Multistage linear receiver for ds-cdma systems

Abstract

A multistage linear receiver for extracting data embedded in a received spread-spectrum signal having a plurality of channels using a direct sequence code division multiple access system. The multistage receiver comprises an initial plurality of spread-spectrum detectors, a plurality of detector weighting devices, a first plurality of product devices, a first combiner, a first plurality of spread-spectrum detectors, a first plurality of weight-product devices and an output combiner. The initial plurality of spread-spectrum detectors despreads and delays the plurality of channels to generate a plurality of detector-output signals. The detector weighting devices weight the plurality of detector-output signals with a plurality of detector weights as a plurality of weighted-detector signals. The plurality of detector-output signals are spread-spectrum processed by the first plurality of product devices to generate a first plurality of spread-spectrum signals which are combined by the first combiner as a first combined signal. The first plurality of spread-spectrum detectors despreads and delays the first combined signal as a first plurality of despread-combined signals which are weighted by the first plurality of weight-product devices to generate a first plurality of weighted signals. The output combiner combines the first plurality of weighted signals and the plurality of weighted-detector signals to extract the data. Additional stages comprising product devices, combiners and weight-product devices may be added as necessary or desired.