Abstract: The at least five simultaneous equations include at least five unknown quantities, namely, a reference time, an error of a clock for measuring a diffusion-code reception time for each of the satellites and the 3-dimensional coordinates of the receiver. The diffusion code is transmitted from each of the satellites at a diffusion-code transmission time expressed as a sum of a time having a value represented by digits expressing a number equal to or greater than one unitary time corresponding to one period of the diffusion code and a time having a value represented by digits expressing a number smaller than the unitary time. The time represented by the digits expressing a number equal to or greater than the unitary time is represented by a sum of the reference time which is a time common to all the satellites and the differential time which varies from satellite to satellite.

Abstract: To provide a GPS receiver capable of acquiring a GPS signal from a plurality of GPS satellites efficiently and at a high speed, and further, capable of performing a positioning calculation at a high degree of accuracy. The FFT processing result of the addition result of the PN code stored in the memory is multiplied by the FFT processing result of the IF data (the received data) stored in a memory, and by inverse-diffusing this result, a correlative value is obtained. By repeating this processing while changing a combination of the PN codes to be added, and the synchronization acquisition processing by means of a plurality of PN codes is performed quickly and with the small number of processing on the basis of these results.