Modified branch metrics for processing soft decisions to account for phase noise impact on cluster

摘要

Modified branch metrics for processing bit-soft decisions to account for phase noise impact on cluster variance (CV). The present invention is able to partition a modulation scheme's constellation into two or more regions, so that the bit-soft decision branch metrics may be adjusted based on the CV of the various constellation points. A confidence level may be attached to the various constellation points based on their particular CVs. There are a number of methods to ascertain the CV of the constellation's points, including finding characteristics of various components in a communication system (transmitter, communication channel and receiver), and any method may be used within various embodiments. The modification of the branch metrics/confidence level may be performed in a communication receiver; the communication receiver may be implemented in a communication system employing the vector orthogonal frequency division multiplexing (VOFDM) portion of the broadband wireless internet forum (BWIF).