CDMA signal chip code generators estimation

Conventional linear and nonlinear intercept receivers are ineffective in detecting direct-sequence spread spectrum (DS/SS) signals if the transmissions are designed to be covert and the chip code sequences are unavailable. The detection problems are exacerbated if the users operate within a code-division multiple access (CDMA) environment. Former researches show that it is possible to use triple correlation techniques to estimate the DS/SS chip code generator. However these researches concerned only with the single DS/SS signal case. The problem of estimation of generators of CDMA signal which is the sum of multiple DS/SS signals is still unsolved. In this paper, triple correlation function (TCF) of CDMA signal is investigated and the way to use TCF to estimate CDMA chip code generators is presented..