Adaptive sequence detection of channel-interleaved trellis-coded modulation signals over multipath fading ISI channels

A new tree-search receiver is proposed for the decoding of the channel-interleaved trellis-code transmitted over fast fading ISI channels. The feedforward channel estimation and the adaptive diversity combining matched filter bank and whitening filter are used, to combine diversity signals and shape the overall response to be causal, symbol-spaced taps. Then, the proposed receiver performs a T-algorithm joint tree-search over the state-machines of the code, the deinterleaver and the causal channel. We use the Ungerboeck's (1982) 8-PSK, 8-state trellis code with a modest block interleaving to show that the proposed receiver achieves the available time-diversity benefit of the code for the fast Rayleigh fading ISI channel, with a very moderate increase in the decoding complexity compared to the uncoded DFE.