Symbol-Rate Second-Order Blind Channel Estimation in Coded Transmissions

This paper proves that second-order symbol-rate blind channel identification is feasible if the transmitted bit stream is encoded and the channel estimator conveniently exploits the code redundancy. This result is surprising because most error correcting codes do not alter the symbols correlation. Despite this, it can be shown that second-order methods can exploit the symbols fourth-order statistical information, which contains part of the code redundant structure. Analytical and numerical results are presented for the BPSK (binary phase shift keying) modulation and simple error-correcting block codes. The extension to more sophisticated coding and modulation schemes seems straightforward although computationally intensive.