Method and apparatus for calibrating radio frequency base stations using antenna arrays
First Claim
1. 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.
4 Assignments
0 Petitions
Accused Products
Abstract
A method operating in a communications station for calibrating the communications station, the communications station including an antenna array of antenna elements, each having associated with it and included in a transmit apparatus chain and a receiver apparatus chain. The method comprises transmitting a prescribed signal from each antenna element using the transmit apparatus chain associated with the antenna element while receiving the transmitted signal in receiver apparatus chains not associated with the antenna. Calibration factors for each antenna element are determined as dependent on the associated transmit apparatus chain and receiver apparatus chain transfer functions using the prescribed signal and each of the signals received during transmissions. A communications station also is described which includes: an antenna array of a plurality of elements, each antenna element having associated with it and included in a transmit apparatus chain and a receiver apparatus chain; transmitting means configured to transmit a prescribed signal from each antenna element while receiving the transmitted signal in at least one receiver apparatus chain not associated with the transmitting antenna element; a memory coupled to the receiver apparatus chains for storing the signals received during the transmissions of the prescribed signals; and a signal processor coupled to the memory and configured to determine calibration factors for each antenna element, the 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 are associated with the particular antenna element.
-
Citations
33 Claims
-
1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method for sending a downlink signal from a communications station to a subscriber unit, 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) performing an experiment at the communications station to determine a set of calibration factors, the set including a single calibration factor for each particular antenna element for which calibration is required, the single calibration factor dependent on the receiver apparatus chain transfer function and the transmit apparatus chain transfer function of the particular antenna element; (b) weighting the downlink signal according to a set of transmit weights to form a set of weighted transmit signals for each antenna element, the transmit weight for the particular antenna element determined from signals received at the antenna array during uplink communications with the subscriber unit and from the single calibration factor of the particular antenna element determined in step (b); and (c) transmitting the weighted transmit signals through the transmit apparatus chains. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A self-calibrating communications station not requiring additional or external equipment for calibration, the communication station comprising
(a) an antenna array with a plurality of antenna elements; -
(b) a receiver apparatus chain for each antenna element, each receiver 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; and(c) a transmit apparatus chain for each antenna element, each transmit apparatus chain including its antenna element, 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; (d) transmitting means configured to transmit a prescribed signal from each antenna element using the antenna element'"'"'s transmit apparatus chain while receiving the transmitted signal in at least one receiver apparatus chain not of the transmitting antenna element; (e) a memory coupled to the receiver apparatus chains for storing the signals received during the transmissions of the prescribed signals; and (f) a signal processor coupled to the memory and configured to determine calibration factors for each antenna element, the 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 prescribed signal and each of the received signals stored in the memory and not requiring any equipment external or in addition to the communication station. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
-
Specification