SIC-based anti near-far effect acquisition method for pseudolites systems

In the Ground-based Pseudolites System, near-field pseudolite signals may interfere and suppress the far-field signals since the existence of near-far effect, causing failure acquisition of the far-field signals. A SIC-based acquisition method anti near-far effect is proposed in this paper, aiming at the acquisition of time-hopping direct sequence spread spectrum (TH-DSSS) signal implemented in this system. Interferences of strong signals to weak signals are reduced by reconstructing local replica of the strong signal and interference cancellation. The proposed method is analyzed in theory and simulation. Simulation results indicate that the SIC-based acquisition method has the ability to reduce the influence of near-far effect, increase the detection probability of weak signals and enlarge the operating range of system without changing the pseudolite base station structure and the framework of corresponding receiver, which provides an effective guarantee for the receiver to capture, track and position in scenarios with strong near-far effect.