Performance of Hybrid Concatenated Trellis Codes CPFSK with Iterative Decoding over Fading Channels

Concatenation is a method of building long codes out of shorter ones, it attempts to meet theproblem of decoding complexity by breaking the required computation into manageable segments.Concatenated Continuous Phase Frequency Shift Keying (CPFSK) facilitates powerful errorcorrection. CPFSK also has the advantage of being bandwidth efficient and compatible with non-linearamplifiers.Bandwidth efficient concatenated coded modulation schemes were designed for communicationover Additive White Gaussian noise (AWGN), and Rayleigh fading channels. An analytical bounds on theperformance of serial concatenated convolutional codes (SCCC), and parallel concatenatedconvolutionalcodes (PCCC), were derived as a base of comparison with the third category known ashybrid concatenated trellis codes scheme (HCTC). An upper bound to the average maximum-likelihoodbit error probability of the three schemes were obtained. Design rules for the parallel, outer, and innercodes that maximize the interleaver's gain were discussed. Finally, a low complexity iterative decodingalgorithm that yields a better performance is proposed.