Digital signal processing techniques, applied to blocks of GPS samples are investigated and tested using GPS software signal simulators and real GPS data. This dissertation discusses the conventional sequential techniques and the disadvantages of these techniques. Furthermore, effects of user-satellite dynamics, oscillator variations, and radio- frequency interference are addressed. Basic block processing approaches are discussed and subdivided into time domain, frequency domain, and time-frequency domain methods. Three case studies are performed to prove the application of discussed block processing techniques for GPS; detection of GPS signals in environments where desired signals are strongly attenuated, tracking of GPS signals under dynamically challenging conditions, and detection and suppression of narrow-band and pulsed radio-interference.