Technique of upstream signal detection in TWACS

Traditional TWACS system can realize the uplink demodulation by judging the positive and negative of sampling modulation current´s accumulation. The demodulation algorithm often uses the square wave to match, but this way is lack of anti-interference ability. In this paper, according to the uplink encoding and the difference time domain, the sampling current signal can be synthesized to a sine signal nearly. Then with the help of the complex wavelet analysis and the algorithm, the synthesis sampling value can be handled and the demodulation will be realized. The simulation and experimental results indicate that the algorithm effectively improve the performance of the traditional demodulation method.