JP6546467B2 - Transmitter, receiver and chip - Google Patents

Description

  The present invention relates to a transmitter, receiver and chip for transmitting data signals and control signals in data frames.

  As a terrestrial digital method method in Japan, ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) method is adopted.

  In the ISDB-T scheme, the transmitting apparatus is a transmission frame (OFDM (a) that is composed of data frames and control signals (TMCC (Transmission and Multiplexing Configuration and Control) signals and AC (Auxiliary Channel) signals) used to transmit data signals. In Orthogonal Frequency Division Multiplexing) frames, data signals such as video and audio are transmitted. Also, the transmission apparatus inserts a control signal into a transmission frame for each transmission frame and transmits it. The receiving apparatus receives data signals such as video and audio by synchronizing transmission frames (see Non-Patent Document 1).

  In addition, a technology for transmitting a control signal as well as a data signal in the above-mentioned data frame is also considered.

"" Transmission method standard for digital terrestrial television broadcasting "ARIB STD-B31", [online], [June 10, 2015 search], Internet <URL: http://www.arib.or.jp/ english / html / overview / doc / 2-STD-B31v2_0.pdf>

  In the technology in which a control signal is included in a data frame and transmitted, the same carrier modulation scheme as the data signal is used for modulation of the control signal. For example, when 4096 QAM (Quadrature Amplitude Modulation) is used for carrier modulation of a data signal, 4096 QAM will be used for carrier modulation of a control signal, and it may be difficult to ensure sufficient reception characteristics of the control signal. .

  In the ISDB-T system, since the data signal is decoded using control information included in the control signal, the control signal is required to have a higher error correction capability than the data signal. On the other hand, the control signal is generally disadvantageous in terms of error correction capability since the error correction code length is shorter than that of the data signal. Therefore, conventionally, the improvement of the reception characteristic of the control signal has only to enhance the resistance of the error correction code to be used, but there is a limit to the improvement of the reception characteristic by the improvement of the resistance of the error correction code.

  An object of the present invention is to provide a transmitting device, a receiving device, and a chip capable of solving the problems described above and improving the reception characteristics of control signals when transmitting data signals and control signals in data frames. It is to do.

In order to solve the above problems, a transmitting apparatus according to the present invention is a transmitting apparatus that carries out carrier modulation of a data frame including a data signal and a control signal used for decoding the data signal , maps it on an IQ plane, and transmits it. And mapping a data signal included in the data frame to a signal point in a signal point arrangement of a predetermined modulation method, and partially controlling a control signal included in the data frame in the signal point arrangement of the predetermined modulation method. The carrier modulation unit is configured to map only to the signal point , and the carrier modulation unit is a signal point other than the outermost signal point in the signal point arrangement of the predetermined modulation scheme, and the distance between the signal points is the predetermined the larger signal point than the distance corresponding to the average power of all signal points of the modulation scheme, you mapping said control signal.

  Further, in the transmitter according to the present invention, a bit interpolator for adding a predetermined bit string of the number of bits according to the predetermined modulation scheme to each bit constituting the control signal, the data signal and the bit interpolator It is preferable to further include a data framing unit that generates the data frame including the control signal to which the predetermined bit string is added and outputs the data frame to the carrier modulation unit.

  In the transmission device according to the present invention, preferably, the bit interpolation unit adds a bit string such that the control signal is transmitted only by either the I signal or the Q signal.

Further, in order to solve the above problems, a receiving apparatus according to the present invention performs transmission by carrier modulation of a data frame including a data signal and a control signal used for decoding the data signal and mapping on an IQ plane. A receiving apparatus for receiving a signal from an apparatus, wherein a data signal received from the transmitting apparatus and included in the data frame is mapped to a signal point in a signal point arrangement of a predetermined modulation scheme, and is also connected to the data frame A carrier including the control signal is extracted and demodulated from a received signal in which a control signal included is mapped only to a part of signal points in the signal point arrangement of the predetermined modulation scheme, and the demodulated signal is obtained. A control signal acquisition unit configured to acquire the control signal by performing demapping according to a signal point to which the control signal is mapped; It includes a data signal acquisition unit for acquiring the data signal using the control signal al the control signal obtaining unit has obtained, and the control signal, except the outermost signal points in the signal constellation of said predetermined modulation method a signal point of, that is mapped distance between signal points in the larger signal point than the distance corresponding to the average power of all signal points of said predetermined modulation method.

  In the reception device according to the present invention, preferably, the control signal acquisition unit demaps the demodulated signal by hard decision based on a reference according to a signal point to which the control signal is mapped.

  Further, in the receiving apparatus according to the present invention, it is preferable that the control signal acquisition unit demaps the demodulated signal by soft decision using positional information of signal points to which the control signal is mapped.

Further, in order to solve the above problems, a chip according to the present invention carries out carrier modulation of a data frame including a data signal and a control signal used for decoding the data signal , maps it on an IQ plane, and transmits it. And a data signal contained in the data frame is mapped to a signal point in a signal point arrangement of a predetermined modulation method, and a control signal contained in the data frame is a signal of the predetermined modulation method The carrier modulation unit is configured to map only a part of signal points in the point arrangement , and the carrier modulation unit is a signal point other than the outermost signal point in the signal point arrangement of the predetermined modulation scheme, and is between signal points The control signal is mapped to a signal point at which the distance of the target signal is greater than the distance according to the average of the powers of all the signal points of the predetermined modulation scheme. You.

Further, in order to solve the above problems, a chip according to the present invention carries out carrier modulation of a data frame including a data signal and a control signal used for decoding the data signal , maps it on an IQ plane, and transmits it. A chip mounted on a receiving device for receiving a signal from a data signal, the data signal received from the transmitting device and included in the data frame being mapped to a signal point in a signal point arrangement of a predetermined modulation scheme; The carrier signal including the control signal is extracted and demodulated from the received signal in which the control signal included in the data frame is mapped to only a part of signal points in the signal point arrangement of the predetermined modulation scheme, and the demodulated signal And a control signal acquisition unit that acquires the control signal by performing demapping according to the signal point to which the control signal is mapped. , And a data signal acquisition unit that acquires the data signal using a control signal by the control signal obtaining unit has obtained from the received signal, the control signal is the outermost in the signal constellation of said predetermined modulation method a signal point other than signal point of, that is mapped distance between signal points in the larger signal point than the distance corresponding to the average power of all signal points of said predetermined modulation method.

  According to the transmitting device, the receiving device, and the chip according to the present invention, when transmitting a data signal and a control signal in a data frame, it is possible to improve the reception characteristics of the control signal.

It is a figure which shows an example of a structure of the transmitter which concerns on one Embodiment of this invention. It is a figure which shows another example of a structure of the transmitter which concerns on one Embodiment of this invention. It is a figure which shows an example of a structure of the receiver which concerns on one Embodiment of this invention. It is a figure which shows the constellation example of 64 QAM. It is a figure which shows the example of arrangement | positioning of the signal point by which the control signal which concerns on one Embodiment of this invention is mapped. It is a figure which shows the example of arrangement | positioning of the signal point by which the control signal which concerns on one Embodiment of this invention is mapped. It is a figure which shows the example of arrangement | positioning of the signal point by which the control signal which concerns on one Embodiment of this invention is mapped.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a block diagram showing an example of the configuration of a transmission apparatus 10 according to an embodiment of the present invention.

  Transmission apparatus 10 shown in FIG. 1 includes error correction coding units 11 and 12, bit interpolation unit 13, data framing unit 14, carrier modulation unit 15, interleaving unit 16, OFDM modulation unit 17, and orthogonality. And a modulation unit 18.

  The error correction coding unit 11 receives the data signal, adds an error correction code to the input data signal (performs error correction coding), and generates a data framing unit for the data signal after error correction coding. Output to 14.

  The error correction coding unit 12 receives the control signal, performs error correction coding on the input control signal, and outputs the control signal of the error correction coding to the bit interpolation unit 13. The control signal input to the error correction coding unit 12 may be a TMCC signal or an AC signal. These control signals usually do not change frequently every transmission frame.

  The bit interpolation unit 13 adds a bit string of a predetermined number of bits to each bit constituting the control signal (control signal after error correction coding) output from the error correction coding unit 12. That is, the bit interpolation unit 13 converts each bit constituting the control signal into a bit string of a predetermined number of bits. The bit interpolation unit 13 outputs the control signal to which the predetermined bit string has been added to the data framing unit 14.

  The data framing unit 14 arranges the data signal output from the error correction coding unit 11 in a data frame. The data frame indicates a buffer area in which a data signal is stored in a fixed amount such as several OFDM symbols. Normally, only data signals are arranged in data frames, but in the present embodiment, control signals are also arranged in data frames. Therefore, the data framing unit 14 arranges the control signal (control signal to which a predetermined bit string is added) output from the bit interpolation unit 13 in a predetermined area in the data frame. The data framing unit 14 outputs a data frame generated by arranging the data signal and the control signal to the carrier modulation unit 15.

  The carrier modulation unit 15 performs carrier modulation on the signal of the data frame output from the data framing unit 14 and outputs the modulation signal to the interleaving unit 16. Here, the carrier modulation unit 15 modulates the data signal and the control signal included in the data frame by the same modulation method. Therefore, there is no need to provide a modulation unit for control signals. Also, as described above, in the ISDB-T system, there is a control signal that does not change frequently for each transmission frame, such as a TMCC signal or an AC signal. Therefore, as such a control signal, the same signal is repeatedly transmitted in transmission frame units. Therefore, on the reception side, addition processing can be performed to increase the reliability by adding signals of a plurality of frames. In the transmitting apparatus 10 shown in FIG. 1, the reliability on the receiving side can be enhanced by transmitting a control signal that does not change frequently for each transmission frame to the data frame. Some control signals change for each frame, such as forward error correction (FEC) pointer information to be described later. The contents of such a control signal change from frame to frame, so the receiving side can not perform addition processing, and decoding is performed using only information in one frame.

  The interleaving unit 16 performs various interleaving processes such as frequency interleaving, time interleaving, and bit interleaving on the modulation signal output from the carrier modulation unit 15, and outputs the signal after the interleaving process to the OFDM modulation unit 17.

  The OFDM modulation unit 17 performs OFDM modulation on the output signal of the interleaving unit 16 by IFFT (Inverse Fast Fourier Transform), and outputs the signal after OFDM modulation to the orthogonal modulation unit 18.

  The orthogonal modulation unit 18 performs orthogonal modulation on the output signal of the OFDM modulation unit 17. The signal after quadrature modulation is transmitted to a receiver not shown in FIG.

  The control information included in the control signal may change every moment in the transmission process. The present invention is also applicable to the case where control information that changes every moment in the transmission process is included in a data frame and transmitted.

  FIG. 2 is a diagram showing an example of the configuration of the transmission device 10a according to the present embodiment, which transmits control information that changes every moment in the transmission process, in a data frame. In addition, in FIG. 2, the same code | symbol is attached | subjected about the structure similar to FIG. 1, and description is abbreviate | omitted.

  The transmitting device 10a shown in FIG. 2 is different from the transmitting device 10 shown in FIG. 1 in that the data framing unit 14 is changed to a data framing unit 14a and that a control signal generating unit 19 is added. . The control signal generation unit 19 includes an error correction coding unit 12, a bit interpolation unit 13, and a pointer generation unit 19a.

  The data framing unit 14 a arranges the data signal output from the error correction coding unit 11 in the data frame, and outputs the data frame after the arrangement of the data signal to the control signal generation unit 19. The data framing unit 14a places, for example, Null in the area in which the control signal in the data frame is placed.

  Here, when the OFDM frame length and the frame length of the FEC frame which is a frame for error correction code (FEC) are different, the receiving apparatus side needs to know information indicating the position of the break of the FEC frame in the OFDM frame. . Therefore, it is necessary to transmit FEC pointer information, which is control information indicating the position of the break of the FEC frame in the OFDM frame, to the receiving apparatus side. The FEC pointer information is information that changes every transmission frame, and is determined according to the arrangement of the data signal in the data frame.

  The pointer generation unit 19a generates, based on the data frame output from the data framing unit 14a, a control signal including control information determined according to the arrangement of the data signal to the data frame, such as FEC pointer information. Then, the pointer generation unit 19 a outputs the generated control signal to the error correction coding unit 12.

  Thereafter, as in the transmitter 10 shown in FIG. 1, error correction coding of the control signal by the error correction coding unit 12 and addition of a bit string by the bit interpolation unit 13 are performed, and the control signal to which a predetermined bit string is added is It is output to the data framing unit 14a.

  The data framing unit 14 a arranges the control signal output from the bit interpolation unit 13 in the area where nulls are arranged in the data frame to generate a data frame, and outputs the generated data frame to the carrier modulation unit 15. .

  As described above, according to the transmission device 10a shown in FIG. 2, it is possible to transmit control information that changes every moment in the transmission process by including it in the data frame. The configuration shown in FIG. 1 may be combined with the configuration shown in FIG.

  Next, the configuration of the receiving device 20 according to the present embodiment will be described.

  FIG. 3 is a block diagram showing an example of the configuration of the receiving device 20 according to the present embodiment. In FIG. 3, a control signal such as FEC pointer information is included in a data frame and transmitted by the transmission device 10a shown in FIG. 2, and the reception device 20 is described as receiving a signal from the transmission device 10a. .

  The receiver 20 shown in FIG. 3 includes an orthogonal demodulator 21, an OFDM demodulator 22, a deinterleaver 23, a control signal demodulator 24, an error correction decoder 25, a carrier demodulator 26, and pointer information extraction. A unit 27 and an error correction decoder 28 are provided. The control signal demodulation unit 24 and the error correction decoding unit 25 constitute a control signal acquisition unit 29a for acquiring a control signal from the reception signal from the transmission device 10a, and the carrier demodulation unit 26, the pointer information extraction unit 27 and the error correction decoding unit Reference numeral 28 constitutes a data signal acquisition unit 29b which acquires a data signal from the reception signal from the transmission device 10a.

  Orthogonal demodulation section 21 receives the received signal received from the transmission apparatus 10a, performs quadrature demodulation on the received signal, and outputs the signal after quadrature demodulation to OFDM demodulation section 22. .

  The OFDM demodulator 22 performs OFDM demodulation on the output signal of the orthogonal demodulator 21 by FFT, and outputs the signal after OFDM demodulation to the deinterleaver 23.

  The deinterleaving unit 23 performs deinterleaving processing corresponding to the interleaving processing by the interleaving unit 16 on the output signal of the OFDM demodulation unit 22, and transmits the deinterleaved signal to the control signal demodulation unit 24 and the carrier demodulation unit 26. Output.

  The control signal demodulation unit 24 extracts the carrier including the control signal from the output signal of the deinterleave unit 23, and the signal (symbol) to be extracted corresponds to the signal point to which the control signal to be described later is mapped. Demapping (specifying a signal point corresponding to a symbol and obtaining a bit value) is performed to obtain a control signal (control signal before error correction decoding), and the control signal is output to the error correction decoding unit 25. As described above, in the data frame, the area in which the control signal is arranged is predetermined. Therefore, the control signal demodulation unit 24 can extract the carrier including the control signal.

  The error correction decoding unit 25 performs error correction decoding on the output signal of the control signal demodulation unit 24 to obtain a control signal. Then, the error correction decoding unit 25 outputs the acquired control signal to a block and pointer information extraction unit 27 in the subsequent stage (not shown in FIG. 3). In the present invention, the error correction code and the error correction decoding for the control signal are not essential. Therefore, the error correction decoder 25 is not an essential component. In this case, the control signal acquisition unit 29 a does not include the error correction decoding unit 25, and the control signal acquired by the control signal demodulation unit 24 is output to the block and pointer information extraction unit 27 in the subsequent stage.

  The carrier demodulation unit 26 demodulates the output signal of the deinterleave unit 23 by the demodulation scheme for the modulation scheme of the carrier modulation unit 15, and outputs the demodulated signal to the pointer information extraction unit 27.

  The pointer information extraction unit 27 extracts FEC pointer information from the control signal output from the error correction decoding unit 25, and based on the extracted FEC pointer information, the demodulated signal output from the carrier demodulation unit 26 is converted to an OFDM signal within an OFDM frame. The position of the break of the FEC frame is added and output to the error correction decoding unit 28.

  The error correction decoding unit 28 performs error correction decoding on the demodulated signal output from the pointer information extraction unit 27 to obtain a data signal, and outputs the obtained data signal to a block in the subsequent stage.

  As described above, error correction decoding is not essential in the present invention. Therefore, the configuration of the data signal acquisition unit 29b illustrated in FIG. 3 is merely an example, and the data signal acquisition unit 29b acquires the data signal from the reception signal using the control signal acquired by the control signal acquisition unit 29a. It suffices to have a configuration for

  Next, operations of the transmission device 10 (transmission device 10a) and the reception device 20 will be described.

  First, the operation of the transmission device 10 (transmission device 10a) will be described.

  In addition, below, the carrier modulation part 15 shall perform carrier modulation by 64 QAM employ | adopted by the ISDB-T system.

  When using 64 QAM, the carrier modulation unit 15 maps the data signal to any of 64 constellation points (signal points) in the constellation arrangement (signal point arrangement) of the IQ plane shown in FIG. On the other hand, the carrier modulation unit 15 maps the control signal only to a part of signal points in the constellation arrangement shown in FIG. For example, the carrier modulation unit 15 maps the control signal only to two signal points indicated by black circles in FIG. 5A, that is, the signal points of “110000” and “000000”. Therefore, the control signal is pseudo-modulated using BPSK (Binary Phase Shift Keying) having a smaller number of modulation multi-values than 64 QAM. Therefore, the reception characteristics of the control signal can be improved. In each of the drawings, signal points to which control signals are mapped are indicated by black circles below.

  The signal points to which the control signal is mapped are not limited to the two points shown in FIG. For example, as shown in FIG. 5B, as a signal point to which the control signal is mapped, a signal point located inside of the signal point selected in FIG. 5A (a signal point of “110011” and “000011 Signal point) may be selected.

  Further, the number of signal points to which the control signal is mapped is not limited to two. The number of signal points to which the control signal is mapped may be, for example, four points (signal points of "00000", "010000", "100000", "110000") as shown in FIG. 5C. . In this case, the control signal is pseudo-modulated using QPSK (Quadrature Phase Shift Keying) having a smaller number of modulation multi-values than 64 QAM. Therefore, the reception characteristics of the control signal can be improved.

  Also, the modulation scheme used for carrier modulation is not limited to 64 QAM, and, for example, another modulation scheme such as 256 QAM may be used.

  FIG. 6 is a diagram showing an arrangement example of signal points to which control signals are mapped when 256 QAM is used for carrier modulation. FIG. 6A shows an example in which the control signal is mapped to two signal points, that is, an example in which the control signal is pseudo-modulated by BPSK. Further, FIG. 6 (b) shows an example in which the control signal is mapped to 16 signal points, that is, an example in which the control signal is pseudo-modulated by 16 QAM.

  In the present invention, only a part of signal points among the signal points used to modulate the data signal may be selected as the signal points to which the control signal is mapped. By so doing, the control signal can be artificially modulated by a modulation scheme having a smaller number of modulation levels than the modulation scheme that modulates the data signal, and the reception characteristics of the control signal can be improved. Therefore, in the present invention, there is no limitation on the modulation scheme used for carrier modulation, and it is possible to flexibly select the signal point for transmitting the control signal. Therefore, the modulation scheme to be used for carrier modulation, the number and the position of the signal points for mapping the control signal can be selected according to the system to be used.

  In the example shown in FIG. 5A, since the outermost signal point is selected, the average power of the control signal is larger than the average power of the data signal. In this case, as the number of control signals to be transmitted increases, the ratio of the power of the data signal to the total signal power decreases, and the reception characteristic of the data signal is degraded. Therefore, as shown in FIG. 5B, by selecting a signal point inside the outermost signal point, the amplitude value is suppressed and the average power of the control signal approaches the average power of the data signal. Deterioration of the reception characteristic of the data signal can be reduced. However, if the distance between the signal points to which the control signal is mapped is short, the reception characteristic of the control signal is degraded. Therefore, it is desirable that there is a certain distance between signal points to which control signals are mapped. For example, it is desirable that a distance about the diameter of a circle (a circle indicating the average of all signal powers) indicated by an alternate long and short dash line in FIG.

  For example, as shown in FIG. 5 (a), 64 QAM is used as the modulation scheme, and when the control signal is pseudo-modulated by BPSK, as shown in FIG. 6 (a), 256 QAM is used as the modulation scheme. The reception characteristics of the control signal are substantially the same as in the case where the control signal is pseudo-modulated by BPSK. Usually, as the modulation multi-level number is larger, the reception characteristic itself is degraded, so the improvement rate of the reception characteristic of the control signal according to the present invention becomes higher.

  The bit interpolation unit 13 adds a bit string corresponding to the position of the signal point to which the control signal is mapped to the control signal. For example, when the control signal is mapped to the signal point of "110000" and the signal point of "000000" as shown in FIG. 5A, the bit interpolator 13 selects bit "1" included in the control signal. The bit string "110000" is converted, and the bit "0" contained in the control signal is converted to the bit string "000000". That is, the bit interpolation unit 13 adds a bit string "10000" to bit "1" included in the control signal, and adds a bit string "00000" to bit "0" included in the control signal. Do. Therefore, assuming that the bit string of the control signal is "001", the bit interpolation unit 13 converts it into 18-bit information "000000 000000 110000".

  Also, consider the case where the control signal is mapped to the signal points of “000000”, “010000”, “100000”, and “110000” as shown in FIG. 5C. In this case, the bit interpolation unit 13 converts the bit string "00" included in the control signal into a bit string "000000", converts the bit string "01" included in the control signal into a bit string "010000", and is included in the control signal. The bit string "10" is converted to the bit string "100000", and the bit string "11" included in the control signal is converted to the bit string "110000". That is, the bit interpolation unit 13 adds the bit string "0000" to each of the bit strings "00", "01", "10", and "11" included in the control signal. Therefore, assuming that the bit string of the control signal is “0110”, the bit interpolation unit 13 converts it into 12-bit information “010000 100000”.

  Thus, the bit interpolation unit 13 converts the bit or bit string included in the control signal into a bit string of the number of bits according to the modulation scheme of the data signal. Thus, by adding a predetermined bit string to the control signal and converting the control signal into a bit string of the number of bits according to the modulation method of the data signal, the selected signal point among the signal points in the constellation arrangement Only the control signals can be mapped.

  In the receiving device 20, the control signal demodulation unit 24 extracts the carrier including the control signal from the received signal on which the deinterleaving process has been performed. Then, the control signal demodulation unit 24 demaps the extracted carrier signal according to the signal point to which the control signal is mapped, obtains a bit value, and acquires the control signal. There are a hard decision and a soft decision as a method of obtaining a bit value.

  As shown in FIG. 5A, when the control signal is mapped to the signal points “110000” and “000000”, the control signal demodulation unit 24 is equidistant from each signal point to which the control signal is mapped. A hard decision is made on the basis of a line (indicated by a broken line in FIG. 5A).

  When soft decision is performed, the control signal demodulation unit 24 performs soft decision using position information of signal points to which the control signal is mapped.

  The control signal may be transmitted only by either the I signal or the Q signal. In this case, the bit interpolation unit 13 assigns the bit of the control signal and a predetermined bit string to one of the I signal component and the Q signal component in the bit information corresponding to the signal point, and the data signal to the other. assign.

  FIG. 7A is a diagram showing an arrangement example of signal points to which control signals are mapped in the case where 64 QAM is used as a modulation scheme and a control signal is transmitted using only a Q signal.

  In the example shown in FIG. 7A, the bit “0” included in the control signal is “100000”, “100010”, “101010”, “101000” surrounded by a dotted-lined square in FIG. 7A. , “001000”, “001010”, “000010”, and “000000” are mapped to any one of eight signals. Also, the bit "1" included in the control signal is eight signal points of "110000", "110010", "111010", "111000", "011000", "011010", "010010", and "010000". It is mapped to one of the signals.

  Here, to which signal point among the eight signal points surrounded by a square the bit “0” included in the control signal is mapped differs depending on the data signal assigned to the I signal component. Similarly, which one of eight signal points the bit "1" included in the control signal is mapped to is different depending on the data signal assigned to the I signal component.

  When the control signal is mapped to the signal point shown in FIG. 7A, assuming that the bit information corresponding to the signal point of 64 QAM is (b0, b1, b2, b3, b4, b5), the Q signal is (b1) , B3, b5). Therefore, when the bit included in the control signal is “0”, the bit interpolation unit 13 sets (b1, b3, b5) = (0, 0, 0), and the bit included in the control signal is “1”. In the case of “(1), (b1, b3, b5) = (1, 0, 0)”. That is, the bit interpolation unit 13 assigns the bit information included in the control signal to b1 among the bit information corresponding to the Q signal, and assigns 0 to b3 and b5. Further, data signals are assigned to the I signal components (b0, b2, b4).

  In FIG. 7A, although the example in which the control signal of 1 bit is mapped to the signal point is described, the present invention is not limited to this. FIG. 7B is a diagram showing an arrangement example of signal points to which control signals are mapped when 256 QAM is used as a modulation method and a control signal of 2 bits is transmitted with only a Q signal.

  In the example shown in FIG. 7B, the bit "00" included in the control signal is mapped to any one of 16 signal points surrounded by a dotted square. Similarly, bit "01" included in the control signal is mapped to any one of 16 signal points in the second row from the top among the four rows of signal points indicated by black circles, The included bit "10" is mapped to any of 16 signal points in the third row from the top among the four rows of signal points indicated by black circles, and the bit "11" included in the control signal is , Out of four rows of signal points indicated by black circles, mapped to any of 16 signal points in the fourth row.

  When the control signal is transmitted using only the Q signal, the control signal demodulation unit 24 can perform demapping based on the Euclidean distance (the distance to the ideal signal point) of the Q signal.

  Since the control signal is transmitted by one of the I signal and the Q signal and the data signal is transmitted by the other, it is possible to suppress the decrease in the transmission rate of the data signal due to the transmission of the control signal. In addition, since the control signal is transmitted across a large number of carriers according to the value of the data signal, it is possible to improve the resistance to frequency selective fading such as multipath.

  As described above, according to the present embodiment, the transmitter 10 (the transmitter 10a) maps the data signal included in the data frame to the signal point in the signal point constellation of the predetermined modulation scheme, and is included in the data frame The carrier modulation unit 15 maps the control signal to only a part of signal points in the signal point arrangement of a predetermined modulation scheme. Further, the receiving device 20 extracts a carrier including a control signal from the reception signal of the transmitting device 10 (transmitting device 10a), demodulates it, and corresponds to a signal point at which the control signal is mapped to the demodulated signal. A control signal acquisition unit 29a that acquires a control signal by performing demapping, and a data signal acquisition unit 29b that acquires a data signal using the control signal acquired by the control signal acquisition unit 29a from the received signal.

  By mapping the control signal only to a part of the signal points in the signal point arrangement of the modulation scheme used for modulation of the data signal, the control signal is artificially modulated by the modulation scheme having a smaller number of modulation levels than the data signal. It will be. Therefore, the reception characteristics of the control signal can be improved.

  A program may be provided that causes a computer to execute each process performed by the transmitting device 10 (transmitting device 10 a) and the receiving device 20. Further, the program may be recorded on a computer readable medium. Here, the computer readable medium storing the program may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, but may be, for example, a storage medium such as a CD (Compact Disc) -ROM (Read Only Memory) or a DVD (Digital Versatile Disc) -ROM. .

  Alternatively, the transmission device 10 (transmission device 10 a) may be configured by a memory storing a program for executing each process performed by the transmission device 10 (transmission device 10 a) and the reception device 20 and a processor executing the program stored in the memory. And a chip mounted on the receiver 20 may be provided.

  Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various changes or modifications based on the present disclosure. Therefore, it should be noted that these variations or modifications are included in the scope of the present invention. For example, functions included in each block can be rearranged so as not to be logically inconsistent, and a plurality of blocks can be combined into one or divided.

DESCRIPTION OF SYMBOLS 10 10a Transmitter 11 12 Error correction coding unit 13 Bit interpolation unit 14 14a Data framing unit 15 Carrier modulation unit 16 Interleave unit 17 OFDM modulation unit 18 Quadrature modulation unit 19 Control signal generation unit 19a Pointer generation unit 20 Reception Device 21 Quadrature demodulation unit 22 OFDM demodulation unit 23 De-interleaving unit 24 Control signal demodulation unit 25 and 28 Error correction decoding unit 26 Carrier demodulation unit 27 Pointer information extraction unit 29a Control signal acquisition unit 29b Data signal acquisition unit

Claims (8)

A transmitting apparatus for carrier modulating a data frame including a data signal and a control signal used for decoding the data signal , mapping the carrier onto an IQ plane, and transmitting it.
The data signal contained in the data frame is mapped to the signal point in the signal point arrangement of a predetermined modulation scheme, and the control signal contained in the data frame is only a part of the signal points in the signal point arrangement of the predetermined modulation scheme comprising a carrier modulation unit that maps to,
The carrier modulation unit is a signal point other than the outermost signal point in the signal point arrangement of the predetermined modulation method, and the distance between the signal points is the average of the powers of all the signal points of the predetermined modulation method. the larger signal point than corresponding distances, transmission and wherein the mapping to Rukoto said control signal. In the transmitter according to claim 1,
A bit interpolation unit for adding a predetermined bit string of the number of bits according to the predetermined modulation scheme to each bit constituting the control signal;
A data framing unit that generates the data frame including the data signal and a control signal to which the predetermined bit string is added by the bit interpolation unit, and outputs the data frame to the carrier modulation unit;
The transmitter apparatus, further comprising: In the transmitter according to claim 2,
The transmitter according to claim 1, wherein the bit interpolator adds a bit string such that the control signal is transmitted by only one of an I signal and a Q signal. A receiving apparatus for receiving a signal from a transmitting apparatus that carrier modulates a data frame including a data signal and a control signal used for decoding the data signal , maps the carrier on an IQ plane, and transmits it.
A data signal received from the transmitter and contained in the data frame is mapped to a signal point in a signal point arrangement of a predetermined modulation scheme, and a control signal contained in the data frame is a signal point of the predetermined modulation scheme The carrier including the control signal is extracted and demodulated from the reception signal mapped to only a part of signal points in the arrangement, and the demodulation corresponding to the signal point to which the control signal is mapped. A control signal acquisition unit that performs mapping to acquire the control signal;
A data signal acquisition unit that acquires the data signal using the control signal acquired by the control signal acquisition unit from the reception signal;
Equipped with
The control signal is a signal point other than the outermost signal point in the signal point arrangement of the predetermined modulation method, and the distance between the signal points corresponds to the average of the powers of all the signal points of the predetermined modulation method. reception apparatus characterized that you have been mapped to the larger signal points than the distance. In the receiver according to claim 4,
A receiver according to claim 1, wherein the control signal acquisition unit demaps the demodulated signal by hard decision based on a reference according to a signal point to which the control signal is mapped. In the receiver according to claim 4,
A receiving apparatus characterized in that the control signal acquisition unit performs demapping on the demodulated signal by soft decision using position information of a signal point to which the control signal is mapped. A chip mounted on a transmitter for carrier-modulating a data frame including a data signal and a control signal used to decode the data signal , mapping the signal on an IQ plane, and transmitting the data frame,
The data signal contained in the data frame is mapped to the signal point in the signal point arrangement of a predetermined modulation scheme, and the control signal contained in the data frame is only a part of the signal points in the signal point arrangement of the predetermined modulation scheme comprising a carrier modulation unit that maps to,
The carrier modulation unit is a signal point other than the outermost signal point in the signal point arrangement of the predetermined modulation method, and the distance between the signal points is the average of the powers of all the signal points of the predetermined modulation method. the larger signal point than corresponding distances, chips, wherein the mapping to Rukoto said control signal. A chip mounted on a receiving apparatus for receiving a signal from a transmitting apparatus that carrier modulates a data frame including a data signal and a control signal used for decoding the data signal , maps the carrier on an IQ plane, and transmits the data frame. ,
A data signal received from the transmitter and contained in the data frame is mapped to a signal point in a signal point arrangement of a predetermined modulation scheme, and a control signal contained in the data frame is a signal point of the predetermined modulation scheme The carrier including the control signal is extracted and demodulated from the reception signal mapped to only a part of signal points in the arrangement, and the demodulation corresponding to the signal point to which the control signal is mapped. A control signal acquisition unit that performs mapping to acquire the control signal;
A data signal acquisition unit that acquires the data signal using the control signal acquired by the control signal acquisition unit from the reception signal;
Equipped with
The control signal is a signal point other than the outermost signal point in the signal point arrangement of the predetermined modulation method, and the distance between the signal points corresponds to the average of the powers of all the signal points of the predetermined modulation method. chips characterized that you have been mapped to the larger signal points than the distance.

Images