Joint demodulation and iterative multi-user decoding for SFH/SSMA networks

We study the problem of multiuser detection in the context of slow frequency hop spread spectrum multiple access (SFH/SSMA) systems. In particular, we study the demodulation and decoding aspects of multiuser reception for SFH/SSMA and propose methods which improve the capacity of the system. In particular, we propose and evaluate the joint demodulation of multiple symbols (defined as 'type') and the use of iterative type decoding after the demodulation. Preliminary results for hard-decision iterative decoding of Reed Solomon (RS) coded SFH/SSMA indicate that capacity improvements in excess of 60% can be achieved with our multiuser detection scheme over the traditional non-collaborative erasure/error-decoding of RS-coded SFH/SSMA. We expect that iterative soft-decision decoding of RS codes will achieve even more significant capacity gains for SFH/SSMA.