Patent ID: 6014405
Filing Date: 2000-01-11
Classification: H04B

Abstract:
An improvement to a spread-spectrum receiver for receiving multiple rays, due to multipath, of a received spread-spectrum signal and for maintaining data integrity without a tracking loop, the received spread-spectrum signal having a chip-sequence signal with a chip rate, f'.sub.c, the multiple rays including a first ray and a second ray, comprising:an analog-to-digital converter for sampling the received spread-spectrum signal at at least twice an approximate chip rate, 2 f.sub.c, of two samples per chip;a shift register, coupled to said analog-to-digital converter, for shifting chips of the chip-sequence signal through said shift register at twice the approximate chip rate;an adder tree, coupled to every other odd register of said shift register, with said shift register and said adder tree cooperatively having an impulse response matched to the chip-sequence signal, said shift register and said adder tree, responsive to the first ray having the chip-sequence signal aligned in every other odd register of said shift register, for detecting a first correlation signal, and said shift register and said adder tree, responsive to the second ray having the chip-sequence signal delayed approximately a half chip from the first ray and aligned in every other odd register of said shift register, for detecting a second correlation signal;a storage register for storing the first correlation signal; anda combiner, coupled to said adder tree and to said storage register, for maximal-ratio combining the first correlation signal with the second correlation signal.