# US 11,310,267 B2 · Secure channel state information with adaptive obfuscation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,310,267 B2 - Document ID: US11310267B2 - Status: Granted - Kind: B2 - Application number: 16/808,587 - Filed: 2020-03-04 - Published: 2020-10-29 - Granted: 2022-04-19 - Earliest claimed: 2019-04-29 - Assignees: Semiconductor Components Industries, LLC - Applicants: Semiconductor Components Industries, LLC - Inventors: Debashis Dash; Hossein Dehghan - Web page: https://patentgrep.com/patent/US11310267B2 ## CPC - H04L 25/0228: {with direct estimation from sounding signals} - G06F 21/606: {by securing the transmission between two devices or processes} - H04B 7/0417: Feedback systems - H04B 7/0617: {for beam forming} - H04L 5/04: the signals being represented by different amplitudes or polarities, e.g. quadriplex - H04L 5/12: the signals being represented by different phase modulations of a single carrier - H04L 9/0875: {based on channel impulse response [CIR]} - H04L 9/12: Transmitting and receiving encryption devices synchronised or initially set up in a particular manner - H04L 63/1475: {Passive attacks, e.g. eavesdropping or listening without modification of the traffic monitored} - H04W 12/02: Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII] - H04W 12/63: Location-dependent; Proximity-dependent - H04L 2209/80: Wireless - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A privacy-enhancing wireless communication method for use by a transmitting wireless device having a first location, the method comprising: obtaining a frame preamble using a transceiver device at a location, wherein the frame preamble includes a predetermined pattern and wherein movement information corresponding to the location is detectable based on channel state information of the transceiver device in accordance with the pre-determined pattern; modifying the predetermined pattern of the frame preamble to include amplitude or phase distortion; and masking the movement information by transmitting, using the transceiver device, a frame including the frame preamble with the modified predetermined pattern. ## Claims ### Claim 1 A privacy-enhancing wireless communication method for use by a transceiver device, the method comprising: obtaining a frame preamble that includes a predetermined pattern enabling unauthorized detection of the transceiver device's movement or lack thereof via measurement of channel state information; modifying the predetermined pattern to include amplitude or phase distortion that masks said movement or lack thereof; transmitting a frame using the frame preamble with the modified pre-determined pattern; instructing two or more receiving devices to respond according to a schedule with frame preambles that include predetermined patterns adjusted with amplitude or phase distortions to concurrently mask the movement or lack thereof of said two or more receiving devices. ### Claim 2 A privacy-enhancing wireless communication method for use by a transceiver device, the method comprising: obtaining a sequence of frames each having a preamble that includes a pre-determined pattern enabling unauthorized detection of the transceiver device's movement or lack thereof via measurement of channel state information; modifying the predetermined pattern of each frame preamble in the sequence to include amplitude or phase distortion that masks said movement or lack thereof, with at least some of the frame preambles having modified predetermined patterns with different amplitude or phase distortion from the modified pre-determined patterns of other frame preambles; and transmitting the sequence of frames using the frame preambles with the modified predetermined patterns. ### Claim 3 (depends on 2) The method of claim 2, wherein the amplitude or phase distortion varies between frames to falsely indicate movement of the transceiver device. ### Claim 4 (depends on 2) The method of claim 2, wherein the amplitude or phase distortion varies between frames to falsely indicate random movement of the transceiver device. ### Claim 5 (depends on 2) The method of claim 2, wherein the amplitude or phase distortion varies between frames to falsely indicate that the transceiver device is not moving. ### Claim 6 (depends on 2) The method of claim 2, wherein the amplitude or phase distortion varies between frames to falsely indicate communication from the transceiver device to another electronic device that is moving. ### Claim 7 (depends on 2) The method of claim 2, wherein the transceiver device is at least one of an access point, a station, a repeater, and a mesh node. ### Claim 8 (depends on 2) The method of claim 2, further comprising: instructing two or more receiving devices to respond according to a schedule with frame preambles that include predetermined patterns adjusted with amplitude or phase distortions to concurrently mask the movement or lack thereof of said two or more receiving devices. ### Claim 9 (depends on 2) The method of claim 2, wherein the predetermined pattern is a training sequence. ### Claim 10 (depends on 2) The method of claim 2, further comprising transmitting to a receiving device decoding parameters for operating on the frame preambles with the modified predetermined patterns to extract the channel state information. ### Claim 11 (depends on 2) The method of claim 2, wherein said modifying includes multiplying each predetermined pattern with a corresponding obfuscation matrix, and wherein the method further comprises coordinating with a receiving device before said modifying to determine which obfuscation matrix to use. ### Claim 12 (depends on 2) The method of claim 2, wherein said modifying includes multiplying each predetermined pattern with a corresponding obfuscation matrix, and wherein the obfuscation matrix varies according to time. ### Claim 13 (depends on 2) The method of claim 2, wherein said modifying includes introducing a time delay or a phase shift between antenna streams, and wherein a magnitude of the time delay or a magnitude of the phase shift varies according to time. ### Claim 14 A wireless transmitter that comprises: one or more antennas; a processor coupled to the one or more antennas; and a memory storing instructions that when executed by the processor cause the processor to: obtain a sequence of frames each having a preamble that includes a predetermined pattern enabling unauthorized detection of the wireless transmitter's movement or lack thereof via measurement of channel state information; modify the predetermined pattern of each frame preamble in the sequence to include amplitude or phase distortion that masks said movement or lack thereof, with at least some of the frame preambles having modified predetermined patterns with different amplitude or phase distortion from the modified predetermined patterns of other frame preambles; and transmit the sequence of frames using the frame preambles with modified predetermined patterns. ### Claim 15 (depends on 14) The transmitter of claim 14, wherein the amplitude or phase distortion varies between frames to falsely indicate movement of the transmitter. ### Claim 16 (depends on 14) The transmitter of claim 14, wherein the amplitude or phase distortion varies between frames to falsely indicate random movement of the transmitter. ### Claim 17 (depends on 14) The transmitter of claim 14, wherein the amplitude or phase distortion varies between frames to falsely indicate that the transmitter is not moving. ### Claim 18 (depends on 14) The transmitter of claim 14, wherein the amplitude or phase distortion varies between frames to falsely indicate communication from the transmitter to another electronic device that is moving. ### Claim 19 (depends on 14) The transmitter of claim 14, wherein the instructions further cause the processor to: instruct two or more receiving devices to respond according to a schedule with frame preambles that include predetermined patterns adjusted with amplitude or phase distortions to concurrently mask the movement or lack thereof of said two or more receiving devices. ### Claim 20 (depends on 14) The transmitter of claim 14, wherein as part of modifying the pre-determined pattern, the instructions cause the processor to introduce a time delay or a phase shift between antenna streams, and wherein a magnitude of the time delay or a magnitude of the phase shift varies according to time.