Adjacent channel interference cancellation for MSK-type signals using antenna diversity

This paper addresses the problem of adjacent channel interference between constant-envelope signals, e.g., MSK-type signals. A technique, based on the BLAST concept, is used to greatly reduce the effects of adjacent channel interference (ACI) and co-channel interference (CCI), for channels with Rayleigh fading. The results show that it is possible to transmit these signals with a very small spacing between channels, under almost any power imbalance between signals, with very small degradation in performance! For example, it is shown that for MSK-type signals it is possible to operate at a channel spacing of 0.4/T_b with very little degradation in detectability performance, due to ACI. All the benefits of antenna diversity are achieved with very little loss due to ACI.