Blind and nonblind nonnegative impulse response ISI channel demodulation using the Richardson-Lucy algorithm

Both blind and nonblind demodulation algorithms based on the Richardson-Lucy algorithm for the one-dimensional intersymbol interference channel with nonnegative impulse response function are proposed and compared numerically with the Viterbi demodulation algorithm and the demodulation algorithms based on the Wiener filter. Simulation results show that the demodulation algorithms based on the Richardson-Lucy algorithm have better bit error rate performance than the demodulation algorithms based on the Wiener filter. With the progressive thresholding, the bit error rate curves of both blind and nonblind Richardson-Lucy-based algorithms are within 0.3 dB from that of the Viterbi algorithm throughout the entire simulated signal-to-noise ratio range. While the complexity of the Viterbi algorithm depends critically on the length of the channel impulse response function, the complexity of the demodulation algorithms based on the Richardson-Lucy algorithm only weakly depends on it