Soft Information Relaying in Fading Channels
Md Anisul Karim, Jinhong Yuan, Zhuo Chen, Jun Li · IEEE Wireless Communications Letters · 2012
This letter considers the mutual information based soft forwarding (MIF) scheme for a memoryless parallel relay network in Rayleigh fading channels. The exact analytical expression for soft noise variance in Rayleigh fading channels is first given. A tight upper bound of the soft noise variance of the relayed signal and the input-output relationship at the relay is then derived. Furthermore, it is revealed that the MIF scheme in Rayleigh fading channels can achieve a full diversity order. Simulation results show that the MIF scheme yields about 0.8 - 1.8 dB signal-to-noise ratio (SNR) gains compared to the various full diversity-achieving schemes in the literature.