# US 2014/0194137 A1 · Method and/or system for obtaining signatures for use in navigation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0194137 A1 - Document ID: US20140194137A1 - Status: Published application - Kind: A1 - Application number: 13/738,912 - Filed: 2013-01-10 - Published: 2014-07-10 - Earliest claimed: 2013-01-10 - Assignees: QUALCOMM Incorporated - Applicants: Qualcomm Incorporated - Inventors: Ju-Yong DO; Saumitra Mohan DAS; Faraz Mohammad MIRZAEI - Web page: https://patentgrep.com/patent/US20140194137A1 ## CPC - H04W 24/00: Supervisory, monitoring or testing arrangements - G01S 5/02524: {Creating or updating the radio-map} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - 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 Disclosed are systems, methods and techniques for obtaining round trip time (RTT) measurements from acquisition of signals at one or more mobile devices, the signals being transmitted by one or more transmitters; approximating locations of the one or more mobile devices while obtaining the RTT measurements; and combining the measurements to determine expected RTT signature values at discrete positions in the area based, at least in part, on the obtained RTT measurements and the approximated locations. ## Claims ### Claim 1 A method comprising: obtaining round trip time (RTT) measurements from acquisition of signals at one or more mobile devices, said signals being transmitted by one or more transmitters; approximating locations of said one or more mobile devices while obtaining said RTT measurements; and combining said RTT measurements to determine expected RTT signature values at discrete positions in an area based, at least in part, on the obtained RTT measurements and the approximated locations. ### Claim 2 (depends on 1) The method of claim 1, and further comprising providing said expected RTT signature values to other mobile devices for use in positioning operations. ### Claim 3 (depends on 2) The method of claim 2, and further comprising: computing expected uncertainty values associated with said expected RTT signature values; and combining said expected uncertainty values with said expected RTT signature values as positioning assistance data. ### Claim 4 (depends on 1) The method of claim 1, wherein combining said RTT measurements to determine said expected RTT signature values comprises interpolating or extrapolating said expected RTT signature values between said approximated locations and said discrete positions. ### Claim 5 (depends on 4) The method of claim 4, wherein interpolating or extrapolating said expected RTT signature values between said approximated locations comprises applying a Gaussian process regression. ### Claim 6 (depends on 4) The method of claim 4, wherein said discrete positions comprise locations defined on grid points defined by a radio heatmap over an indoor area. ### Claim 7 (depends on 1) The method of claim 1, and further comprising: sorting said RTT measurements based, at least in part, by multiple types of receivers employed at said one or more mobile devices to acquire said signals; and combining said RTT measurements from a selected type of said multiple types of receivers to determine particular expected RTT signature values for application by said selected type of said multiple types of receiver. ### Claim 8 (depends on 7) The method of claim 7, and further comprising constructing multiple radio heatmaps corresponding to said multiple types of receivers based, at least in part, on said expected RTT signature values for the application. ### Claim 9 (depends on 7) The method of claim 7, wherein said multiple types of receivers are based, at least in part, on properties of said multiple types of receivers to select a component from among multiple components for computation of an RTT measurement. ### Claim 10 (depends on 9) The method of claim 9, wherein the multiple components comprise at least one line of sight component and at least one multipath component. ### Claim 11 (depends on 1) The method of claim 1, wherein said approximated locations are based, at least in part, on ground truth measurements obtained from said one or more mobile devices. ### Claim 12 An apparatus comprising: a communication interface; and one or more processors to: access round trip time (RTT) measurement values received at said communication interface, said RTT measurement values obtained from acquisition of signals at one or more mobile devices, said signals being transmitted by one or more transmitters; approximate locations of said one or more mobile devices while obtaining said RTT measurement values; and combine said RTT measurement values to determine expected RTT signature values at discrete positions in an area based, at least in part, on the obtained RTT measurement values and the approximated locations. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein said one or more processors are further to provide said expected RTT signature values to other mobile devices for use in positioning operations. ### Claim 14 (depends on 12) The apparatus of claim 12, wherein said one or more processors are further to combine said RTT measurement values to determine said expected RTT signature values by interpolating or extrapolating said expected RTT signature values between said approximate locations and said discrete positions. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein interpolating or extrapolating said expected RTT signature values between said approximate locations comprises applying a Gaussian process regression. ### Claim 16 (depends on 14) The apparatus of claim 14, wherein said discrete positions comprise locations defined on grid points defined by a radio heatmap over an indoor area. ### Claim 17 (depends on 14) The apparatus of claim 14, wherein said one or more processors are further to: sort said RTT measurement values based, at least in part, by multiple types of receivers employed at said one or more mobile devices to acquire said signals; and combine said RTT measurement values from a selected type of said multiple types of receivers to determine particular expected RTT signature values for application by said selected type of said multiple types of receiver. ### Claim 18 An article comprising: a storage medium comprising machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to: obtain round trip time (RTT) measurements from acquisition of signals at one or more mobile devices, said signals being transmitted by one or more transmitters; approximate locations of said one or more mobile devices while obtaining said RTT measurements; and combine said RTT measurements to determine expected RTT signature values at discrete positions in an area based, at least in part, on the obtained RTT measurements and the approximated locations. ### Claim 19 (depends on 18) The article of claim 18, wherein said instructions are further executable by said special purpose computing apparatus to provide said expected RTT signature values to other mobile devices for use in positioning operations. ### Claim 20 (depends on 18) The article of claim 18, wherein said instructions are further executable by said special purpose computing apparatus to combine said RTT measurements to determine expected RTT signatures by interpolating or extrapolating said expected RTT signature values between said approximate locations and said discrete positions. ### Claim 21 (depends on 20) The article of claim 20, wherein interpolating or extrapolating said expected RTT signature values between said approximate locations comprises applying a Gaussian process regression. ### Claim 22 (depends on 20) The article of claim 20, wherein said discrete positions comprise locations defined on grid points defined by a radio heatmap over an indoor area. ### Claim 23 (depends on 20) The article of claim 20, wherein said instructions are further executable by said special purpose computing apparatus to: sort said RTT measurements based, at least in part, by multiple types of receivers employed at said one or more mobile devices to acquire said signals; and combine said RTT measurements from a selected type of said multiple types of receivers to determine particular expected RTT signature values for application by said selected type of said multiple types of receivers. ### Claim 24 An apparatus comprising: means for obtaining round trip time (RTT) measurements from acquisition of signals at one or more mobile devices, said signals being transmitted by one or more transmitters; means for approximating locations of said one or more mobile devices while obtaining said RTT measurements; and means for combining said RTT measurements to determine expected RTT signature values at discrete positions in an area based, at least in part, on the obtained RTT measurements and the approximated locations. ### Claim 25 A method comprising, at a mobile device: approximating a location of said mobile device; obtaining one or more round trip time (RTT) measurements from acquisition of one or more signals at said mobile device, said one or more signals being transmitted by one or more transmitters; and transmitting one or more messages comprising said approximated location and said one or more RTT measurements to a server for use in computing expected RTT signature values at discrete positions in an area. ### Claim 26 (depends on 25) The method of claim 25, wherein the one or more messages further identify a type of receiver used by said mobile device to acquire said one or more signals. ### Claim 27 (depends on 25) The method of claim 25, and further comprising receiving one or more messages comprising said computed expected RTT signature values for use in positioning operations at said mobile device. ### Claim 28 A mobile device comprising: a transceiver to transmit and receive signals over a wireless communication link; and one or more processors to: obtain one or more round trip time (RTT) measurements from acquisition of one or more signals at said transceiver, said signals being transmitted by one or more transmitters; and initiate transmission of one or more messages through said transceiver comprising an approximate location of said mobile device and said one or more RTT measurements to a server for use in computing expected RTT signature values at discrete positions in an area. ### Claim 29 (depends on 28) The mobile device of claim 28, and further comprising one or more inertial sensors, and wherein said one or more processors are further to determine said approximate location of said mobile device based, at least in part, on one or more measurements obtained from said one or more inertial sensors. ### Claim 30 (depends on 28) The mobile device of claim 28, wherein the one or more messages further identify a type of receiver used by said mobile device to acquire said one or more signals. ### Claim 31 (depends on 28) The mobile device of claim 28, wherein the or more processors are further to obtain one or more messages received at said transceiver comprising said computed expected RTT signature values for use in positioning operations at said mobile device. ### Claim 32 A mobile device comprising: means for approximating a location of said mobile device; means for obtaining one or more round trip time (RTT) measurements from acquisition of one or more signals at said mobile device, said one or more signals being transmitted by one or more transmitters; and means for transmitting one or more messages comprising said approximated location and said one or more RTT measurements to a server for use in computing expected RTT signature values at discrete positions in an area. ### Claim 33 An article comprising: a storage medium comprising machine-readable instructions stored thereon which are executable by a special purpose computing apparatus in a mobile device to: approximate a location of said mobile device; obtain one or more round trip time (RTT) measurements from acquisition of one or more signals at said mobile device, said one or more signals being transmitted by one or more transmitters; and transmit one or more messages comprising said approximated location and said one or more RTT measurements to a server for use in computing expected RTT signature values at discrete positions in an area.