# US 2025/0147149 A1 · System and method for segmented frequency domain correlation with doppler binning > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0147149 A1 - Document ID: US20250147149A1 - Status: Published application - Kind: A1 - Application number: 18/387,726 - Filed: 2023-11-07 - Published: 2025-05-08 - Earliest claimed: 2023-11-07 - Assignees: Rockwell Collins, Inc. - Applicants: Rockwell Collins, Inc. - Inventors: Ryan M. Murphy - Web page: https://patentgrep.com/patent/US20250147149A1 ## CPC - G01S 7/356: {involving particularities of FFT processing} - H04L 25/0222: {Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency} - H04B 17/221: {of receiver antennas, e.g. as to amplitude or phase} - H04J 13/00: Code division multiplex systems (for frequency hopping H04B1/713) - 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 - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) ## Abstract A communication system in a mobile platform receives a signal and applies a plurality of Doppler offsets within a range of potential Doppler offsets. Spectral analysis is performed for correlators in each of the Doppler offset signals, and a signal with a best correlation score is used to identify the actual Doppler offset of the signal. The signal is padded by some predetermined length and correlators are segmented. A polynomial interpolator corrects the sample rate for each one of the Doppler offsets signals. ## Claims ### Claim 1 A computer apparatus in a mobile platform comprising: at least one antenna; and at least one processor in data communication with a memory storing processor executable code for configuring the at least one processor to: receive a signal via the at least one antenna; apply a plurality of Doppler offsets to the signal; associate each Doppler offset signal with a Doppler bin; and perform spectral analysis on each Doppler offset signal to identify at least one Doppler offset resulting in a highest correlator score. ### Claim 2 (depends on 1) The computer apparatus of claim 1, wherein the at least one processor is further configured to pad a correlator of each Doppler offset signal by a predefined amount. ### Claim 3 (depends on 2) The computer apparatus of claim 2, wherein the at least one processor is further configured to: replicate each Doppler offset signal; pad a correlator of each replicated Doppler offset signal by a predefined amount; and apply a delay to each padded, replicated Doppler offset signal. ### Claim 4 (depends on 3) The computer apparatus of claim 3, wherein the at least one processor is further configured to segment each correlator of each Doppler offset signal, each segment being defined by a sample rate and a number of samples. ### Claim 5 (depends on 3) The computer apparatus of claim 3, wherein the at least one processor is further configured to: convert time-domain samples to frequency-domain samples; and produce a matrix of complex fast Fourier transform outputs for each padded, Doppler offset signal and padded, replicated Doppler offset signal. ### Claim 6 (depends on 1) The computer apparatus of claim 1, wherein the at least one processor is further configured to apply polynomial interpolation to each Doppler offset signal to correct a sample rate. ### Claim 7 (depends on 1) The computer apparatus of claim 1, wherein the at least one processor is further configured to segment each correlator of each Doppler offset signal. ### Claim 8 A method comprising: receiving a signal; applying a plurality of Doppler offsets to the signal; associating each Doppler offset signal with a Doppler bin; and performing spectral analysis on each Doppler offset signal to identify at least one Doppler offset resulting in a highest correlator score. ### Claim 9 (depends on 8) The method of claim 8, further comprising padding a correlator of each Doppler offset signal by a predefined amount. ### Claim 10 (depends on 9) The method of claim 9, further comprising: replicating each Doppler offset signal; padding a correlator of each replicated Doppler offset signal by a predefined amount; and applying a delay to each padded, replicated Doppler offset signal. ### Claim 11 (depends on 10) The method of claim 10, further comprising segmenting each correlator of each Doppler offset signal, each segment being defined by a sample rate and a number of samples. ### Claim 12 (depends on 10) The method of claim 10, further comprising: converting time-domain samples to frequency-domain samples; and producing a matrix of complex fast Fourier transform outputs for each padded, Doppler offset signal and padded, replicated Doppler offset signal. ### Claim 13 (depends on 8) The method of claim 8, further comprising applying polynomial interpolation to each Doppler offset signal to correct a sample rate. ### Claim 14 A communication system in a mobile platform comprising: at least one antenna; and at least one processor in data communication with a memory storing processor executable code for configuring the at least one processor to: receive a signal via the at least one antenna; apply a plurality of Doppler offsets to the signal; associate each Doppler offset signal with a Doppler bin; and perform spectral analysis on each Doppler offset signal to identify at least one Doppler offset resulting in a highest correlator score. ### Claim 15 (depends on 14) The communication system of claim 14, wherein the at least one processor is further configured to pad a correlator of each Doppler offset signal by a predefined amount. ### Claim 16 (depends on 15) The communication system of claim 15, wherein the at least one processor is further configured to: replicate each Doppler offset signal; pad a correlator of each replicated Doppler offset signal by a predefined amount; and apply a delay to each padded, replicated Doppler offset signal. ### Claim 17 (depends on 16) The communication system of claim 16, wherein the at least one processor is further configured to segment each correlator of each Doppler offset signal, each segment being defined by a sample rate and a number of samples. ### Claim 18 (depends on 16) The communication system of claim 16, wherein the at least one processor is further configured to: convert time-domain samples to frequency-domain samples; and produce a matrix of complex fast Fourier transform outputs for each padded, Doppler offset signal and padded, replicated Doppler offset signal. ### Claim 19 (depends on 14) The communication system of claim 14, wherein the at least one processor is further configured to apply polynomial interpolation to each Doppler offset signal to correct a sample rate. ### Claim 20 (depends on 14) The communication system of claim 14, wherein the at least one processor is further configured to segment each correlator of each Doppler offset signal.