Incremental frequency, amplitude and phase tracker (IFAPT) for coherent demodulation over fast flat fading channels

IFAPT estimates the parameters of piece-wise linear approximation to assumed continuous narrow-band signals. Its simple, recursive nature enables direct interaction with recursive algorithms, such as the Viterbi and the BCJR in the APP SISO module, used for iteratively decoding concatenated codes. An augmented APP (A/sup 2/P/sup 2/)-module, containing IFAPT and BCJR algorithms is applied to iterative decoding serial concatenated convolutional codes under Rayleigh fading conditions, with diversity reception.