This paper analyzes the basic characteristics of the civilian Pseudo-Random Sequence(PRS) codes in three bands of the Global Position System(GPS) signals
including generation configuration
modulating mode
message structure and signal energy.In connection with the features of L1 C/A code
it discusses the improvement of the civil PRS codes on GPS L2 and L5 signals
describes the differences and advantages of data and dataless channels and the functions of the Neumann-Hoffman(NH) code at L5 and qualitatively analyzes the effects of the new PRS code structure and modulation mode on the acquisition and anti-interference performances of the GPS signals.