Digital data transmitting apparatus and digital data receiving apparatus
To provide a digital data transmitting apparatus and a digital data receiving apparatus that can realize, even when a transmission channel characteristic changes because of aged deterioration or the like of a relay, improvement of a reception performance following the change. A transmitting apparatus 1 generates a multiplexing frame formed by N slots including control information, data, outer parities, stuff bits, and inner parities and added with synchronization, pilot, and a transmission control signal and a parity and transmits data of the respective slots in a transmission system designated by the transmission control signal. In this case, pilot signals are symbols allocated to all signal points in order determined in advance for each of modulation schemes. A receiving apparatus 2 rewrites a phase error table 214 to calculate a phase error and performs synchronous detection according to the pilot signals. The receiving apparatus 2 also rewrites a likelihood table 235 to perform inner code decoding. Consequently, since reception processing adapted to distortion of a transmission channel characteristic can be performed, improvement of a reception performance can be realized.
1. A transmitting apparatus used for a system that transmits data according to a digital modulation scheme for shifting amplitude and phase, the transmitting apparatus comprising:
means for mapping, for each number of bits per symbol corresponding to respective signal points of the modulation scheme, transmission data to the signal points;
means for applying, in predefined order, signal point mapping to all symbols allocated to the respective signal points of the modulation scheme;
means for periodically time-division multiplexing a signal point signal generated by mapping the symbols in the predefined order on a signal point signal generated by mapping the transmission data to generate a time division multiplex signal; and
means for applying orthogonal modulation to the generated time division multiplex signal and transmitting orthogonal modulated carrier signal,
wherein the transmitting apparatus periodically time-division multiplexes the signal in predefined order, orthogonally modulates the signal, and transmits the signal with symbols allocated to the respective signal points of the digital modulation scheme set as pilot signals.
2. The transmitting apparatus according to claim 1 , wherein the digital modulation scheme for shifting amplitude and phase is 16APSK, 16QAM, 32APSK, or 32QAM.
3. The transmitting apparatus according to claim 1 , wherein the transmitting apparatus further comprises LDPC encoding means for encoding by an LDPC code to the transmission data.
4. The transmitting apparatus according to claim 1 , wherein the system is a data transmission system for time-division multiplexing and for transmitting with plural kinds of digital modulation schemes.
5. The transmitting apparatus according to claim 4 , wherein one or more of 32APSK, 16APSK, 32QAM, and 16QAM is included as the digital modulation scheme.
6. A transmitting apparatus used for a system that transmits data according to a digital modulation scheme for shifting amplitude and phase, the transmitting apparatus comprising:
means for mapping, for each number of bits per symbol corresponding to respective signal points of the modulation scheme, transmission data to the signal points;
means for applying, in predefined order, signal point mapping to at least one of signal points on respective concentric circles of symbols allocated to the respective signal points of the modulation scheme;
means for periodically time-division multiplexing a signal point signal generated by mapping the symbols in the predefined order on a signal point signal generated by mapping the transmission data to generate a time division multiplex signal; and
means for applying orthogonal modulation to the generated time division multiplex signal and transmitting orthogonal modulated carrier signal,
wherein the transmitting apparatus periodically time-division multiplexes the signal in predefined order, orthogonally modulates the signal, and transmits the signal with symbols allocated to the respective signal points of the digital modulation scheme set as pilot signals.
7. The transmitting apparatus according to claim 6 , wherein the digital modulation scheme for shifting amplitude and phase is 16APSK, 16QAM, 32APSK, or 32QAM.
8. The transmitting apparatus according to claim 6 , wherein the transmitting apparatus further comprises LDPC encoding means for encoding by an LDPC code to the transmission data.
9. The transmitting apparatus according to claim 6 , wherein the system is a data transmission system for time-division multiplexing and for transmitting with plural kinds of digital modulation schemes.
10. The transmitting apparatus according to claim 9 , wherein one or more of 32APSK, 16APSK, 32QAM, and 16QAM is included as the digital modulation scheme.