ADAPTIVE MODULATION/DEMODULATION METHOD AND RADIO COMMUNICATIONS SYSTEMS

摘要

An adaptive modulation/demodulation method and a wireless communication system are provided to improve throughput by independently determining modulation and demodulation multi-level numbers at receiving and transmitting communication apparatuses. An encoder(101) of a transmitting apparatus performs an encoding on transmitting data. The encoder(101) is comprised of an encoding unit(102) for a turbo encoding and a convolution encoding and an interleaving unit(103) for randomly changing a data order. Interleaved data are mapped with 64QAM(Quadrature Amplitude Modulation) symbols, QPSK(Quadrature Phase Shift Keying) symbols, and 16QAM symbols(104). Regardless of a modulation multi-level number selected by the transmitting apparatus, the mapped data are demodulated in a receiving apparatus by selecting a demodulation multi-level number based on a propagation path condition. A soft decision is inputted to a decoder(106). The decoder(106) is comprised of a deinterleaving unit(107) and a decoding unit(108).