Patent ID: 7383025

Claim:
A method for processing radio frequency (RF) signals for receiving and transmitting, comprising: (a) in a receiver, generating a first receive local oscillator (LO) signal by a first receive local oscillator source ( 5 ), wherein the frequency of the first receive LO signal is frequency hopped; mixing the first receive LO signal in a Mixer ( 4 ) with a received RF signal to produce an intermediate frequency (IF) receive signal; filtering the IF receive signal, with hopped frequencies, by a receive IF Filter ( 6 ) to produce a filtered receive signal; generating a second receive LO signal by a second receive local oscillator source ( 8 ), wherein the frequency of the second receive LO signal is frequency hopped corresponding to the variation of the frequencies of the filtered receive signal so that the first receive LO signal and the second receive LO signal form a spread and despread pair located in the receiver; mixing the second receive LO signal in a Mixer ( 7 ) with the filtered receive signal to produce a dehopped receive signal; and filtering the dehopped receive signal, with a Filter ( 9 ) for further processing; (b) in a transmitter, generating a first transmit LO signal by a first transmit local oscillator source ( 12 ), wherein the frequency of the first transmit LO signal is frequency hopped; mixing the first transmit LO signal in a Mixer ( 11 ) with a signal to be transmitted to produce an IF transmit signal; filtering the IF transmit signal, with hopped frequencies, by a transmit IF Filter ( 13 ) to produce a filtered transmit signal; generating a second transmit LO signal by a second transmit local oscillator source ( 15 ), wherein the frequency of the second transmit LO signal is frequency hopped corresponding to the variation of the frequencies of the filtered transmit signal so that the first transmit LO signal and the second transmit LO signal form a spread and despread pair located in the transmitter; mixing the second transmit LO signal in a Mixer ( 14 ) with the filtered transmit signal to produce a dehopped transmit signal; and filtering the dehopped transmit signal with a Filter ( 16 ) for further processing.