Patent ID: 6037898
Filing Date: 2000-03-14
Classification: H01Q,H04W

Abstract:
A method for calibrating a communications station without requiring any equipment in addition or external to the communication station, the communications station comprising an antenna array with a plurality of antenna elements, a receiver apparatus chain for each antenna element, and a transmit apparatus chain for each antenna element, each receiver apparatus chain including its antenna element, and each transmit apparatus chain including its antenna element, relative phase and amplitude behavior of each receiver apparatus chain essentially describable by a receiver apparatus chain transfer function for said each receiver apparatus chain, relative phase and amplitude behavior of each transmit apparatus chain essentially describable by a transmit apparatus chain transfer function for said each transmit apparatus chain, the method comprising:(a) transmitting a first prescribed signal from a first antenna element through a first transmit apparatus chain while receiving the transmitted signal in at least one antenna element through its receiver apparatus chain, the receiving antenna element not the first antenna element, the first antenna element being part of the first transmit apparatus chain;(b) repeating step (a) transmitting prescribed signals from other antenna elements through other transmit apparatus chains until prescribed signals have been transmitted from all antenna elements for which calibration factors are required, and any prescribed signal transmission from any particular antenna element has been received by a sufficient number of the other antenna elements to determine the required set of calibration factors; and(c) determining calibration factors for each antenna element used in said step (a) and the repetitions of said step (b), each antenna element having one or more calibration factors for a particular antenna element based on the transmit apparatus chain and receiver apparatus chain transfer functions of the transmit and receiver apparatus chains, respectively, that include the particular antenna element, said determining using the first prescribed signal and the prescribed signals and each of the signals received in step (a) and the repetitions (b),the method not requiring any equipment in addition or external to the communication station.