A system and method for improving acquisition sensitivity and tracking performance of a GPS receiver using multiple antennas is provided. In an embodiment, the acquisition sensitivity can be improved by determining the correlation weight of each received path signal associated with one antenna from a plurality of antennas and then combining the path signals based on their respective correlation weight. In another embodiment, carrier offset correction information of each path signal is individually determined and then summed together to be used for tracking the code phase in a code phase tracking loop. The code phase tracking loop generates an early code and a late code that are used to determine the code phase error. The system includes digital adaptive filters to mitigate narrowband and broadband noises of a received GPS signal, wherein the digital adaptive filters are switched on periodically or by external events.