A two-stage maximum likelihood sequence estimation technique and its application to data transmission protocol in digital cellular radio

A two-stage maximum likelihood sequence estimation (MLSE) technique is developed for improving digital transmission performance over the proposed Telecommunications Industry Association (TIA) North American TDMA digital cellular radio channels. The authors also investigate two simple retransmission schemes, retransmission before and after channel decoding, for possible implementation in the radio link protocol (RLP) within the proposed standard (IS-54). Simulation results indicate that the stage-one MLSE equalizer is about 3-4 dB away from the optimal performance in the wide signal-to-noise range at a vehicle speed equal to 60 mph. The results also show that retransmission before coding is a more effective way to improve the system performance