A METHOD OF INITIAL SYNCHRONIZATION OF GPS RECEIVER WHICH IS EFFECTIVE AT WEAK SIGNAL ENVIRONMENT

摘要

The present invention relates to a conventional initial synchronization method in the GPS vehicle navigation systems, GPS, particularly in a weak signal environment smoothly to obtain the satellite signal related to the initial synchronization method for a GPS receiver to output an accurate vehicle location information. ; The initial synchronization method in the GPS receiver for the car navigation system of the present invention is a GPS receiver, determine a signal from radio frequency to baseband first step of converting a value converted into processible transmission frequency band, the converted state correlator for correlation of spread signal generated in the GPS signal, and a sixth step of transmitting output signals a second step, a third step the output signal to form a scalar output to screen the result of the initial sync correlator, comparing the value of the scalar Chemical Acquisition result with a predetermined threshold value for determining the detection signal in the initial synchronization has succeeded a fourth step, the fourth step if it is found to fail in claim 5 for determining the properties of the pseudo noise code phase and frequency information of the signal required in the second stage diffusion step, with the spread determined by the information in the fifth step as the initial synchronization method in the GPS receiver for a vehicle navigation system of claim 6 comprising the step of delivering a correlator to generate a signal, wherein the third step includes accumulating the output signal of the correlator a first synchronization, the first synchronization detecting the differential cumulative value and, a differential detection screen positive real parts of the square root of the value obtained, the square root is characterized in that the output of the initial synchronization result is a scalar value and thereby accumulate the second motive.