Distributed Space-Time 4CPFSK Trellis Codes for Amplify & Forward Relaying

Continuous phase frequency shift keying is a power/bandwidth efficient modulation technique, hence, attractive for use in relay/cooperative systems employing inexpensive nonlinear power amplifiers. We investigate optimum distributed space-time 4-ary continuous phase frequency shift keying trellis codes for amplify & forward relaying method and propose novel codes for relay transmission systems. The error performances of the classical and novel codes are investigated for one and two-relay systems using various transmission protocols.