Blind Separation Of The Antenna Array Signal

Blind Source Separation (BSS) problem is to separate individual source signals from a set of mixed signals without the prior information about source signals and the channel, assuming the mixed process is linear and time-fixed. BSS has been currently an active-research area belonging to signal processing. Because blind signal processing techniques do not need prior information of the original source signals and channel, they have significant value in theory study and broad foreground in practical applications in the fields of digital communication, array signal processing, underwater acoustic signal processing, biomedical signal processing, image signal processing, speech signal processing, etc.This paper mainly researches on blind separation problem of array signal, and proposes a blind separation method for array signal. This method is based on EASI algorithm. The main contributions are as follows:(1) The recent research findings are collected,sorted and generalized, the basic theory and algorithms are introduced. In order to evaluate blind separation performance more completely, several performance indexes of blind signal separation are presented.(2) The received signal model for narrow band array signals is analyzed. According to feature of received signals, this paper proposes a blind separation method for narrow-band time-delay mixture signals. This method transforms the array narrow-band time-delay mixture signals received to complex-valued instantaneous mixture signals which can be separated by the BSS algorithm .Simulation results show that the method can be used to separate the received array mixture signals effectively.(3) In project application, real environment is very complex, so we must consider influence of real environment on signal separation performance. This can guide us to apply blind separation techniques in practice project. Through simulation and experiment to factors of real environment, we can find theirs rule and reason of algorithm's failure.(4) The aim of BSS is to extract signals from mixed signals, so as beamforming technology. Through comparison BSS with beamforming technology, advantage of BSS can be found. Beam forming must depend on direction matrix of antenna array. But in practice precision direction matrix isn't obtained. Blind signal separation techniques only need received signals to separate.This paper studies on blind separation of narrow-band array signals, and develops existing algorithm, successfully separates array signals and analyses influence of real environment on signal separation performance.