# US 2013/0278463 A1 · Antenna arrangement for doa estimation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278463 A1 - Document ID: US20130278463A1 - Status: Published application - Kind: A1 - Application number: 13/453,364 - Filed: 2012-04-23 - Published: 2013-10-24 - Earliest claimed: 2012-04-18 - Assignees: Telefonaktiebolaget L M Ericsson (publ) - Inventors: Andreas NILSSON; Fredrik Athley - Web page: https://patentgrep.com/patent/US20130278463A1 ## CPC - G01S 3/74: Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals (systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14) - G01S 3/043: {Receivers} - G01S 3/22: derived from different combinations of signals from separate antennas, e.g. comparing sum with difference - G01S 3/38: using adjustment of real or effective orientation of directivity characteristic of an antenna or an antenna system to give a desired condition of signal derived from that antenna or antenna system, e.g. to give a maximum or minimum signal (G01S3/16, G01S3/28 take precedence) - H01Q 1/246: {specially adapted for base stations} - H01Q 5/00: Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements (combinations of separate active antenna units operating in different wavebands and connected to a common feeder system H01Q21/30) - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract An antenna arrangement including at least two antenna functions arranged to cover a certain angular sector, each antenna function comprising a corresponding antenna port. The antenna arrangement is configured to perform: a first direction of arrival (DOA) estimation for a transmitting device at a first frequency, and a second DOA estimation for the transmitting device at a second frequency, wherein the second frequency has a larger magnitude than the first frequency, and wherein at least one second frequency grating lobe is apparent in the angular sector at the second frequency. The antenna arrangement is configured to: distinguish the at least one second frequency grating lobe from a second frequency main lobe using results from the first DOA estimation, and identify a pointing direction of the second frequency main lobe as a resulting DOA estimation. Related methods are also described. ## Claims ### Claim 1 An antenna arrangement comprising: at least two antenna functions arranged to cover a certain angular sector, each antenna function comprising a corresponding antenna port, wherein the antenna arrangement is configured to perform: a first direction of arrival (DOA) estimation for a transmitting device at a first frequency, and a second DOA estimation for the transmitting device at a second frequency, wherein the second frequency has a larger magnitude than the first frequency, and wherein at least one second frequency grating lobe is apparent in the angular sector at the second frequency, wherein the antenna arrangement is configured to: distinguish the at least one second frequency grating lobe from a second frequency main lobe using results from the first DOA estimation, and identify a pointing direction of the second frequency main lobe as a resulting DOA estimation. ### Claim 2 (depends on 1) An antenna arrangement according to claim 1, wherein the first DOA estimation results in a first frequency main lobe having a pointing direction and a second DOA estimation results in a second frequency main lobe having a pointing direction that is the same as the pointing direction of the first frequency main lobe, and wherein the antenna arrangement is configured to distinguish the second frequency grating lobe from the second frequency main lobe by comparing the pointing direction of the first frequency main lobe to a pointing direction of the at least one second frequency grating lobe. ### Claim 3 (depends on 1) An antenna arrangement according to claim 1, wherein the first DOA estimation results in a first frequency main lobe having a pointing direction and a second DOA estimation results in a second frequency main lobe having a pointing direction that is the same as the pointing direction of the first frequency main lobe, wherein the first DOA estimation results in at least one first frequency grating lobe, and wherein the antenna arrangement is configured to distinguish the second frequency grating lobe from the second frequency main lobe by comparing the pointing direction of the first frequency main lobe, the pointing direction of the first frequency grating lobe, and the pointing direction of the second frequency grating lobe. ### Claim 4 (depends on 1) An antenna arrangement according to claim 1, wherein the antenna arrangement is configured to perform further DOA estimations for the transmitting device at further corresponding frequencies, each of said corresponding frequencies being of larger magnitude than the first frequency. ### Claim 5 (depends on 1) An antenna arrangement according to claim 1, wherein the antenna arrangement is comprised in a wireless communication system node, the node comprising at least two antenna arrangements, wherein each antenna arrangement is configured to cover a certain angular sector. ### Claim 6 (depends on 1) An antenna arrangement according to claim 1, wherein the antenna ports are connected to a beamforming device. ### Claim 7 (depends on 6) An antenna arrangement according to claim 6, wherein the beamforming device comprises a control unit arranged to control the beamforming and the DOA estimation. ### Claim 8 A method for estimating direction of arrival (DOA) for a transmitting device, the method comprising: performing a first DOA estimation for the transmitting device at a first frequency; performing a second DOA estimation for the transmitting device at a second frequency, the second frequency being of larger magnitude than the first frequency, the second DOA estimation resulting in at least one second frequency grating lobe and a second frequency main lobe; separating the second frequency grating lobe from the second frequency main lobe using results from the first DOA estimation; and forming a resulting DOA estimation from the pointing direction of the second frequency main lobe. ### Claim 9 (depends on 8) A method according to claim 8, wherein the first DOA estimation results in a first frequency main lobe having a pointing direction that is the same as the pointing direction of the second frequency main lobe, and wherein separating the second frequency grating lobe from the second frequency main lobe comprises comparing a pointing direction of the first frequency main lobe, a pointing direction of the second frequency main lobe and a pointing direction of the second frequency grating lobe. ### Claim 10 (depends on 8) A method according to claim 8, wherein the first DOA estimation results in a first frequency main lobe having a pointing direction that is the same as the pointing direction of the second frequency main lobe and at least one first frequency grating lobe, wherein separating the second frequency grating lobe from the second frequency main lobe comprises comparing the pointing direction of the first frequency main lobe, the pointing direction of the first frequency grating lobe, the pointing direction of the second frequency main lobe, and the pointing direction of the second frequency grating lobe. ### Claim 11 (depends on 8) A method according to claim 8, further comprising: performing further DOA estimations for the transmitting device at further corresponding frequencies, each of said corresponding frequencies being of larger magnitude than the first frequency. ### Claim 12 (depends on 8) A method according to claim 8, wherein the method uses beamforming for performing the DOA estimations. ### Claim 13 An antenna arrangement for estimating a direction of arrival (DOA) for a transmitting device, the antenna arrangement comprising: at least two antenna functions; and a control unit connected to the at least two antenna functions, wherein the control unit is configured to determine a first preliminary DOA estimation for the transmitting device, wherein the first preliminary DOA estimation is determined at a first frequency that produces a first frequency main lobe corresponding to an actual DOA for the transmitting device, wherein the control unit is configured to calculate a second preliminary DOA estimation for the transmitting device, wherein the second preliminary DOA estimation is determined at a second frequency that is larger in magnitude than the first frequency and that produces a second frequency main lobe corresponding to the actual DOA for the transmitting device, and at least one second frequency grating lobe, wherein the control unit is configured to distinguish the second frequency main lobe from the at least one second frequency grating lobe by comparing the first preliminary DOA estimation to the second preliminary DOA estimation, and wherein the control unit is configured to identify the pointing direction of the second frequency main lobe as an actual DOA estimation. ### Claim 14 (depends on 13) The antenna arrangement according to claim 13, wherein the control unit is configured to determine a first preliminary DOA estimation for the transmitting device by way of beamforming with the at least two antenna functions. ### Claim 15 A method for estimating direction of arrival (DOA) for a transmitting device, the method comprising: producing a first preliminary DOA estimation for the transmitting device at a first frequency, the first frequency being selected to produce a first frequency main lobe corresponding to an actual DOA for the transmitting device; producing a second preliminary DOA estimation or the transmitting device at a second frequency, the second frequency being selected to be larger in magnitude than the first frequency and to produce a second frequency main lobe corresponding to the actual DOA for the transmitting device and at least one second frequency grating lobe; distinguishing the second frequency grating lobe from the second frequency main lobe using results from the first preliminary DOA estimation; and identifying an actual DOA estimation from the pointing direction of the second frequency main lobe. ### Claim 16 (depends on 15) The method according to claim 15, wherein producing a first preliminary DOA estimation for the transmitting device is performed by way of beamforming.