# US 11,444,707 B2 · Angle of arrival estimation in a radio communications network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,707 B2 - Document ID: US11444707B2 - Status: Granted - Kind: B2 - Application number: 16/420,848 - Filed: 2019-05-23 - Published: 2019-09-12 - Granted: 2022-09-13 - Earliest claimed: 2019-05-23 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Sven Petersson; Fredrik Athley; Andreas Nilsson - Web page: https://patentgrep.com/patent/US11444707B2 ## CPC - H04B 17/27: for locating or positioning the transmitter - G01S 3/48: the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured - H01Q 3/267: {Phased-array testing or checking devices} - H04B 7/0617: {for beam forming} - H04B 7/0848: {Joint weighting} - H04B 7/086: {using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming} - H04L 5/0023: {Time-frequency-space} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04W 72/51: based on terminal or device properties - G01S 3/04: Details - G01S 3/16: using amplitude comparison of signals derived sequentially from receiving antennas or antenna systems having differently-oriented directivity characteristics or from an antenna system having periodically-varied orientation of directivity characteristic - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04B: TRANSMISSION - 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) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract There is provided mechanisms for estimating angle of arrival of a radio signal in a radio communications network. A method is performed by a radio transceiver device. The radio transceiver device comprises an antenna array that, by means of analog beamforming, is configured to shift between at least two phase center locations. The method comprises obtaining measurements of the radio signal as received by the antenna array using two mutually different phase center locations. The method comprises estimating the angle of arrival of the radio signal using the measurements as obtained using the two mutually different phase center locations. ## Claims ### Claim 1 A radio transceiver device for estimating angle of arrival of a radio signal in a radio communications network, the radio transceiver device comprising: an antenna array; and processing circuitry, the processing circuitry being configured to cause the radio transceiver device to: configure the antenna array to have a first phase center location (p1); while the antenna array is configured to have the first phase center location obtain a first measurement of the radio signal; configure the antenna array to have a second phase center location (p2), wherein p2 is different than p1; while the antenna array is configured to have the second phase center location obtain a second measurement of the radio signal; and estimate the angle of arrival of the radio signal using the obtained measurements, wherein the angle of arrival of the radio signal is estimated using a phase difference between measurements as obtained using the first phase center location (p1) and measurements as obtained using the second phase center location (p2). ### Claim 2 (depends on 1) The radio transceiver device of claim 1, wherein the radio transceiver device is a radio access network (RAN) node. ### Claim 3 (depends on 1) The radio transceiver device of claim 1, wherein the radio transceiver device is a user equipment (UE). ### Claim 4 (depends on 1) The radio transceiver device of claim 1, wherein p1 and p2 are separated at least by half a wavelength of an operating frequency of the received radio signal. ### Claim 5 (depends on 1) The radio transceiver device of claim 1, wherein the antenna array comprises antenna elements, and wherein adjacent antenna elements are separated at least by half a wavelength of an operating frequency of the received radio signal. ### Claim 6 (depends on 1) The radio transceiver device of claim 1, wherein the antenna array comprises a first set of antenna elements and a second set of antenna elements, when the radio signal is received by the antenna array using the first phase center location (p1) only the first set of the antenna elements is used to receive the radio signal, when the radio signal is received by the antenna array using the second phase center location (p2) only the second set of the antenna elements is used to receive the radio signal, and the second set of antenna elements is partly but not fully overlapping with the first set of antenna elements. ### Claim 7 (depends on 1) The radio transceiver device of claim 1, wherein the antenna array comprises antenna elements, and the antenna array is configured to shift between the first phase center location and the second phase center location by selectively switching on and off at least one of the antenna elements. ### Claim 8 (depends on 7) The radio transceiver device of claim 7, wherein at least one of the antenna elements is configured to be selectively switched on and off by selectively switching on and off a low-noise amplifier, an attenuator, or a switch of said at least one of the antenna elements. ### Claim 9 (depends on 7) The radio transceiver device of claim 7, wherein the antenna elements have two mutually orthogonal polarizations, and wherein both orthogonal polarizations are simultaneously switched on and off as the at least one of the antenna elements is selectively switched on and off. ### Claim 10 (depends on 1) The radio transceiver device of claim 1, wherein the antenna array comprises antenna elements, and the antenna array is configured to shift between the first phase center location and the second phase center location by selectively increasing and reducing gain of a low-noise amplifier of at least one of the antenna elements. ### Claim 11 (depends on 1) The radio transceiver device of claim 1, wherein the antenna array is configured to simultaneously receive the radio signal in two mutually orthogonal polarizations. ### Claim 12 (depends on 11) The radio transceiver device of claim 11, wherein one intermediate value of the angle of arrival is estimated for each of the two mutually orthogonal polarizations, and wherein the angle of arrival is estimated using a combination of the intermediate values. ### Claim 13 (depends on 1) The radio transceiver device of claim 1, wherein a first receive beam is used to receive the radio signal while the antenna array has the first phase center location (p1), a second receive beam is used to receive the radio signal while the antenna array has the second phase center location (p2), the first receive beam is created only using phase shifts of antenna elements of the antenna array, and the second receive beam is created only using phase shifts of antenna elements of the antenna array. ### Claim 14 (depends on 1) The radio transceiver device of claim 1, wherein a first receive beam is used to receive the radio signal while the antenna array has the first phase center location (p1), a second receive beam is used to receive the radio signal while the antenna array has the second phase center location (p2), the first receive beam is created using a combination of phase shifts and amplitude tapering of antenna elements of the antenna array, and the second receive beam is created using a combination of phase shifts and amplitude tapering of antenna elements of the antenna array. ### Claim 15 (depends on 1) The radio transceiver device of claim 1, wherein the antenna array is a two-dimensional antenna array, and the angle of arrival is estimated in two dimensions. ### Claim 16 (depends on 1) The radio transceiver device of claim 1, wherein the radio signal is received from a second radio transceiver device, and the first recited radio transceiver device is configured to: i) select a beam according to the angle of arrival and ii) communicate with the second radio transceiver device using the selected beam. ### Claim 17 A method for estimating angle of arrival of a radio signal in a radio communications network, the method comprising: configuring the antenna array to have a first phase center location (p1); while the antenna array is configured to have the first phase center location, obtaining a first measurement of the radio signal; configure the antenna array to have a second phase center location (p2), wherein p2 is different than p1; while the antenna array is configured to have the second phase center location, obtaining a second measurement of the radio signal; and estimating the angle of arrival of the radio signal using the obtained measurements wherein estimating the angle of arrival of the radio signal using the obtained measurements comprises estimating the angle of arrival using a phase difference between measurements as obtained using the first phase center location (p1) and measurements as obtained using the second phase center location (p2). ### Claim 18 (depends on 17) The method of claim 17, wherein the radio transceiver device is a radio access network (RAN) node. ### Claim 19 (depends on 17) The method of claim 17, wherein the radio transceiver device is a user equipment (UE). ### Claim 20 (depends on 17) The method of claim 17, wherein p1 and p2 are separated at least by half a wavelength of an operating frequency of the received radio signal. ### Claim 21 (depends on 17) The method of claim 17, wherein the antenna array comprises antenna elements, and wherein adjacent antenna elements are separated at least by half a wavelength of an operating frequency of the received radio signal. ### Claim 22 (depends on 17) The method of claim 17, wherein the antenna array comprises a first set of antenna elements and a second set of antenna elements, when the radio signal is received by the antenna array using the first phase center location (p1) only the first set of the antenna elements is used to receive the radio signal, when the radio signal is received by the antenna array using the second phase center location (p2) only the second set of the antenna elements is used to receive the radio signal, and the second set of antenna elements is partly but not fully overlapping with the first set of antenna elements. ### Claim 23 (depends on 17) The method of claim 17, wherein the antenna array comprises antenna elements, and the antenna array is configured to shift between the first phase center location and the second phase center location by selectively switching on and off at least one of the antenna elements. ### Claim 24 (depends on 23) The method of claim 23, wherein at least one of the antenna elements is configured to be selectively switched on and off by selectively switching on and off a low-noise amplifier, an attenuator, or a switch of said at least one of the antenna elements. ### Claim 25 (depends on 23) The method of claim 23, wherein the antenna elements have two mutually orthogonal polarizations, and wherein both orthogonal polarizations are simultaneously switched on and off as the at least one of the antenna elements is selectively switched on and off. ### Claim 26 (depends on 17) The method of claim 17, wherein the antenna array comprises antenna elements, and the antenna array is configured to shift between the first phase center location and the second phase center location by selectively increasing and reducing gain of a low-noise amplifier of at least one of the antenna elements. ### Claim 27 (depends on 17) The method of claim 17, wherein the antenna array is configured to simultaneously receive the radio signal in two mutually orthogonal polarizations. ### Claim 28 (depends on 27) The method of claim 27, wherein one intermediate value of the angle of arrival is estimated for each of the two mutually orthogonal polarizations, and wherein the angle of arrival is estimated using a combination of the intermediate values. ### Claim 29 (depends on 17) The method of claim 17, wherein a first receive beam is used to receive the radio signal while the antenna array has the first phase center location (p1), a second receive beam is used to receive the radio signal while the antenna array has the second phase center location (p2), the first receive beam is created only using phase shifts of antenna elements of the antenna array, and the second receive beam is created only using phase shifts of antenna elements of the antenna array. ### Claim 30 (depends on 17) The method of claim 17, wherein a first receive beam is used to receive the radio signal while the antenna array has the first phase center location (p1), a second receive beam is used to receive the radio signal while the antenna array has the second phase center location (p2), the first receive beam is created using a combination of phase shifts and amplitude tapering of antenna elements of the antenna array, and the second receive beam is created using a combination of phase shifts and amplitude tapering of antenna elements of the antenna array. ### Claim 31 (depends on 17) The method of claim 17, wherein the antenna array is a two-dimensional antenna array, and the angle of arrival is estimated in two dimensions. ### Claim 32 (depends on 17) The method of claim 17, wherein the radio signal is received from a second radio transceiver device, and the first recited radio transceiver device is configured to: i) select a beam according to the angle of arrival and ii) communicate with the second radio transceiver device using the selected beam.