Analysis of strategies for serial-search spread-spectrum code acquisition-direct approach

A `direct´ approach to obtain statistics of the code acquisition time for serial-search spread-spectrum receivers is presented, which combines the idea of algebraic characterization of the search with transform domain methods. This is a very general unified technique, yielding many other known results as special cases. One of the major advantages of the direct approach is that the effect of the search strategy on moments of the acquisition times can be isolated from the effect of the detection/verification logic. This fact will permit one both to analyze all known search strategies-confirming several conclusions regarding their comparative performance-and to propose two novel strategies (alternate search) which outperform the conventional ones when the code rewinding time is small in comparison to the dwell times. Optimum search strategy based on the maximum a posteriori criterion (MAP) is analyzed, thus ensuring an absolute and uniform basis of comparison. The two new strategies perform well by this measure