An iterative blind adaptive receiver for DS-SSMA systems

Spread-spectrum signals with long signature sequences are considered in this paper. Particularly, a linear receiver proposed in Wong et al. (1996, 1998) for direct-sequence spread-spectrum multiple access systems is extended to its iterative form. This extension is most applicable in situations with high processing gain, where it is necessary at times to use a large number of correlators to acquire the PN sequence, e.g. in GPS. Like its noniterative counterpart in Wong et al., the receiver structure consists of a matched filter followed by a tapped delay line that can be provisioned for use with antenna arrays. Similarly the iterative blind adaptive algorithm (BAA) has the same ability to combine multipaths, suppress multiple-access interference (MAI), and suppress narrowband interference. The iterative BAA demonstrates faster convergence time due to processing more measurements of interference outside the delay spread of the signal.