JP7078361B2 - MIMO receiver - Google Patents

Description

The present invention relates to a digital signal transmission method, and particularly relates to a device for transmitting an OFDM (Orthogonal Frequency Division Multiplexing) signal using MIMO (Multiple-Input Multiple-Output) technology. ..

Generally, in a wireless communication system, by using MIMO technology, information can be transmitted from a plurality of antennas on a carrier wave of the same frequency, and the transmission capacity can be increased. Since different information can be transmitted from a plurality of antennas, when the information to be transmitted is one stream, it is necessary to distribute the stream to the plurality of antennas by some means.

FIG. 10 is a diagram illustrating a group of FEC (Forward Error Correction) blocks in which information to be transmitted is stored. The MIMO transmitter of the wireless transmission system sequentially configures the FEC block group of the FEC blocks # 1, # 2, # 3, # 4, ... Shown in FIG. 10, and sets the bit string of the FEC block according to the subcarrier modulation method. It is converted into a carrier symbol and distributed to multiple antennas.

FIG. 11 is a diagram illustrating a configuration example of the FEC block, and shows a case where an LDPC code is used as an internal code and a BCH code is used as an external code. This FEC block is composed of a header, a payload, a BCH code parity, a stuff bit, and an LDPC (Low Density Parity Check) code parity. The FEC block length is 44,880 bits. Information to be transmitted is stored in the payload of the FEC block.

As a technique for distributing information to be transmitted to a plurality of antennas, a method of Patent Document 1, a method of Non-Patent Document 1, and the like have been proposed. The method of Patent Document 1 is to alternately distribute to two antennas for each carrier symbol in a wireless communication system that performs 2-input 2-output MIMO transmission using horizontally polarized waves and vertically polarized waves.

Specifically, the MIMO transmitter distributes the odd-numbered carrier symbol to the antenna of the first system and the even-numbered carrier symbol to the antenna of the second system. As a result, the information to be transmitted is distributed to each of the polarizations, so that even if there is a difference in characteristics between the polarizations, the influence can be dispersed and the effect of error correction can be exhibited.

Further, the method of Non-Patent Document 1 is premised on MIMO transmission of 2 inputs and 2 outputs using horizontally polarized waves and vertically polarized waves, as in the method of Patent Document 1. The method of Non-Patent Document 1 is to arrange carrier symbols in order on two OFDM subcarriers corresponding to two antennas and then distribute them to two antennas.

FIG. 12 is a diagram illustrating the method of Non-Patent Document 1. As shown in FIG. 12, the MIMO transmitter uses the carrier symbols of the FEC blocks # 1, # 2, # 3, # 4, ... Of the FEC blocks as two OFDM subcarriers corresponding to the two antennas. Arrange in order.

The MIMO transmitter arranges the carrier symbols of the FEC block group in order, and then performs frequency and interpolar interleaving for each symbol. Frequency and interpolar interleaving is an interleaving for all OFDM subcarriers corresponding to the two antennas.

In the example of FIG. 12, in the first symbol, all the carrier symbols of FEC blocks # 1 and # 2 and some of the preceding carrier symbols of all the carrier symbols of FEC block # 3 are targeted. Interleave is done. Further, in the second symbol, interleaving is performed for the succeeding carrier symbol, all the carrier symbols of the FEC block # 4, etc. among all the carrier symbols of the FEC block # 3.

The MIMO transmitter distributes the carrier symbol after interleaving to the antenna of the first system and the antenna of the second system, and as shown in FIG. 12, as the OFDM signal of the first antenna system and the OFDM signal of the second antenna system, respectively. Send.

By the interleaving process, the carrier symbols are rearranged (the order is changed) between the polarizations (between the antennas). As a result, even if there is a large difference in characteristics between the polarizations, the influence can be dispersed and stable transmission can be realized. Further, it is known that this method has better characteristics than the method of Patent Document 1.

Japanese Unexamined Patent Publication No. 2016-149740

Shingo Asakura, "Measures to improve characteristic deterioration due to differences in transmission line characteristics between polarizations", NHK Science & Technical Research Laboratories R & D, No.136, pp.16-23, November 2012

In the MIMO transmitter and MIMO receiver that constitute a wireless transmission system using MIMO technology, it is necessary to confirm the propagation status and isolate the fault that has occurred during the development, manufacture, and operation of the MIMO transmitter and the MIMO receiver. For that purpose, it is useful to obtain characteristics for each of a plurality of transmitting antenna systems (system including a high frequency part and a propagation path).

However, in the above-mentioned method of Patent Document 1 and the method of Non-Patent Document 1, the characteristics of each transmitting antenna system cannot be obtained from the data demodulated by the MIMO receiver, and which transmitting antenna system has a problem? Cannot be determined. This is because the information to be transmitted is distributed and transmitted from the MIMO transmitter to the plurality of transmitting antenna systems, and the demodulated data is the data obtained through the plurality of transmitting antenna systems.

As described above, in the MIMO transmitter, a method of distributing the carrier symbol to a plurality of transmitting antenna systems has been desired so that the characteristics of each transmitting antenna system can be obtained from the demodulated data.

Therefore, the present invention has been made to solve the above problems, and an object thereof is to provide a MIMO receiving device capable of obtaining characteristics for each transmitting antenna system in a wireless transmission system using MIMO technology. To do.

In order to solve the above-mentioned problems, the MIMO receiving device according to claim 1 is a MIMO receiving device that receives an OFDM signal transmitted from a plurality of transmitting antennas via a plurality of receiving antennas, and each of the plurality of receiving antennas is used. For each receiving antenna system corresponding to, the propagation path response is estimated based on the extraction unit that extracts the control signal from the signal in the frequency region of the OFDM signal and the pilot signal included in the control signal extracted by the extraction unit. Then, a MIMO detection unit that performs MIMO detection based on the signal in the frequency region and the propagation path response and generates a carrier symbol for each transmission antenna system corresponding to each of the plurality of transmission antennas, and each transmission antenna system. In addition, a compositing unit that extracts a carrier symbol having an FEC block as a unit from the carrier symbol generated by the MIMO detection unit and synthesizes the carrier symbol having the FEC block as a unit for each transmitting antenna system. The carrier symbol in units of the FEC block synthesized by the synthesis unit is decoded, the bit error rate for each transmission antenna system is calculated, and the FEC block for obtaining the characteristics for each transmission antenna system is restored. It is characterized by including a decoding unit for extracting information to be transmitted from the page load of the FEC block restored by the decoding unit, and an information extraction unit for extracting information to be transmitted.

Further, in the MIMO receiving device according to claim 2 , in the MIMO receiving device according to claim 1 , the on / off control signal included in the control signal extracted by the synthesis unit and the extraction unit indicates ON. If so, deinterleaving is performed for each symbol for all the carrier symbols for each transmitting antenna system generated by the MIMO detection unit, and the deinterleaving carrier symbol is output for each transmitting antenna system. When the on / off control signal indicates off, the deinterleave unit that outputs the carrier symbol for each transmission antenna system generated by the MIMO detection unit and the deinterleavement unit for each transmission antenna system. A carrier symbol extraction unit that extracts the carrier symbol in units of the FEC block from the carrier symbol output by the interleave unit, and the FEC block for each transmission antenna system extracted by the carrier symbol extraction unit are units. It is characterized by having a block synthesizing unit for synthesizing the carrier symbol.

Further, in the MIMO receiving device according to claim 3 , in the MIMO receiving device according to claim 1 or 2 , the first switching control signal included in the control signal extracted by the synthesis unit and the extraction unit is the FEC. When the block is shown, for each of the transmitting antenna systems, the carrier symbol having the FEC block as a unit and a predetermined test signal for determining the characteristics of the transmitting antenna system including the propagation path are for testing. Among the carrier symbols, the carrier symbol with the FEC block as a unit is selected, the carrier symbol with the FEC block as a unit for each transmission antenna system is synthesized, and the first switching control signal is the test carrier. When the symbol is shown, the test carrier symbol is selected from the carrier symbol and the test carrier symbol in the unit of the FEC block for each transmission antenna system, and the test carrier symbol is selected based on the test carrier symbol. It is characterized in that data for determining the characteristics of each transmitting antenna system is calculated.

Further, the MIMO receiving device according to claim 4 is the MIMO receiving device according to claim 1 or 2 , wherein the information extraction unit is the transmission target from the payload of the FEC block restored by the decoding unit. The second switching control signal included in the control signal extracted by the extraction unit after extracting the information or the test information including the test signal for determining the characteristics of the transmission antenna system including the propagation path is the transmission target. When the information of the above is shown, the information of the transmission target extracted from the page of the FEC block is output, and when the second switching control signal indicates the test information, the page of the FEC block is shown. Based on the test information for each transmitting antenna system extracted from the above, data for determining the characteristics of each transmitting antenna system is calculated.

As described above, according to the present invention, in a wireless transmission system using MIMO technology, it is possible to obtain the characteristics of each transmitting antenna system.

It is a block diagram which shows the structural example of the MIMO transmission apparatus by embodiment of this invention. It is a figure explaining the example of the process of allocating a carrier symbol into two systems in the FEC block unit, and the example of the process of allocating to the data carrier of an OFDM frame. It is a block diagram which shows the structural example of the MIMO receiving apparatus by embodiment of this invention. It is a block diagram which shows the structural example of the distribution part provided in the MIMO transmission apparatus of Example 1. FIG. It is a block diagram which shows the structural example of the synthesis part provided in the MIMO receiving apparatus of Example 1. FIG. It is a block diagram which shows the structural example of the distribution part provided in the MIMO transmission apparatus of Example 2. FIG. It is a block diagram which shows the structural example of the synthesis part provided in the MIMO receiving apparatus of Example 2. FIG. It is a block diagram which shows the structural example of the FEC block constituent part provided in the MIMO transmission apparatus of Example 3. FIG. It is a block diagram which shows the configuration example of the packet extraction part provided in the MIMO receiving apparatus of Example 3. FIG. It is a figure explaining the FEC block group in which the information of a transmission target is stored. It is a figure explaining the configuration example of the FEC block. It is a figure explaining the method of non-patent document 1. FIG.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is characterized in that the carrier symbol is distributed to a plurality of transmitting antenna systems in units of FEC blocks. As a result, on the receiving side, by analyzing the demodulated data, the characteristics of each transmitting antenna system can be obtained, and the problematic transmitting antenna system can be determined. Hereinafter, an example of a radio transmission device (FPU: Field Pick-up Unit) for program material that performs MIMO transmission with 2 inputs and 2 outputs using horizontally polarized waves and vertically polarized waves will be described.

[MIMO transmitter]
First, a MIMO transmitter will be described. FIG. 1 is a block diagram showing a configuration example of a MIMO transmitter according to an embodiment of the present invention. The MIMO transmission device 1 includes an FEC block configuration unit 10, a BCH coding unit 11, an energy diffusion unit 12, an LDPC coding unit 13, a bit interleaving unit 14, a symbol mapping unit 15, a distribution unit 16, and a time interleaving unit 17-1. , 17-2, TMCC signal generation unit 18, OFDM frame configuration unit 19-1, 19-2, IFFT and GI addition unit 20-1, 20-2, orthogonal modulation unit 21-1,21-2, high frequency unit It is equipped with 22-1, 22-2 and a common polarization antenna 23.

The polarization shared antenna 30 (high frequency section 31 described later) described later via the time interleaving section 17-1 via the high frequency section 22-1 and the polarization shared antenna 23 (transmission antenna on the high frequency section 22-1 side (horizontal polarization)). The system up to the receiving antenna on the -1 side (horizontal polarization) is used as the first transmitting antenna system. Further, the polarization shared antenna 30 (high frequency described later) described later is passed from the time interleaving section 17-2 via the high frequency section 22-2 and the polarization shared antenna 23 (transmitting antenna on the high frequency section 22-2 side (vertical polarization)). The system up to the receiving antenna on the 31-2 side (vertically polarized wave) is used as the second transmitting antenna system.

The FEC block component 10 inputs an MPEG-2 TS (Transport Stream) TS packet in which compressed and encoded video and audio are multiplexed. Then, the FEC block configuration unit 10 removes the first synchronization byte (1 byte length) from the 188-byte long TS packet, and sequentially stores the 187-byte long TS packet in the payload of the FEC block. The FEC block component 10 adds a header to the payload, constitutes the FEC block shown in FIG. 11, and outputs the FEC block including the header and the payload to the BCH coding unit 11.

TS is a continuous stream of 188-byte fixed-length TS packets. As shown in FIG. 11, the FEC block is composed of a header, a payload, a BCH code parity, a stuff bit, and an LDPC code parity, and has a length of 44,880 bits. The header is generated by the FEC block component 10, and the payload contains a TS packet having a length of 187 bytes by the FEC block component 10. Further, the BCH code parity is added by the BCH coding unit 11 described later, the stuff bit is added by the energy spreading unit 12 described later, and the LDPC code parity is added by the LDPC coding unit 13 described later.

The BCH coding unit 11 inputs an FEC block including a header and a payload from the FEC block configuration unit 10, encodes the header and the payload using a BCH code which is an external code, and generates BCH code parity. Then, the BCH coding unit 11 adds the BCH code parity to the header and the payload, and outputs the FEC block including the header, the payload and the BCH code parity to the energy spreading unit 12.

The energy diffusion unit 12 inputs an FEC block including a header, a payload, and a BCH code parity from the BCH coding unit 11, and adds a stuff bit having a length of 6 bits to the header, the payload, and the BCH code parity. Then, the energy diffusion unit 12 applies energy diffusion to the header, payload, BCH code parity, and stuff bits so that bits 0 or 1 do not continue for a long time, and the FEC block after energy diffusion is converted into an LDPC coding unit. Output to 13.

The LDPC coding unit 13 inputs an FEC block from the energy diffusion unit 12. Then, the LDPC coding unit 13 encodes the header, payload, BCH code parity and stuff bit after energy diffusion contained in the FEC block using the LDPC code which is an internal code, and generates LDPC coded parity. The LDPC coding unit 13 adds LDPC code parity to the header, payload, BCH code parity, and stuff bit after energy diffusion to form an FEC block having a length of 44,880 bits. The LDPC coding unit 13 outputs the FEC block to the bit interleaving unit 14.

The bit interleaving unit 14 inputs an FEC block from the LDPC coding unit 13, and in order to improve the performance of LDPC decoding, the FEC block is subjected to bit interleaving according to the subcarrier modulation method. Then, the bit interleaving unit 14 outputs the bit string of the FEC block after the bit interleaving to the symbol mapping unit 15.

The symbol mapping unit 15 inputs the bit string of the FEC block from the bit interleaving unit 14, symbol-maps the bit string of the FEC block according to the subcarrier modulation method, and generates 44,880 / log2M carrier symbols. M indicates the number of modulation multi-values. Then, the symbol mapping unit 15 outputs the carrier symbol to the distribution unit 16.

The distribution unit 16 inputs a carrier symbol from the symbol mapping unit 15, and distributes the carrier symbol into two systems (two polarizations) in FEC block units. As a result, the carrier symbol of the FEC block unit is distributed to the first transmitting antenna system and the second transmitting antenna system, respectively.

After the distribution process, the distribution unit 16 assigns the carrier symbol of the FEC block unit of the first transmission antenna system to the data carrier of the OFDM frame. Further, the distribution unit 16 also assigns the carrier symbol of the FEC block unit of the second transmission antenna system to the data carrier of the OFDM frame. Then, the distribution unit 16 outputs the carrier symbol of the FEC block unit of the first transmitting antenna system to the time interleaving unit 17-1, and the carrier symbol of the FEC block unit of the second transmitting antenna system is output to the time interleaving unit 17-2. Output. The details of the distribution unit 16 will be described later.

FIG. 2 is a diagram illustrating an example of a process of allocating a carrier symbol to two systems in units of FEC blocks and an example of a process of allocating a carrier symbol to a data carrier of an OFDM frame. In the example of FIG. 2, the odd-numbered FEC blocks # 1, # 3, ... Are distributed to the first transmitting antenna system, and the even-numbered FEC blocks # 2, # 4, ... Are distributed to the second transmitting antenna system. It is distributed to. Then, the odd-numbered FEC blocks # 1, # 3, ... Are transmitted as OFDM signals of the first transmitting antenna system, and the even-numbered FEC blocks # 2, # 4, ... Of the second transmitting antenna system. It is transmitted as an OFDM signal.

Further, in the first symbol of the first transmitting antenna system, all the carrier symbols of the FEC block # 1 and some of the preceding carrier symbols of all the carrier symbols of the FEC block # 3 are the data of the OFDM frame. Assigned to a carrier. In the first symbol of the second transmitting antenna system, all the carrier symbols of the FEC block # 2 and some of the preceding carrier symbols of all the carrier symbols of the FEC block # 4 become the data carriers of the OFDM frame. Assigned. As shown in FIG. 2, the carrier symbol is also assigned to the data carrier of the OFDM frame for the second and subsequent symbols.

After the distribution and allocation processing, the distribution unit 16 performs frequencies for all the carrier symbols of the first transmission antenna system and the carrier symbols of the second transmission antenna system for each symbol according to an on / off control signal (not shown). And inter-polarization interleaving.

Specifically, the distribution unit 16 does not perform frequency and interpolar interleaving processing when the on / off control signal indicates off. In this case, as described above, the distribution unit 16 outputs the carrier symbol of the FEC block unit of the first transmitting antenna system to the time interleaving unit 17-1. Further, the distribution unit 16 outputs the carrier symbol of the FEC block unit of the second transmitting antenna system to the time interleaving unit 17-2. As a result, the receiving side can obtain the characteristics of each transmitting antenna system by analyzing the demodulated data in FEC block units.

On the other hand, when the on / off control signal indicates on, the distribution unit 16 performs frequency and interpolar interleaving processing. In this case, the distribution unit 16 outputs the carrier symbol after interleaving to the time interleaving units 17-1 and 17-2. As a result, even when there is frequency selective fading due to multipath waves, or when there is a reception power difference between polarizations, error correction performance on the receiving side can be brought out by distributing the error, and transmission characteristics can be obtained. Can be improved.

That is, when the frequency and interpolar interleaving processing is performed, the information of the transmission target in the FEC block unit is distributed to the first transmission antenna system and the second transmission antenna system, respectively, so that the error can be dispersed. As a result, the receiving side can obtain the comprehensive characteristics of both transmitting antenna systems by analyzing the demodulated data.

The time interleaving unit 17-1 inputs the carrier symbol of the first transmitting antenna system from the distribution unit 16, and performs time interleaving on the carrier symbol to give a different delay time for each carrier in the time axis direction. As a result, by dispersing the errors due to fading in which the received power is momentarily lowered, it becomes easy to restore the original signal by error correction and decoding on the receiving side. The time interleaving unit 17-1 outputs the carrier symbol after the time interleaving to the OFDM frame component unit 19-1.

The time interleaving unit 17-2 inputs the carrier symbol of the second transmitting antenna system from the distribution unit 16, performs the same processing as the time interleaving unit 17-1, and uses the carrier symbol after the time interleaving as the OFDM frame component unit 19-2. Output to.

The TMCC signal generation unit 18 generates TMCC signals, AC signals, pilot signals and the like, and outputs these signals to OFDM frame components 19-1 and 19-2.

The TMCC signal is a synchronization signal for synchronizing OFDM frames, information for transmitting a subcarrier modulation method and the like to the receiving side, and the like. The TMCC signal includes an on / off control signal indicating whether or not interleaving between frequencies and polarizations is performed, a switching control signal for switching a test signal when distributing FEC blocks, and a test signal when embedding a packet. Includes switching control signals for. Details of these on / off control signals and switching control signals will be described later.

The AC signal is a signal used by the user to transmit additional information. The pilot signal is used as a known signal on the receiving side, and is a signal used to estimate the propagation path response from the received pilot signal. The receiving side can perform MIMO detection by forming a signal sequence orthogonal to each other in horizontally polarized waves and vertically polarized waves.

The OFDM frame configuration unit 19-1 inputs the carrier symbol after the time interleaving of the first transmitting antenna system from the time interleaving unit 17-1, and also inputs the TMCC signal, AC signal, pilot signal, etc. from the TMCC signal or the like generation unit 18. input. Then, the OFDM frame component 19-1 adds a TMCC signal, an AC signal, a pilot signal, and the like to the carrier symbol to form an OFDM frame. The OFDM frame configuration unit 19-1 outputs the OFDM frame to the IFF and the GI addition unit 20-1.

The OFDM frame configuration unit 19-2 inputs the carrier symbol after the time interleaving of the second transmitting antenna system from the time interleaving unit 17-2, and also inputs the TMCC signal, AC signal, pilot signal, etc. from the TMCC signal or the like generation unit 18. input. Then, the OFDM frame configuration unit 19-2 performs the same processing as the OFDM frame configuration unit 19-1, and outputs the OFDM frame to the OFDM and the GI addition unit 20-2. This constitutes each OFDM frame for horizontal and vertical polarization.

The OFDM and GI addition units 20-1 input the OFDM frame of the first transmission antenna system from the OFDM frame configuration unit 19-1. Then, the IFFT and the GI addition unit 20-1 convert the signal in the frequency domain into the signal in the time domain by performing an OFDM (Inverse Fast Fourier Transform) for each symbol of the OFDM frame. After the Fourier transform, the IFFT and the GI addition unit 20-1 add a GI (Guard Interval) to the signal in the time domain, and the signal in the time domain after the Fourier and GI additions are sent to the orthogonal modulation unit 21-1. Output.

The IFF and GI addition unit 20-2 input the OFDM frame of the second transmission antenna system from the OFDM frame configuration unit 19-2, perform the same processing as the IFF and GI addition unit 20-1, and after the IFF and GI are added. The signal in the time domain is output to the orthogonal modulation unit 21-2.

The orthogonal modulation unit 21-1 inputs a signal in the time region of the first transmission antenna system from the IFFT and the GI addition unit 20-1, performs orthogonal modulation on the signal in the time region, obtains an intermediate frequency signal, and obtains an intermediate frequency signal. The frequency signal is output to the high frequency unit 22-1.

The orthogonal modulation unit 21-2 inputs signals in the time domain of the second transmitting antenna system from the IFFT and the GI addition unit 20-2, performs the same processing as the orthogonal modulation unit 21-1, and converts the intermediate frequency signal into the high frequency unit 22. Output to -2.

The high frequency unit 22-1 inputs the intermediate frequency signal of the first transmission antenna system from the orthogonal modulation unit 21-1, and converts the intermediate frequency signal into the radio frequency of the microwave band. The high frequency unit 22-2 inputs the intermediate frequency signal of the second transmission antenna system from the quadrature modulation unit 21-2, and performs the same processing as the high frequency unit 22-1.

Then, the radio frequency signal converted by the high frequency units 22-1 and 22-2 is transmitted from the polarization shared antenna 23 as a horizontally and vertically polarized OFDM signal. The polarization shared antenna 23 is composed of an antenna of a first transmitting antenna system that transmits an OFDM signal of horizontally polarized waves and an antenna of a second transmitting antenna system that transmits an OFDM signal of vertically polarized waves.

As described above, according to the MIMO transmitter 1 of the embodiment of the present invention, the distribution unit 16 distributes the carrier symbol into two systems in the FEC block unit, and the carrier symbol in the FEC block unit of the first transmission antenna system is OFDM. In addition to allocating to the data carrier of the frame, the carrier symbol of the FEC block unit of the second transmission antenna system is assigned to the data carrier of the OFDM frame. The radio frequency signal generated by the first transmitting antenna system and the radio frequency signal generated by the second transmitting antenna system are the horizontally polarized OFDM signal and the vertically biased signal from the polarization shared antenna 23, respectively. It is transmitted as a wave OFDM signal.

As a result, in a wireless transmission system using MIMO technology, the receiving side can obtain the characteristics of each antenna system by analyzing the demodulated data in FEC block units, and determine the problematic antenna system. Can be done.

[MIMO receiver]
Next, the MIMO receiver will be described. FIG. 3 is a block diagram showing a configuration example of a MIMO receiver according to an embodiment of the present invention. The MIMO receiving device 2 includes a polarization sharing antenna 30, high frequency units 31-1 and 31-2, orthogonal demodulation units 32-1 and 32-2, GI removal and FFT units 33-1 and 33-2, TMCC signals and the like. Extraction unit 34, MIMO detection unit 35, time deinterleave part 36-1, 36-2, synthesis unit 37, LLR (Log-Likelihood Ratio) calculation unit 38, bit deinterleave unit 39, LDPC decoding unit. It includes 40, an energy back diffusion unit 41, a BCH decoding unit 42, and a packet extraction unit 43. The MIMO receiving device 2 basically performs the reverse processing with respect to the MIMO transmitting device 1 shown in FIG.

The MIMO receiving device 2 transmits the horizontally and vertically polarized OFDM signals, which are the radio frequency signals of the first transmitting antenna system and the second transmitting antenna system, transmitted from the MIMO transmitting device 1 via the polarization shared antenna 30. Receive. The polarization shared antenna 30 is composed of an antenna of a first receiving antenna system that receives a horizontally polarized OFDM signal and an antenna of a second receiving antenna system that receives a vertically polarized OFDM signal.

The high frequency unit 31-1 inputs the OFDM signal of the first receiving antenna system from the polarization shared antenna 30, converts the radio frequency signal into an intermediate frequency signal, and outputs the intermediate frequency signal to the orthogonal demodulation unit 32-1. .. The high frequency unit 31-2 inputs the OFDM signal of the second receiving antenna system from the polarization shared antenna 30, performs the same processing as the high frequency unit 31-1 and outputs the intermediate frequency signal to the orthogonal demodulation unit 32-2. The processing by the high frequency units 31-1 and 31-2 corresponds to the processing by the high frequency units 22-1 and 22-2 shown in FIG.

The orthogonal demodulation unit 32-1 inputs the intermediate frequency signal of the first receiving antenna system from the high frequency unit 31-1, performs orthogonal demodulation on the intermediate frequency signal, removes the signal after the orthogonal demodulation by GI, and FFT unit 33-. Output to 1. The orthogonal demodulation unit 32-2 inputs the intermediate frequency signal of the second receiving antenna system from the high frequency unit 31-2, performs the same processing as the orthogonal demodulation unit 32-1, and removes the signal after the orthogonal demodulation and removes the GI from the FFT unit. Output to 33-2. The processing by the quadrature demodulation units 32-1 and 32-2 corresponds to the processing by the quadrature modulation units 21-1,21-2 shown in FIG.

The GI removal and FFT unit 33-1 inputs the signal after orthogonal demodulation of the first receiving antenna system from the orthogonal demodulation unit 32-1. Then, the GI removal and the FFT unit 33-1 removes the GI from the signal after orthogonal demodulation, and FFT (Fast Fourier Transform) for each symbol of the signal from which the GI is removed, thereby performing the time domain. Convert the signal to a signal in the frequency range. The GI removal and FFT unit 33-1 outputs a signal in the frequency domain to the TMCC signal extraction unit 34 and the MIMO detection unit 35.

The GI removal and FFT unit 33-2 inputs the signal after the orthogonal demodulation of the second receiving antenna system from the orthogonal demodulation unit 32-2, performs the same processing as the GI removal and FFT unit 33-1, and performs the same processing as the signal in the frequency domain. Is output to the TMCC signal extraction unit 34 and the MIMO detection unit 35. The GI removal and the processing by the FFT units 33-1 and 33-2 correspond to the processing by the IFFT and the GI addition units 20-1 and 20-2 shown in FIG.

The TMCC signal extraction unit 34 inputs signals in the frequency domain of the first receiving antenna system from the GI removal and FFT unit 33-1, and also inputs signals in the frequency domain of the second receiving antenna system from the GI removal and FFT unit 33-2. Enter the signal. Then, the TMCC signal extraction unit 34 extracts a TMCC signal, an AC signal, a pilot signal, etc. from the signal in the frequency region of the first receiving antenna system and the signal in the frequency region of the second receiving antenna system, and the TMCC signal, the AC signal, etc. , Pilot signals, etc. are output to a predetermined component (not shown).

Specifically, the TMCC signal extraction unit 34 outputs the pilot signal to the MIMO detection unit 35. Further, the TMCC signal extraction unit 34 has an on / off control signal indicating whether or not to perform frequency and interpolar interleaving from the TMCC signal, a switching control signal for switching a test signal at the time of FEC block distribution, and a packet. Each switching control signal for switching the test signal at the time of embedding is extracted.

The TMCC signal extraction unit 34 outputs an on / off control signal to the synthesis unit 37. Further, when the TMCC signal extraction unit 34 extracts a switching control signal for switching the test signal at the time of FEC block distribution from the TMCC signal, the TMCC signal extraction unit 34 outputs the switching control signal to the synthesis unit 37. When the TMCC signal extraction unit 34 extracts a switching control signal for switching the test signal at the time of packet embedding from the TMCC signal, the TMCC signal extraction unit 34 outputs the switching control signal to the packet extraction unit 43. The processing by the TMCC signal extraction unit 34 corresponds to the processing of the TMCC signal generation unit 18 shown in FIG.

The MIMO detection unit 35 inputs a signal in the frequency domain of the first receiving antenna system from the GI removal and FFT unit 33-1, and also inputs a signal in the frequency domain of the second receiving antenna system from the GI removal and FFT unit 33-2. input. Further, the MIMO detection unit 35 inputs the pilot signal of the first receiving antenna system and the pilot signal of the second receiving antenna system from the TMCC signal extraction unit 34.

The MIMO detection unit 35 estimates the propagation path response based on the pilot signal of the first receiving antenna system and the pilot signal of the second receiving antenna system. Then, the MIMO detection unit 35 performs MIMO detection based on the signal in the frequency domain of the first receiving antenna system, the signal in the frequency domain of the second receiving antenna system, and the propagation path response, thereby crossing the mixture in the propagation path. Cancel the polarization component. The MIMO detection unit 35 obtains an estimated value of the transmission symbol for each transmission antenna system (estimated value of the transmission symbol of horizontal polarization and estimation value of transmission symbol of vertical polarization). For MIMO detection, for example, a zero forcing method with a small amount of calculation is used.

The MIMO detection unit 35 outputs the transmission symbol estimation value for each transmission antenna system to the time deinterleave units 36-1 and 36-2 as the carrier symbol of the first transmission antenna system and the carrier symbol of the second transmission antenna system, respectively. ..

The time deinterleave unit 36-1 inputs the carrier symbol of the first transmission antenna system from the MIMO detection unit 35, and applies the time deinterleave to the carrier symbol. Then, the time deinterleave unit 36-1 outputs the carrier symbol after the time deinterleave to the synthesis unit 37.

The time deinterleave unit 36-2 inputs the carrier symbol of the second transmitting antenna system from the MIMO detection unit 35, performs the same processing as the time deinterleave unit 36-1, and synthesizes the carrier symbol after the time deinterleave unit 37. Output to. The processing by the time deinterleaving units 36-1 and 36-2 corresponds to the processing by the time interleaving units 17-1 and 17-2 shown in FIG.

The synthesis unit 37 inputs the carrier symbol of the first transmitting antenna system from the time deinterleaving unit 36-1, and inputs the carrier symbol of the second transmitting antenna system from the time deinterleaving unit 36-2.

The synthesis unit 37 extracts the carrier symbol of the FEC block unit of the first transmission antenna system from the carrier symbol of the first transmission antenna system (data carrier of the OFDM frame). Further, the synthesis unit 37 extracts the carrier symbol of the FEC block unit of the second transmission antenna system from the carrier symbol of the second transmission antenna system (data carrier of the OFDM frame).

The synthesizing unit 37 synthesizes the carrier symbols of the FEC block unit of the first transmitting antenna system and the carrier symbols of the FEC block unit of the second transmitting antenna system by alternately arranging them in the FEC block unit. Then, the synthesis unit 37 outputs the carrier symbol of the FEC block unit after synthesis to the LLR calculation unit 38. The processing by the synthesis unit 37 corresponds to the processing by the distribution unit 16 shown in FIG. The details of the synthesis unit 37 will be described later.

After inputting the carrier symbol of the first transmitting antenna system and the carrier symbol of the second transmitting antenna system, the synthesis unit 37 of the first transmitting antenna system and the second transmitting antenna system according to an on / off control signal (not shown). For all carrier symbols, frequency and interpolar deinterleaving are performed for each symbol.

Specifically, the synthesis unit 37 does not perform frequency and interpolar deinterleaving processing when the on / off control signal indicates off. In this case, as described above, the synthesizing unit 37 performs a process of extracting a carrier symbol in FEC block units and a process of synthesizing the carrier symbol. As a result, the carrier symbol of the first transmitting antenna system is a signal of the FEC block unit, and the carrier symbol of the second transmitting antenna system is also a signal of the FEC block unit. That is, the MIMO receiving device 2 can obtain the characteristics of each transmitting antenna system by analyzing the demodulated data in FEC block units.

On the other hand, when the on / off control signal indicates on, the synthesis unit 37 performs frequency and interpolar deinterleaving processing. In this case, the synthesizing unit 37 performs a process of extracting the carrier symbol after deinterleaving and a process of synthesizing the carrier symbol. The carrier symbol of the first transmitting antenna system is not a signal in FEC block units. The same applies to the carrier symbol of the second transmitting antenna system. As a result, the MIMO receiving device 2 can obtain the characteristics of the entire transmitting antenna system by analyzing the demodulated data.

The LLR calculation unit 38 inputs the carrier symbol of the FEC block unit after synthesis from the synthesis unit 37, and calculates the log-likelihood ratio for each bit as a soft determination value for use in LDPC decoding. Then, the LLR calculation unit 38 outputs the log-likelihood ratio for each bit to the bit deinterleave unit 39.

The bit deinterleave unit 39 inputs the log-likelihood ratio for each bit from the LLR calculation unit 38, and applies bit deinterleave to the log-likelihood ratio for each bit. Then, the bit deinterleave unit 39 outputs the log-likelihood ratio for each bit after the bit deinterleave to the LDPC decoding unit 40. The processing by the bit deinterleaving unit 39 corresponds to the processing by the bit interleaving unit 14 shown in FIG.

The LDPC decoding unit 40 inputs the log-likelihood ratio for each bit after the bit deinterleave from the bit deinterleave unit 39, and performs LDPC decoding based on the log-likelihood ratio for each bit. The LDPC decoding unit 40 performs a parity check on the header, the payload, the BCH code parity, and the stuff bit using the LDPC code parity among the header, the payload, the BCH code parity, the stuff bit, and the LDPC code parity included in the FEC block. Correct the error. Then, the LDPC decoding unit 40 outputs the LDPC decoding result of the header, the payload, the BCH code parity, and the stuff bit included in the FEC block to the energy reverse diffusion unit 41. The processing by the LDPC decoding unit 40 corresponds to the processing by the LDPC coding unit 13 shown in FIG.

The energy reverse diffusion unit 41 inputs the LDPC decoding result of the header, payload, BCH code parity, and stuff bit included in the FEC block from the LDPC decoding unit 40. Then, the energy back-diffusion unit 41 performs energy back-diffusion on the LDPC decoding result for each bit, and removes the stuff bit having a length of 6 bits from the signal after the energy back-diffusion. The energy reverse diffusion unit 41 outputs the header, payload, and BCH code parity signal included in the FEC block to the BCH decoding unit 42. The processing by the energy back diffusion unit 41 corresponds to the processing by the energy diffusion unit 12 shown in FIG.

The BCH decoding unit 42 inputs the header, payload, and BCH code parity signal included in the FEC block from the energy reverse diffusion unit 41. Then, the BCH decoding unit 42 performs BCH decoding by performing a parity check on the header and the payload using the BCH code parity among the header, the payload and the BCH code parity included in the FEC block and correcting the error. conduct. The BCH decoding unit 42 outputs the header and payload included in the FEC block to the packet extraction unit 43. The processing by the BCH decoding unit 42 corresponds to the processing by the BCH coding unit 11 shown in FIG.

The packet extraction unit 43 inputs the header and payload included in the FEC block from the BCH decoding unit 42, and extracts the TS packet from the payload of the FEC block. The packet extraction unit 43 adds a synchronization byte to the TS packet, restores the 188-byte length MPEG-2 TS TS packet, and outputs the TS packet. The processing by the packet extraction unit 43 corresponds to the processing by the FEC block configuration unit 10 shown in FIG.

As described above, according to the MIMO receiver 2 of the embodiment of the present invention, the synthesizer 37 extracts the carrier symbol of the FEC block unit of the first transmitting antenna system from the carrier symbol of the first transmitting antenna system. From the carrier symbol of the second transmitting antenna system, the carrier symbol of the FEC block unit of the second transmitting antenna system is extracted. Then, the synthesizing unit 37 synthesizes by alternately arranging the carrier symbol of the FEC block unit of the first transmitting antenna system and the carrier symbol of the FEC block unit of the second transmitting antenna system in the FEC block unit.

As a result, in a wireless transmission system using MIMO technology, the MIMO receiver 2 can obtain the characteristics of each transmitting antenna system by analyzing the demodulated data in units of FEC blocks, which is a problematic transmitting antenna system. Can be judged.

Therefore, the development or post-manufacturing test of the MIMO transmitting device 1 and the MIMO receiving device 2 can be efficiently performed, and the cost can be reduced. Further, in operation, it is possible to quickly isolate the failure of the MIMO transmitting device 1 and the MIMO receiving device 2 and evaluate the propagation status, and it is possible to improve the efficiency of business operation.

[Example 1]
Next, the MIMO transmitting device 1 and the MIMO receiving device 2 of the first embodiment will be described. In the first embodiment, in order to obtain the characteristics of each transmitting antenna system, the carrier symbol of the FEC block unit is distributed to the two transmitting antenna systems.

(Distribution unit 16 / Example 1)
First, the distribution unit 16 provided in the MIMO transmission device 1 of the first embodiment will be described. FIG. 4 is a block diagram showing a configuration example of the distribution unit 16 provided in the MIMO transmission device 1 of the first embodiment. The distribution unit 16 includes a block distribution unit 50, data carrier allocation units 51-1 and 51-2, and a frequency and interpolar interleaving unit 52.

The block distribution unit 50 inputs a carrier symbol from the symbol mapping unit 15, and distributes the carrier symbol to the first transmission antenna system and the second transmission antenna system alternately in FEC block units. When the FEC block at the head of the OFDM frame is distributed to the first transmitting antenna system, the odd-numbered FEC block is distributed to the first transmitting antenna system, and the even-numbered FEC block is distributed to the second transmitting antenna system.

The block distribution unit 50 outputs the carrier symbol of the FEC block unit distributed to the first transmission antenna system to the data carrier allocation unit 51-1. Further, the block distribution unit 50 outputs the carrier symbol of the FEC block unit distributed to the second transmission antenna system to the data carrier allocation unit 51-2.

The data carrier allocation unit 51-1 inputs the carrier symbol of the FEC block unit of the first transmission antenna system from the block distribution unit 50, and allocates the carrier symbol of the FEC block unit to the data carrier of the OFDM frame in order. Then, the data carrier allocation unit 51-1 outputs the carrier symbol assigned to the data carrier of the OFDM frame to the frequency and interpolar interleaving unit 52.

The data carrier allocation unit 51-2 inputs a carrier symbol for each FEC block of the second transmission antenna system from the block distribution unit 50, and performs the same processing as the data carrier allocation unit 51-1. Then, the data carrier allocation unit 51-2 outputs the carrier symbol assigned to the data carrier of the OFDM frame to the frequency and interpolar interleaving unit 52.

The frequency and polarization interleaving unit 52 inputs the carrier symbol of the first transmission antenna system assigned to the data carrier of the OFDM frame from the data carrier allocation unit 51-1. Further, the frequency and interpolar interleaving unit 52 inputs the carrier symbol of the second transmission antenna system assigned to the data carrier of the OFDM frame from the data carrier allocation unit 51-2. Further, the frequency and interpolar interleaving unit 52 inputs a preset on / off control signal.

When the on / off control signal indicates on, the frequency-to-polarization interleaving unit 52 combines the carrier symbol of the first transmitting antenna system and the carrier symbol of the second transmitting antenna system for each symbol. Then, the frequency and interpolar interleaving unit 52 performs frequency and interpolar interleaving for all of the carrier symbol of the first transmitting antenna system and the carrier symbol of the second transmitting antenna system for each symbol. That is, the frequency and interpolar interleaving unit 52 for each symbol, with respect to all the carrier symbols of the first transmitting antenna system and the carrier symbols of the second transmitting antenna system, in that order, the first transmitting antenna system and the second transmitting antenna. Performs the process of replacing the entire system.

The frequency and interpolar interleaving unit 52 divides all the carrier symbols after the frequency and interpolar interleaving into two systems, and the carrier symbol of the first transmitting antenna system after the frequency and interpolar interleaving is transferred to the time interleaving unit 17-1. Output. Further, the frequency and interpolar interleaving unit 52 outputs the carrier symbol of the second transmitting antenna system after the frequency and interpolar interleaving to the time interleaving unit 17-2.

On the other hand, when the on / off control signal indicates off, the frequency and interpolar interleaving unit 52 uses the carrier symbol of the first transmitting antenna system input from the data carrier allocation unit 51-1 as it is in the time interleaving unit 17-1. Output to. Further, the frequency and interpolar interleaving unit 52 outputs the carrier symbol of the second transmitting antenna system input from the data carrier allocation unit 51-2 to the time interleaving unit 17-2 as it is.

The preset on / off control signal is transmitted to the MIMO receiver 2 as a part of the TMCC signal.

(Synthesis unit 37 / Example 1)
Next, the synthesis unit 37 provided in the MIMO receiving device 2 of the first embodiment will be described. FIG. 5 is a block diagram showing a configuration example of the synthesis unit 37 provided in the MIMO receiving device 2 of the first embodiment. The synthesis unit 37 includes a frequency and polarization deinterleavement unit 60, carrier symbol extraction units 61-1 and 61-2, and a block composition unit 62. The synthesizing unit 37 performs the reverse processing on the distribution unit 16 shown in FIG.

The MIMO receiving device 2 of the first embodiment provided with the synthesizing unit 37 shown in FIG. 5 is a first transmitting antenna system and a second transmitting antenna system transmitted from the MIMO transmitting device 1 provided with the sorting unit 16 shown in FIG. Receive the OFDM signal of.

The frequency-to-polarization deinterleaved section 60 inputs the carrier symbol of the first transmitting antenna system from the time deinterleaved section 36-1 and the carrier symbol of the second transmitting antenna system from the time deinterleaved section 36-2. Further, the frequency and interpolar deinterleaving unit 60 inputs an on / off control signal from the TMCC signal extraction unit 34. This on / off control signal is a signal obtained from the received TMCC signal.

When the on / off control signal indicates ON, the frequency-to-polarization deinterleavement unit 60 combines the carrier symbol of the first transmitting antenna system and the carrier symbol of the second transmitting antenna system for each symbol. Then, the frequency and interpolar deinterleaving unit 60 performs frequency and interpolar deinterleaving for all of the carrier symbol of the first transmitting antenna system and the carrier symbol of the second transmitting antenna system for each symbol. That is, the frequency and polarization-to-polarization deinterleaving unit 60 performs the order of the carrier symbol of the first transmitting antenna system and the carrier symbol of the second transmitting antenna system for the first transmitting antenna system and the second transmitting for each symbol. Performs restoration processing for the entire antenna system.

The frequency and interpolar deinterleaving unit 60 outputs the carrier symbol of the first transmitting antenna system after the frequency and interpolarization deinterleaving to the carrier symbol extraction unit 61-1. Further, the frequency and interpolar deinterleaving unit 60 outputs the carrier symbol of the second transmitting antenna system after the frequency and interpolarization deinterleaving to the carrier symbol extraction unit 61-2.

On the other hand, when the on / off control signal indicates off, the frequency and polarization-to-polarization deinterleave unit 60 uses the carrier symbol of the first transmitting antenna system input from the time deinterleave unit 36-1 as it is in the carrier symbol extraction unit 61. Output to -1. Further, the frequency and polarization interpolar deinterleaving unit 60 outputs the carrier symbol of the second transmitting antenna system input from the time deinterleaving unit 36-2 to the carrier symbol extraction unit 61-2 as it is. The processing by the frequency and interpolar deinterleaving unit 60 corresponds to the processing by the frequency and interpolarizing interleaving unit 52 shown in FIG.

The carrier symbol extraction unit 61-1 inputs the carrier symbol of the first transmitting antenna system from the frequency and interpolar deinterleaving unit 60. Then, the carrier symbol extraction unit 61-1 extracts the carrier symbol of the FEC block unit of the first transmission antenna system from the carrier symbol of the first transmission antenna system (from the data carrier of the OFDM frame). The carrier symbol extraction unit 61-1 outputs the carrier symbol of the FEC block unit of the first transmission antenna system to the block synthesis unit 62.

The carrier symbol extraction unit 61-2 inputs the carrier symbol of the second transmitting antenna system from the frequency and interpolar deinterleaving unit 60. Then, the carrier symbol extraction unit 61-2 performs the same processing as the carrier symbol extraction unit 61-1, and outputs the carrier symbol of the FEC block unit of the second transmission antenna system to the block synthesis unit 62. The processing by the carrier symbol extraction units 61-1 and 61-2 corresponds to the processing by the data carrier allocation units 51-1 and 51-2 shown in FIG.

The block synthesis unit 62 inputs the carrier symbol of the FEC block unit of the first transmission antenna system from the carrier symbol extraction unit 61-1, and the carrier symbol extraction unit 61-2 to the carrier of the FEC block unit of the second transmission antenna system. Enter the symbol.

The block synthesizing unit 62 synthesizes the carrier symbols of the FEC block unit of the first transmitting antenna system and the carrier symbols of the FEC block unit of the second transmitting antenna system by alternately arranging them in the FEC block unit. Then, the block synthesis unit 62 outputs the carrier symbol of the FEC block unit after synthesis to the LLR calculation unit 38. The processing by the block synthesizing unit 62 corresponds to the processing by the block distribution unit 50 shown in FIG.

As described above, in the MIMO receiving device 2 of the first embodiment, the BCH decoding unit 42 in the subsequent stage of the synthesis unit 37 shown in FIG. 5 detects the number of erroneous bits, although the number is limited. It is possible to easily measure the bit error rate after LDPC decoding.

Therefore, when the on / off control signal indicates off and the frequency and interpolar deinterleaving unit 60 does not perform frequency and interpolar deinterleaving, the carrier symbol for each transmitting antenna system is in FEC block units. It is a signal. That is, the bit error rate can be calculated from the demodulated data for each transmitting antenna system, and the characteristics of each transmitting antenna system can be obtained.

On the other hand, when the on / off control signal indicates on and the frequency and interpolar deinterleaving unit 60 performs frequency and interpolar deinterleaving, the carrier symbol for each transmitting antenna system is a signal for each FEC block. is not. That is, based on the bit error rate calculated from the demodulated data, it is possible to obtain a comprehensive characteristic that combines both transmitting antenna systems.

[Example 2]
Next, the MIMO transmitting device 1 and the MIMO receiving device 2 of the second embodiment will be described. In the second embodiment, in order to obtain the characteristics of each transmitting antenna system, the carrier symbol of the FEC block unit is distributed to the two transmitting antenna systems, and the carrier symbol and the test signal are switched and transmitted.

(Distribution unit 16 / Example 2)
First, the distribution unit 16 provided in the MIMO transmission device 1 of the second embodiment will be described. FIG. 6 is a block diagram showing a configuration example of the distribution unit 16 provided in the MIMO transmission device 1 of the second embodiment. The distribution unit 16 includes a block distribution unit 50, a test signal generation unit 53, a test signal switching unit 54-1 and 54-2, a data carrier allocation unit 51-1 and 51-2, and a frequency and polarization interleaving unit 52. It is equipped with.

The distribution unit 16 provided in the MIMO transmission device 1 of the first embodiment shown in FIG. 4 is compared with the distribution unit 16 provided in the MIMO transmission device 1 of the second embodiment shown in FIG. Both distribution units 16 are common in that they include a block distribution unit 50, data carrier allocation units 51-1 and 51-2, and a frequency and interpolar interleaving unit 52. On the other hand, the distribution unit 16 provided in the MIMO transmission device 1 of the second embodiment has the configuration of the distribution unit 16 provided in the MIMO transmission device 1 of the first embodiment, and further, the test signal generation unit 53 and the test signal switching unit 54-. It differs in that it has 1,54-2. In FIG. 6, the parts common to FIG. 4 are designated by the same reference numerals as those in FIG. 4, and detailed description thereof will be omitted.

The test signal generation unit 53 generates a carrier symbol of a preset test signal, and outputs this to the test signal switching unit 54-1 as a test carrier symbol of the first transmission antenna system. Further, the test signal generation unit 53 outputs the test carrier symbol of the second transmitting antenna system to the test signal switching unit 54-2.

The test signal is also known in the MIMO receiver 2, and is used to determine the characteristics of each transmitting antenna system including the propagation path. For example, the ITU-T O.151 PN code (generation polynomial x ²³ + X ¹⁸ + 1) for calculating the bit error rate is used. The test carrier symbol of the first transmitting antenna system output to the test signal switching unit 54-1 and the test carrier symbol of the second transmitting antenna system output to the test signal switching unit 54-2 have the same data. It may be different data.

The test signal switching unit 54-1 inputs the carrier symbol of the FEC block unit of the first transmission antenna system from the block distribution unit 50, and inputs the test carrier symbol of the first transmission antenna system from the test signal generation unit 53. do. Further, the test signal switching unit 54-1 inputs a preset switching control signal. The switching control signal is a signal for switching between the carrier symbol for each FEC block and the carrier symbol for testing when the FEC block is distributed by the block distribution unit 50.

When the switching control signal indicates an FEC block, the test signal switching unit 54-1 selects a carrier symbol for each FEC block of the first transmission antenna system input from the block distribution unit 50, and selects this as a data carrier allocation unit. Output to 51-1. On the other hand, when the switching control signal indicates a test signal, the test signal switching unit 54-1 selects the test carrier symbol of the first transmission antenna system input from the test signal generation unit 53 and assigns this to the data carrier. Output to unit 51-1.

The test signal switching unit 54-2 inputs the carrier symbol of the FEC block unit of the second transmission antenna system from the block distribution unit 50, and inputs the test carrier symbol of the second transmission antenna system from the test signal generation unit 53. do. Further, the test signal switching unit 54-2 inputs a preset switching control signal. This switching control signal is the same as the switching control signal input by the test signal switching unit 54-1.

The test signal switching unit 54-2 performs the same processing as the test signal switching unit 54-1, and according to the switching control signal, the carrier symbol of the FEC block unit of the second transmitting antenna system or the test carrier symbol of the second transmitting antenna system. Is output to the data carrier allocation unit 51-2.

In normal operation, the carrier symbols of the FEC block units of the first transmitting antenna system and the second transmitting antenna system input from the block distribution unit 50 are selected in the test signal switching units 54-1 and 54-2.

The data carrier allocation unit 51-1 inputs the carrier symbol of the FEC block unit of the first transmission antenna system or the test carrier symbol of the first transmission antenna system from the test signal switching unit 54-1, and inputs the input carrier symbol. Allocate to the data carriers of OFDM frames in order. The data carrier allocation unit 51-2 inputs the carrier symbol of the FEC block unit of the second transmission antenna system or the test carrier symbol of the second transmission antenna system from the test signal switching unit 54-2, and the data carrier allocation unit 51 Perform the same processing as -1.

The preset switching control signal is transmitted to the MIMO receiver 2 as a part of the TMCC signal.

(Synthesis unit 37 / Example 2)
Next, the synthesis unit 37 provided in the MIMO receiving device 2 of the second embodiment will be described. FIG. 7 is a block diagram showing a configuration example of the synthesis unit 37 provided in the MIMO receiving device 2 of the second embodiment. The synthesis unit 37 includes a frequency and polarization deinterleavement unit 60, a carrier symbol extraction unit 61-1, 61-2, a test signal switching unit 63-1, 63-2, a test signal determination unit 64, and a block composition unit 62. I have. The synthesizing unit 37 performs the reverse processing on the distribution unit 16 shown in FIG.

Comparing the synthesizer 37 provided in the MIMO receiver 2 of Example 1 shown in FIG. 5 with the synthesizer 37 provided in the MIMO receiver 2 of Example 2 shown in FIG. 7, both synthesizers 37 have frequencies. It is common in that it includes a deinterleaved unit 60 between polarizations, carrier symbol extraction units 61-1 and 61-2, and a block synthesis unit 62. On the other hand, the synthesis unit 37 provided in the MIMO receiving device 2 of the second embodiment has the configuration of the synthesis unit 37 provided in the MIMO receiving device 2 of the first embodiment, and further, the test signal switching units 63-1 and 63-2 and the test signal switching unit 63-1 and 63-2. The difference is that the test signal determination unit 64 is provided. In FIG. 7, the parts common to FIG. 5 are designated by the same reference numerals as those in FIG. 5, and detailed description thereof will be omitted.

The MIMO receiving device 2 of the second embodiment receives the OFDM signals of the first transmitting antenna system and the second transmitting antenna system transmitted from the MIMO transmitting device 1 of the second embodiment.

The carrier symbol extraction unit 61-1 inputs the carrier symbol of the first transmitting antenna system from the frequency and interpolar deinterleaving unit 60. Then, the carrier symbol extraction unit 61-1 extracts the carrier symbol of the FEC block unit or the test carrier symbol of the FEC unit from the input carrier symbol. The carrier symbol extraction unit 61-1 outputs the carrier symbol of the FEC block unit of the first transmission antenna system or the test carrier symbol of the FEC unit of the first transmission antenna system to the test signal switching unit 63-1.

The carrier symbol extraction unit 61-2 performs the same processing as the carrier symbol extraction unit 61-1, and from the carrier symbol of the second transmission antenna system, the carrier symbol of the FEC block unit of the second transmission antenna system or the second transmission antenna system. Extract the test carrier symbol for each FEC block. Then, the carrier symbol extraction unit 61-2 outputs the carrier symbol of the FEC block unit of the second transmitting antenna system or the test carrier symbol of the FEC unit of the second transmitting antenna system to the test signal switching unit 63-2.

The test signal switching unit 63-1 inputs the carrier symbol of the FEC block unit of the first transmission antenna system or the test carrier symbol of the FEC block unit of the first transmission antenna system from the carrier symbol extraction unit 61-1. Further, the test signal switching unit 63-1 inputs a switching control signal from the TMCC signal extraction unit 34. This switching control signal is a signal obtained from the received TMCC signal.

When the switching control signal indicates an FEC block, the test signal switching unit 63-1 outputs the carrier symbol of the FEC block of the first transmission antenna system to the block synthesis unit 62. On the other hand, when the switching control signal indicates a test signal, the test signal switching unit 63-1 outputs the test carrier symbol for each FEC block of the first transmission antenna system to the test signal determination unit 64.

The test signal switching unit 63-2 inputs the carrier symbol of the FEC block unit of the second transmitting antenna system or the test carrier symbol of the FEC block unit of the second transmitting antenna system from the carrier symbol extraction unit 61-2. Further, the test signal switching unit 63-2 inputs a switching control signal from the TMCC signal extraction unit 34. This switching control signal is the same as the switching control signal input by the test signal switching unit 63-1.

The test signal switching unit 63-2 performs the same processing as the test signal switching unit 63-1 and outputs the carrier symbol of the FEC block unit of the second transmission antenna system to the block synthesis unit 62 according to the switching control signal. Alternatively, the test signal switching unit 63-2 outputs the test carrier symbol for each FEC block of the second transmitting antenna system to the test signal determination unit 64. The processing by the test signal switching units 63-1 and 63-2 corresponds to the processing by the test signal switching units 54-1 and 54-2 shown in FIG.

The test signal determination unit 64 inputs a test carrier symbol for each FEC block of the first transmission antenna system from the test signal switching unit 63-1. Further, the test signal determination unit 64 inputs a test carrier symbol for each FEC block of the second transmission antenna system from the test signal switching unit 63-2.

The test signal determination unit 64 performs demapping for generating bit data from the test carrier symbol for each FEC block of the first transmission antenna system. Then, the test signal determination unit 64 calculates the bit error rate of the first transmission antenna system based on the generated bit data and the bit data of the preset test signal. Further, the test signal determination unit 64 performs demapping for generating bit data from the test carrier symbol of the FEC block unit of the second transmitting antenna system. Then, the test signal determination unit 64 calculates the bit error rate of the second transmission antenna system based on the generated bit data and the bit data of the preset test signal.

As described above, when the on / off control signal indicates off and the switching control signal indicates a test signal, the test carrier symbol of the first transmitting antenna system is transmitted via the first transmitting antenna system. It is transmitted and the test carrier symbol of the second transmitting antenna system is transmitted via the second transmitting antenna system. That is, in the MIMO receiving device 2 of the second embodiment, the test signal determination unit 64 can calculate the bit error rate for each transmitting antenna system, and can obtain the characteristics for each transmitting antenna system.

On the other hand, when the on / off control signal indicates on and the switching control signal indicates a test signal, the test carrier symbol of the first transmitting antenna system is the first transmitting antenna system and the second transmitting antenna system. Distributed to. The same applies to the test carrier symbol of the second transmitting antenna system. That is, the test signal determination unit 64 can calculate the total bit error rate of both transmission antenna systems combined, and can obtain the total characteristics.

The bit error rate calculated by the test signal determination unit 64 is a value that does not consider the error correction of the LDPC code and the BCH code. Although it is possible to calculate the bit error rate in the BCH decoding unit 42 provided in the MIMO receiving device 2 of the above-described first embodiment, the error correction is not possible due to the poor condition of the transmitting antenna system such as the propagation path. If possible, the bit error rate cannot be calculated. On the other hand, the test signal determination unit 64 provided in the MIMO receiving device 2 of the second embodiment can calculate the bit error rate even when the condition of the transmitting antenna system such as the propagation path is bad. , The characteristics of each transmitting antenna system can be surely obtained as compared with the first embodiment.

[Example 3]
Next, the MIMO transmitting device 1 and the MIMO receiving device 2 of the third embodiment will be described. In the third embodiment, in order to obtain the characteristics of each transmitting antenna system, the video and audio signals and the test signal are switched and stored in the payload of the FEC block, and the carrier symbol of the FEC block unit is distributed to the two transmitting antenna systems. Send.

(FEC block component 10, distribution unit 16 / Example 3)
First, the FEC block component 10 provided in the MIMO transmission device 1 of the third embodiment will be described. FIG. 8 is a block diagram showing a configuration example of the FEC block configuration unit 10 provided in the MIMO transmission device 1 of the third embodiment. The FEC block configuration unit 10 includes test signal generation units 70-1 and 70-2, and a TS packet switching and embedding unit 71.

The test signal generation unit 70-1 generates a TS packet including a preset test signal, and outputs the TS packet as a test TS packet of the first transmission antenna system to the TS packet switching and embedding unit 71. The test signal generation unit 70-2 performs the same processing as the test signal generation unit 70-1, and outputs the test TS packet of the second transmission antenna system to the TS packet switching and the embedding unit 71.

The test signal is also known in the MIMO receiver 2, and is used to determine the characteristics of each transmitting antenna system including the propagation path. For example, the ITU-T O.151 PN code (generation polynomial x ²³ + X ¹⁸ + 1) for calculating the bit error rate is used. The test signal used by the test signal generation unit 70-1 and the test signal used by the test signal generation unit 70-2 may be the same data or different data.

The TS packet switching and embedding unit 71 inputs an MPEG-2 TS TS packet in which compression-encoded video and audio are multiplexed. Further, the TS packet switching and embedding unit 71 inputs the test TS packet of the first transmission antenna system and the test TS packet of the second transmission antenna system from the test signal generation units 70-1 and 70-2 in advance. Input the set switching control signal. The switching control signal is a signal for switching between the TS packet of the video and audio signals and the TS packet for testing when the TS packet is embedded in the FEC block by the TS packet switching and the embedding unit 71.

When the switching signal indicates a video and audio signal, the TS packet switching and embedding unit 71 selects the TS packet of the MPEG-2 TS in which the compressed video and audio are multiplexed, and the synchronization byte at the beginning thereof. (1 byte length) is removed, and 187 byte length TS packets are sequentially stored in the payload of the FEC block.

On the other hand, when the switching signal indicates a test signal, the TS packet switching and embedding unit 71 selects the test TS packet of the first transmitting antenna system and the test TS packet of the second transmitting antenna system. Then, the TS packet switching and embedding unit 71 removes the synchronization byte (1 byte length) at the beginning thereof, and removes the TS packet having a length of 187 bytes (TS packet for testing the first transmission antenna system or test for the second transmission antenna system). TS packets) are sequentially stored in the payload of the FEC block.

Specifically, the TS packet switching and embedding unit 71 alternately performs a test TS packet having a length of 187 bytes in the first transmission antenna system or a test TS packet having a length of 187 bytes in the second transmission antenna system, alternately for each FEC block. Are sequentially stored in the payload of the FEC block. For example, when the test TS packet of the first transmitting antenna system is stored in the FEC block at the beginning of the OFDM frame, the 187-byte long test TS packet of the first transmitting antenna system is stored in the odd-numbered FEC block. .. Further, the 187-byte long test TS packet of the second transmitting antenna system is stored in the even-numbered FEC block.

The TS packet switching and embedding unit 71 adds a header to the payload to form the FEC block shown in FIG. The TS packet switching and embedding unit 71 outputs the FEC block of the video and audio signals including the header and the payload, or the FEC block of the test signal including the header and the payload to the BCH coding unit 11.

In normal operation, an MPEG-2 TS TS packet in which compressed coded video and audio are multiplexed is selected, and an FEC block of video and audio signals is configured.

The preset switching control signal is transmitted to the MIMO receiver 2 as a part of the TMCC signal.

Since the distribution unit 16 provided in the MIMO transmission device 1 of the third embodiment is the same as the distribution unit 16 of FIG. 4 provided in the MIMO transmission device 1 of the first embodiment, the description thereof will be omitted here.

(Synthesis unit 37, packet extraction unit 43 / Example 3)
Next, the synthesis unit 37 and the packet extraction unit 43 provided in the MIMO receiving device 2 of the third embodiment will be described. Since the synthesis unit 37 provided in the MIMO receiving device 2 of the third embodiment is the same as the synthesis unit 37 of FIG. 5 provided in the MIMO receiving device 2 of the first embodiment, the description thereof will be omitted here.

FIG. 9 is a block diagram showing a configuration example of the packet extraction unit 43 provided in the MIMO receiving device 2 of the third embodiment. The packet extraction unit 43 includes a TS packet extraction unit 80, a TS packet distribution unit 81, and test signal determination units 82-1 and 82-2.

The TS packet extraction unit 80 inputs the header and payload included in the FEC block from the BCH decoding unit 42, and extracts the TS packet from the payload of the FEC block. Then, the TS packet extraction unit 80 adds a synchronization byte to the beginning of the TS packet, restores the original TS packet having a length of 188 bytes, and outputs the TS packet to the TS packet distribution unit 81.

The TS packet distribution unit 81 inputs a TS packet from the TS packet extraction unit 80, and also inputs a switching control signal from the TMCC signal extraction unit 34. This switching control signal is a signal obtained from the received TMCC signal.

The TS packet distribution unit 81 distributes the TS packet of the video and audio signals and the TS packet of the test signal according to the switching signal. Specifically, when the switching control signal indicates a video and audio signal, the TS packet distribution unit 81 outputs the input TS packet as a TS packet of the video and audio signals as it is. On the other hand, when the switching control signal indicates a test signal, the TS packet distribution unit 81 alternately supplies the test TS packet of the first transmission antenna system and the test TS packet of the second transmission antenna system for each FEC block. Sort. The TS packet distribution unit 81 outputs the test TS packet of the first transmission antenna system to the test signal determination unit 82-1 and outputs the test TS packet of the second transmission antenna system to the test signal determination unit 82-2. ..

The test signal determination unit 82-1 inputs the test TS packet of the first transmission antenna system from the TS packet distribution unit 81, and extracts the test signal from the test TS packet of the first transmission antenna system. Then, the test signal determination unit 82-1 calculates the bit error rate based on the extracted test signal and the preset test signal.

Here, when the on / off control signal indicates off and interleaving is not performed in the frequency and interpolar interleaving unit 52 of the distribution unit 16 provided in the MIMO transmission device 1, the test signal determination unit 82-1 determines. , The bit error rate of the first transmitting antenna system is calculated. On the other hand, when the on / off control signal indicates on and interleaving is performed in the frequency and interpolar interleaving unit 52 of the distribution unit 16 provided in the MIMO transmitter 1, the test signal determination unit 82-1 determines. The bit error rate in which the first transmitting antenna system and the second transmitting antenna system are combined is calculated.

The test signal determination unit 82-2 inputs the test TS packet of the second transmission antenna system from the TS packet distribution unit 81, and extracts the test signal from the test TS packet of the second transmission antenna system. Then, the test signal determination unit 82-2 calculates the bit error rate based on the extracted test signal and the preset test signal.

Here, when the on / off control signal indicates off and interleaving is not performed in the frequency and interpolar interleaving unit 52 of the distribution unit 16 provided in the MIMO transmitter 1, the test signal determination unit 82-2 determines. , The bit error rate of the second transmitting antenna system is calculated. On the other hand, when the on / off control signal indicates on and interleaving is performed in the frequency and interpolar interleaving unit 52 of the distribution unit 16 provided in the MIMO transmission device 1, the test signal determination unit 82-2 determines the interleaving. The bit error rate in which the first transmitting antenna system and the second transmitting antenna system are combined is calculated.

As described above, when the on / off control signal indicates off and the switching control signal indicates a test signal, the test TS packet of the first transmission antenna system is transmitted via the first transmission antenna system. The TS packet for testing the second transmitting antenna system is transmitted and transmitted via the second transmitting antenna system. That is, the test signal determination units 82-1 and 82-2 can calculate the bit error rate for each transmitting antenna system, and can obtain the characteristics for each transmitting antenna system.

On the other hand, when the on / off control signal indicates on and the switching control signal indicates a test signal, the test TS packet of the first transmission antenna system is distributed to the two transmission antenna systems, and the second transmission antenna system is distributed. The same applies to the test TS packet of the transmitting antenna system. That is, the test signal determination units 82-1 and 82-2 can calculate the total bit error rate in which both transmission antenna systems are combined, and can obtain the comprehensive characteristics.

The bit error rate calculated by the test signal determination units 82-1 and 82-2 is a value (value after error correction) in consideration of error correction of the LDPC code and the BCH code. Although it is possible to calculate the bit error rate in the BCH decoding unit 42 provided in the MIMO receiving device 2 of the above-described first embodiment, the error correction is not possible due to the poor condition of the transmitting antenna system such as the propagation path. If possible, the bit error rate cannot be calculated. On the other hand, in the test signal determination units 82-1 and 82-2 provided in the MIMO receiving device 2 of the third embodiment, the condition of the transmitting antenna system such as the propagation path is bad and error correction is impossible. However, since the known test signal is used, the bit error rate can be calculated, so that the characteristics of each transmitting antenna system can be surely obtained as compared with the first embodiment.

Further, although it is possible to calculate the bit error rate in the test signal determination unit 64 provided in the MIMO receiving device 2 of the above-described second embodiment, the bit error rate in consideration of the error correction of the LDPC code and the BCH code is also possible. Cannot be calculated. On the other hand, the test signal determination units 82-1 and 82-2 provided in the MIMO receiver 2 of the third embodiment can calculate the bit error rate in consideration of the error correction of the LDPC code and the BCH code. Unlike the second embodiment, the characteristics in the same situation as the actual operation can be obtained.

Although the present invention has been described above with reference to Examples 1, 2, and 3, the present invention is not limited to the above Examples 1, 2, and 3, and can be variously modified without departing from the technical idea. be. For example, the LDPC decoding unit 40 of the MIMO receiving device 2 may not perform the LDPC decoding process according to a predetermined setting. Further, the BCH decoding unit 42 may not perform the BCH decoding process according to a predetermined setting. As a result, the MIMO receiving device 2 has a bit error rate before error correction of the LDPC code and BCH code (before LDPC decoding and BCH decoding), and a bit error rate after error correction of the LDPC code and before error correction of the BCH code. , And the bit error rate after error correction of the LDPC code and the BCH code can be calculated, respectively.

Further, in the first, second, and third embodiments, the block distribution unit 50 of the distribution unit 16 provided in the MIMO transmission device 1 alternately uses the carrier symbol as a unit of one FEC block, and the first transmission antenna system and the first transmission unit. 2 I tried to distribute to the transmitting antenna system. On the other hand, the block distribution unit 50 may alternately distribute the carrier symbols to the first transmission antenna system and the second transmission antenna system in units of a predetermined number (s) of FEC blocks.

Further, in the first, second, and third embodiments, a wireless communication system that performs MIMO transmission with two inputs and two outputs with two transmitting antenna systems and two receiving antenna systems has been described as an example. The present invention is not limited to MIMO transmission with 2 inputs and 2 outputs, and is also applicable to MIMO transmission by another number of transmitting antenna systems and receiving antenna systems.

1 MIMO transmitter 2 MIMO receiver 10 FEC block component 11 BCH coding unit 12 Energy diffusion unit 13 LDPC coding unit 14 Bit interleaving unit 15 Symbol mapping unit 16 Distribution unit 17 Hours interleaving unit 18 TMCC signal generation unit 19 OFDM Frame component 20 IFFT and GI addition 21 Orthogonal modulation section 22,31 High frequency section 23,30 Polarization shared antenna 32 Orthogonal demodulation section 33 GI removal and FFT section 34 TMCC signal extraction section 35 MIMO detection section 36 hours deinterleavement section 37 Synthesis unit 38 LLR calculation unit 39 Bit deinterleave part 40 LDPC decoding unit 41 Energy back diffusion unit 42 BCH decoding unit 43 Packet extraction unit 50 Block distribution unit 51 Data carrier allocation unit 52 Frequency and polarization-to-polarization interleaving unit 53,70 Test signal Generation unit 54, 63 Test signal switching unit 60 Frequency and polarization deinterleavement unit 61 Carrier symbol extraction unit 62 Block synthesis unit 64,82 Test signal determination unit 71 TS packet switching and embedding unit 80 TS packet extraction unit 81 TS packet distribution unit

Claims (4)

In a MIMO receiver that receives OFDM signals transmitted from a plurality of transmitting antennas via a plurality of receiving antennas.
An extraction unit that extracts a control signal from a signal in the frequency domain of the OFDM signal for each receiving antenna system corresponding to each of the plurality of receiving antennas.
Propagation path response is estimated based on the pilot signal included in the control signal extracted by the extraction unit, MIMO detection is performed based on the signal in the frequency domain and the propagation path response, and each of the plurality of transmitting antennas. A MIMO detector that generates a carrier symbol for each transmission antenna system corresponding to
A carrier symbol having an FEC block as a unit is extracted from the carrier symbol generated by the MIMO detection unit for each transmitting antenna system, and the carrier symbol having the FEC block as a unit for each transmitting antenna system is synthesized. And the synthesis part to do
The carrier symbol in units of the FEC block synthesized by the synthesis unit is decoded, the bit error rate for each transmission antenna system is calculated, and the FEC block for obtaining the characteristics for each transmission antenna system is restored. Decoding part to do,
An information extraction unit that extracts information to be transmitted from the page load of the FEC block restored by the decoding unit, and an information extraction unit.
A MIMO receiver characterized by being equipped with. In the MIMO receiving device according to claim 1 ,
The synthesis unit is
When the on / off control signal included in the control signal extracted by the extraction unit indicates ON, each symbol is used for all the carrier symbols for each transmission antenna system generated by the MIMO detection unit. Deinterleave is performed, and the carrier symbol after the deinterleave is output for each transmission antenna system.
When the on / off control signal indicates off, the deinterleave unit that outputs the carrier symbol for each transmission antenna system generated by the MIMO detection unit and the deinterleave unit.
A carrier symbol extraction unit that extracts the carrier symbol in units of the FEC block from the carrier symbol output by the deinterleavement unit for each transmission antenna system.
A block synthesis unit that synthesizes the carrier symbol in units of the FEC block for each transmission antenna system extracted by the carrier symbol extraction unit, and a block synthesis unit.
A MIMO receiver characterized by being equipped with. In the MIMO receiving device according to claim 1 or 2 .
The synthesis unit is
When the first switching control signal included in the control signal extracted by the extraction unit indicates the FEC block, the carrier symbol and the propagation path with the FEC block as a unit for each transmission antenna system. Among the test carrier symbols composed of predetermined test signals for determining the characteristics of the transmitting antenna system including the above, the carrier symbol with the FEC block as a unit is selected, and the FEC block for each transmitting antenna system is selected. By synthesizing the carrier symbol as a unit,
When the first switching control signal indicates the test carrier symbol, the test carrier symbol among the carrier symbol and the test carrier symbol in the unit of the FEC block is used for each transmission antenna system. A MIMO receiver which is selected and, based on the test carrier symbol, calculates data for determining the characteristics of each transmitting antenna system. In the MIMO receiving device according to claim 1 or 2 .
The information extraction unit
Information including the transmission target information or test information including a test signal for determining the characteristics of the transmission antenna system including the propagation path is extracted from the payload of the FEC block restored by the decoding unit.
When the second switching control signal included in the control signal extracted by the extraction unit indicates the information of the transmission target, the information of the transmission target extracted from the payload of the FEC block is output.
When the second switching control signal indicates the test information, in order to determine the characteristics of each transmitting antenna system based on the test information of each transmitting antenna system extracted from the payload of the FEC block. A MIMO receiver characterized by calculating the data of.

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