A Coherent Demodulation Method for Short Burst Communication

Information is an important feature of modern warfare. In the information warfare network, unmanned aerial vehicle (UAV) relay communication has caused research interest in many countries due to its high mobility and low construction cost. In order to meet the requirements of high relative speed, anti-interference and anti-reconnaissance, short burst direct sequence spread spectrum (DSSS) has become a commonly used communication means. The traditional coherent demodulation method needs to feedback the carrier estimation result, and the synchronization time is too long. The successive compensation based fast Fourier transform (SCBFFT) coherent demodulation method proposed in this paper has an open-loop structure. It uses twice FFT operations to estimate and compensate the carrier frequency offset and phase successively, and has the advantage of short carrier synchronization time. The coherent demodulation performance of the method is simulated and tested at low signal to noise ratio (SNR). The results show that the SCBFFT method can achieve coherent demodulation performance close to the theoretical bit error rate (BER) at low SNR.