Abstract: Presents the application of SPW (signal processing worksystem) in the design of a wideband multi-rate modem. Algorithms for high speed multi-rate modem are discussed. Based on the processing stages of the transceiver to be implemented, simulation platform in SPW are established with different processing structures and parameters. The optimal demodulator structure and parameters are obtained in terms of performance and implementation complexity. Simulation results showed that bit error rate (BER) degradation of the designed quadrature phase shift keying (QPSK) modem is less than 0.2dB compared to the theoretical value. Hardware testing results showed that the BER performance of the designed modem is in good agreement with the simulation results and verified the validity and effectiveness of simulation platform.