# US 11,792,049 B2 · Positioning using synthesized wideband channel estimation and synchronized receivers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,792,049 B2 - Document ID: US11792049B2 - Status: Granted - Kind: B2 - Application number: 17/695,819 - Filed: 2022-03-15 - Published: 2022-09-15 - Granted: 2023-10-17 - Earliest claimed: 2021-03-15 - Assignees: PhasorLab, Inc. - Applicants: PhasorLab, Inc. - Inventors: Joshua C. Park; Paul Christopher McFarthing; Jian Cui - Web page: https://patentgrep.com/patent/US11792049B2 ## CPC - H04L 25/0224: {using sounding signals} - H04L 5/001: {the frequencies being arranged in component carriers} - H04L 5/0016: {Time-frequency-code} - H04L 5/003: {Arrangements for allocating sub-channels of the transmission path} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 25/0204: {of multiple channels} - H04L 25/0216: {with estimation of channel length} - H04L 25/0232: {by interpolation between sounding signals} - H04L 25/0242: {using matrix methods} - H04W 4/029: Location-based management or tracking services - 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 A method of positioning using a shortest path based on a synthesized wideband channel estimate is described. In some embodiments, a method is disclosed, comprising: distributing an uplink schedule to a plurality of synchronized nodes; continuously capturing a reference signal across a plurality of carrier frequencies until frequency coverage for the synthetic wide band is achieved; removing frequency offset; calculating a plurality of channel estimates for the captured reference signal; aligning the plurality of channel estimates; combining the plurality of channel estimates to construct a single channel estimate of the synthetic wide band; deriving a shortest delay for the received reference signal; and using the derived shortest delay to estimate a time of arrival and thereby determine an estimated location. ## Claims ### Claim 1 A method for positioning using synthesized wideband channel estimation, comprising: capturing, at at least one receiver node, a first received signal of a reference signal from a transmitter at a first carrier frequency; performing a reconfiguration to enable signal reception at a second carrier frequency; capturing a second received signal of the reference signal from the transmitter at the second carrier frequency; continuing to capture subsequent received signals until a plurality of frequencies in a synthetic wideband channel are sufficiently represented in a set of received signals; calculating segment channel estimates by performing channel estimation on each of the set of received signals; aligning overlapping sections of the calculated segment channel estimates to form a combined channel estimate of the synthetic wideband channel; deriving a shortest path delay value from a plurality of delays based on the combined channel estimate; deriving a time of arrival for the first received signal from the shortest path delay value; and estimating a position of the transmitter using the derived time of arrival, thereby using a channel estimate of a synthesized wideband channel to estimate the position of the transmitter. ### Claim 2 (depends on 1) The method of claim 1, wherein the reference signal is an arbitrary signal. ### Claim 3 (depends on 1) The method of claim 1, wherein the reference signal is one of a Long Term Evolution (LTE) or 5G sounding reference signal (SRS). ### Claim 4 (depends on 1) The method of claim 1, further comprising distributing a uplink schedule to at least one receiver node. ### Claim 5 (depends on 1) The method of claim 1, further comprising distributing a synchronized channel hopping sequence to a plurality of synchronized receivers; and, capturing a plurality of signals according to the synchronized channel hopping sequence. ### Claim 6 (depends on 1) The method of claim 1, further comprising: capturing the reference signal at a plurality of synchronized receiver nodes; and, estimating the position of the transmitter at each of the plurality of synchronized receiver nodes. ### Claim 7 (depends on 1) The method of claim 1, further comprising estimating the position of the transmitter at each of a plurality of synchronized receiver nodes; and, using the estimated position from the plurality of synchronized receiver nodes to increase positional accuracy. ### Claim 8 (depends on 1) The method of claim 1, further comprising removing at least one of carrier frequency offset and sampling frequency offset from a received reference signal at the at least one receiver node. ### Claim 9 (depends on 1) The method of claim 1, further comprising calculating the channel estimate with a frequency domain signal. ### Claim 10 (depends on 1) The method of claim 1, further comprising aligning overlapping sections subsequent to a transform from time domain into frequency domain. ### Claim 11 (depends on 1) The method of claim 1, further comprising aligning overlapping sections of the calculated channel estimates by adding or subtracting a phase from each channel estimate of the calculated channel estimates, thereby forming a continuous channel response when combined. ### Claim 12 (depends on 1) The method of claim 1, further comprising interpolating gaps in the calculated channel estimates. ### Claim 13 (depends on 1) The method of claim 1, wherein deriving a plurality of delays is performed using a matrix pencil algorithm. ### Claim 14 (depends on 1) The method of claim 1, wherein the combined channel estimate is continuous in phase. ### Claim 15 A method of positioning using a shortest path based on a synthesized wideband channel estimate, comprising: continuously capturing a reference signal across a plurality of carrier frequencies until frequency coverage for the synthetic wide band is achieved; removing frequency offset for each of the plurality of carrier frequency captures; calculating a plurality of channel estimates for the plurality of carrier frequency captures; aligning the plurality of channel estimates; combining the plurality of channel estimates to construct a single channel estimate of the synthetic wide band; deriving a shortest delay for the received reference signal using the single channel estimate of the synthetic wide band; and using the derived shortest delay to estimate a time of arrival and thereby determine an estimated location. ### Claim 16 (depends on 15) The method of claim 15, further comprising distributing an uplink schedule to a plurality of synchronized nodes. ### Claim 17 (depends on 15) The method of claim 15, wherein continuously capturing the reference signal comprises repeatedly capturing the reference signal.