A method of processing a digital signal derived from an analog input signal of a GNSS receiver, a GNSS receiver base band circuit for carrying out the method and a GNSS receiver

摘要

An acquisition unit of a GNSS receiver base band circuit comprises a correlator (40) with a correlator shift register (43) to which a correlation sequence derived from a basic sequence characteristic for a satellite is fed by a code generator (41). Each of the N=32 or more memory cells of the correlator shift register (43) is connected to two correlator cells (44a, 44b) for multiplying digital values of the correlator sequence from the memory cell with data values of a data sequence, adding up the products and storing the sum in a register as a correlation value pertaining to one of N relative phase positions of the correlation sequence relative to the data sequence during a correlation phase. During a subsequent read-out phase the registers of each row of correlator cells (44a; 44b) are connected to form a daisy chain and the correlation values are fed through the same to appear sequentially at the output of the last register in the row while the correlator shift register (43) and the rows of registers are sequentially filled with initial values for the next correlation phase.