Phase Noise Suppression Algorithm Based on Modified LLR Metric in SC-FDMA System

Abstract EN

In single-carrier frequency-division multiple-access (SC-FDMA) receivers in the long-term evolution uplink, phase noise is one of the major radio-frequency front-end impairments that degrade system performance.

To address this issue, we propose a new log-likelihood ratio (LLR) computation algorithm.

A signal model with residual phase noise is considered in the algorithm.

Based on this model, we derive a closed-form expression of the likelihood function of the received symbol and calculate more accurate LLR information.

Thus the accuracy of the decoder is increased and the performance of the SC-FDMA system is improved.

Simulation results show that our proposed algorithm achieves superior bit error rate (BER) performance compared with the existing LLR calculation algorithms in high-order quadrature amplitude modulations (QAM).