Synchronization and AGC proposal for IEEE 802.11 a burst OFDM systems

Synchronization is critical in the design of an OFDM receiver. Large timing offsets result in a loss of orthogonality between subcarriers, ISI, and severe bit error degradation. To minimize this degradation, standards incorporate preambles intended for all OFDM acquisition functions including automatic gain control (AGC) and synchronization. Several synchronization algorithms have been proposed. Unfortunately, these proposals do not take into account AGC effects which degrade results in practice. To address this problem, we have built an FPGA implementation of both an AGC and synchronization system. Based on these results, in this paper we propose a novel standard compliant auto-correlation synchronization algorithm and AGC interface, then measure the total system performance.