The Direct Wave Purifying Based on WIFI Signal for Passive Radar

Using the WIFI signal as a passive radar, transmission is getting more and more widely attention. Based on IEEE 802.11 standard, the signal structure, ambiguity function, and side peak of WIFI have been made detailed analysis in this paper, and it also shows that the ambiguity function has a good pin shape. Meanwhile, in order to obtain an effective direct wave signal, a constant modulus algorithm (CMA) is used to suppress the interference brought by the multipath clutter. Furthermore, an adaptive step method is adopted to improve the convergence speed of the algorithm, and it gets a good purification effect. Simulation results show that the method is effective and has a better performance in suppressing multipath clutter interference, making an improved in detection performance.