Channel Estimation, Carrier Recovery, and Data Detection in the Presence of Phase Noise in OFDM Relay Systems

Due to its time-varying nature, oscillator phase noise can significantly degrade the performance of the channel estimation, carrier recovery, and data detection blocks in high-speed wireless communication systems. In this paper, we propose a new data-aided joint channel,
carrier frequency offset (CFO)
and phase noise estimator for
orthogonal frequency division multiplexing (OFDM)
relay systems. For the data transmission phase, we propose a new iterative receiver that tracks phase noise and detects the transmitted symbols. Additionally, we derive the
hybrid Cramér–Rao lower bound
for evaluating the performance of channel estimation and carrier recovery algorithms in OFDM relay networks. Extensive simulations demonstrate that the application of the proposed estimation and receiver blocks significantly improves the performance of OFDM relay networks in the presence of phase noise and CFO.