The Study Of High Speed Modem With Multi-rate And Multi-mode

Firstly, the conception of the high spead modem with multi-rate and multi-mode, and the overview of Mobile Self-Organized Network are introduced in this paper. As the base platform for Mobile Self-Organized Network, three modulation modes of variable-rate-supported M-ary orthogonal spread spectrum, π/4-DQPSK and 16QAM are mainly studied. The simulation algorithm, implementation scheme and the design of some key modules based on FPGA are described in detail, besides. Both the results of the measurement on different modulation modes and the analysis of BER performance are given. A rapid symbol timing scheme is proposed in this paper based on noncoherent demodulation. Finally, the design of MAC layer and the organization of Mobile Self-Organized Network which has three backbone nodes are introduced, and the measurement result is also presented.