Patent ID: 6327299
Filing Date: 2001-12-04
Classification: H04B,H04L

Abstract:
A method of measuring the quality of an orthogonal transmit diversity signal in a wireless communications system, wherein the orthogonal transmit diversity signal is produced by a transmitter having first and second radio frequency diversity signals for transmitting from first and second transmit diversity antennas, the method comprising the steps of:producing a radio frequency sample signal that represents the sum of the first and second radio frequency diversity signals;down-converting the radio frequency sample signal to produce a down-converted signal having first and second components corresponding to the first and second radio frequency diversity signals, respectively;recovering, from the first component, a first time reference of the first radio frequency diversity signal; andusing the first time reference, measuring a characteristic of the second component that is indicative of a difference in delay between the first and second radio frequency diversity signals,wherein the step of producing a radio frequency sample signal that represents the sum of the first and second radio frequency diversity signals further includes:coupling to the first radio frequency diversity signal to produce a first sampled signal;coupling to the second radio frequency diversity signal to produce a second sampled signal; andsumming the first and second sampled signals to produce a radio frequency sample signal that represents the sum of the first second radio frequency diversity signals.