A synchronization acquisition algorithm using pilot symbols for OFDM in HF communications

Traditional algorithms of OFDM signal detection and synchronization acquisition do not always cater for the situation in low SNR. In allusion to the character of HF channel, a synchronization acquisition scheme is proposed in this paper for the troublesome HF channels. Based on joint time and frequency offset estimation and employing an m-sequence, a reliable signal detection scheme is obtained by modulated pilot symbols, which are also utilized in an attempt to capture frequency and time offset acquisition. Theoretic analysis and simulations show that this scheme works properly at low SNR in HF communications.