Noise Suppression Threshold Channel Estimation Method Using RC and SRRC Filters in OFDM Systems

Abstract

Orthogonal frequency division multiplexing (OFDM) has been widely used in modern wireless communication systems. In OFDM system, channel estimation is a key technology to improve the system performance. However, most conventional channel estimation methods cannot suppress the noise effectively, which affects the quality of the final received OFDM signals. To solve this problem, this paper utilizes the raise cosine (RC) filter and square root raise cosine (SRRC) filter to suppress the inter-symbol-interference (ISI) and the noise in OFDM-RC and OFDM-SRRC systems. The proposed method first filters out the noise by using RC filter or SRRC filter, while obtaining the noise standard deviation as the threshold. Then, the impact of noise is further reduced by setting the noise suppression threshold. Simulation results are shown to verify the effectiveness of the OFDM-RC and OFDM-SRRC systems over multipath propagation conditions.