A heuristic approach to optimization of the decision-directed maximum-likelihood feedforward carrier phase error detection algorithm

Using a heuristic approach, the performance of the self-synchronized decision-directed maximum-likelihood (ML) feedforward (FF) carrier phase error detection (PED) algorithm has been optimized. Compared to the original algorithm, it has been shown that for uncoded single channel (O)QPSK modems the optimized algorithm has a better phase error variance at low to medium signal to noise ratio (SNR). Further simulations have shown that the noise performance of the optimized algorithm at medium to high SNRs is superior to that of some well-known algorithms; the noise performance approaches the Cramer-Rao bound (CRB). This proves that the optimized algorithm has less tracking jitter at medium to high SNR which is a desirable feature in improving the BER performance.