GPS Signal Acquisition and Sensitivity Analysis Using Different Algorithms on a Software Receiver

In this paper three different acquisition algorithms are implemented in a GPS software receiver and compared by the correlation strategy employed. Their theoretical models are first analyzed and then implemented in Mat lab. Both simulated GPS data and realistic signals from a Sat-Surf receiver are used to verify the performance of the acquisition schemes. The software acquisition approach provides flexibility and low cost for algorithm redesign and improved intermediate frequency selection capability. The performances of serial search in time domain, parallel search in time and frequency domain acquisition algorithms are compared and evaluated using different incoming signals Carrier-to-Noise density ratios. The serial search acquisition algorithm in time domain has the advantage of working both on block of data or sample. The main disadvantage is the bigger acquisition time it requires. The acquisition in time domain employing FFT is a very fast acquisition algorithm.