Patent ID: 6360078
Filing Date: 2002-03-19
Classification: H03J

Abstract:
A method of compensating for the group time delay asymmetry of an intermediate frequency (IF) filter of a radio frequency (RF) receiver in a time of arrival (TOA) measurement comprising:downconverting a first RF filtered signal to a first IF frequency signal by a first radio frequency local oscillator (RF LO) frequency, where the first RF LO frequency is equal to a center frequency of the first RF filtered signal minus the frequency of the first IF frequency signal; passing the first IF frequency signal through an IF filter; performing a first TOA signal measurement; downconverting a second RF filtered signal to a second IF frequency signal by a second RF LO frequency, where the second RF LO frequency is equal to a center frequency of the second RF filtered signal plus the frequency of the second IF frequency signal; passing the second IF frequency signal through an IF filter; performing a second TOA signal measurement; compensating for any group time delay asymmetry in the IF filter using the first and second TOA measurements.