Identification of an identifiable code sequence in a received signal by correlation with summed different-phase replicas of the sequence

摘要

A receiver for a unique word sequence or a spreading code sequence includes a memory which is preloaded with all possible phases of the code. The sequence in the received signal is correlated, in parallel, with sums of various ones of the different phases of the code. Thus, the received code is correlated with all possible phases of a replica of its own code. Consequently, one of the sums will exhibit a correlation peak, which indicates that the desired phase of the code is included in that particular sum. The other sums will not exhibit a correlation peak, and are is discarded. The different phases in the one sum which displayed correlation are divided into new sums, each having fewer phases, and the correlation is again performed. Again, those sums exhibiting no correlation are discarded, and the sum exhibiting correlation is divided into sums of fewer codes.