DIGITAL CORRELATION UNIT

摘要

PROBLEM TO BE SOLVED: To provide a digital correlation unit that can realize respective correlation arithmetic operations for in-phase and quadrature components with common multipliers and adders so as to halve the number of both the multipliers and the adders having been required for the conventional digital correlation unit thereby reducing the scale of gates. SOLUTION: A digital correlation circuit is provided with a 1st selection means that selects an in-phase component or a quadrature component, a 1st storage means that stores a 1st spread code corresponding to the in-phase component of a received signal with a spread code length L, a 2nd storage means that stores a 2nd spread code corresponding to the quadrature component of the received signal with the spread code length L, L-sets of 2nd selection means that select either of the 1st and 2nd spread codes, L-sets of multipliers multiply the selection result by the 1st selection means with the selection result by the 2nd selection means, (L-1)-sets of 2-stage transfer type shift registers, (L-2)-sets of adders, a register means with a summing function that receives an output of the shift register placed at a head receiving an output of the corresponding multiplier and receives a sum of outputs of the shift registers placed at the next and succeeding stages corresponding to the multipliers and an output of the shift register placed at the pre-stage, an output adder that sums an output of a final stage of the register means with the summing function and an output of the corresponding multiplier, and in-phase/quadrature component registers alternately storing an output of the output adder.