Efficient communication over the discrete-time memoryless Rayleigh fading channel with turbo coding/decoding

Communication over the discrete time memoryless Rayleigh fading channel is investigated. Codes achieving bit error rate (BER) lower than 10(-4) at bit energy over the noise spectral density ratio (E-b/N-o) of 1 to 2dB from th e channel capacity limit were found with coding rates of 0.05 to 0.36 bits per channel use. Similar codes with rates of up to 0.57 also performed reas onably close to the capacity limit. The codes are serial concatenation of t urbo code and a modulation code such as Pulse Position Modulation (PPM). Th e receiver is based on joint iterative decoding of the turbo code and the m odulation code. Information theoretic arguments are used to form guidelines for code design and to estimate performance of the iterative decoder.