Fast delay estimation for asynchronous CDMA communications systems

We present a simple and fast delay estimation approach to signal acquisition for direct-sequence CDMA communication systems. The main idea is to first intentionally map a lower-dimensional objective function into a higher-dimensional one by change of parameter variables. In doing so, we are able to view the objective function in a parameter space of a higher dimension. In such a higher dimensional parameter space, the structure of the compressed likelihood function is revealed. We can then take full advantage of ridge structure of the objective function in efficiently estimating signal parameters.