An adaptive coding scheme for mobile radio systems

An adaptive error-control coding scheme for binary digital FM mobile radio transmission is proposed. The scheme uses code combining through packet retransmissions. The number of transmissions of a packet is proportional to the channel fading/noise levels, which is in contrast to time diversity techniques where a fixed number of repetitions of a data packet is performed even in the absence of channel errors. Furthermore, the receiver uses received signal envelopes as channel state information which significantly improves the throughput and bit error rate (BER) performance. Performance of the proposed scheme is analyzed for Rayleigh fading channels with additive white Gaussian noise (AWGN), cochannel interference, and random FM noise