Research On The Location Of DS-SS Signal Emitterand Simulations

Passive location, which can work silently for quite long time, is an important reconnaissance strategy. This paper provides a scenario aiming at location of a DS-SS communication signal emitter. Starting with estimating TDOAs of the DS-SS signals, the scenario projects first a fast correlation method that can reduce the amount of calculation to a small fraction of original amount by means of FFT. However, the cross correlation method suffers a lot from the small delay multi-paths and jamming. Frequency domain subspace method with interleaving can solve these two problems. This algorithm exerts extensive efforts to solve three problems, the low input SNR, limited frequency samples and biased estimation of the channel frequency response in normal subspace TDOA methods, distinguishing multi-path signals with arrival difference less than 1 chip time from each other, acquiring high precision and super resolution TDOAs. Receiving the signals by passive match filter can suppress most jamming. Following the TDOA estimating methods provided is interception of the DS-SS code in noisy and interferential background, in order to utilize the super resolution method to estimate the TDOAs of unknown DS-SS signals. Based on the high precession, super resolution estimate of TDOAs, the target is located with the least square error. An AOA value is added to the TDOAs when it is convenient to get the AOA information in the main base. As the AOA estimation belongs to another task, no more discussion provides here. Colligating the TDOAs and the only one AOA, TDOA-AOA-2LS, a method that can get optimum results is provided. Compared with twice in TDOA-2LS utilizing only the TDOA information, this method approximates only once, so as to keep location errors'rms achieving the Cramer-Rho bound with larger TDOA errors tolerance. The simulation indicates that this scenario satisfies tactic location, supplying theoretic foundation for location of DS-SS signal emitter.