Digital on-board multicarrier demodulator for mobile satellite communications

The development of an electrical demonstration model of a 32-channel on-board multicarrier demodulator for the return up-link of a (land) mobile satellite communication system is described. Continuous-mode coded speech and data as well as data packets are transmitted at a rate of 9.6 kb/s using filtered QPSK modulation. The implementation is fully digital. The design and obtained performance of the demultiplexer, based on the highly modular and computationally efficient hierarchical multistage method, and the subsequent demodulator are described. Good demodulator acquisition and tracking performance are obtained by the use of parameter estimation techniques and sophisticated frequency, phase and timing control loops.<<ETX>>