Adaptive step-size p-modulo correlation phase algorithm for use in digital QAM systems

This paper proposes a new adaptation algorithm named Adaptive Step-Size p-Modulo Correlation Phase Algorithm (ASS-pModuloCPhiA) for adaptive filters used in digital QAM systems. The algorithm employs “p-modulus” of the correlation between the error and filter input, and an adaptive step-size control algorithm. The ASS-pModuloCPhiA achieves significant improvement in filter convergence speed of the pModuloCPhiA, while it preserves robustness of the latter algorithm against two types of impulse noise found in adaptive filtering systems: one in observation noise and another at filter input. Through analysis and experiments, we demonstrate its effectiveness. We also find that the filter convergence behavior does not depend on the value of p, allowing the use of p = infinity.