The Capacity of Successive DF Relaying and Using Soft Multiple-Symbol Differential Sphere Detection

The conventional single-relay aided two-phase cooperative network employing a so-called soft-input soft-output multiple-symbol differential sphere detection (SISO-MSDSD) and operating in a distributed turbo decoding mode incurs a high complexity and imposes a 50% half-duplex relaying induced throughput loss. In this paper, we combat both of these critical problems. We commence by evaluating the Discrete-input Continuous-output Memoryless Channel (DCMC) capacity of the Decode-and-Forward (DF) based successive relaying aided networks (SRAN) as our theoretical benchmark. Then a relay-aided SISO-MSDSD is designed, which is then incorporated in the DF based SRAN. As our novel contribution, we demonstrate that the proposed transceiver is capable of significantly reducing the system’s complexity, whilst recovering the 50% half-duplex relaying induced throughput loss. The system is capable of performing within 2.9 dB from the corresponding noncoherent DCMC capacity