A ´quantized´ channel approach to blind equalization

A blind identification algorithm for unknown linear channels is proposed. The algorithm operates over a grid in the channel space that is made finer by using the maximum likelihood criterion to confine the estimated channel in the neighborhood of the original unknown channel. The nature of the algorithm leads to efficient parallel implementation, and its storage requirements are only those of the Viterbi algorithm. Simulation examples have shown that identification of the channels considered is possible within 500 symbols and often within 50-100 symbols. The algorithm can be used as a start-up technique in conjunction with other identification methods. Implementation of the algorithm with a varying quantizing step is also possible.