Radiometric detection of direct-sequence spread spectrum signals with interference excision using the wavelet transform

One of the most important properties of direct-sequence spread spectrum signals (DSSS) is their low probability of intercept. Determination of the presence of such signals can be performed by radiometer-based intercept receivers that detect the signal's presence by measuring received power. However, conventional intercept receivers often fail when they operate in the presence of narrow-band interference because of their inability to differentiate between jammer and DSSS signal energy. An intercept receiver which employs wavelet transform domain-based excision is described. The receiver detects BPSK DSSS signals in the presence of narrow-band interference by employing adaptive interference rejection techniques to suppress the interference before measuring power. The improvement in the system performance over that of conventional radiometric detection only is shown by presenting numerical simulation results in the form of receiver operating characteristics (ROC's). Performance is also compared to that for intercept receivers that use FFT-based excision systems techniques.