# US 11,308,712 B2 · Imaging system using WiFi signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,308,712 B2 - Document ID: US11308712B2 - Status: Granted - Kind: B2 - Application number: 16/831,967 - Filed: 2020-03-27 - Published: 2020-10-01 - Granted: 2022-04-19 - Earliest claimed: 2019-03-29 - Assignees: Board of Trustees of Michigan State University - Applicants: Board of Trustees of Michigan State University - Inventors: Jeffrey Nanzer - Web page: https://patentgrep.com/patent/US11308712B2 ## CPC - G01S 13/89: for mapping or imaging - G01S 13/003: {Bistatic radar systems; Multistatic radar systems} - G06F 17/141: {Discrete Fourier transforms} - G06V 10/143: Sensing or illuminating at different wavelengths - G06V 10/147: Details of sensors, e.g. sensor lenses (fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19) - G06V 20/194: {using hyperspectral data, i.e. more or other wavelengths than RGB} - 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 - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A passive incoherent millimeter-wave imaging system includes a receiver array including a plurality of receive modules configured to receive a scene signal reflected from a scene. The scene signal is reflected in response to a plurality of incoherent communication signals being reflected off the scene, and the plurality of incoherent communication signals are spatially and temporally incoherent at a point when reaching the scene. ## Claims ### Claim 1 A passive incoherent millimeter-wave imaging system comprising: a receiver array including a plurality of receive modules configured to receive a scene signal reflected from a scene, wherein the scene signal is reflected in response to a plurality of incoherent communication signals being reflected off the scene, and wherein the plurality of incoherent communication signals are spatially and temporally incoherent at a point when reaching the scene; a passive incoherent millimeter-wave image processor configured to receive the scene signal reflected from the scene, determining a scene visibility of the scene signal reflected from the scene and construct a reconstructed scene based on a transformation of the scene visibility; and a display module configured to display the reconstructed scene. ### Claim 2 (depends on 1) The imaging system of claim 1 wherein the passive incoherent millimeter-wave image processor is configured to construct the reconstructed scene by: determining a sampled visibility using the scene visibility and a sampling function. ### Claim 3 (depends on 2) The imaging system of claim 2 wherein the sampled visibility is a product of the scene visibility and the sampling function. ### Claim 4 (depends on 2) The imaging system of claim 2 wherein the passive incoherent millimeter-wave image processor is configured to construct the reconstructed scene by: determining an inverse Fourier Transform of the sampled visibility as the transformation to form the reconstructed scene. ### Claim 5 (depends on 1) The imaging system of claim 1 wherein: the plurality of incoherent communication signals are received from a plurality of wireless communication devices. ### Claim 6 (depends on 5) The imaging system of claim 5 wherein: the plurality of incoherent communication signals are received from the plurality of wireless communication devices in response to a distance between the receiver array and each wireless router of the plurality of wireless communication devices being less than a predetermined threshold. ### Claim 7 (depends on 5) The imaging system of claim 5 wherein: each communication device of the plurality of wireless communication devices produces an unsynchronized signal that is incoherent at the scene. ### Claim 8 (depends on 7) The imaging system of claim 7 wherein: each communication device of the plurality of wireless communication devices produces a signal at the same or a different frequency. ### Claim 9 (depends on 1) The imaging system of claim 1 wherein: each incoherent communication signal of the plurality of incoherent communication signals are based on different frequency sources. ### Claim 10 (depends on 1) The imaging system of claim 1 wherein: the plurality of incoherent communication signals are received from a plurality of wireless devices. ### Claim 11 (depends on 1) The imaging system of claim 1 wherein: the plurality of incoherent communication signals include at least three incoherent communication signals. ### Claim 12 (depends on 1) The imaging system of claim 1, wherein: the receiver array is configured to receive the scene signal at a set of spatial frequencies; and the set of spatial frequencies are based on a distance and an angle between pairs of receiving modules. ### Claim 13 (depends on 1) The imaging system of claim 1, wherein the passive incoherent millimeter-wave image processing module constructs the reconstructed scene using spatial frequency sampling. ### Claim 14 An imaging system comprising: (a) a receiver array, a display device, and a processor with an associated memory configured to store instructions, wherein the receiver array is configured to receive a scene signal reflected from a scene, wherein the scene signal is reflected in response to a plurality of incoherent communication signals being reflected off the scene, and wherein the plurality of incoherent communication signals are spatially and temporally incoherent at a point when reaching the scene; and (b) the instructions cause the processor to construct a reconstructed scene by: receiving at least three incoherent communication signals reflected off the scene at the receiver array; determining a scene visibility based on the at least three incoherent communication signals; identifying a sampling function; calculating a sampled visibility based on the scene visibility and the sampling function; and performing an inverse Fourier transform of the sampled visibility to construct the reconstructed scene. ### Claim 15 (depends on 14) The imaging system of claim 14 wherein: the receiver array is a sparse array. ### Claim 16 (depends on 14) The imaging system of claim 14 wherein the receiver array is arranged in a T-shaped configuration. ### Claim 17 (depends on 14) The imaging system of claim 14 wherein the receiver array is arranged in a Y-shaped configuration. ### Claim 18 (depends on 14) The imaging system of claim 14 wherein: the plurality of incoherent communication signals are received from a plurality of wireless communication devices in response to a distance between the receiver array and each wireless communication device of the plurality of wireless communication devices being less than a predetermined threshold. ### Claim 19 (depends on 18) The imaging system of claim 18 wherein: each communication device of the plurality of wireless communication devices produces an unsynchronized signal that is incoherent at the scene and at the same or a different frequency. ### Claim 20 An passive incoherent millimeter-wave imaging method comprising: receiving, from a plurality of communication devices, a scene signals including a plurality of incoherent communication signals reflected off a scene, wherein the scene signal is received by a receiver array including a plurality of receive modules, and wherein the plurality of incoherent communication signals are spatially and temporally incoherent at a point when reaching the scene; constructing a reconstructed scene based on the scene signal reflected from the scene by: determining a scene visibility based on the scene signals; identifying a sampling function; calculating a sampled visibility based on the scene visibility and the sampling function; and performing an inverse Fourier transform of the sampled visibility to construct the reconstructed scene; and displaying the reconstructed scene on a display screen.