Feedforward Joint Phase and Timing Estimation with OQPSK Modulation

We propose an algorithm for joint carrier phase and timing estimation with offset quadriphase modulation (OQPSK) signaling. The derivation is based on maximum-likelihood arguments and leads to a feedforward structure that operates on signal samples taken at bit rate. Phase and timing algorithms operate in parallel—not sequentially—and provide their estimates in a fixed time. The synchronizer is readily implemented in digital form and is particularly suitable for burst mode transmissions. Its performance is analytically assessed and verified by simulations. Comparisons are made with other methods described in the literature