WO2015045078A1 - Transmission device, reception device, and signal transmission method - Google Patents

Transmission device, reception device, and signal transmission method Download PDF

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Publication number
WO2015045078A1
WO2015045078A1 PCT/JP2013/076148 JP2013076148W WO2015045078A1 WO 2015045078 A1 WO2015045078 A1 WO 2015045078A1 JP 2013076148 W JP2013076148 W JP 2013076148W WO 2015045078 A1 WO2015045078 A1 WO 2015045078A1
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Prior art keywords
transmission
stations
transmitting
signal
space
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PCT/JP2013/076148
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French (fr)
Japanese (ja)
Inventor
慎悟 朝倉
研一 村山
誠 田口
拓也 蔀
澁谷 一彦
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日本放送協会
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Priority to PCT/JP2013/076148 priority Critical patent/WO2015045078A1/en
Publication of WO2015045078A1 publication Critical patent/WO2015045078A1/en

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/02Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/022Site diversity; Macro-diversity
    • H04B7/024Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/02Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0686Hybrid systems, i.e. switching and simultaneous transmission
    • H04B7/0689Hybrid systems, i.e. switching and simultaneous transmission using different transmission schemes, at least one of them being a diversity transmission scheme
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/02Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0667Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal
    • H04B7/0669Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal using different channel coding between antennas
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/238Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
    • H04N21/2383Channel coding or modulation of digital bit-stream, e.g. QPSK modulation

Definitions

  • the present invention relates to a transmission apparatus, a reception apparatus, and a signal transmission method in a transmission system that performs MIMO (Multi-Input Multi-Output) transmission using a plurality of OFDM (Orthogonal Frequency Division Multiplexing) signals.
  • MIMO Multi-Input Multi-Output
  • OFDM Orthogonal Frequency Division Multiplexing
  • ISDB-T Integrated Services Digital Broadcasting Terrestrial
  • a Japanese terrestrial digital broadcasting system realizes high-definition broadcasting (or multiple standard image quality broadcasting) for fixed receivers.
  • next-generation terrestrial digital broadcasting system it is required to provide services with a larger amount of information such as 3D high-definition broadcasting and super high-definition with 16 times the resolution of high-definition instead of conventional high-definition. Therefore, a MIMO system that performs MIMO transmission using a plurality of transmission / reception antennas has been proposed as a technique for expanding the data transmission capacity by radio.
  • SDM space division multiplexing
  • STC space-time codes
  • the first feature is that a transmission station having a plurality of antennas has a plurality of transmission stations, and in a system to which the first scheme and the second scheme can be applied, the plurality of transmission stations should transmit to the receiving apparatus.
  • a transmission device that generates a signal comprising: a transmission unit that transmits a control signal including information indicating which of the first method and the second method should be applied to the reception device; Is a method of performing space-time coding using a plurality of antennas provided in different transmission stations and performing space division multiplexing using a plurality of antennas provided in each of the plurality of transmission stations.
  • space division multiplexing is performed using a plurality of antennas provided in each of the plurality of transmission stations without performing space-time coding using a plurality of antennas provided in different transmission stations.
  • a method of performing is performed using a plurality of antennas provided in each of the plurality of transmission stations without performing space-time coding using a plurality of antennas provided in different transmission stations.
  • the first scheme is applied to the transmission stations adjacent to each other when the transmission areas of the transmission stations adjacent to each other among the plurality of transmission stations overlap.
  • the second scheme is applied to the adjacent transmission stations when the transmission areas of the adjacent transmission stations among the plurality of transmission stations do not overlap.
  • information indicating which of the first method and the second method should be applied is represented by 1 bit.
  • information indicating which of the first method and the second method should be applied is included in a transmission control signal including a transmission parameter.
  • the second feature has a plurality of transmitting stations as transmitting stations having a plurality of antennas.
  • OFDM symbols transmitted from the plurality of transmitting stations are transmitted.
  • a receiving device for receiving comprising: a receiving unit that receives a control signal including information indicating which of the first method and the second method should be applied, wherein the first method is different from each other Is a system that performs space-time coding using a plurality of antennas provided in the antenna and performs space division multiplexing using a plurality of antennas provided in each of the plurality of transmitting stations, and the second system is different from each other.
  • a third feature is that a plurality of transmitting stations are provided as transmitting stations having a plurality of antennas, and the plurality of transmissions are transmitted from a transmitting apparatus to a receiving apparatus in a system to which the first scheme and the second scheme are applicable.
  • a signal transmission method for transmitting a signal via a station, the control signal including information indicating which of the first method and the second method should be applied from the transmitting device to the receiving device The first method performs space-time coding using a plurality of antennas provided in different transmission stations, and also includes a plurality of transmission stations provided in each of the plurality of transmission stations.
  • a method of performing space division multiplexing using an antenna wherein the second method uses the plurality of transmitting stations without performing space-time coding using a plurality of antennas provided in different transmitting stations.
  • FIG. 1 is a block diagram showing a configuration of a transmission apparatus according to the first embodiment of the present invention.
  • FIG. 2 is a diagram illustrating a 4 ⁇ 2 MIMO system including a transmission device and a reception device according to the first embodiment of the present invention.
  • FIG. 3 is a diagram illustrating an example of a transmission area of a transmission station.
  • FIG. 4 is a block diagram showing a configuration of the OFDM modulation unit in the transmission apparatus according to the first embodiment of the present invention.
  • FIG. 5 is a block diagram showing a configuration of the receiving apparatus according to the first embodiment of the present invention.
  • FIG. 6 is a block diagram showing a configuration of an OFDM demodulator in the receiving apparatus according to the first embodiment of the present invention.
  • FIG. 1 is a block diagram showing a configuration of a transmission apparatus according to the first embodiment of the present invention.
  • FIG. 2 is a diagram illustrating a 4 ⁇ 2 MIMO system including a transmission device and a reception device according to the first embodiment of
  • FIG. 7 is a diagram illustrating a 2 ⁇ 2 MIMO system including a transmission device and a reception device according to the first embodiment of the present invention.
  • FIG. 8 is a diagram illustrating an arrangement example of pilot signals of OFDM signals transmitted by the transmission apparatus according to the first embodiment of the present invention.
  • FIG. 1 is a block diagram illustrating a configuration example of a transmission apparatus according to the first embodiment of the present invention.
  • the transmission apparatus 1 includes an error correction encoding unit 10 (10-1 and 10-2), a carrier modulation unit 11 (11-1 and 11-2), and a space-time encoding unit 12 (12-1 and 12-2) and an OFDM modulation unit 13.
  • the input signal to the transmission apparatus 1 is two TS (Transport Stream) signals (TS1 and TS2).
  • a TS dividing device or the like may be arranged before the input of the transmission apparatus 1 and a TS signal after dividing one system TS into two systems may be input to the transmission apparatus 1.
  • the transmitting apparatus 1 outputs four types of OFDM signals in two systems, and the two types of OFDM signals are transmitted to a first transmitting station 14-1 (hereinafter referred to as “transmitting station A”), and the remaining two types of OFDM signals Is transmitted to the second transmitting station 14-2 (hereinafter referred to as “transmitting station B").
  • the error correction coding unit 10 performs error correction coding on the TS signal and outputs it to the carrier modulation unit 11.
  • error correction for example, a BCH code is used as an outer code, and an LDPC (Low Density Parity Check) code is used as an inner code.
  • LDPC Low Density Parity Check
  • Carrier modulation section 11-1 maps the transmission signal to the IQ plane for each subcarrier according to a predetermined modulation scheme, generates first carrier modulation signal a, and outputs the first carrier modulation signal a to space-time coding section 12-1 To do.
  • Carrier modulation section 11-2 maps the transmission signal to the IQ plane for each subcarrier according to a predetermined modulation scheme, generates second carrier modulation signal b, and outputs it to space-time coding section 12-2 To do.
  • the space-time encoding unit 12 performs space-time encoding on the carrier modulation signal generated by the carrier modulation unit 11 to generate a space-time encoded signal, and outputs the generated signal to the OFDM modulation unit 13.
  • Alamouti STBC Space-Time Block Coding
  • the space-time coding unit 12-1 uses the first carrier modulation signal a generated by the carrier modulation unit 11-1 as the space-time coding.
  • Encoding (STBC encoding) is performed to generate a first space-time encoded signal a 1 and a second space-time encoded signal a 2 , and output them to the OFDM modulator 13.
  • the space-time coding unit 12-2 performs space-time coding (STBC coding) on the second carrier modulation signal b generated by the carrier modulation unit 11-2 and performs third space-time coding.
  • STBC coding space-time coding
  • the signal b 1 and the fourth space-time encoded signal b 2 are generated and output to the OFDM modulation unit 13.
  • m represents a certain discrete time
  • * represents a complex conjugate.
  • the OFDM modulation unit 13 inserts a pilot signal and a control signal into the four types of space-time encoded signals (a 1 , a 2 , b 1 , b 2 ) generated by the space-time encoding unit 12 to provide two systems 4 A type of OFDM signal is generated and transmitted to transmitting station A and transmitting station B.
  • the OFDM modulation unit 13 transmits the OFDM signals of the first space-time encoded signal and the third space-time encoded signal (a 1 , b 1 ) to the transmitting station A, and the second space-time code And the OFDM signal of the fourth space-time encoded signal (a 2 , b 2 ) are transmitted to the transmitting station B. That is, the transmission apparatus 1 performs STBC encoding with the transmission stations A and B as a set.
  • the transmitting station 14-1 (transmitting station A) performs MIMO transmission by SDM from the transmitting antennas A-tx1 and A-tx2.
  • the transmission station 14-2 (transmission station B) performs MIMO transmission by SDM from the transmission antennas B-tx1 and B-tx2.
  • the transmitting station 14 implements SDM by using one of two antennas as a horizontally polarized wave and the other as a vertically polarized wave.
  • FIG. 2 is a diagram illustrating a 4 ⁇ 2 MIMO system including a transmission apparatus and a reception apparatus according to the present invention.
  • the signals ⁇ a 1 (m), a 2 (m), b 1 (m), b 2 (m) ⁇ transmitted from the two transmitting stations 14 at time m are ⁇ x 1 , x 2 , X 3 , x 4 ⁇ , which are all different signals. Therefore, even when the D / U ratio of inter-SFN interference becomes 0 dB, frequency selective fading due to inter-SFN interference can be prevented.
  • FIG. 3 is a diagram showing an example of the transmission area (broadcast area, service area) of the transmission station.
  • four transmission stations A, B, C and D and their transmission areas a, b, c and d are shown.
  • STBC encoding with the transmitting stations A and B as a set
  • STBC encoding with the transmitting stations C and D as a set
  • signals transmitted from the transmitting stations A and C and transmitted from the transmitting stations B and D are transmitted.
  • the different signals can be different signals.
  • symbols A and C are circled to indicate that the signals transmitted from the transmitting stations A and C are the same.
  • the symbols B and D are enclosed by squares.
  • the receiving device located in the area where the transmission areas a and b overlap receives the signals transmitted from the transmitting stations A and B at the same time, but the signals transmitted from the transmitting stations A and B are different. Frequency selective fading due to interference can be prevented.
  • a receiving device located in an area where the transmission areas a and d overlap each other receives signals transmitted from the transmission stations A and D at the same time, but the signals transmitted from the transmission stations A and D are different. , Frequency selective fading due to inter-SFN interference can be prevented.
  • FIG. 4 is a block diagram showing a configuration of the OFDM modulation unit 13. As shown in FIG. 4, the OFDM modulation unit 13 includes a pilot / control signal insertion unit 130 and an OFDM signal generation unit 134.
  • the pilot / control signal insertion unit 130 includes pilot signals (SP signals) having different patterns and control for the four types of transmission signals (a 1 , b 1 , a 2 , b 2 ) generated by the space-time encoding unit 12.
  • a signal (TMCC signal or AC signal) is inserted to generate four types of OFDM symbols. More specifically, pilot / control signal insertion section 130 includes pilot signal generation section 131, control signal generation section 132, and OFDM symbol configuration section 133 (133-1 to 133-4).
  • Pilot signal generation section 131 has a predetermined amplitude and phase, generates a pilot signal for inserting a pilot signal for estimating a transmission path response at a predetermined position, and OFDM symbol configuration section 133 Output to.
  • the control signal generation unit 132 has a predetermined amplitude and phase, generates a control signal for inserting a control signal for notifying the receiving apparatus of control information at a predetermined position, and generates an OFDM symbol configuration Output to the unit 133.
  • the control information includes information on transmission parameters such as a carrier modulation scheme, an interleave length, and the number of segments.
  • the OFDM symbol configuration unit 133 inserts the pilot signal and control signal input from the pilot signal generation unit 131 into the four types of transmission signals (a1, b1, a2, and b2) input from the carrier modulation unit 11.
  • the OFDM symbols are generated by arranging them and output to the OFDM signal generator 134.
  • the OFDM signal generation unit 134 generates four types of OFDM signals by performing inverse Fourier transform and orthogonal modulation on each carrier of the four types of OFDM symbols generated by the pilot / control signal insertion unit 130, and transmits the four types of OFDM signals via the transmission station 14. Output to four transmission antennas A-tx1, A-tx2, B-tx1, and B-tx2. More specifically, the OFDM signal generation unit 134 includes an inverse Fourier transform unit 135 (135-1 and 135-2), a GI addition unit 136 (136-1 and 136-2), and an orthogonal modulation unit 137 (137-). 1 and 137-2) and a D / A converter 138 (138-1 and 138-2). In order to synchronize the four OFDM signals, the OFDM signal generation unit 134 supplies a clock having the same frequency to each block.
  • the inverse Fourier transform unit 135 performs an IFFT (Inverse Fast Fourier Transform) process on the OFDM symbol input from the OFDM symbol configuration unit 133 to generate an effective symbol signal in the time domain, and adds a GI Output to the unit 136.
  • IFFT Inverse Fast Fourier Transform
  • the GI adding unit 136 inserts a guard interval obtained by copying the latter half of the effective symbol signal at the head of the effective symbol signal input from the inverse Fourier transform unit 135 and outputs the guard interval to the orthogonal modulation unit 137.
  • the guard interval is inserted in order to reduce intersymbol interference when receiving an OFDM signal, and is set so that the delay time of the multipath delay wave does not exceed the guard interval length.
  • the orthogonal modulation unit 137 performs orthogonal modulation processing on the baseband signal input from the GI addition unit 136 to generate an OFDM signal, and outputs the OFDM signal to the D / A conversion unit 138.
  • the D / A conversion unit 138 converts the OFDM signal input from the quadrature modulation unit 137 into an analog signal.
  • the receiving device receives the OFDM signal transmitted from the transmitting device 1 via a plurality of receiving antennas.
  • the OFDM signal receiver 2 includes an OFDM demodulator 20, a space-time code decoder 21, a carrier demodulator 22 (22-1 and 22-2), and an error correction code decoder 23. (23-1 and 23-2).
  • the OFDM demodulator 20 demodulates the received four systems of four types of OFDM signals to generate two types of baseband signals (c 1 , c 2 ), and uses two types of transmission path responses (h 1 , h 2 ).
  • FIG. 6 is a block diagram showing a configuration of the OFDM demodulator 20.
  • the OFDM demodulator 20 includes an A / D converter 200 (200-1 and 200-2), an orthogonal demodulator 201 (201-1 and 201-2), and a GI remover 202 ( 202-1 and 202-2), Fourier transform unit 203 (203-1 and 203-2), control signal extraction unit 204, pilot signal generation unit 205, and pilot signal extraction unit 206 (206-1 and 206). -2), a transmission path response estimation section 207 (207-1 and 207-2), and a transmission path response interpolation section 208 (208-1 and 208-2).
  • the A / D conversion unit 200 converts an analog reception signal input from the reception antenna rx into a digital signal and outputs the digital signal to the orthogonal demodulation unit 201.
  • the orthogonal demodulation unit 201 generates a baseband signal for the signal input from the A / D conversion unit 200 and outputs the baseband signal to the GI removal unit 202.
  • the GI removal unit 202 removes the guard interval from the signal input from the quadrature demodulation unit 201 to extract an effective symbol signal, and outputs it to the Fourier transform unit 203.
  • the Fourier transform unit 203 performs FFT (Fast Fourier Transform) processing on the effective symbol signal extracted by the GI removal unit 202 to generate complex baseband signals c 1 and c 2, and generates a pilot signal.
  • the data is output to the extraction unit 206.
  • the control signal extraction unit 204 extracts a control signal from the complex baseband signals c 1 and c 2 generated by the Fourier transform unit 203 and outputs control information to the pilot signal generation unit 205.
  • Pilot signal generation section 205 generates a pilot signal having the same amplitude and phase as the pilot signal inserted by transmission apparatus 1 and outputs the position information of the pilot signal inserted by transmission apparatus 1 to pilot signal extraction section 206.
  • the amplitude value and phase value of the pilot signal are output to the transmission path response estimation unit 207.
  • the pilot signal extraction unit 206 extracts a pilot signal from the complex baseband signals c 1 and c 2 generated by the Fourier transform unit 203 based on the position information input from the pilot signal generation unit 205, and estimates the transmission channel response. Output to the unit 207.
  • the transmission path response estimation unit 207 calculates a transmission path response using the pilot signal extracted by the pilot signal extraction unit 206.
  • Transmission path response interpolation section 208 performs transmission path response interpolation processing based on part or all of the transmission path response calculated by transmission path response estimation section 207, and calculates transmission path responses for all subcarriers.
  • the space-time code decoding unit 21 transmits channel responses h 11 , h 12 , h 13 , h calculated by the channel response estimation unit 207 from the complex baseband signals c 1 and c 2 generated by the Fourier transform unit 203. 14, space-time code decoding is performed using h 21 , h 22 , h 23 , and h 24 to generate a carrier modulation signal.
  • the space-time code decoding method will be described below.
  • Complex baseband signals c 1 and c 2 that are input to the space-time code decoding unit 21 are complex baseband signals a 1 , a 2 , b 1 , and b 2 transmitted from the transmission device 1, and the following formula (1 It is considered that noises z 1 and z 2 are added through a transmission line having a transmission line response h represented by). Therefore, the complex baseband signals c 1 and c 2 are expressed by the following equation (2).
  • Equation (2) From Equations (2) and (4), STBC decoding is equivalent to finding x 1 , x 2 , x 3 , and x 4 by solving the following Equation (5).
  • Equation (4) ZF (Zero Forcing), MMSE (Minimum Mean Square Error), MLD (Maximum Likelihood Detection), etc. can be applied.
  • ZF Zero Forcing
  • MMSE Minimum Mean Square Error
  • MLD Maximum Likelihood Detection
  • the space-time code decoding unit 21 includes the complex baseband signals c 1 and c 2 , the transmission path responses h 11 , h 12 , h 13 , h 14 and the transmission path response h that are input from the OFDM demodulation unit 20. 21 , h 22 , h 23 , h 24, and carrier modulation signals x 1 , x 2 , x 3 , x 4 (ie, a (m), a (m + 1), b (m) according to equation (7) , B (m + 1)).
  • SFBC Space-Frequency Block Coding
  • the carrier demodulation unit 22 demodulates the carrier modulation signal generated by the space-time code decoding unit 21 for each subcarrier, and outputs the demodulated signal to the error correction code decoding unit 23.
  • the error correction code decoding unit 23 performs error correction on the signal input from the carrier demodulation unit 22 and decodes the signal transmitted from the transmission device 1.
  • the transmission apparatus 1 constructs STC-MIMO between a plurality of transmission stations 14, generates a modulated wave having a complex conjugate relationship, and performs MIMO transmission by SDM from each of the two antennas of the plurality of transmission stations 14. I do.
  • the receiving apparatus 2 uses two antennas, and each performs STC reception.
  • signals ⁇ a 1 (m), a 2 (m), b 1 (m), b 2 (m) ⁇ is ⁇ x 1 , x 2 , x 3 , x 4 ⁇ , which are all different signals. Therefore, even when the D / U ratio of SFN interference becomes 0 dB, frequency selective fading can be prevented.
  • FIG. 7 is a diagram illustrating a 2 ⁇ 2 MIMO system including a transmission device and a reception device according to the present invention.
  • the receiving apparatus 2 receives only a signal transmitted from one transmitting station A, 2 ⁇ 2 MIMO transmission is performed as shown in FIG.
  • the receiving apparatus 2 receives only the space-time encoded signals a 1 and b 1 , and there is no data redundancy and a diversity effect cannot be obtained, but the signal ⁇ a 1 (m), a 1 (m + 1), b 1 (m), b 1 (m + 1) ⁇ are ⁇ x 1 , ⁇ x * 2 , x 3 , ⁇ x * 4 ⁇ as described above, and the transmission signal x1, x2, x3, and x4 can be transmitted.
  • the receiving apparatus 2 receives only the transmission signal of the transmitting station B, it means that only the signals a 2 and b 2 are received, and the transmission signals x 1 , x 2 , x 3 , and x 4 are transmitted. Is possible. Therefore, in a transmission area (isolated transmission area) that is isolated without being adjacent to the transmission areas of other transmission stations as in the transmission area c shown in FIG. 3, the transmission path response may be calculated as 2 ⁇ 2 MIMO.
  • the receiving device 2 cannot determine whether or not the installed area is an isolated transmission area.
  • the receiving apparatus 2 always calculates the transmission path response as 4 ⁇ 2 MIMO
  • a noise component instead of 0 is applied to a part of the transmission path response of the above formula (1).
  • the components of the transmission path response of the above formula (1) are h 13 , h 14 , h 23 , h 24 A noise component is applied instead of zero.
  • the decoding accuracy is worse than when the transmission path response is calculated as 2 ⁇ 2 MIMO.
  • the receiving apparatus 2 demodulates 4 ⁇ 2 MIMO using all of the four patterns of OFDM signals, only the patterns 1 and 2 or only the patterns 3 and 4 are used.
  • the symbol period for interpolation of the transmission path response is long, there is a possibility that the reception level may vary with time, and the dynamic characteristics deteriorate.
  • the symbol period required for interpolation of the transmission path response is 8 symbols, and when demodulating 4 ⁇ 2 MIMO, the symbol period required for interpolation of the transmission path response is 16 symbols.
  • the diversity effect due to STC can be expected by setting it to 4 ⁇ 2 MIMO, but if it is an isolated transmission area, not only the diversity effect due to STC cannot be expected when it is set to 4 ⁇ 2 MIMO. Dynamic characteristics will deteriorate.
  • the transmission apparatus 1 uses a transmission control signal such as a TMCC signal to determine whether the transmission area of the transmission station 14 is an isolated transmission area that is not adjacent to the transmission areas of other transmission stations.
  • the receiving apparatus 2 determines the MIMO demodulation method based on the transmission area information. For example, when the transmission area is not an isolated transmission area, the reception device 2 decodes the STC-SFN with 4 ⁇ 2 MIMO. On the other hand, when the transmission area of the transmission station 14 is an isolated transmission area, the receiving apparatus 2 decodes as 2 ⁇ 2 MIMO, thereby improving the dynamic characteristics as compared with the case of decoding as 4 ⁇ 2 MIMO STC-SFN. can do.
  • the transmission control signal is a data carrier obtained by performing MIMO-OFDM modulation on data such as a TS (Transport Stream) signal, such as a TMCC signal, after performing processing such as error correction coding / mapping.
  • a TS Transport Stream
  • TMCC Transport Stream
  • the transmission control signal is mapped to a carrier different from the data carrier in the OFDM frame.
  • the receiving apparatus 2 can perform MIMO depending on whether the transmission signals of both the transmission stations A and B can be received, only the transmission signal of the transmission station A can be received, or only the transmission signal of the transmission station B can be received.
  • the demodulation process is different. Therefore, the pilot signal arrangement pattern (hereinafter referred to as “pilot pattern”) generated by the pilot signal generation unit 131 of the transmission apparatus 1 can separate four signals transmitted from the two transmission stations A and B on the reception side. In addition, it is necessary to make the pattern separable on the receiving side even with only two signals transmitted from one transmitting station.
  • FIG. 8 is a diagram illustrating an example of a pilot pattern of an OFDM signal transmitted by the transmission apparatus 1.
  • Patterns 1 to 4 indicate pilot patterns of OFDM signals transmitted from the respective transmission antennas.
  • a circle means a null pilot signal with no signal.
  • 1 and -1 mean that the pilot signals are inverted in sign.
  • Others mean non-pilot signals such as data signals and control signals.
  • the right direction is the carrier (frequency) direction, and the downward direction is the symbol (time) direction.
  • Pilot signal generating section 131 generates pilot signals shown in patterns 1 and 2 for transmitting station A, and generates pilot signals shown in patterns 3 and 4 for transmitting station B.
  • the OFDM signal of pattern 1 is transmitted from the transmission antenna A-tx1 of the transmission station A
  • the OFDM signal of pattern 2 is transmitted from the transmission antenna A-tx2 of the transmission station A
  • the transmission antenna B-tx1 of the transmission station B is transmitted.
  • the pattern 3 OFDM signal is transmitted
  • the pattern 4 OFDM signal is transmitted from the transmission antenna B-tx2 of the transmission station B.
  • the control signal generator 132 generates a control signal for notifying control information including transmission area information indicating whether or not the transmission area of the transmission station 14 is an isolated transmission area.
  • the transmission apparatus 1 can notify the reception apparatus 2 whether or not the transmission area of the transmission station 14 is an isolated transmission area.
  • the transmission area information can be 1-bit information indicating whether or not the transmission area of the transmission station 14 is an isolated transmission area.
  • the receiving device 2 cannot determine whether the transmitting station is A or B only with 1-bit transmission area information indicating whether or not the transmission area is an isolated transmission area. This can be dealt with by fixing the pilot pattern to either one of the transmitting stations A and B. Alternatively, the receiving apparatus 2 may determine the pilot pattern so that the error is smaller after the transmitting station demodulates using both A and B pilot patterns.
  • control signal generation unit 132 indicates transmission area information 2 indicating whether the transmission area of the transmission station 14 is an isolated transmission area and whether the transmission station 14 is the transmission station A or the transmission station B. It can be bit information.
  • the control signal generation unit 132 may use the transmission area information as ID information for identifying the transmission station 14.
  • one bit of the transmission area information is a transmission signal type bit for distinguishing signals transmitted from the transmission station. That is, when the transmitting station 14 transmits the OFDM signals of the first space-time encoded signal and the third space-time encoded signal (a 1 , b 1 ), the transmission signal type bit is set to 0, and the transmitting station When 14 transmits OFDM signals of the second space-time encoded signal and the fourth space-time encoded signal (a 2 , b 2 ), the transmission signal type bit is set to 1.
  • transmitting stations A and C transmit OFDM signals of space-time encoded signals (a 1 , b 1 ), and transmitting stations B and D transmit OFDM signals of space-time encoded signals (a 2 , b 2 ).
  • IDs of transmitting stations A, B, C, and D are 00, 10, 01, and 11, respectively.
  • the type of transmission signal can be identified at the same time as identifying the transmission station 14 by the ID.
  • the reception device 2 can determine that it is an isolated transmission area because there is only one transmission station.
  • the control signal extraction unit 204 extracts a control signal from the complex baseband signals c 1 and c 2 input from the Fourier transform unit 203.
  • the control information is output not only to the pilot signal generation unit 205 but also to the transmission path response estimation unit 207.
  • pilot signal generation unit 205 determines from the transmission area information that the transmission area is not an isolated transmission station area, the pilot signal generation unit 205 generates four types of pilot signals. Pilot signal generation section 205 generates two types of pilot signals when it is determined from the transmission area information that the transmission area is an isolated transmission area.
  • the transmission path response estimation unit 207 calculates a transmission path response using four types of pilot signals. Further, when it is determined from the transmission area information that the transmission area is an isolated transmission station area, the transmission path response estimation unit 207 calculates a transmission path response using two types of pilot signals.
  • 4 ⁇ 2 MIMO (first scheme) and 2 ⁇ 2 MIMO (second scheme) are applicable to the system according to the embodiment.
  • 4 ⁇ 2 MIMO (first scheme) uses a plurality of antennas (for example, A-tx1 and B-tx1 shown in FIG. 2 or A-tx2 and B-tx2 shown in FIG. 2) provided in different transmission stations.
  • STC Space Time Codes
  • 2 ⁇ 2 MIMO (second scheme) is used for a plurality of antennas (for example, A-tx1 and B-tx1 shown in FIG. 2 or A-tx2 and B- A plurality of antennas (for example, A-tx1 and A-tx2 shown in FIG. 2 or the like shown in FIG. 2), without performing space-time coding (STC: Space Time Codes) using tx2).
  • STC Space Time Codes
  • the transmission apparatus 1 transmits a control signal including information indicating which of 4 ⁇ 2 MIMO (first scheme) and 2 ⁇ 2 MIMO (second scheme) should be applied to the reception device 2.
  • 4 ⁇ 2 MIMO (first scheme) may be applied to transmission stations adjacent to each other when the transmission areas of the transmission stations adjacent to each other among a plurality of transmission stations overlap.
  • 2 ⁇ 2 MIMO (second scheme) is preferably applied to adjacent transmission stations when the transmission areas of the adjacent transmission stations among the plurality of transmission stations do not overlap.
  • the embodiment is not limited to this.
  • the 4 ⁇ 2 MIMO (first method) or 2 ⁇ 2 MIMO (second method) method to be applied is determined according to the position of the transmitting stations adjacent to each other, the geographical conditions around each transmitting station, and the like. May be.
  • the transmission apparatus 1 transmits the transmission area information indicating whether the transmission area of the transmission station 14 is an isolated transmission area that is not adjacent to the transmission areas of other transmission stations (that is, 4 A control signal including information indicating which of ⁇ 2 MIMO (first scheme) and 2 ⁇ 2 MIMO (second scheme) is to be transmitted is transmitted.
  • 4 ⁇ 2 MIMO STC ⁇ is used using four types of pilot signals. Decode as SFN.
  • decoding is performed as STC-SFN with 2 ⁇ 2 MIMO, so that dynamic characteristics are improved as compared with a case where decoding is always performed as STC-SFN with 4 ⁇ 2 MIMO. Will be able to.
  • space-time encoded signals a 1 , a 2 , b 1 , and b 2 are obtained by STBC encoding.
  • the value is as follows.
  • frequency selective fading due to inter-SFN interference can be prevented, which is useful for any application that performs MIMO transmission.

Abstract

This system has a plurality of transmission stations (14-1, 14-2) as transmission stations having a plurality of antennas, and is able to adopt a first method and a second method, wherein a transmission device (1), which generates a signal to be transmitted from the plurality of transmission stations to a reception device (2), is provided with a transmission unit that transmits to the reception device a control signal containing information indicating which method of the first method and second method is to be adopted, the first method being a method of performing spatio-temporal encoding using a plurality of antennas provided to different transmission stations, and performing space division multiplexing using the plurality of antennas provided respectively to the plurality of transmission stations, and the second method being a method of performing space division multiplexing using the plurality of antennas provided respectively to the plurality of transmission stations without performing spatio-temporal encoding using the plurality of antennas provided to different transmission stations.

Description

送信装置、受信装置、及び信号送信方法Transmitting apparatus, receiving apparatus, and signal transmitting method
 本発明は、複数のOFDM(Orthogonal Frequency Division Multiplexing:直交周波数分割多重)信号を用いてMIMO(Multi Input Multi Output)伝送を行う伝送システムにおける、送信装置、受信装置、及び信号送信方法に関する。 The present invention relates to a transmission apparatus, a reception apparatus, and a signal transmission method in a transmission system that performs MIMO (Multi-Input Multi-Output) transmission using a plurality of OFDM (Orthogonal Frequency Division Multiplexing) signals.
  日本の地上デジタル放送方式であるISDB-T(Integrated Services Digital Broadcasting - Terrestrial)は、固定受信機向けにハイビジョン放送(又は複数標準画質放送)を実現している。次世代の地上デジタル放送方式では、従来のハイビジョンに変わり、3Dハイビジョン放送やハイビジョンの16倍の解像度を持つスーパーハイビジョンなど、さらに情報量の多いサービスを提供することが求められている。そこで、無線によるデータ伝送容量を拡大するための手法として、複数の送受信アンテナを用いてMIMO伝送を行うMIMOシステムが提案されている。 ISDB-T (Integrated Services Digital Broadcasting Terrestrial), a Japanese terrestrial digital broadcasting system, realizes high-definition broadcasting (or multiple standard image quality broadcasting) for fixed receivers. In the next-generation terrestrial digital broadcasting system, it is required to provide services with a larger amount of information such as 3D high-definition broadcasting and super high-definition with 16 times the resolution of high-definition instead of conventional high-definition. Therefore, a MIMO system that performs MIMO transmission using a plurality of transmission / reception antennas has been proposed as a technique for expanding the data transmission capacity by radio.
 MIMOシステムでは、空間分割多重(SDM:Space Division Multiplexing)や、時空間符号(STC:Space Time Codes)が行われることが知られている(例えば、特許文献1参照)。 In the MIMO system, it is known that space division multiplexing (SDM) and space-time codes (STC) are performed (for example, see Patent Document 1).
 しかしながら、地上デジタル放送エリアにおいてSFN(Single Frequency Network)を組む場合、複数の送信局から同一周波数の電波が送信されるため、受信点によってはSFN間干渉による周波数選択性フェージングが発生するという問題があった。 However, when SFN (Single Frequency Network) is formed in the terrestrial digital broadcasting area, radio waves of the same frequency are transmitted from a plurality of transmitting stations, and therefore there is a problem that frequency selective fading due to inter-SFN interference occurs depending on the reception point. there were.
特開2005―136492号公報JP 2005-136492 A
 第1の特徴は、複数のアンテナを有する送信局として複数の送信局を有しており、第1方式及び第2方式を適用可能なシステムにおいて、前記複数の送信局から受信装置に送信すべき信号を生成する送信装置であって、前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報を含む制御信号を前記受信装置に送信する送信部を備え、前記第1方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行うとともに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であり、前記第2方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行わずに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であることを要旨とする。 The first feature is that a transmission station having a plurality of antennas has a plurality of transmission stations, and in a system to which the first scheme and the second scheme can be applied, the plurality of transmission stations should transmit to the receiving apparatus. A transmission device that generates a signal, comprising: a transmission unit that transmits a control signal including information indicating which of the first method and the second method should be applied to the reception device; Is a method of performing space-time coding using a plurality of antennas provided in different transmission stations and performing space division multiplexing using a plurality of antennas provided in each of the plurality of transmission stations. In the two schemes, space division multiplexing is performed using a plurality of antennas provided in each of the plurality of transmission stations without performing space-time coding using a plurality of antennas provided in different transmission stations. And summarized in that a method of performing.
 第1の特徴において、前記第1方式は、前記複数の送信局のうち、互いに隣接する送信局のそれぞれが有する送信エリアが重複する場合に、前記互いに隣接する送信局に適用される。 In the first feature, the first scheme is applied to the transmission stations adjacent to each other when the transmission areas of the transmission stations adjacent to each other among the plurality of transmission stations overlap.
 第1の特徴において、前記第2方式は、前記複数の送信局のうち、互いに隣接する送信局のそれぞれが有する送信エリアが重複しない場合に、前記互いに隣接する送信局に適用される。 In the first feature, the second scheme is applied to the adjacent transmission stations when the transmission areas of the adjacent transmission stations among the plurality of transmission stations do not overlap.
 第1の特徴において、前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報は、1ビットで表される。 In the first feature, information indicating which of the first method and the second method should be applied is represented by 1 bit.
 第1の特徴において、前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報は、伝送パラメータを含む伝送制御信号に含まれる。 In the first feature, information indicating which of the first method and the second method should be applied is included in a transmission control signal including a transmission parameter.
 第2の特徴は、複数のアンテナを有する送信局として複数の送信局を有しており、第1方式及び第2方式を適用可能なシステムにおいて、前記複数の送信局から送信されるOFDMシンボルを受信する受信装置であって、前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報を含む制御信号を受信する受信部を備え、前記第1方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行うとともに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であり、前記第2方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行わずに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式である。 The second feature has a plurality of transmitting stations as transmitting stations having a plurality of antennas. In a system to which the first scheme and the second scheme can be applied, OFDM symbols transmitted from the plurality of transmitting stations are transmitted. A receiving device for receiving, comprising: a receiving unit that receives a control signal including information indicating which of the first method and the second method should be applied, wherein the first method is different from each other Is a system that performs space-time coding using a plurality of antennas provided in the antenna and performs space division multiplexing using a plurality of antennas provided in each of the plurality of transmitting stations, and the second system is different from each other. A system that performs space division multiplexing using a plurality of antennas provided in each of the plurality of transmitting stations, without performing space-time coding using a plurality of antennas provided in the transmitting station. That.
 第3の特徴は、複数のアンテナを有する送信局として複数の送信局を有しており、第1方式及び第2方式を適用可能なシステムにおいて、送信装置から受信装置に対して前記複数の送信局を介して信号を送信する信号送信方法であって、前記送信装置から前記受信装置に対して、前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報を含む制御信号を前記受信装置に送信するステップを備え、前記第1方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行うとともに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であり、前記第2方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行わずに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式である。 A third feature is that a plurality of transmitting stations are provided as transmitting stations having a plurality of antennas, and the plurality of transmissions are transmitted from a transmitting apparatus to a receiving apparatus in a system to which the first scheme and the second scheme are applicable. A signal transmission method for transmitting a signal via a station, the control signal including information indicating which of the first method and the second method should be applied from the transmitting device to the receiving device The first method performs space-time coding using a plurality of antennas provided in different transmission stations, and also includes a plurality of transmission stations provided in each of the plurality of transmission stations. A method of performing space division multiplexing using an antenna, wherein the second method uses the plurality of transmitting stations without performing space-time coding using a plurality of antennas provided in different transmitting stations. A method of performing space division multiplexing using a plurality of antennas provided in each.
図1は、本発明の第1の実施形態に係る送信装置の構成を示すブロック図である。FIG. 1 is a block diagram showing a configuration of a transmission apparatus according to the first embodiment of the present invention. 図2は、本発明の第1の実施形態に係る送信装置及び受信装置を備える4×2MIMOシステムを示す図である。FIG. 2 is a diagram illustrating a 4 × 2 MIMO system including a transmission device and a reception device according to the first embodiment of the present invention. 図3は、送信局の送信エリアの例を示す図である。FIG. 3 is a diagram illustrating an example of a transmission area of a transmission station. 図4は、本発明の第1の実施形態に係る送信装置におけるOFDM変調部の構成を示すブロック図である。FIG. 4 is a block diagram showing a configuration of the OFDM modulation unit in the transmission apparatus according to the first embodiment of the present invention. 図5は、本発明の第1の実施形態に係る受信装置の構成を示すブロック図である。FIG. 5 is a block diagram showing a configuration of the receiving apparatus according to the first embodiment of the present invention. 図6は、本発明の第1の実施形態に係る受信装置におけるOFDM復調部の構成を示すブロック図である。FIG. 6 is a block diagram showing a configuration of an OFDM demodulator in the receiving apparatus according to the first embodiment of the present invention. 図7は、本発明の第1の実施形態に係る送信装置及び受信装置を備える2×2MIMOシステムを示す図である。FIG. 7 is a diagram illustrating a 2 × 2 MIMO system including a transmission device and a reception device according to the first embodiment of the present invention. 図8は、本発明の第1の実施形態に係る送信装置が送信するOFDM信号のパイロット信号の配置例を示す図である。FIG. 8 is a diagram illustrating an arrangement example of pilot signals of OFDM signals transmitted by the transmission apparatus according to the first embodiment of the present invention.
 以下、本発明の実施形態について、図面を参照して詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
 (第1の実施形態)
 [送信装置]
 送信装置は、OFDM信号をn個の送信局から各2本の送信アンテナを介して送信する。本実施形態では、n=2の場合を例に説明する。図1は、本発明の第1の実施形態に係る送信装置の構成例を示すブロック図である。図1に示すように、送信装置1は、誤り訂正符号化部10(10-1及び10-2)と、キャリア変調部11(11-1及び11-2)と、時空間符号化部12(12-1及び12-2)と、OFDM変調部13と、を備える。送信装置1への入力信号は、2系統のTS(Transport Stream)信号(TS1及びTS2)とする。なお、送信装置1の入力前段にTS分割装置などを配置し、1系統のTSを2系統に分割した後のTS信号を送信装置1に入力してもよい。送信装置1は2系統4種類のOFDM信号を出力し、2種類のOFDM信号は第1の送信局14-1(以下、「送信局A」という)に送信され、残りの2種類のOFDM信号は第2の送信局14-2(以下、「送信局B」という)に送信される。
(First embodiment)
[Transmitter]
The transmitting apparatus transmits an OFDM signal from n transmitting stations via two transmitting antennas. In this embodiment, a case where n = 2 is described as an example. FIG. 1 is a block diagram illustrating a configuration example of a transmission apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the transmission apparatus 1 includes an error correction encoding unit 10 (10-1 and 10-2), a carrier modulation unit 11 (11-1 and 11-2), and a space-time encoding unit 12 (12-1 and 12-2) and an OFDM modulation unit 13. The input signal to the transmission apparatus 1 is two TS (Transport Stream) signals (TS1 and TS2). Note that a TS dividing device or the like may be arranged before the input of the transmission apparatus 1 and a TS signal after dividing one system TS into two systems may be input to the transmission apparatus 1. The transmitting apparatus 1 outputs four types of OFDM signals in two systems, and the two types of OFDM signals are transmitted to a first transmitting station 14-1 (hereinafter referred to as “transmitting station A”), and the remaining two types of OFDM signals Is transmitted to the second transmitting station 14-2 (hereinafter referred to as "transmitting station B").
 誤り訂正符号化部10は、TS信号を誤り訂正符号化し、キャリア変調部11へ出力する。誤り訂正は、例えば外符号としてBCH符号を用い、内符号としてLDPC(Low Density Parity Check)符号を用いる。 The error correction coding unit 10 performs error correction coding on the TS signal and outputs it to the carrier modulation unit 11. For error correction, for example, a BCH code is used as an outer code, and an LDPC (Low Density Parity Check) code is used as an inner code.
 キャリア変調部11-1は、送信信号をサブキャリアごとに所定の変調方式に応じてIQ平面へマッピングして、第1のキャリア変調信号aを生成し、時空間符号化部12-1に出力する。キャリア変調部11-2は、送信信号をサブキャリアごとに所定の変調方式に応じてIQ平面へマッピングして、第2のキャリア変調信号bを生成し、時空間符号化部12-2に出力する。 Carrier modulation section 11-1 maps the transmission signal to the IQ plane for each subcarrier according to a predetermined modulation scheme, generates first carrier modulation signal a, and outputs the first carrier modulation signal a to space-time coding section 12-1 To do. Carrier modulation section 11-2 maps the transmission signal to the IQ plane for each subcarrier according to a predetermined modulation scheme, generates second carrier modulation signal b, and outputs it to space-time coding section 12-2 To do.
 時空間符号化部12は、キャリア変調部11により生成されたキャリア変調信号を時空間符号化して時空間符号化信号を生成し、OFDM変調部13に出力する。時空間符号化としてAlamoutiのSTBC(Space-Time Block Coding)を適用した場合、時空間符号化部12-1は、キャリア変調部11-1により生成された第1のキャリア変調信号aを時空間符号化(STBC符号化)して、第1の時空間符号化信号a及び第2の時空間符号化信号aを生成し、OFDM変調部13に出力する。同様に、時空間符号化部12-2は、キャリア変調部11-2により生成された第2のキャリア変調信号bを時空間符号化(STBC符号化)して、第3の時空間符号化信号b及び第4の時空間符号化信号bを生成し、OFDM変調部13に出力する。 The space-time encoding unit 12 performs space-time encoding on the carrier modulation signal generated by the carrier modulation unit 11 to generate a space-time encoded signal, and outputs the generated signal to the OFDM modulation unit 13. When Alamouti STBC (Space-Time Block Coding) is applied as the space-time coding, the space-time coding unit 12-1 uses the first carrier modulation signal a generated by the carrier modulation unit 11-1 as the space-time coding. Encoding (STBC encoding) is performed to generate a first space-time encoded signal a 1 and a second space-time encoded signal a 2 , and output them to the OFDM modulator 13. Similarly, the space-time coding unit 12-2 performs space-time coding (STBC coding) on the second carrier modulation signal b generated by the carrier modulation unit 11-2 and performs third space-time coding. The signal b 1 and the fourth space-time encoded signal b 2 are generated and output to the OFDM modulation unit 13.
 送信したい複素ベースバンド信号がx,x,x,x(ここで、x=a(m),x=a(m+1),x=b(m),x=b(m+1)である)とすると、STBC符号化により時空間符号化信号a,a,b,bは以下のような値となる。ここで、mはある離散時間を表し、は複素共役を表す。 The complex baseband signals to be transmitted are x 1 , x 2 , x 3 , x 4 (where x 1 = a (m), x 2 = a (m + 1), x 3 = b (m), x 4 = b (M + 1)), the space-time encoded signals a 1 , a 2 , b 1 , and b 2 have the following values by STBC encoding. Here, m represents a certain discrete time, and * represents a complex conjugate.
 a(m)=x
 a(m+1)=-x
 a(m)=x
 a(m+1)=x
 b(m)=x
 b(m+1)=-x
 b(m)=x
 b(m+1)=x
a 1 (m) = x 1
a 1 (m + 1) = − x * 2
a 2 (m) = x 2
a 2 (m + 1) = x * 1
b 1 (m) = x 3
b 1 (m + 1) = − x * 4
b 2 (m) = x 4
b 2 (m + 1) = x * 3
 OFDM変調部13は、時空間符号化部12により生成された4種類の時空間符号化信号(a,a,b,b)にパイロット信号及び制御信号を挿入して2系統4種類のOFDM信号を生成し、送信局A及び送信局Bに送信する。このとき、OFDM変調部13は、第1の時空間符号化信号及び第3の時空間符号化信号(a,b)のOFDM信号を送信局Aに送信し、第2の時空間符号化信号及び第4の時空間符号化信号(a,b)のOFDM信号を送信局Bに送信する。つまり、送信装置1は、送信局A,Bを組み
としてSTBC符号化を行う。
The OFDM modulation unit 13 inserts a pilot signal and a control signal into the four types of space-time encoded signals (a 1 , a 2 , b 1 , b 2 ) generated by the space-time encoding unit 12 to provide two systems 4 A type of OFDM signal is generated and transmitted to transmitting station A and transmitting station B. At this time, the OFDM modulation unit 13 transmits the OFDM signals of the first space-time encoded signal and the third space-time encoded signal (a 1 , b 1 ) to the transmitting station A, and the second space-time code And the OFDM signal of the fourth space-time encoded signal (a 2 , b 2 ) are transmitted to the transmitting station B. That is, the transmission apparatus 1 performs STBC encoding with the transmission stations A and B as a set.
 送信局14-1(送信局A)は、送信アンテナA-tx1及びA-tx2から、SDMによるMIMO送信を行う。送信局14-2(送信局B)は、送信アンテナB-tx1及びB-tx2から、SDMによるMIMO送信を行う。例えば、送信局14は2本のアンテナのうち、一方を水平偏波とし、他方を垂直偏波とすることによりSDMを実現する。 The transmitting station 14-1 (transmitting station A) performs MIMO transmission by SDM from the transmitting antennas A-tx1 and A-tx2. The transmission station 14-2 (transmission station B) performs MIMO transmission by SDM from the transmission antennas B-tx1 and B-tx2. For example, the transmitting station 14 implements SDM by using one of two antennas as a horizontally polarized wave and the other as a vertically polarized wave.
 図2は、本発明による送信装置及び受信装置を備える4×2MIMOシステムを示す図である。2つの送信局14から時刻mに送信される信号{a(m),a(m),b(m),b(m)}は、上述したように{x,x,x,x}であり、全て異なる信号である。そのため、SFN間干渉のD/U比が0dBとなる場合でも、SFN間干渉による周波数選択性フェージングを防止することができる。 FIG. 2 is a diagram illustrating a 4 × 2 MIMO system including a transmission apparatus and a reception apparatus according to the present invention. As described above, the signals {a 1 (m), a 2 (m), b 1 (m), b 2 (m)} transmitted from the two transmitting stations 14 at time m are {x 1 , x 2 , X 3 , x 4 }, which are all different signals. Therefore, even when the D / U ratio of inter-SFN interference becomes 0 dB, frequency selective fading due to inter-SFN interference can be prevented.
 図3は、送信局の送信エリア(放送エリア、サービスエリア)の例を示す図である。図中には4つの送信局A,B,C,Dとその送信エリアa,b,c,dを示している。送信局A,Bを組みとしてSTBC符号化を行い、送信局C,Dを組みとしてSTBC符号化を行うことにより、送信局A,Cから送信される信号と、送信局B,Dから送信される信号を異なる信号とすることができる。図中では、送信局A,Cから送信される信号が同一であることを示すために符号A,Cを丸で囲って示している。また、送信局B,Dから送信される信号が同一であり、かつ送信局A,Cから送信される信号と異なることを示すために符号B,Dを四角で囲って示している。送信エリアa,bの重なる領域に位置する受信装置は、送信局A,Bから送信される信号を同時に受信することになるが、送信局A,Bから送信される信号は異なるため、SFN間干渉による周波数選択性フェージングを防止することができる。同様に、送信エリアa,dの重なる領域に位置する受信装置は、送信局A,Dから送信される信号を同時に受信することになるが、送信局A,Dから送信される信号は異なるため、SFN間干渉による周波数選択性フェージングを防止することができる。 FIG. 3 is a diagram showing an example of the transmission area (broadcast area, service area) of the transmission station. In the figure, four transmission stations A, B, C and D and their transmission areas a, b, c and d are shown. By performing STBC encoding with the transmitting stations A and B as a set and performing STBC encoding with the transmitting stations C and D as a set, signals transmitted from the transmitting stations A and C and transmitted from the transmitting stations B and D are transmitted. The different signals can be different signals. In the figure, symbols A and C are circled to indicate that the signals transmitted from the transmitting stations A and C are the same. Further, in order to show that the signals transmitted from the transmitting stations B and D are the same and are different from the signals transmitted from the transmitting stations A and C, the symbols B and D are enclosed by squares. The receiving device located in the area where the transmission areas a and b overlap receives the signals transmitted from the transmitting stations A and B at the same time, but the signals transmitted from the transmitting stations A and B are different. Frequency selective fading due to interference can be prevented. Similarly, a receiving device located in an area where the transmission areas a and d overlap each other receives signals transmitted from the transmission stations A and D at the same time, but the signals transmitted from the transmission stations A and D are different. , Frequency selective fading due to inter-SFN interference can be prevented.
 図4は、OFDM変調部13の構成を示すブロック図である。図4に示すように、OFDM変調部13は、パイロット・制御信号挿入部130と、OFDM信号生成部134とを備える。 FIG. 4 is a block diagram showing a configuration of the OFDM modulation unit 13. As shown in FIG. 4, the OFDM modulation unit 13 includes a pilot / control signal insertion unit 130 and an OFDM signal generation unit 134.
 パイロット・制御信号挿入部130は、時空間符号化部12により生成された4種類の送信信号(a,b,a,b)にそれぞれ異なるパターンのパイロット信号(SP信号)及び制御信号(TMCC信号やAC信号)を挿入して4種類のOFDMシンボルを生成する。より詳細には、パイロット・制御信号挿入部130は、パイロット信号生成部131と、制御信号生成部132と、OFDMシンボル構成部133(133-1~133-4)と、を備える。 The pilot / control signal insertion unit 130 includes pilot signals (SP signals) having different patterns and control for the four types of transmission signals (a 1 , b 1 , a 2 , b 2 ) generated by the space-time encoding unit 12. A signal (TMCC signal or AC signal) is inserted to generate four types of OFDM symbols. More specifically, pilot / control signal insertion section 130 includes pilot signal generation section 131, control signal generation section 132, and OFDM symbol configuration section 133 (133-1 to 133-4).
 パイロット信号生成部131は、予め定められた振幅と位相を有し、伝送路応答を推定するためのパイロット信号を予め定められた位置に挿入するためにパイロット信号を生成し、OFDMシンボル構成部133に出力する。 Pilot signal generation section 131 has a predetermined amplitude and phase, generates a pilot signal for inserting a pilot signal for estimating a transmission path response at a predetermined position, and OFDM symbol configuration section 133 Output to.
 制御信号生成部132は、予め定められた振幅と位相を有し、制御情報を受信装置に通知するための制御信号を予め定められた位置に挿入するために制御信号を生成し、OFDMシンボル構成部133に出力する。制御情報には、キャリア変調方式、インターリーブ長、セグメント数などの伝送パラメータに関する情報が含まれる。 The control signal generation unit 132 has a predetermined amplitude and phase, generates a control signal for inserting a control signal for notifying the receiving apparatus of control information at a predetermined position, and generates an OFDM symbol configuration Output to the unit 133. The control information includes information on transmission parameters such as a carrier modulation scheme, an interleave length, and the number of segments.
 OFDMシンボル構成部133は、キャリア変調部11から入力される4種類の送信信号(a1,b1,a2,b2)に対して、パイロット信号生成部131から入力されるパイロット信号及び制御信号を挿入して配置することによりOFDMシンボルを生成し、OFDM信号生成部134に出力する。 The OFDM symbol configuration unit 133 inserts the pilot signal and control signal input from the pilot signal generation unit 131 into the four types of transmission signals (a1, b1, a2, and b2) input from the carrier modulation unit 11. The OFDM symbols are generated by arranging them and output to the OFDM signal generator 134.
 OFDM信号生成部134は、パイロット・制御信号挿入部130により生成された4種類のOFDMシンボルの各キャリアを逆フーリエ変換及び直交変調して4種類のOFDM信号を生成し、送信局14を介して4本の送信アンテナA-tx1,A-tx2,B-tx1,B-tx2に出力する。より詳細には、OFDM信号生成部134は、逆フーリエ変換部135(135-1及び135-2)と、GI付加部136(136-1及び136-2)と、直交変調部137(137-1及び137-2)と、D/A変換部138(138-1及び138-2)と、を備える。なお、4本のOFDM信号の同期を取るために、OFDM信号生成部134は、各ブロックに同一周波数のクロックを供給する。 The OFDM signal generation unit 134 generates four types of OFDM signals by performing inverse Fourier transform and orthogonal modulation on each carrier of the four types of OFDM symbols generated by the pilot / control signal insertion unit 130, and transmits the four types of OFDM signals via the transmission station 14. Output to four transmission antennas A-tx1, A-tx2, B-tx1, and B-tx2. More specifically, the OFDM signal generation unit 134 includes an inverse Fourier transform unit 135 (135-1 and 135-2), a GI addition unit 136 (136-1 and 136-2), and an orthogonal modulation unit 137 (137-). 1 and 137-2) and a D / A converter 138 (138-1 and 138-2). In order to synchronize the four OFDM signals, the OFDM signal generation unit 134 supplies a clock having the same frequency to each block.
 逆フーリエ変換部135は、OFDMシンボル構成部133から入力されるOFDMシンボルに対して、IFFT(Inverse Fast Fourier Transform:逆高速フーリエ変換)処理を施して時間領域の有効シンボル信号を生成し、GI付加部136に出力する。 The inverse Fourier transform unit 135 performs an IFFT (Inverse Fast Fourier Transform) process on the OFDM symbol input from the OFDM symbol configuration unit 133 to generate an effective symbol signal in the time domain, and adds a GI Output to the unit 136.
 GI付加部136は、逆フーリエ変換部135から入力される有効シンボル信号の先頭に、有効シンボル信号の後半部分をコピーしたガードインターバルを挿入し、直交変調部137に出力する。ガードインターバルは、OFDM信号を受信する際にシンボル間干渉を低減させるために挿入されるものであり、マルチパス遅延波の遅延時間がガードインターバル長を超えないように設定される。 The GI adding unit 136 inserts a guard interval obtained by copying the latter half of the effective symbol signal at the head of the effective symbol signal input from the inverse Fourier transform unit 135 and outputs the guard interval to the orthogonal modulation unit 137. The guard interval is inserted in order to reduce intersymbol interference when receiving an OFDM signal, and is set so that the delay time of the multipath delay wave does not exceed the guard interval length.
 直交変調部137は、GI付加部136から入力されるベースバンド信号に対して直交変調処理を施してOFDM信号を生成し、D/A変換部138に出力する。 The orthogonal modulation unit 137 performs orthogonal modulation processing on the baseband signal input from the GI addition unit 136 to generate an OFDM signal, and outputs the OFDM signal to the D / A conversion unit 138.
 D/A変換部138は、直交変調部137から入力されるOFDM信号をアナログ信号に変換する。 The D / A conversion unit 138 converts the OFDM signal input from the quadrature modulation unit 137 into an analog signal.
 [受信装置]
 次に、本発明の一実施形態に係る受信装置について説明する。
[Receiver]
Next, a receiving apparatus according to an embodiment of the present invention will be described.
 受信装置は、送信装置1から送信されるOFDM信号を複数本の受信アンテナを介して受信する。本実施形態では、受信アンテナの数が2本の場合を例に説明する。図5は、本発明の第1の実施形態に係る受信装置の構成例を示すブロック図である。図5に示すように、OFDM信号の受信装置2は、OFDM復調部20と、時空間符号復号部21と、キャリア復調部22(22-1及び22-2)と、誤り訂正符号復号部23(23-1及び23-2)と、を備える。 The receiving device receives the OFDM signal transmitted from the transmitting device 1 via a plurality of receiving antennas. In this embodiment, a case where the number of receiving antennas is two will be described as an example. FIG. 5 is a block diagram showing a configuration example of the receiving apparatus according to the first embodiment of the present invention. As shown in FIG. 5, the OFDM signal receiver 2 includes an OFDM demodulator 20, a space-time code decoder 21, a carrier demodulator 22 (22-1 and 22-2), and an error correction code decoder 23. (23-1 and 23-2).
 OFDM復調部20は、受信した2系統4種類のOFDM信号を復調して2種類のベースバンド信号(c,c)を生成するとともに、パイロット信号を用いて2種類の伝送路応答(h,h)を推定する。 The OFDM demodulator 20 demodulates the received four systems of four types of OFDM signals to generate two types of baseband signals (c 1 , c 2 ), and uses two types of transmission path responses (h 1 , h 2 ).
 図6は、OFDM復調部20の構成を示すブロック図である。図6に示すように、OFDM復調部20は、A/D変換部200(200-1及び200-2)と、直交復調部201(201-1及び201-2)と、GI除去部202(202-1及び202-2)と、フーリエ変換部203(203-1及び203-2)と、制御信号抽出部204と、パイロット信号生成部205と、パイロット信号抽出部206(206-1及び206-2)と、伝送路応答推定部207(207-1及び207-2)と、伝送路応答補間部208(208-1及び208-2)と、を備える。 FIG. 6 is a block diagram showing a configuration of the OFDM demodulator 20. As shown in FIG. 6, the OFDM demodulator 20 includes an A / D converter 200 (200-1 and 200-2), an orthogonal demodulator 201 (201-1 and 201-2), and a GI remover 202 ( 202-1 and 202-2), Fourier transform unit 203 (203-1 and 203-2), control signal extraction unit 204, pilot signal generation unit 205, and pilot signal extraction unit 206 (206-1 and 206). -2), a transmission path response estimation section 207 (207-1 and 207-2), and a transmission path response interpolation section 208 (208-1 and 208-2).
 A/D変換部200は、受信アンテrxから入力されるアナログの受信信号をデジタル信号に変換し、直交復調部201に出力する。 The A / D conversion unit 200 converts an analog reception signal input from the reception antenna rx into a digital signal and outputs the digital signal to the orthogonal demodulation unit 201.
 直交復調部201は、A/D変換部200から入力される信号に対してベースバンド信号を生成し、GI除去部202に出力する。 The orthogonal demodulation unit 201 generates a baseband signal for the signal input from the A / D conversion unit 200 and outputs the baseband signal to the GI removal unit 202.
 GI除去部202は、直交復調部201から入力される信号に対して、ガードインターバルを除去して有効シンボル信号を抽出し、フーリエ変換部203に出力する。 The GI removal unit 202 removes the guard interval from the signal input from the quadrature demodulation unit 201 to extract an effective symbol signal, and outputs it to the Fourier transform unit 203.
 フーリエ変換部203は、GI除去部202により抽出された有効シンボル信号に対して、FFT(Fast Fourier Transform:高速フーリエ変換)処理を施して複素ベースバンド信号c,cを生成し、パイロット信号抽出部206に出力する。 The Fourier transform unit 203 performs FFT (Fast Fourier Transform) processing on the effective symbol signal extracted by the GI removal unit 202 to generate complex baseband signals c 1 and c 2, and generates a pilot signal. The data is output to the extraction unit 206.
 制御信号抽出部204は、フーリエ変換部203により生成された複素ベースバンド信号c,cから制御信号を抽出し、制御情報をパイロット信号生成部205に出力する。 The control signal extraction unit 204 extracts a control signal from the complex baseband signals c 1 and c 2 generated by the Fourier transform unit 203 and outputs control information to the pilot signal generation unit 205.
 パイロット信号生成部205は、送信装置1により挿入されるパイロット信号と同じ振幅及び位相をもつパイロット信号を生成し、送信装置1により挿入されるパイロット信号の位置情報をパイロット信号抽出部206に出力し、パイロット信号の振幅値及び位相値を伝送路応答推定部207に出力する。 Pilot signal generation section 205 generates a pilot signal having the same amplitude and phase as the pilot signal inserted by transmission apparatus 1 and outputs the position information of the pilot signal inserted by transmission apparatus 1 to pilot signal extraction section 206. The amplitude value and phase value of the pilot signal are output to the transmission path response estimation unit 207.
 パイロット信号抽出部206は、フーリエ変換部203により生成された複素ベースバンド信号c,cから、パイロット信号生成部205から入力される位置情報に基づいてパイロット信号を抽出し、伝送路応答推定部207に出力する。 The pilot signal extraction unit 206 extracts a pilot signal from the complex baseband signals c 1 and c 2 generated by the Fourier transform unit 203 based on the position information input from the pilot signal generation unit 205, and estimates the transmission channel response. Output to the unit 207.
 伝送路応答推定部207は、パイロット信号抽出部206により抽出されたパイロット信号を用いて伝送路応答を算出する。 The transmission path response estimation unit 207 calculates a transmission path response using the pilot signal extracted by the pilot signal extraction unit 206.
 伝送路応答補間部208は、伝送路応答推定部207により算出された伝送路応答の一部又は全部を基にして伝送路応答の補間処理を行い、全サブキャリアについて伝送路応答を算出する。 Transmission path response interpolation section 208 performs transmission path response interpolation processing based on part or all of the transmission path response calculated by transmission path response estimation section 207, and calculates transmission path responses for all subcarriers.
 時空間符号復号部21は、フーリエ変換部203により生成された複素ベースバンド信号c,cから、伝送路応答推定部207により算出された伝送路応答h11,h12,h13,h14,21,h22,h23,h24を用いて時空間符号復号し、キャリア変調信号を生成する。以下に、時空間符号復号方法について説明する。 The space-time code decoding unit 21 transmits channel responses h 11 , h 12 , h 13 , h calculated by the channel response estimation unit 207 from the complex baseband signals c 1 and c 2 generated by the Fourier transform unit 203. 14, space-time code decoding is performed using h 21 , h 22 , h 23 , and h 24 to generate a carrier modulation signal. The space-time code decoding method will be described below.
 時空間符号復号部21への入力となる複素ベースバンド信号c,cは、送信装置1から送信された複素ベースバンド信号a,a,b,bが、次式(1)で表される伝送路応答hを有する伝送路を通過し、ノイズz,zが付加されたものと考えられる。よって、複素ベースバンド信号c,cは次式(2)で表される。 Complex baseband signals c 1 and c 2 that are input to the space-time code decoding unit 21 are complex baseband signals a 1 , a 2 , b 1 , and b 2 transmitted from the transmission device 1, and the following formula (1 It is considered that noises z 1 and z 2 are added through a transmission line having a transmission line response h represented by). Therefore, the complex baseband signals c 1 and c 2 are expressed by the following equation (2).
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
 時刻m+1において伝送路応答が変化しないとすると、時刻m+1における入力c,cは次式(3)で表され、式(3)の両辺の複素共役をとると、次式(4)が導出される。 Assuming that the transmission line response does not change at time m + 1, the inputs c 1 and c 2 at time m + 1 are expressed by the following equation (3). Taking the complex conjugate of both sides of equation (3), the following equation (4) is obtained. Derived.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
 
Figure JPOXMLDOC01-appb-M000004
 
 式(2),(4)より、STBCの復号は、次式(5)を解いてx,x,x,xを求めることに相当する。 From Equations (2) and (4), STBC decoding is equivalent to finding x 1 , x 2 , x 3 , and x 4 by solving the following Equation (5).
Figure JPOXMLDOC01-appb-M000005
 
Figure JPOXMLDOC01-appb-M000005
 
 式(4)を解くには、ZF(Zero Forcing)、MMSE(Minimum Mean Squared Error)、MLD(Maximum Likelihood Detection)などを適用することができる。4つのストリームの分離にZFを適用する場合、以下の手順となる。式(5)において、ウェイト行列Wを次式(6)で定義する。 To solve equation (4), ZF (Zero Forcing), MMSE (Minimum Mean Square Error), MLD (Maximum Likelihood Detection), etc. can be applied. When ZF is applied to the separation of four streams, the procedure is as follows. In equation (5), the weight matrix W is defined by the following equation (6).
Figure JPOXMLDOC01-appb-M000006
 
Figure JPOXMLDOC01-appb-M000006
 
 式(5)の両辺に、左からウェイト行列Wを乗算すると、次式(7)が導出される。 Multiplying both sides of equation (5) by weight matrix W from the left, the following equation (7) is derived.
Figure JPOXMLDOC01-appb-M000007
 
Figure JPOXMLDOC01-appb-M000007
 
 式(6)の雑音成分を無視すると、x,x,x,xは次式(8)により求められる。 If the noise component of Expression (6) is ignored, x 1 , x 2 , x 3 , and x 4 are obtained by the following Expression (8).
Figure JPOXMLDOC01-appb-M000008
 
Figure JPOXMLDOC01-appb-M000008
 
 このように、時空間符号復号部21は、OFDM復調部20から入力される複素ベースバンド信号c,c、伝送路応答h11,h12,h13,h14、及び伝送路応答h21,h22,h23,h24を用いて、式(7)によりキャリア変調信号x,x,x,x(すなわち、a(m),a(m+1),b(m),b(m+1))を算出する。 Thus, the space-time code decoding unit 21 includes the complex baseband signals c 1 and c 2 , the transmission path responses h 11 , h 12 , h 13 , h 14 and the transmission path response h that are input from the OFDM demodulation unit 20. 21 , h 22 , h 23 , h 24, and carrier modulation signals x 1 , x 2 , x 3 , x 4 (ie, a (m), a (m + 1), b (m) according to equation (7) , B (m + 1)).
 なお、時空間符号化としてSFBC(Space-Frequency Block Coding)を適用した場合も、STBCと同様の手順で符号化、復号が可能である。STBCの説明において、mはある離散時間を表しているが、mがあるサブキャリア番号を表すものとして読み替えることで、SFBCを適用できる。 In addition, even when SFBC (Space-Frequency Block Coding) is applied as space-time coding, encoding and decoding can be performed in the same procedure as STBC. In the description of STBC, m represents a certain discrete time, but SFBC can be applied by replacing m as representing a certain subcarrier number.
 キャリア復調部22は、時空間符号復号部21により生成されたキャリア変調信号に対して、サブキャリアごとに復調を行い、誤り訂正符号復号部23に出力する。 The carrier demodulation unit 22 demodulates the carrier modulation signal generated by the space-time code decoding unit 21 for each subcarrier, and outputs the demodulated signal to the error correction code decoding unit 23.
 誤り訂正符号復号部23は、キャリア復調部22から入力される信号に対して、誤り訂正を行い、送信装置1から送信された信号を復号する。 The error correction code decoding unit 23 performs error correction on the signal input from the carrier demodulation unit 22 and decodes the signal transmitted from the transmission device 1.
 このように、送信装置1は、複数の送信局14間でSTC-MIMOを構築し、複素共役の関係にある変調波を生成し、複数の送信局14の各2つのアンテナからSDMによるMIMO送信を行う。受信装置2は、2つのアンテナを用いて、それぞれがSTC受信を行う。本実施形態のように2つの送信局14を用いて4×2MIMO伝送を行う場合には、時刻mに送信される信号{a(m),a(m),b(m),b(m)}は{x,x,x,x}となり全て異なる信号である。そのため、SFN干渉のD/U比が0dBとなる場合でも、周波数選択性フェージングを防止することができるようになる。 As described above, the transmission apparatus 1 constructs STC-MIMO between a plurality of transmission stations 14, generates a modulated wave having a complex conjugate relationship, and performs MIMO transmission by SDM from each of the two antennas of the plurality of transmission stations 14. I do. The receiving apparatus 2 uses two antennas, and each performs STC reception. When 4 × 2 MIMO transmission is performed using two transmission stations 14 as in the present embodiment, signals {a 1 (m), a 2 (m), b 1 (m), b 2 (m)} is {x 1 , x 2 , x 3 , x 4 }, which are all different signals. Therefore, even when the D / U ratio of SFN interference becomes 0 dB, frequency selective fading can be prevented.
 (第2の実施形態)
 次に、本発明の第2の実施形態について説明する。
(Second Embodiment)
Next, a second embodiment of the present invention will be described.
 図7は、本発明による送信装置及び受信装置備える2×2MIMOシステムを示す図である。受信装置2が1つの送信局Aから送信される信号のみを受信する場合は、図7に示すように2×2MIMO伝送となる。この場合、受信装置2は時空間符号化信号a,bのみ受信していることになり、データの冗長性はなくダイバーシチ効果は得られないが、送信局Aから送信される信号{a(m),a(m+1),b(m),b(m+1)}は上述したように{x,-x ,x,-x }であり、送信信号x1,x2,x3,x4を伝送可能である。同様に、受信装置2が送信局Bの送信信号のみを受信する場合は、信号a,bのみ受信していることになり、送信信号x,x,x,xを伝送可能である。よって、図3に示す送信エリアcのように、他の送信局の送信エリアと隣接せずに孤立する送信エリア(孤立送信エリア)においては、2×2MIMOとして伝送路応答を算出すればよい。 FIG. 7 is a diagram illustrating a 2 × 2 MIMO system including a transmission device and a reception device according to the present invention. When the receiving apparatus 2 receives only a signal transmitted from one transmitting station A, 2 × 2 MIMO transmission is performed as shown in FIG. In this case, the receiving apparatus 2 receives only the space-time encoded signals a 1 and b 1 , and there is no data redundancy and a diversity effect cannot be obtained, but the signal {a 1 (m), a 1 (m + 1), b 1 (m), b 1 (m + 1)} are {x 1 , −x * 2 , x 3 , −x * 4 } as described above, and the transmission signal x1, x2, x3, and x4 can be transmitted. Similarly, when the receiving apparatus 2 receives only the transmission signal of the transmitting station B, it means that only the signals a 2 and b 2 are received, and the transmission signals x 1 , x 2 , x 3 , and x 4 are transmitted. Is possible. Therefore, in a transmission area (isolated transmission area) that is isolated without being adjacent to the transmission areas of other transmission stations as in the transmission area c shown in FIG. 3, the transmission path response may be calculated as 2 × 2 MIMO.
 しかし、受信装置2は、設置されるエリアが孤立送信エリアであるか否かを判別することができない。受信装置2が常に4×2MIMOとして伝送路応答を算出した場合、孤立送信エリアにおいては上記式(1)の伝送路応答の一部の成分に0ではなく雑音成分を適用することになる。例えば、図7に示すように、受信装置2が送信局Bからの信号を受信しない場合には、上記式(1)の伝送路応答のh13、h14、h23、h24の成分に0ではなく雑音成分を適用することになる。その結果、孤立送信エリアにおいては、2×2MIMOとして伝送路応答を算出した場合よりも復号精度が悪くなってしまう。 However, the receiving device 2 cannot determine whether or not the installed area is an isolated transmission area. When the receiving apparatus 2 always calculates the transmission path response as 4 × 2 MIMO, in the isolated transmission area, a noise component instead of 0 is applied to a part of the transmission path response of the above formula (1). For example, as shown in FIG. 7, when the receiving device 2 does not receive a signal from the transmitting station B, the components of the transmission path response of the above formula (1) are h 13 , h 14 , h 23 , h 24 A noise component is applied instead of zero. As a result, in the isolated transmission area, the decoding accuracy is worse than when the transmission path response is calculated as 2 × 2 MIMO.
 さらに、後述する図8に示すパイロット信号を用いる場合、受信装置2は、4パターンのOFDM信号全てを用いて4×2MIMOを復調する場合は、パターン1,2のみ又はパターン3,4のみのOFDM信号を用いて2×2MIMOを復調する場合と比較して、伝送路応答の補間にかかるシンボル期間が長いために受信レベルの時間変動が発生するおそれがあり、動特性が劣化する。2×2MIMOを復調する場合は、伝送路応答の補間にかかるシンボル期間は8シンボルであり、4×2MIMOを復調する場合は、伝送路応答の補間にかかるシンボル期間は16シンボルである。そのため、孤立送信エリアでない場合には4×2MIMOとすることでSTCによるダイバーシチ効果が期待できるが、孤立送信エリアである場合には、4×2MIMOとするとSTCによるダイバーシチ効果が期待できないだけでなく、動特性が劣化してしまう。 Furthermore, when using the pilot signal shown in FIG. 8 to be described later, when the receiving apparatus 2 demodulates 4 × 2 MIMO using all of the four patterns of OFDM signals, only the patterns 1 and 2 or only the patterns 3 and 4 are used. Compared with the case where 2 × 2 MIMO is demodulated using a signal, since the symbol period for interpolation of the transmission path response is long, there is a possibility that the reception level may vary with time, and the dynamic characteristics deteriorate. When demodulating 2 × 2 MIMO, the symbol period required for interpolation of the transmission path response is 8 symbols, and when demodulating 4 × 2 MIMO, the symbol period required for interpolation of the transmission path response is 16 symbols. Therefore, if it is not an isolated transmission area, the diversity effect due to STC can be expected by setting it to 4 × 2 MIMO, but if it is an isolated transmission area, not only the diversity effect due to STC cannot be expected when it is set to 4 × 2 MIMO. Dynamic characteristics will deteriorate.
 そこで、第2の実施形態の送信装置1は、TMCC信号などの伝送制御信号を用いて、送信局14の送信エリアが他の送信局の送信エリアと隣接しない孤立送信エリアであるか否かを示す送信エリア情報を送信し、受信装置2は、送信エリア情報に基づいてMIMO復調方法を決定する。例えば、送信エリアが孤立送信エリアでない場合には、受信装置2は4×2MIMOのSTC-SFNとして復号する。一方、送信局14の送信エリアが孤立送信エリアである場合には、受信装置2は2×2MIMOとして復号することで、4×2MIMOのSTC-SFNとして復号する場合に比べて、動特性を改善することができる。 Therefore, the transmission apparatus 1 according to the second embodiment uses a transmission control signal such as a TMCC signal to determine whether the transmission area of the transmission station 14 is an isolated transmission area that is not adjacent to the transmission areas of other transmission stations. The receiving apparatus 2 determines the MIMO demodulation method based on the transmission area information. For example, when the transmission area is not an isolated transmission area, the reception device 2 decodes the STC-SFN with 4 × 2 MIMO. On the other hand, when the transmission area of the transmission station 14 is an isolated transmission area, the receiving apparatus 2 decodes as 2 × 2 MIMO, thereby improving the dynamic characteristics as compared with the case of decoding as 4 × 2 MIMO STC-SFN. can do.
 ここで、伝送制御信号は、TMCC信号などのように、TS(Transport Stream)信号などのデータを誤り訂正符号化・マッピング等の処理を行った後に、MIMO-OFDM変調することによって得られるデータキャリアの伝送パラメータ(変調方式、セグメント数、符号化率等)を示す信号、所定数のサブキャリア(周波数軸)及び所定数のシンボル数(時間軸)によって定義されるOFDMフレームの同期をとるための同期信号等を含む信号である。伝送制御信号は、OFDMフレームにおいて、データキャリアとは異なるキャリアにマッピングされる。 Here, the transmission control signal is a data carrier obtained by performing MIMO-OFDM modulation on data such as a TS (Transport Stream) signal, such as a TMCC signal, after performing processing such as error correction coding / mapping. To synchronize OFDM frames defined by a signal indicating transmission parameters (modulation method, number of segments, coding rate, etc.), a predetermined number of subcarriers (frequency axis), and a predetermined number of symbols (time axis) It is a signal including a synchronization signal and the like. The transmission control signal is mapped to a carrier different from the data carrier in the OFDM frame.
 第2の実施形態の受信装置2は、送信局A,Bの両方の送信信号を受信可能か、送信局Aの送信信号のみ受信可能か、送信局Bの送信信号のみ受信可能かによって、MIMO復調の処理が異なる。そのため、送信装置1のパイロット信号生成部131が生成するパイロット信号の配置パターン(以下、「パイロットパターン」という)は、2つの送信局A,Bから送信される4つの信号を受信側で分離可能であり、かつ一方の送信局から送信される2つの信号だけでも受信側で分離可能なパターンとする必要がある。 The receiving apparatus 2 according to the second embodiment can perform MIMO depending on whether the transmission signals of both the transmission stations A and B can be received, only the transmission signal of the transmission station A can be received, or only the transmission signal of the transmission station B can be received. The demodulation process is different. Therefore, the pilot signal arrangement pattern (hereinafter referred to as “pilot pattern”) generated by the pilot signal generation unit 131 of the transmission apparatus 1 can separate four signals transmitted from the two transmission stations A and B on the reception side. In addition, it is necessary to make the pattern separable on the receiving side even with only two signals transmitted from one transmitting station.
 図8は、送信装置1が送信するOFDM信号のパイロットパターンの例を示す図である。パターン1~4は、各送信アンテナから送信されるOFDM信号のパイロットパターンを示している。図中において、丸は無信号のヌルパイロット信号であることを意味する。また、1と-1は、それぞれ符号が反転したパイロット信号であることを意味する。その他は、データ信号や制御信号などの非パイロット信号を意味する。なお、図中のOFDM信号は、右方向がキャリア(周波数)方向であり、下方向がシンボル(時間)方向である。パイロット信号生成部131は、送信局A用にパターン1,2に示すパイロット信号を生成し、送信局B用にパターン3,4に示すパイロット信号を生成する。つまり、送信局Aの送信アンテナA-tx1からパターン1のOFDM信号を送信し、送信局Aの送信アンテナA-tx2からパターン2のOFDM信号を送信し、送信局Bの送信アンテナB-tx1からパターン3のOFDM信号を送信し、送信局Bの送信アンテナB-tx2からパターン4のOFDM信号を送信する。 FIG. 8 is a diagram illustrating an example of a pilot pattern of an OFDM signal transmitted by the transmission apparatus 1. Patterns 1 to 4 indicate pilot patterns of OFDM signals transmitted from the respective transmission antennas. In the figure, a circle means a null pilot signal with no signal. Further, 1 and -1 mean that the pilot signals are inverted in sign. Others mean non-pilot signals such as data signals and control signals. In the OFDM signal in the figure, the right direction is the carrier (frequency) direction, and the downward direction is the symbol (time) direction. Pilot signal generating section 131 generates pilot signals shown in patterns 1 and 2 for transmitting station A, and generates pilot signals shown in patterns 3 and 4 for transmitting station B. That is, the OFDM signal of pattern 1 is transmitted from the transmission antenna A-tx1 of the transmission station A, the OFDM signal of pattern 2 is transmitted from the transmission antenna A-tx2 of the transmission station A, and the transmission antenna B-tx1 of the transmission station B is transmitted. The pattern 3 OFDM signal is transmitted, and the pattern 4 OFDM signal is transmitted from the transmission antenna B-tx2 of the transmission station B.
 制御信号生成部132は、送信局14の送信エリアが孤立送信エリアであるか否かを示す送信エリア情報を含む制御情報を通知するための制御信号を生成する。これにより、送信装置1は、送信局14の送信エリアが孤立送信エリアであるか否かを受信装置2に通知することができる。例えば、送信エリア情報は、送信局14の送信エリアが孤立送信エリアであるか否かを示す1ビットの情報とすることができる。なお、送信エリアが孤立送信エリアであるか否かを示す1ビットの送信エリア情報のみでは、受信装置2は送信局がA、Bのいずれなのかを判別できないが、孤立送信エリアのパイロットパターンを送信局A、Bのいずれかのパイロットパターンに固定とすることで対応することができる。あるいは、受信装置2は、送信局がA、B両方のパイロットパターンを用いて復調した後、エラーが少ない方にパイロットパターンを決定するようにしてもよい。 The control signal generator 132 generates a control signal for notifying control information including transmission area information indicating whether or not the transmission area of the transmission station 14 is an isolated transmission area. Thereby, the transmission apparatus 1 can notify the reception apparatus 2 whether or not the transmission area of the transmission station 14 is an isolated transmission area. For example, the transmission area information can be 1-bit information indicating whether or not the transmission area of the transmission station 14 is an isolated transmission area. Note that the receiving device 2 cannot determine whether the transmitting station is A or B only with 1-bit transmission area information indicating whether or not the transmission area is an isolated transmission area. This can be dealt with by fixing the pilot pattern to either one of the transmitting stations A and B. Alternatively, the receiving apparatus 2 may determine the pilot pattern so that the error is smaller after the transmitting station demodulates using both A and B pilot patterns.
 また、制御信号生成部132は、送信エリア情報を、送信局14の送信エリアが孤立送信エリアであるか否か、及び送信局14が送信局Aであるか送信局Bであるかを示す2ビットの情報とすることができる。 In addition, the control signal generation unit 132 indicates transmission area information 2 indicating whether the transmission area of the transmission station 14 is an isolated transmission area and whether the transmission station 14 is the transmission station A or the transmission station B. It can be bit information.
 また、制御信号生成部132は、送信エリア情報を、送信局14を識別するID情報としてもよい。ただし、この場合には、送信エリア情報のうち1ビットは、送信局から送信される信号を区別するための送信信号種別ビットとする。つまり、送信局14が第1の時空間符号化信号及び第3の時空間符号化信号(a,b)のOFDM信号を送信する場合には、送信信号種別ビットを0とし、送信局14が第2の時空間符号化信号及び第4の時空間符号化信号(a,b)のOFDM信号を送信する場合には、送信信号種別ビットを1とする。例えば、送信局A,Cが時空間符号化信号(a,b)のOFDM信号を送信し、送信局B,Dが時空間符号化信号(a,b)のOFDM信号を送信する場合に、最上位ビットを送信信号種別ビットとすると、送信局A,B,C、DのIDをそれぞれ00,10,01,11とする。これにより、IDによって送信局14を識別すると同時に、送信信号の種別を識別することができる。また、受信装置2は、受信した送信エリア情報の値が1つのみである場合には、送信局が1つしか存在しないため、孤立送信エリアであると判定することができる。 Further, the control signal generation unit 132 may use the transmission area information as ID information for identifying the transmission station 14. In this case, however, one bit of the transmission area information is a transmission signal type bit for distinguishing signals transmitted from the transmission station. That is, when the transmitting station 14 transmits the OFDM signals of the first space-time encoded signal and the third space-time encoded signal (a 1 , b 1 ), the transmission signal type bit is set to 0, and the transmitting station When 14 transmits OFDM signals of the second space-time encoded signal and the fourth space-time encoded signal (a 2 , b 2 ), the transmission signal type bit is set to 1. For example, transmitting stations A and C transmit OFDM signals of space-time encoded signals (a 1 , b 1 ), and transmitting stations B and D transmit OFDM signals of space-time encoded signals (a 2 , b 2 ). In this case, assuming that the most significant bit is a transmission signal type bit, IDs of transmitting stations A, B, C, and D are 00, 10, 01, and 11, respectively. Thus, the type of transmission signal can be identified at the same time as identifying the transmission station 14 by the ID. In addition, when there is only one value of the received transmission area information, the reception device 2 can determine that it is an isolated transmission area because there is only one transmission station.
 制御信号抽出部204は、フーリエ変換部203から入力される複素ベースバンド信号c,cから制御信号を抽出する。第2の実施形態では、制御信号に送信エリア情報が含まれるため、制御情報をパイロット信号生成部205だけでなく、伝送路応答推定部207にも出力する。 The control signal extraction unit 204 extracts a control signal from the complex baseband signals c 1 and c 2 input from the Fourier transform unit 203. In the second embodiment, since transmission area information is included in the control signal, the control information is output not only to the pilot signal generation unit 205 but also to the transmission path response estimation unit 207.
 パイロット信号生成部205は、送信エリア情報から、送信エリアが孤立送信局エリアではないと判定した場合には、4種類のパイロット信号を生成する。また、パイロット信号生成部205は、送信エリア情報から、送信エリアが孤立送信エリアであると判定した場合には、2種類のパイロット信号を生成する。 When the pilot signal generation unit 205 determines from the transmission area information that the transmission area is not an isolated transmission station area, the pilot signal generation unit 205 generates four types of pilot signals. Pilot signal generation section 205 generates two types of pilot signals when it is determined from the transmission area information that the transmission area is an isolated transmission area.
 伝送路応答推定部207は、送信エリア情報から、送信エリアが孤立送信局エリアではないと判定した場合には、4種類のパイロット信号を用いて伝送路応答を算出する。また、伝送路応答推定部207は、送信エリア情報から、送信エリアが孤立送信局エリアであると判定した場合には、2種類のパイロット信号を用いて伝送路応答を算出する。 When it is determined from the transmission area information that the transmission area is not an isolated transmission station area, the transmission path response estimation unit 207 calculates a transmission path response using four types of pilot signals. Further, when it is determined from the transmission area information that the transmission area is an isolated transmission station area, the transmission path response estimation unit 207 calculates a transmission path response using two types of pilot signals.
 上述したように、実施形態に係るシステムでは、4×2MIMO(第1方式)及び2×2MIMO(第2方式)が適用可能である。4×2MIMO(第1方式)は、互いに異なる送信局に設けられる複数のアンテナ(例えば、図2に示すA-tx1及びB-tx1、或いは、図2に示すA-tx2及びB-tx2)を用いて時空間符号化(STC:Space Time Codes)を行うとともに、複数の送信局のそれぞれに設けられる複数のアンテナ(例えば、図2に示すA-tx1及びA-tx2或いは、図2に示すB-tx1及びB-tx2)を用いて空間分割多重(SDM:Space Division Multiplexing)を行う方式である。一方で、2×2MIMO(第2方式)は、互いに異なる送信局に設けられる複数のアンテナ(例えば、図2に示すA-tx1及びB-tx1、或いは、図2に示すA-tx2及びB-tx2)を用いて時空間符号化(STC:Space Time Codes)を行わずに、複数の送信局のそれぞれに設けられる複数のアンテナ(例えば、図2に示すA-tx1及びA-tx2或いは、図2に示すB-tx1及びB-tx2)を用いて空間分割多重(SDM:Space Division Multiplexing)を行う方式である。 As described above, 4 × 2 MIMO (first scheme) and 2 × 2 MIMO (second scheme) are applicable to the system according to the embodiment. 4 × 2 MIMO (first scheme) uses a plurality of antennas (for example, A-tx1 and B-tx1 shown in FIG. 2 or A-tx2 and B-tx2 shown in FIG. 2) provided in different transmission stations. Are used to perform space-time coding (STC: Space Time Codes) and a plurality of antennas (for example, A-tx1 and A-tx2 shown in FIG. 2 or B shown in FIG. 2). This is a scheme for performing space division multiplexing (SDM) using -tx1 and B-tx2). On the other hand, 2 × 2 MIMO (second scheme) is used for a plurality of antennas (for example, A-tx1 and B-tx1 shown in FIG. 2 or A-tx2 and B- A plurality of antennas (for example, A-tx1 and A-tx2 shown in FIG. 2 or the like shown in FIG. 2), without performing space-time coding (STC: Space Time Codes) using tx2). This is a method of performing space division multiplexing (SDM) using B-tx1 and B-tx2) shown in FIG.
 ここで、送信装置1は、4×2MIMO(第1方式)及び2×2MIMO(第2方式)のいずれの方式を適用すべきかを示す情報を含む制御信号を受信装置2に送信する。 Here, the transmission apparatus 1 transmits a control signal including information indicating which of 4 × 2 MIMO (first scheme) and 2 × 2 MIMO (second scheme) should be applied to the reception device 2.
 上述したように、4×2MIMO(第1方式)は、複数の送信局のうち、互いに隣接する送信局のそれぞれが有する送信エリアが重複する場合に、互いに隣接する送信局に適用されることが好ましい。一方で、2×2MIMO(第2方式)は、複数の送信局のうち、互いに隣接する送信局のそれぞれが有する送信エリアが重複しない場合に、互いに隣接する送信局に適用されることが好ましい。 As described above, 4 × 2 MIMO (first scheme) may be applied to transmission stations adjacent to each other when the transmission areas of the transmission stations adjacent to each other among a plurality of transmission stations overlap. preferable. On the other hand, 2 × 2 MIMO (second scheme) is preferably applied to adjacent transmission stations when the transmission areas of the adjacent transmission stations among the plurality of transmission stations do not overlap.
 但し、実施形態は、これに限定されるものではない。例えば、互いに隣接する送信局の位置、各送信局の周辺の地理的状況等によって、4×2MIMO(第1方式)及び2×2MIMO(第2方式)のいずれの方式を適用すべきかを決定してもよい。 However, the embodiment is not limited to this. For example, the 4 × 2 MIMO (first method) or 2 × 2 MIMO (second method) method to be applied is determined according to the position of the transmitting stations adjacent to each other, the geographical conditions around each transmitting station, and the like. May be.
 このように、第2の実施形態では、送信装置1は、送信局14の送信エリアが他の送信局の送信エリアと隣接しない孤立送信エリアであるか否かを示す送信エリア情報(すなわち、4×2MIMO(第1方式)及び2×2MIMO(第2方式)のいずれの方式を適用すべきかを示す情報)を含む制御信号を送信する。受信装置2は、制御信号に含まれる送信エリア情報を抽出し、送信エリア情報から送信エリアが孤立送信局エリアではないと判定した場合には4種類のパイロット信号を用いて4×2MIMOのSTC-SFNとして復号する。一方、送信エリアが孤立送信局エリアであると判定した場合には2×2MIMOのSTC-SFNとして復号するため、常に4×2MIMOのSTC-SFNとして復号する場合に比べて、動特性を改善することができるようになる。 As described above, in the second embodiment, the transmission apparatus 1 transmits the transmission area information indicating whether the transmission area of the transmission station 14 is an isolated transmission area that is not adjacent to the transmission areas of other transmission stations (that is, 4 A control signal including information indicating which of × 2 MIMO (first scheme) and 2 × 2 MIMO (second scheme) is to be transmitted is transmitted. When receiving apparatus 2 extracts transmission area information included in the control signal and determines that the transmission area is not an isolated transmission station area from the transmission area information, 4 × 2 MIMO STC− is used using four types of pilot signals. Decode as SFN. On the other hand, when it is determined that the transmission area is an isolated transmission station area, decoding is performed as STC-SFN with 2 × 2 MIMO, so that dynamic characteristics are improved as compared with a case where decoding is always performed as STC-SFN with 4 × 2 MIMO. Will be able to.
 上述の実施例は、個々に代表的な例として説明したが、本発明の趣旨及び範囲内で、多くの変更及び置換ができることは当業者に明らかである。したがって、本発明は、上述の実施形態によって制限するものと解するべきではなく、特許請求の範囲から逸脱することなく、種々の変形や変更が可能である。例えば、本実施形態では2シンボルを2シンボル時間で送信するSTBC符号を用いて4×2MIMO伝送を行う場合を例に説明したが、本発明はこれに限定されるものではなく、例えば、3シンボルを4シンボル時間で送信するSTBC符号を用いて4×4MIMO伝送を行う場合にも適用することができる。 The above-described embodiments have been described as typical examples, but it will be apparent to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications and changes can be made without departing from the scope of the claims. For example, in this embodiment, the case where 4 × 2 MIMO transmission is performed using an STBC code that transmits two symbols in two symbol times has been described as an example, but the present invention is not limited to this, and for example, three symbols The present invention can also be applied to the case where 4 × 4 MIMO transmission is performed using an STBC code that transmits a 4 symbol time.
 例えば、s(m)、s(m+1)、s(m+2)を4本の送信アンテナで送信する場合には、STBC符号化により時空間符号化信号a,a,b,bは以下のような値となる。 For example, when s (m), s (m + 1), and s (m + 2) are transmitted using four transmission antennas, space-time encoded signals a 1 , a 2 , b 1 , and b 2 are obtained by STBC encoding. The value is as follows.
 a(m)=s(m)
 a(m+1)=s(m+1)
 a(m+2)=s(m+2)
 a(m+3)=0
 a(m)=-s(m+1)
 a(m+1)=s(m)
 a(m+2)=0
 a(m+3)=s(m+2)
 b(m)=-s(m+2)
 b(m+1)=0
 b(m+2)=s(m)
 b(m+3)=-s(m+1)
 b(m)=0
 b(m+1)=-s(m+2)
 b(m+2)=s(m+1)
 b(m+3)=s(m)
a 1 (m) = s (m)
a 1 (m + 1) = s (m + 1)
a 1 (m + 2) = s (m + 2)
a 1 (m + 3) = 0
a 2 (m) = − s * (m + 1)
a 2 (m + 1) = s * (m)
a 2 (m + 2) = 0
a 2 (m + 3) = s (m + 2)
b 1 (m) = − s * (m + 2)
b 1 (m + 1) = 0
b 1 (m + 2) = s * (m)
b 1 (m + 3) = − s (m + 1)
b 2 (m) = 0
b 2 (m + 1) = − s * (m + 2)
b 2 (m + 2) = s * (m + 1)
b 2 (m + 3) = s (m)
 このように、本発明によれば、SFN間干渉による周波数選択性フェージングを防止することができるので、MIMO伝送を行う任意の用途に有用である。  Thus, according to the present invention, frequency selective fading due to inter-SFN interference can be prevented, which is useful for any application that performs MIMO transmission.

Claims (7)

  1.  複数のアンテナを有する送信局として複数の送信局を有しており、第1方式及び第2方式を適用可能なシステムにおいて、前記複数の送信局から受信装置に送信すべき信号を生成する送信装置であって、
     前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報を含む制御信号を前記受信装置に送信する送信部を備え、
     前記第1方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行うとともに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であり、
     前記第2方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行わずに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であることを特徴とする送信装置。
    Transmitting apparatus that has a plurality of transmitting stations as a transmitting station having a plurality of antennas, and that generates signals to be transmitted from the plurality of transmitting stations to a receiving apparatus in a system to which the first scheme and the second scheme can be applied Because
    A transmission unit that transmits a control signal including information indicating which of the first method and the second method should be applied to the reception device;
    The first scheme is a scheme in which space-time coding is performed using a plurality of antennas provided in different transmission stations, and space division multiplexing is performed using a plurality of antennas provided in each of the plurality of transmission stations. Yes,
    The second method is a method of performing space division multiplexing using a plurality of antennas provided in each of the plurality of transmission stations without performing space-time coding using a plurality of antennas provided in different transmission stations. A transmitter characterized by the above.
  2.  前記第1方式は、前記複数の送信局のうち、互いに隣接する送信局のそれぞれが有する送信エリアが重複する場合に、前記互いに隣接する送信局に適用されることを特徴とする請求項1に記載の送信装置。 The first method is applied to the adjacent transmission stations when the transmission areas of the adjacent transmission stations among the plurality of transmission stations overlap each other. The transmitting device described.
  3.  前記第2方式は、前記複数の送信局のうち、互いに隣接する送信局のそれぞれが有する送信エリアが重複しない場合に、前記互いに隣接する送信局に適用されることを特徴とする請求項1に記載の送信装置。 The said 2nd system is applied to the said mutually adjacent transmission station, when the transmission area which each of the mutually adjacent transmission station does not overlap among these transmission stations is characterized by the above-mentioned. The transmitting device described.
  4.  前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報は、1ビットで表されることを特徴とする請求項1に記載の送信装置。 2. The transmission apparatus according to claim 1, wherein information indicating which of the first method and the second method is to be applied is represented by 1 bit.
  5.  前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報は、伝送パラメータを含む伝送制御信号に含まれることを特徴とする請求項1に記載の送信装置。 The transmission apparatus according to claim 1, wherein information indicating which of the first method and the second method is to be applied is included in a transmission control signal including a transmission parameter.
  6.  複数のアンテナを有する送信局として複数の送信局を有しており、第1方式及び第2方式を適用可能なシステムにおいて、前記複数の送信局から送信されるOFDMシンボルを受信する受信装置であって、
     前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報を含む制御信号を受信する受信部を備え、
     前記第1方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行うとともに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であり、
     前記第2方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行わずに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であることを特徴とする受信装置。
    In a system having a plurality of transmitting stations as a transmitting station having a plurality of antennas and applicable to the first scheme and the second scheme, a receiving apparatus that receives OFDM symbols transmitted from the plurality of transmitting stations. And
    A receiving unit that receives a control signal including information indicating which of the first method and the second method should be applied;
    The first scheme is a scheme in which space-time coding is performed using a plurality of antennas provided in different transmission stations, and space division multiplexing is performed using a plurality of antennas provided in each of the plurality of transmission stations. Yes,
    The second method is a method of performing space division multiplexing using a plurality of antennas provided in each of the plurality of transmission stations without performing space-time coding using a plurality of antennas provided in different transmission stations. A receiving apparatus characterized by the above.
  7.  複数のアンテナを有する送信局として複数の送信局を有しており、第1方式及び第2方式を適用可能なシステムにおいて、送信装置から受信装置に対して前記複数の送信局を介して信号を送信する信号送信方法であって、
     前記送信装置から前記受信装置に対して、前記第1方式及び前記第2方式のいずれの方式を適用すべきかを示す情報を含む制御信号を前記受信装置に送信するステップを備え、
     前記第1方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行うとともに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であり、
     前記第2方式は、互いに異なる送信局に設けられる複数のアンテナを用いて時空間符号化を行わずに、前記複数の送信局のそれぞれに設けられる複数のアンテナを用いて空間分割多重を行う方式であることを特徴とする信号送信方法。 
    In a system that has a plurality of transmitting stations as a transmitting station having a plurality of antennas and can apply the first method and the second method, a signal is transmitted from the transmitting device to the receiving device via the plurality of transmitting stations. A signal transmission method for transmitting,
    A step of transmitting a control signal including information indicating which of the first method and the second method should be applied from the transmitting device to the receiving device;
    The first scheme is a scheme in which space-time coding is performed using a plurality of antennas provided in different transmission stations, and space division multiplexing is performed using a plurality of antennas provided in each of the plurality of transmission stations. Yes,
    The second method is a method of performing space division multiplexing using a plurality of antennas provided in each of the plurality of transmission stations without performing space-time coding using a plurality of antennas provided in different transmission stations. A signal transmission method characterized by:
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