Processing direct-sequence spread-spectrum signals for improved acquisition performance in the presence of strong narrow-band interference

The performance of a direct-sequence spread-spectrum coarse acquisition system operating in the presence of narrowband interference is considered under two processing strategies. The first strategy uses the arbitrary phase present at the input as the reference phase for all correlation operations, while the second uses a prediction filter to suppress narrowband interference. Performance is considered for both short and long spreading codes when either sinusoidal or narrowband Gaussian interference is present in the input signal. While the performance using the first method is consistently better when the same reference phase is used, the overall performance is usually superior under the second method, because an optimal reference phase may be chosen