Low-complexity compensation of sampling offset with cross-correlation and early-late gate for OFDM receivers

Abstract

This paper proposes a method for compensation of sampling offset for orthogonal frequency division multiplexing (OFDM) used in wireless local area networks (WLAN). Sampling offset is a typical transmission interference used in OFDM systems that introduce large error when synchronized data is demodulated. In this regard, an appropriate offset compensation method with a simple structure can be adopted to mitigate the impacts of sampling offset by using cross-correlation and early-late gate compensation methods for OFDM receivers instead of conventional methods that use algorithms with analog and mixed mode loops implementations. When bit error rate (BER) is at 10-3, simulation with the method without sampling offset compensation showed a signal noise rate (SNR) curve of about 25 dB, while the SNR curve of the method with offset compensation as proposed in this paper is about 26 dB. The comparisons show that the proposed system sacrifices performance by 1 dB to realize the benefit of compensating sampling offset. This sacrifice of 1 dB in performance is within the system’s tolerance range. Furthermore, the method overcomes the impact of sampling offset without additional hardware resource in WLAN applications.