Synchronization and Equalization for Joint Close-In and Reciprocal Mixing Phase Noise Distortion Compensation in Packet-Based OFDM Systems

In many modern and emerging communication systems, phase noise distortion represents a major source of performance degradation. This distortion arises from two mechanisms: close-in phase noise distortion of the desired signal itself and reciprocal mixing of the interfering blockers. Recently, a promising approach that jointly compensates for both distortion mechanisms have been reported. This approach, which employs a suitably designed auxiliary receiver path, requires adaptive combining of two receiver paths. In this article, a method for rapidly estimating these combining weights in the context of the widely employed packet-based orthogonal frequency division multiplexing (OFDM) systems is presented. Specifically, a maximum-likelihood-based estimator for determining gain and phase mismatches between the two paths and a robust minimum mean-squared-error combiner are proposed. The effectiveness of the proposed approach has been validated experimentally and shown to achieve significant performance improvements compared to conventional approaches.