A code-aided adaptive equalizer using soft decision-directed algorithm and convolutional coding for fading channels

We propose to use a soft decision-directed least mean square algorithm in a code-aided equalizer for fading channels. The soft-output Viterbi algorithm is used in decoding the convolutional code used. The soft output is then fed to the equalizer to adjust the tap coefficients (gains) of the equalizer. Simulation and analysis results are presented for bit error rate performance in a multipath environment for various Doppler rates (normalized Doppler rates equal to 0.001, 0.002 and 0.005, respectively). The proposed equalizer provides significant performance improvement in terms of bit error rate compared to other conventional equalization schemes.