An improved detection algorithm based on frequency-domain PN-sequence for OFDM in wideband HF communication

Orthogonal-frequency-division-multiplex (OFDM) transmission, which is used in wideband HF communication, is often plagued by narrowband interference (NBI). Usually, the performance of traditional time-domain solutions of OFDM synchronization acquisition deteriorates in the presence of NBI. In this paper, frequency-domain signal detection algorithms have been investigated, by modulating PN-sequence on pilot symbol. A simplified POST-FFT detection algorithm is obtained by equivalently simplifying the existing method, without sacrificing the performance of acquisition. Meanwhile, an improvement is achieved. Simulations show that the performance of the improved algorithm is at least 4dB better than the existing algorithm, in the AWGN channel, typical HF channel and HF channel with interference of 3 kHz bandwidth.