Further results on interference cancellation and space-time block codes

Space-time block codes (STBC) make use of a rich algebraic structure to provide diversity gains with small decoding complexity. We show that the rich algebraic structure of STBC reduces the hardware and software complexity of interference cancellation (IC) techniques. Additionally, after the IC stage, transmitted symbols can still be recovered with space-time diversity gains. We present three illustrative examples of IC in wireless networks where cochannel users employ STBC. First, we show that any STBC that is based on an orthogonal design allows IC of two cochannel users with simple linear processing. Second, we show that for S.M. Alamouti's STBC (see IEEE Journal on Selected Areas in Communication, vol.16, no.8, p.1451-8, 1998), K>2 users can be detected with simple linear processing, while still ensuring space-time diversity gains. Third, capitalizing on recent work on single-carrier frequency-domain STBC, we study how the aforementioned IC schemes can be modified for frequency-selective channels.