It is well known that the Viterbi and Viterbi Monomial- Based Phase Estimator, which includes the Mth Power Estimator, performs poorly for cross QAM signals. However, it is shown here that by allowing the power of the monomial to be negative, much improved performance can be realized at medium to high signalto- noise ratios (SNR). Monte Carlo simulations are used to demonstrate the efficacy of this novel simple extension, for 32- and 128-QAM systems. In principle, this extension can also be applied to other constellations, e.g., (4,12)-PSK.
Cartwright, K. and E. Kaminsky, “A Simple Improvement to the Viterbi and Viterbi Monomial-Based Phase Estimators", in IEEE Globecom 2006 Conf. Proc., San Francisco, CA, 27 Nov.-1 Dec. 2006, 6 pp.