Institute of Electrical & Electronic Engineers
Orthogonal Frequency Division Multiplexing (OFDM) systems in fast time-varying channels suffer from Inter-Carrier Interference (ICI), which necessitates the use of ICI mitigating equalizers. The performance of the equalizers strongly depends on the Channel Estimation (CE). Estimating the channel matrix in the frequency domain using pilot estimates can only provide limited performance, because pilots are also corrupted by ICI. The authors propose two approaches for reliability-based ICI pre-cancellation at the receiver to improve CE. Firstly, a log-likelihood ratio window is used to optimize the interpolation points for CE. Secondly, a post-processor is employed to improve the estimates of the pilots' neighbors.