# US 2014/0152504 A1 · Method and system for measuring direction of arrival of wireless signal using circular array displacement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152504 A1 - Document ID: US20140152504A1 - Status: Published application - Kind: A1 - Application number: 13/691,806 - Filed: 2012-12-02 - Published: 2014-06-05 - Earliest claimed: 2012-12-02 - Assignees: Khalifa University of Science, Technology & Research (KUSTAR) - Inventors: Ahmed Rashed KULAIB; Jason Wee Peng NG; Raed M. SHUBAIR; Mahmoud A. AL-QUTAYRI - Web page: https://patentgrep.com/patent/US20140152504A1 ## CPC - G01S 5/04: Position of source determined by a plurality of spaced direction-finders - 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: 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 ## Abstract The various embodiments herein provide a Uniform Circular Displaced Sensor Array (UC-DSA) system and method for measuring/estimating Direction of Arrival (DOA) of a wireless signal. The UC-DSA system comprises at least a set of two circular antenna arrays. The two circular antenna arrays have a number of elements. A Radio frequency (RF) receiver captures a wireless signal incident on a circular antenna array. A Direction of Arrival (DOA) estimator processes a received input signal and a Triangulation system provides the exact location of the source of the wireless signal. The two circular antenna arrays with the same number of elements are placed on different radii, and are shifted to have equal separation between inner elements and outer elements. ## Claims ### Claim 1 A Uniform Circular Displaced Sensor Array (UC-DSA) system for measuring Direction Of Arrival (DOA) of a wireless signal, the system comprising: at least a set of two circular antenna arrays wherein all circular antenna arrays have a number of elements; a Radio frequency (RF) receiver, wherein the RF receiver captures a wireless signal incident on a circular antenna array; a Direction Of Arrival (DOA) estimator for processing a received input signal; and a triangulation system, wherein the circular antenna arrays with the elements are placed on different radii, and are shifted to have at least half a wavelength separation between inner elements and outer elements. ### Claim 2 (depends on 1) The system according to claim 1, wherein each circular antenna array comprises at-least three antennas, and wherein each circular antenna array receives a wireless signal from a random signal source. ### Claim 3 (depends on 1) The system according to claim 1, wherein the two circular antenna arrays are an inner antenna array and an outer antenna array, and wherein the two circular antenna arrays are arranged in concentric circles of different radii, and wherein the two concentric circular antenna array forms a Displaced Sensor Array (DSA). ### Claim 4 (depends on 1) The system according to claim 1, wherein each circular antenna array comprises a number of antenna elements, and wherein the distance between the antennas in each circular antenna array is equal, and wherein the distance between each element is equal to a preset minimum distance. ### Claim 5 (depends on 1) The system according to claim 1, wherein the minimum distance between the elements is equal to half a wavelength of an incident wireless signal. ### Claim 6 A method of estimating a Direction Of Arrival (DOA) of a wireless signal by using a Uniform Circular Displaced Sensor Array (UC-DSA) configuration system, the method comprises: providing two or more nodes for detecting a wireless signal in a vicinity, wherein a node is a device capable of transmitting and receiving wireless signals; arranging a circular antenna array at each node for receiving the detected wireless signal, wherein at least two circular antenna array are arranged, and wherein the antenna elements are arranged in concentric circles, and wherein the antenna elements are separated by a preset minimum distance; passing the detected and received wireless signal to a RF receiver, wherein the RF receiver captures the received wireless signal for processing; estimating the DOA of the received wireless signal by a DOA estimator; localize the position of the target using estimated DOAs. ### Claim 7 (depends on 6) The method according to claim 6, wherein at least two circular antenna arrays have a number of elements. ### Claim 8 (depends on 6) The method according to claim 6, wherein an outer circular antenna array is shifted by an angle so that elements at the outer circular antenna array are separated from elements at the inner circular antenna array by an equal distance. ### Claim 9 (depends on 6) The method according to claim 6, wherein elements at the outer circular antenna array are separated by an equal distance. ### Claim 10 (depends on 6) The method according to claim 6, wherein elements at the inner circular antenna array are separated by an equal distance. ### Claim 11 (depends on 6) The method according to claim 6, wherein the preset minimum distance between the elements is equal to half a wavelength of an incident wireless signal. ### Claim 12 A method of estimating the Direction of Arrival (DOA) by a DOA estimator comprising a DOA estimation algorithm, the method comprises: receiving a signal from an inner circular antenna array of a set of two circular antenna arrays through a Radio Frequency (RF) receiver; receiving a signal from an outer circular antenna array of the set of two circular antenna arrays through a Radio Frequency (RF) receiver; processing the signal from inner circular antenna array and outer circular antenna array, wherein the processing comprises summing of an output of an inner antenna to an output of a displaced outer antenna, and wherein a summation of the output of the inner antenna to the output of the displaced outer antenna results in the formation of output samples; creating several covariance matrices (R) from the samples; taking an average of the covariance matrices (R); calculating a noise eigenvector by evaluating the averaged covariance matrix (R); computing a MUltiple SIgnal Classification (MUSIC) spectrum by using the noise eigenvector; and identifying the DOA of the wireless signal from a peak in the power spectrum. ### Claim 13 (depends on 12) The method according to claim 12, wherein at least two circular antenna arrays have a number of elements. ### Claim 14 (depends on 12) The method according to claim 12, wherein an outer circular antenna array is shifted by an angle so that elements at the outer circular antenna array are separated from elements at the inner circular antenna array by an equal distance. ### Claim 15 (depends on 12) The method according to claim 12, wherein elements at the outer circular antenna array are separated by an equal distance. ### Claim 16 (depends on 12) The method according to claim 12, wherein elements at the inner circular antenna array are separated by an equal distance. ### Claim 17 (depends on 12) The method according to claim 12, wherein the minimum distance between the elements is equal to half a wavelength of an incident wireless signal.