Based On The Gsm Signal For Passive Radar Technology Research

In recent years, advanced electronic attack technologies continue to challenge traditional radar system, including four major threats: electronic interference, minimum altitude breakthrough, anti-radiation missile and invisible technique. Because being good at combating these four challenges, civil signal based passive radar has attracted world's attention. On the other hand, with the increasing demand of human for mobile communication, wireless communication technology is gradually becoming mature and three generations of communications systems have already occurred, the fourth generation is also being developed. Wireless communication network is of wide distribution, large redundancy and being flexible in organizing a network, so it attracts more and more radar researcher's attentions. This paper focuses on the research of GSM signals based passive radar system, achieve the target location and tracking with the interference of strong direct signal. The works completed are as follows:1. Take a deep study of the GSM protocol; Analyze the GSM signal's frame structure and the main technologies used in the system; According to the wireless channel division method, choose the optimalizing channel as the non-cooperate illuminator, and make a comment on it's suitability of being an illuminator.2. The passive radar system is similar to the traditional bistatic (multi-static) radar. Considering the GSM Station Distribution and the realization of back end signal processing algorithm, propose a"time delay and Doppler frequency shift"based T3R1 location method. The receiver includes two separate antennas, one receives direct signal from the GSM base station and the other receives the echo signal form the target. On this basis, the direct path interference cancellation is completed, using NLMS based closed loop adaptive algorithm. And this technology is verified by the measured signal.3. Due to the weak transmitting power and complex transmission environment, passive radar system has a short detecting range. This paper discussed the detecting range of the passive radar system in macro-cell and micro-cell systems. To increase the detecting range, proposes several schemes, they are as follows: Non-coherent accumulation technology, joint-location technology by using more GSM base stations, and multiple channels multiplexing in a single GSM base station. Then studies the phase compensation and coherent integration algorithm. And the simulation certificates the validity of the proposed scheme.