Laboratory performance of spread spectrum detectors

The laboratory performance of four spread-spectrum (SS) detectors (full-band and partial-band radiometers, chip-rate detector (CRD) and squaring carrier detector) was measured for direct sequence (DS) and frequency hop (FH) SS signals, FH/DS hybrids, and time hop (TH) DS signals. Probability of detection as a function of input SNR for a constant false-alarm rate was measured for numerous combinations of SS waveform and detector. Theories are compiled from the literature and extended as necessary to provide a unified theoretical description. The results usually agree with theory to within one dB. A constant-false-alarm-rate method was used to reduce the drift problem of radiometers. The fact that chip-rate and squaring-carrier detectors have a much reduced drift problem is confirmed. It is concluded that the four SS detectors used are relatively simple and inexpensive devices with laboratory detection performance close to theoretical