DIRECT-SEQUENCE SPREAD-SPECTRUM NARROW-BAND INTERFERENCE REJECTION USING PROPERTY RESTORATION

A new method of rejecting narrowband interference in direct-sequence s pread spectrum (DS/SS) communications is presented, A typical approach is to reject the interference using a filter with large attenuation a t the interference frequencies before despreading. The interference re jection method presented in this paper incorporates vector space proje ction techniques to suppress the correlated interference, Several sign al characteristics are formulated which lead to constraint surfaces in the vector space of possible solutions, These constraint surfaces des cribe interference rejection solutions which introduce minimal distort ion to the spread spectrum signal and simultaneously remove the interf erence, The constraint surfaces essentially correspond to spread spect rum signal estimates which, after interference rejection, conform to k nown characteristics of the transmitted spread spectrum signal, The fo rmulation of the surfaces relies on prior knowledge about the spread s pectrum signal correlation and spectral properties.