Principle and signal processing method of TD-LTE based passive radar

TD-LTE (Time division duplex-long term evolution) is a mainstream standard of the fourth generation mobile communication led by China. In this paper, a TD-LTE base-station signal is proposed to achieve passive detection of targets as external radiation sources. First, it is proposed that the detection distance of the passive radar can be enhanced using multi-static radar according to the characteristics of TD-LTE. The processing of passive radar signal of TD-LTE is then given. By reconstructing the reference signal according to the 3GPP standard, pure multi-base station signals can be attained without demodulation. Finally, the characteristics of the ambiguity function of OFDM (orthogonal frequency division multiplexing) signal is analyzed. The reasons and positions of side peaks are deduced, and the ambiguity is resolved via frequency domain synthesis. The availability of the method proposed is proven using actual signals.