# US 2021/0278924 A1 · Nyquist signal to noise reduction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0278924 A1 - Document ID: US20210278924A1 - Status: Published application - Kind: A1 - Application number: 17/086,744 - Filed: 2020-11-02 - Published: 2021-09-09 - Earliest claimed: 2019-10-31 - Assignees: Tactual Labs Co. - Applicants: Tactual Labs Co. - Inventors: Shawn Lee - Web page: https://patentgrep.com/patent/US20210278924A1 ## CPC - G06F 3/0418: {for error correction or compensation, e.g. based on parallax, calibration or alignment} - G06F 3/011: {Arrangements for interaction with the human body, e.g. for user immersion in virtual reality (blind teaching G09B21/00)} - G06F 3/04166: {Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving (Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184)} - G06F 3/0446: {using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes} - H04B 15/00: Suppression or limitation of noise or interference (by means associated with receiver H04B1/10) - H04B 17/345: Interference values ({signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]} H04B17/336) - G06F 2203/04101: 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04B: TRANSMISSION ## Abstract A method for avoiding noise in a display involves scanning a display at a sampling rate that is less than the Nyquist level sampling. After scanning the signals received at less than the Nyquist level, the measured signals are processed in order to determine where noise may be present. Subsequently, future scans are performed at a Fast Fourier Transform is performed on the results. This is used to determine at which frequencies there is noise. Subsequent scans can be taken to determine touch events that avoid locations where noise is present. ## Claims ### Claim 1 A method for avoiding noise in a sensing system, comprising: sampling a first plurality of signals received at receiving antennas at a sampling rate less than a Nyquist sampling rate for signals transmitted during a first period of time; performing a Discrete Fourier Transform on measurements of the first plurality of signals; determining noise from performance of the Discrete Fourier Transform on the first plurality of signals; sampling a second plurality of signals received at receiving antennas at a sampling rate that is at least a Nyquist sampling rate for signals transmitted during a second period of time; performing a Discrete Fourier Transform on measurements of the second plurality of signals; and determining events from results of performing a Discrete Fourier Transform on measurements of the second plurality of signals while avoiding noise determined from the first plurality of signals. ### Claim 2 (depends on 1) The method of claim 1, wherein the sampling rate for the first plurality of signals transmitted during the first plurality of time is a half Nyquist sampling rate. ### Claim 3 (depends on 1) The method of claim 1, wherein the sampling rate for the second plurality signals transmitted during the second plurality of time is a twice Nyquist sampling rate. ### Claim 4 (depends on 1) The method of claim 1, further comprising sampling a third plurality of signals received at receiving antennas at a sampling rate less than a Nyquist sampling rate for signals transmitted during a third period of time; performing a Discrete Fourier Transform on measurements of the third plurality of signals; and determining noise from performance of the Discrete Fourier Transform on the third plurality of signals. ### Claim 5 (depends on 4) The method of claim 4, wherein the sampling of the third plurality of signals is not performed until mis-identified events exceed a threshold level. ### Claim 6 (depends on 1) The method of claim 1, wherein performing the Discrete Fourier Transform on measurements of the second plurality of signals comprises placing measurements of each of the second plurality of signals into bins. ### Claim 7 (depends on 6) The method of claim 6, wherein bins correlated with noise are avoided when determining events. ### Claim 8 (depends on 6) The method of claim 6, wherein bins correlated with noise and bins impacted by the bins correlated with noise are avoided when determining events. ### Claim 9 (depends on 1) The method of claim 1, wherein the events are touch events from a touch sensitive display device. ### Claim 10 (depends on 1) The method of claim 1, wherein the events are motion and pose events of a body part. ### Claim 11 (depends on 1) The method of claim 1, wherein the Discrete Fourier Transform is a Fast Fourier Transform. ### Claim 12 (depends on 1) The method of claim 1, wherein each signal transmitted during the second period of time is frequency orthogonal to each other signal transmitted during the second period of time. ### Claim 13 A sensing system, comprising: a plurality of antennas adapted to receive signals; a processor adapted to; sample a first plurality of signals received at the plurality of receiving antennas at a sampling rate less than a Nyquist sampling rate for signals transmitted during a first period of time; perform a Discrete Fourier Transform on measurements of the first plurality of signals; determine noise from performance of the Discrete Fourier Transform on the first plurality of signals; sample a second plurality of signals received at receiving antennas at a sampling rate that is at least a Nyquist sampling rate for signals transmitted during a second period of time; perform a Discrete Fourier Transform on measurements of the second plurality of signals; and determine events from results of performing a Discrete Fourier Transform on measurements of the second plurality of signals while avoiding noise determined from the first plurality of signals. ### Claim 14 (depends on 13) The system of claim 13, wherein the sampling rate for the first plurality of signals transmitted during the first plurality of time is a half Nyquist sampling rate. ### Claim 15 (depends on 13) The system of claim 13, wherein the sampling rate for the second plurality signals transmitted during the second plurality of time is a twice Nyquist sampling rate. ### Claim 16 (depends on 13) The system of claim 13, wherein the processor is adapted to place the measurements of the second plurality of signals into bins. ### Claim 17 (depends on 16) The system of claim 16, wherein the processor is adapted to not use bins correlated with noise when determining events. ### Claim 18 (depends on 16) The system of claim 16, wherein the processor is adapted to not use bins correlated with noise and bins impacted by the bins correlated with noise when determining events. ### Claim 19 (depends on 13) The system of claim 13, wherein the events are touch events from a touch sensitive display device. ### Claim 20 (depends on 13) The system of claim 13, wherein the events are motion and pose events of a body part.