When acquiring GPS signal

signal strength and noise level is time varying in the environments

indoor

in urban street or in the woods.In the challenging environments

adaptive scheme is considered to be employed in GPS receiver design in this paper.Derived from conventional adaptive structure

a novel method of noise level estimation is proposed which fully considers the characteristic of GPS signal.Furthermore

possible large Doppler shift is seldom considered in existing adaptive structure.Aiming at the possible Doppler shift

a solution based on partial correlation is proposed.In the final part of this paper

simulation is carried out to test this novel structure.The experimental results of the proposed method demonstrate more stable acquisition performance than conventional ones.