Adaptive interference reduction using manipulated signal statistics

Digital direct-sequence spread-spectrum receivers are well known to suffer from severe impairments in deterministic types of interference, due to the inherent analog-to-digital converter nonlinearities. In the present paper a digital direct-sequence spread-spectrum receiver with an integrated adaptive interference reduction scheme is presented. Adaptive interference reduction is accomplished by exploiting the nonlinearity of a 2-bit analog-to-digital converter with a pair of magnitude thresholds centered around a fixed sign threshold. The magnitude thresholds are adjusted by means of a statistical control loop. The received signal´s magnitude distribution and zero-crossings are used to estimate the composition of the interference. The performance of the proposed receiver in the presence of combined additive white Gaussian noise and continuous wave interference has been investigated