Adaptive interference rejection for noncoherent digital direct sequence spread spectrum receivers

The applicability of an adaptive two-bit analog-to-digital technique to noncoherent digital direct-sequence (DS) receivers using single-bit digital correlators is discussed. Operation in the presence of additive white Gaussian noise, (AWGN), continuous wave (CW), and combined CW/AWGN interference is investigated. Receiver performance is evaluated by means of the output signal-to-noise ratio (SNR) of a square-law receiver. Bit error rate (BER) computations are provided to demonstrate the performance of the two-bit analog-to-digital converter (ADC) in a DS matched-filter receiver for code shift keyed data. Two-bit ADC applicability to the detection of DS signals with unknown phase and time-of-arrival, namely synchronization preamble detection and code acquisition, is demonstrated by receiver operating characteristic computations