Analysis of direct P-code acquisition

Global Positioning System (GPS) signal acquisition consists of a two-dimensional search in a time/frequency space to synchronize a receiver-generated reference signal with the received GPS signal in code phase and frequency. User uncertainties in code phase and frequency offsets determine the size of the region to be searched, and hence, the code acquisition time. Encrypted P(Y) code, transmitted on L-1 and L-2 frequencies, provides more precise (16 m - spherical error probable (SEP)) user positioning inherently more jamming immunity than does C/A code. The purpose of this study is to explore and use existing signal detection concepts to quantify the time to achieve direct acquisition of the P(Y) code in a jamming environment. Of particular interest is the mitigating effect parallel processing has in shrinking acquisition time in the presence of initial (receiver) position, time, velocity, and frequency errors and/or uncertainties.