Design and analysis of practical common phase error mitigation for OFDM-UWB systems

We propose an efficient common phase error (CPE) mitigation scheme for orthogonal frequency division multiplexing (OFDM) based ultra-wideband (UWB) systems. We consider the phase errors resulting from both residual carrier frequency offset and random phase noise. The CPE estimator employs a pilot-tone based and channel frequency response weighted approach for achieving low-complexity intra-OFDM-symbol estimation. We demonstrate that the error involved in the intra-OFDM-symbol based CPE estimate can be effectively reduced by further introducing an inter-OFDM-symbol smoothing technique, for which a choice can be made between using 1st-order and 2nd-order low-pass filtering by analyzing their respective error reduction performance. Analytical results and numerical examples show the effectiveness of the proposed scheme in different multi-path fading scenarios and signal-to-noise ratio regimes.