# US 10,313,166 B2 · Backward-compatible signal variations for data augmentation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,313,166 B2 - Document ID: US10313166B2 - Status: Granted - Kind: B2 - Application number: 15/934,879 - Filed: 2018-03-23 - Published: 2018-08-02 - Granted: 2019-06-04 - Earliest claimed: 2016-09-28 - Assignees: The MITRE Corporation - Applicants: The MITRE Corporation - Inventors: Brady O'Hanlon - Web page: https://patentgrep.com/patent/US10313166B2 ## CPC - G01S 19/02: Details of the space or ground control segments - 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 A system and method for augmenting the data capacity of pre-existing communications channels is provided. In one example, a subcarrier waveform of the system can be dithered based on data generated by an additional source and then transmitted. The dithered subcarrier can be passed through a plurality of matched filters so as to ascertain which dither pattern was used, thus ultimately allowing for the demodulation of the additional data source. The system and methods provided herein can be implemented with minimal impact to legacy users of the system as implementation of the dithering scheme can have minimal impact to the performance of receivers that are not equipped to demodulate the dithered waveforms. ## Claims ### Claim 1 A method for receiving an augmented data rate global navigation satellite system transmission, the method comprising: generating an expected data sequence; generating a subcarrier waveform; applying a first dithering scheme to a first portion the generated subcarrier waveform based on a first data, wherein the first portion includes a plurality of sub-portions, and wherein the first dithering scheme includes shifting a first sub-portion of the first portion of the generated subcarrier waveform in time in a first direction; applying a second dithering scheme to the first portion of the generated subcarrier waveform, wherein the second dithering scheme includes shifting the first sub-portion of the first portion of the generated waveform in time in a second direction; generating a first matched filter based on the expected data sequence and the first subcarrier waveform dithering pattern; generating a second matched filter based on the expected data sequence and the second subcarrier waveform dither pattern; receiving a transmitted signal; applying the first matched filter to the received transmitted signal to generate a first demodulated signal; applying the second matched filter to the received transmitted signal to generate a second demodulated signal; and comparing the first demodulated signal and the second demodulated signal to determine whether the received transmitted signal included the first dithering pattern or the second dithering pattern. ### Claim 2 (depends on 1) The method of claim 1, wherein the first dithering scheme includes shifting the first sub-portion of the first portion of the generated subcarrier waveform in the first direction and shifting a second sub-portion of the first portion of the generated subcarrier waveform in the second direction. ### Claim 3 (depends on 2) The method of claim 2, wherein a number of the sub-portions of the plurality of sub-portions of the first portion that are shifted in the first direction is equal to a number of the sub-portions of the plurality of sub-portions of the first portion that are shifted in the second direction. ### Claim 4 (depends on 1) The method of claim 1, wherein the second dithering scheme includes shifting the first sub-portion of the second portion of the generated subcarrier waveform in the second direction and shifting a second sub-portion of the second portion of the generated subcarrier waveform in the first direction. ### Claim 5 (depends on 4) The method of claim 4, wherein a number of the sub-portions of the plurality of sub-portions of the second portion that are shifted in the second direction is equal to a number of the sub-portions of the plurality of sub-portions of the second portion that are shifted in the first direction. ### Claim 6 (depends on 1) The method of claim 1, wherein the global navigation satellite system transmits and receives binary offset subcarrier signals. ### Claim 7 A non-transitory computer readable storage medium having stored thereon a set of instructions for receiving an augmented data rate global navigation satellite system transmission that when executed by a computing device, cause the computing device to: generate an expected data sequence; generate a subcarrier waveform; apply a first dithering scheme to a first portion the generated subcarrier waveform based on a first data, wherein the first portion includes a plurality of sub-portions, and wherein the first dithering scheme includes shifting a first sub-portion of the first portion of the generated subcarrier waveform in time in a first direction; apply a second dithering scheme to the first portion of the generated subcarrier waveform, wherein the second dithering scheme includes shifting the first sub-portion of the first portion of the generated waveform in time in a second direction; generate a first matched filter based on the expected data sequence and the first subcarrier waveform dithering pattern; generate a second matched filter based on the expected data sequence and the second subcarrier waveform dither pattern; receive a transmitted signal; apply the first matched filter to the received transmitted signal to generate a first demodulated signal; apply the second matched filter to the received transmitted signal to generate a second demodulated signal; and compare the first demodulated signal and the second demodulated signal to determine whether the received transmitted signal included the first dithering pattern or the second dithering pattern. ### Claim 8 (depends on 7) The non-transitory computer readable storage medium of claim 7, wherein the first dithering scheme includes shifting the first sub-portion of the first portion of the generated subcarrier waveform in the first direction and shifting a second sub-portion of the first portion of the generated subcarrier waveform in the second direction. ### Claim 9 (depends on 8) The non-transitory computer readable storage medium of claim 8, wherein a number of the sub-portions of the plurality of sub-portions of the first portion that are shifted in the first direction is equal to a number of the sub-portions of the plurality of sub-portions of the first portion that are shifted in the second direction. ### Claim 10 (depends on 7) The non-transitory computer readable storage medium of claim 7, wherein the second dithering scheme includes shifting the first sub-portion of the second portion of the generated subcarrier waveform in the second direction and shifting a second sub-portion of the second portion of the generated subcarrier waveform in the first direction. ### Claim 11 (depends on 10) The non-transitory computer readable storage medium of claim 10, wherein a number of the sub-portions of the plurality of sub-portions of the second portion that are shifted in the second direction is equal to a number of the sub-portions of the plurality of sub-portions of the second portion that are shifted in the first direction. ### Claim 12 (depends on 7) The non-transitory computer readable storage medium of claim 7, wherein the global navigation satellite system transmits and receives binary offset subcarrier signals. ### Claim 13 A computing system comprising: one or more processors, the one or more processors configured to: generate an expected data sequence; generate a subcarrier waveform; apply a first dithering scheme to a first portion the generated subcarrier waveform based on a first data, wherein the first portion includes a plurality of sub-portions, and wherein the first dithering scheme includes shifting a first sub-portion of the first portion of the generated subcarrier waveform in time in a first direction; apply a second dithering scheme to the first portion of the generated subcarrier waveform, wherein the second dithering scheme includes shifting the first sub-portion of the first portion of the generated waveform in time in a second direction; generate a first matched filter based on the expected data sequence and the first subcarrier waveform dithering pattern; generate a second matched filter based on the expected data sequence and the second subcarrier waveform dither pattern; receive a transmitted signal; apply the first matched filter to the received transmitted signal to generate a first demodulated signal; apply the second matched filter to the received transmitted signal to generate a second demodulated signal; and compare the first demodulated signal and the second demodulated signal to determine whether the received transmitted signal included the first dithering pattern or the second dithering pattern. ### Claim 14 (depends on 13) The computing system of claim 13, wherein the first dithering scheme includes shifting the first sub-portion of the first portion of the generated subcarrier waveform in the first direction and shifting a second sub-portion of the first portion of the generated subcarrier waveform in the second direction. ### Claim 15 (depends on 14) The computing system of claim 14, wherein a number of the sub-portions of the plurality of sub-portions of the first portion that are shifted in the first direction is equal to a number of the sub-portions of the plurality of sub-portions of the first portion that are shifted in the second direction. ### Claim 16 (depends on 13) The computing system of claim 13, wherein the second dithering scheme includes shifting the first sub-portion of the second portion of the generated subcarrier waveform in the second direction and shifting a second sub-portion of the second portion of the generated subcarrier waveform in the first direction. ### Claim 17 (depends on 16) The computing system of claim 16, wherein a number of the sub-portions of the plurality of sub-portions of the second portion that are shifted in the second direction is equal to a number of the sub-portions of the plurality of sub-portions of the second portion that are shifted in the first direction. ### Claim 18 (depends on 13) The computing system of claim 13, wherein the global navigation satellite system transmits and receives binary offset subcarrier signals.