Output) and a control circuit that controls correction of phase fluctuations of the signal using information regarding transmission precoding of the signal in a transmitting device.

[0160] In one embodiment of the present disclosure, the receiving circuit receives a demodulation reference signal to which the transmit precoding is not applied, and a phase tracking reference signal to which the transmit precoding is not applied, and the control circuit uses the demodulation reference signal to perform a separation process of the signal in the channel of the MIMO transmission, uses the phase tracking reference signal to correct phase fluctuations of the signal after the separation process, and performs stream separation of the signal after correcting the phase fluctuations based on the information.

[0161] In one embodiment of the present disclosure, the receiving circuit receives a demodulation reference signal to which the transmit precoding is applied and a phase tracking reference signal to which the transmit precoding is applied, and the control circuit uses the demodulation reference signal and the information to perform a separation process of the signal in the channel of the MIMO transmission, uses the phase tracking reference signal and the information to correct phase fluctuations of the signal after the separation process, and performs stream separation of the signal after correcting the phase fluctuations based on the information.

[0162] A receiving device according to one embodiment of the present disclosure includes a receiving circuit for receiving a signal transmitted via MIMO (Multiple-Input Multiple-Output), and a control circuit for performing a separation process of the signal in a channel of the MIMO transmission using a demodulation reference signal in a first time resource in which a demodulation reference signal to which transmit precoding is applied to the signal in the transmitting device is arranged, and performing the separation process using the phase tracking reference signal in a second time resource in which a phase tracking reference signal to which the transmit precoding is applied is arranged.

[0163] In one embodiment of the present disclosure, the control circuit performs frequency-direction interpolation on a channel estimation value estimated using the phase tracking reference signal, using a channel estimation value estimated using the demodulation reference signal, in the second time resource.

[0164] In a receiving method according to one embodiment of the present disclosure, a receiving device receives a signal transmitted via MIMO (Multiple-Input Multiple-Output), and controls correction of phase fluctuations of the signal using information regarding transmission precoding for the signal in a transmitting device.

[0165] In a receiving method according to one embodiment of the present disclosure, a receiving device receives a signal transmitted via MIMO (Multiple-Input Multiple-Output), and in a first time resource in which a demodulation reference signal to which transmit precoding is applied to the signal in a transmitting device is arranged, performs a separation process of the signal in a channel of the MIMO transmission using the demodulation reference signal, and in a second time resource in which a phase tracking reference signal to which the transmit precoding is applied is arranged, performs the separation process using the phase tracking reference signal. [Industrial Applicability]

[0166] One aspect of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0167] 100,300,500 Transmitting device 101,301,501 Encoding section 102 Modulation section 103,302,502 Multiplex section 104 Precoding section 105 OFDM Modulation Section 106 Radio transmitter 107,201 Antennas 200,400,600 receiving device 202 Radio receiving unit 203 OFDM demodulation section 204 First channel estimation unit 205 Second channel estimation unit 206,404,602 MIMO receiving processor 207 Demodulation section 208 Decoding section 401 Channel Estimation Unit 402 Phase Fluctuation Estimation Unit 403 Precoding information storage unit 405 Phase Fluctuation Correction Unit 406 Precoding removal unit 601 Channel matrix correction unit

Claims

1. A receiving circuit for receiving signals transmitted via MIMO (Multiple-Input Multiple-Output), A control circuit for controlling correction of phase fluctuations of the signal by using information related to transmission precoding of the signal in a transmitting device; A receiving device comprising:

2. The receiving circuit receives a demodulation reference signal to which the transmit precoding is not applied, and a phase tracking reference signal to which the transmit precoding is not applied, The control circuit includes: Performing a signal separation process in the channel of the MIMO transmission using the demodulation reference signal; Using the phase tracking reference signal, correcting phase variations of the signal after the separation process; performing stream separation of the signal after correcting the phase variation based on the information; 2. The receiving device according to claim 1.

3. The receiving circuit receives a demodulation reference signal to which the transmit precoding is applied and a phase tracking reference signal to which the transmit precoding is applied; The control circuit includes: performing a signal separation process in a channel of the MIMO transmission using the demodulation reference signal and the information; using the phase tracking reference signal and the information to correct phase variations of the signal after the separation process; performing stream separation of the signal after correcting the phase variation based on the information; 2. The receiving device according to claim 1.

4. A receiving circuit for receiving signals transmitted via MIMO (Multiple-Input Multiple-Output), A control circuit that performs a separation process of the signal in the channel of the MIMO transmission using a demodulation reference signal in a first time resource in which a demodulation reference signal to which a transmission precoding is applied to the signal in the transmitting device is arranged, and performs the separation process using the phase tracking reference signal in a second time resource in which a phase tracking reference signal to which the transmission precoding is applied is arranged; A receiving device comprising:

5. the control circuit performs, in the second time resource, interpolation in a frequency direction for a channel estimation value estimated by using the phase tracking reference signal, using a channel estimation value estimated by using the demodulation reference signal.

5. The receiving device according to claim 4.

6. The receiving device Receives signals transmitted via MIMO (Multiple-Input Multiple-Output) Controlling correction of phase fluctuations of the signal using information related to transmission precoding for the signal in a transmitting device. Receiving method.

7. The receiving device Receives signals transmitted via MIMO (Multiple-Input Multiple-Output) In a first time resource in which a demodulation reference signal to which transmission precoding is applied to the signal in the transmitting device is arranged, a separation process of the signal in the channel of the MIMO transmission is performed using the demodulation reference signal, and in a second time resource in which a phase tracking reference signal to which the transmission precoding is applied is arranged, the separation process is performed using the phase tracking reference signal. Receiving method.

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