Patent ID: 7010022
Filing Date: 2006-03-07
Classification: H04B

Abstract:
1. A spread spectrum receiver receiving a spread spectrum signal spread in bandwidth by a predetermined spreading code, comprising: a local oscillator for outputting a local signal with a predetermined frequency, a local spreading code generating means for generating a local spreading code according to the spreading code of the received signal, and a direct conversion circuit for generating a reference local signal based on the local signal from the local oscillator and the local spreading code from the local spreading generating means, generating two signals having a phase difference based on the received signal and the reference local signal, and despreading based on two signals having a phase difference; wherein the direct conversion circuit comprises: a multiplier for multiplying the local signal by the local spreading code and outputting the same as the reference local signal, a first phase shifter for shifting the received signal in phase, a second phase shifter for shifting the reference local signal in phase, a first adder for adding the reference local signal and an output signal of the first shifter, a second adder for adding the received signal and an output signal of the second phase shifter, a first detector for detecting a signal level of an output of the first adder, and a second detector for detecting a signal level of an output of the second adder.