# US 2015/0146584 A1 · System and method for transmit and receive antenna patterns calibration for time division duplex (tdd) systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0146584 A1 - Document ID: US20150146584A1 - Status: Published application - Kind: A1 - Application number: 14/467,415 - Filed: 2014-08-25 - Published: 2015-05-28 - Earliest claimed: 2013-11-26 - Assignees: Magnolia Broadband Inc. - Applicants: Magnolia Broadband Inc. - Inventors: Sherwin J. WANG; Haim HAREL; Kenneth KLUDT; Phil F. CHEN - Web page: https://patentgrep.com/patent/US20150146584A1 ## CPC - H04B 7/0617: {for beam forming} - H04B 1/56: with provision for simultaneous communication in two directions - H04B 7/0665: {Feed forward of transmit weights to the receiver} - H04B 17/12: of transmit antennas, e.g. of the amplitude or phase - H04B 17/221: {of receiver antennas, e.g. as to amplitude or phase} - H04B 7/0682: {using phase diversity (e.g. phase sweeping)} - H04B: TRANSMISSION ## Abstract A method and system for calibrating transmit and receive antenna patterns for time division duplex (TDD) is described. A station in a communications network comprises at least two antennas configured to operate together for both transmitting and receiving modes. A phase setting difference between the transmit and receive antenna patterns may be determined and used to determine a relative amplitude setting for the transmit antenna pattern and/or a relative amplitude setting for the receive antenna pattern. ## Claims ### Claim 1 A method of configuring a station in a communications network comprising at least two antennas configured to operate together for both transmitting and receiving modes, and a plurality of radio circuits configured to transmit and receive via said antennas in a time division duplex (TDD) communication protocol, the method comprising: determining a phase setting difference between the transmit and receive antenna patterns of said at least two of said antennas operating together; and using said phase setting difference, determining one or both of: a relative amplitude setting for the transmit antenna pattern and a relative amplitude setting for the receive antenna pattern. ### Claim 2 (depends on 1) The method of claim 1 comprising using said phase setting difference to determine both of the relative amplitude setting for the transmit antenna pattern and the relative amplitude setting for the receive antenna pattern; and further comprising: determining an amplitude setting difference between transmit and receive antenna patterns as the difference between said relative amplitude settings. ### Claim 3 (depends on 1) The method of claim 1 wherein the determination of the phase setting difference is based on the difference between nulls in the transmit and receive antenna patterns. ### Claim 4 (depends on 1) The method of claim 1 comprising determining a relative amplitude setting for the receive antenna pattern and using the relative amplitude setting for the receive antenna pattern to determine the relative amplitude setting for the transmit antenna pattern. ### Claim 5 (depends on 1) The method of claim 1 wherein the relative amplitude setting for the receive antenna pattern is determined for nulling a signal received at said at least two antennas from another station in the communications network. ### Claim 6 (depends on 1) The method of claim 1 wherein the relative amplitude setting for the transmit antenna pattern is determined for nulling a signals transmitted by said at least two antennas to another station in the communications network. ### Claim 7 (depends on 1) The method of claim 1 wherein the determination of the relative amplitude setting for the receive antenna pattern is based on channel estimation on signals received by said at least two antennas from another station in the communications network. ### Claim 8 (depends on 1) The method of claim 1 wherein the determination of the relative amplitude setting for the transmit antenna pattern comprises: transmitting signals from two antennas using a predetermined relative amplitude; recording a data rate corresponding to said transmitted signals; repeating said transmitting and recording for a range of different relative amplitudes; and determining the relative amplitude setting for the transmit antenna pattern as the relative amplitude corresponding to a minimum data rate. ### Claim 9 (depends on 8) The method of claim 8 comprising determining the relative amplitude setting for the receive antenna pattern prior to the transmission of signals, wherein the relative amplitudes used for said transmitting are determined based on the relative amplitude setting for the receive antenna pattern. ### Claim 10 (depends on 8) The method of claim 8 comprising determining a relative phase setting for the receive antenna pattern prior to the transmission of signals, wherein the predetermined relative amplitudes used for said transmitting are determined based on the relative phase setting for the receive antenna pattern. ### Claim 11 (depends on 10) The method of claim 10 wherein the relative phase setting for the receive antenna pattern is determined based on channel estimation. ### Claim 12 A system comprising: a plurality of antennas configured to operate together for both transmitting and receiving, a plurality of radio circuits configured to transmit and receive via said antennas in a time division duplex (TDD) communication protocol; and a baseband processor configured to determine a phase setting difference between the transmit and receive antenna patterns of said at least two of said antennas operating together; and using said phase setting difference, determine one or both of: a relative amplitude setting for the transmit antenna pattern and a relative amplitude setting for the receive antenna pattern. ### Claim 13 (depends on 12) The system of claim 12 wherein the baseband processor is further configured to use said phase setting difference to determine both of the relative amplitude setting for the transmit antenna pattern and the relative amplitude setting for the receive antenna pattern; and determine an amplitude setting difference between transmit and receive antenna patterns as the difference between said relative amplitude settings. ### Claim 14 (depends on 12) The system of claim 12 wherein the baseband processor is configured to determine the phase setting difference based on the difference between nulls in the transmit and receive antenna patterns. ### Claim 15 (depends on 12) The system of claim 12 wherein the baseband processor is configured to determine a relative amplitude setting for the receive antenna pattern and use the relative amplitude setting for the receive antenna pattern to determine the relative amplitude setting for the transmit antenna pattern. ### Claim 16 (depends on 12) The system of claim 12 wherein the baseband processor is configured to determine the relative amplitude setting for the receive antenna pattern for nulling a signal received at said at least two antennas from another station in the communications network and to determine the relative amplitude setting for the transmit antenna pattern for nulling signals transmitted by said at least two antennas to another station in the communications network. ### Claim 17 (depends on 12) The system of claim 12 wherein the baseband processor is configured to determine the relative amplitude setting and the relative phase setting for the receive antenna pattern based on channel estimation on signals received by said at least two antennas from another station in the communications network. ### Claim 18 (depends on 12) The system of claim 12 wherein the baseband processor is configured to determine the relative amplitude setting for the transmit antenna pattern by: transmitting signals from two antennas using a predetermined relative amplitude; recording a data rate corresponding to said transmitted signals; repeating said transmitting and recording for a range of different relative amplitudes; and determining the relative amplitude setting for the transmit antenna pattern as the relative amplitude corresponding to a minimum data rate. ### Claim 19 (depends on 18) The system of claim 18 wherein the baseband processor is configured to determine the relative amplitude setting for the receive antenna pattern prior to the transmission of signals, wherein the predetermined relative amplitudes used for said transmitting are determined based on the relative amplitude setting for the receive antenna pattern. ### Claim 20 (depends on 18) The system of claim 18 wherein the baseband processor is configured to determine a relative phase setting for the receive antenna pattern prior to the transmission of signals, wherein the predetermined relative amplitudes used for said transmitting are determined based on the relative phase setting for the receive antenna pattern. ### Claim 21 A method of configuring a station in a communications network comprising at least two antennas configured to operate together for both transmitting and receiving modes, and a plurality of radio circuits configured to transmit and receive via said antennas in a time division duplex (TDD) communication protocol, the method comprising using a predetermined phase difference between receive and transmit antenna patterns for at least two antennas operating together to determine one or both of: a relative amplitude setting for the transmit antenna pattern and a relative amplitude setting for the receive antenna pattern, to achieve a null in a signal received from or transmitted to another station by said at least two antennas.