Turbo and convolutional code comparison using a partially-processed satellite system in benign and Rayleigh faded channels (U)

(U) A binary symmetric channel uplink and an additive Gaussian channel downlink were cascaded and used to model a partially processed satellite system. We then studied the use of a rate 1/2 turbo code compared to a rate 1/2 convolutional code in the context of such a system. The downlink modulation used was DPSK. Channel interleaving was used to transform pair or burst errors caused by DPSK demodulation or fading respectively, into less correlated error events. This paper presents comparative simulation results for the end-to-end bit error rate performance of the two forward-error correction schemes when the uplink, downlink, or both links are affected by benign and by fading channels. In the fading cases, a unique metric transformation was used to improve the end-to-end BER performance.