# US 11,443,727 B2 · Synchronized multichannel loopback within embedded architectures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,443,727 B2 - Document ID: US11443727B2 - Status: Granted - Kind: B2 - Application number: 16/773,474 - Filed: 2020-01-27 - Published: 2020-08-06 - Granted: 2022-09-13 - Earliest claimed: 2019-01-31 - Assignees: Harman Becker Automotive Systems GmbH - Applicants: Harman Becker Automotive Systems GmbH - Inventors: Juergen Heinrich Zollner - Web page: https://patentgrep.com/patent/US11443727B2 ## CPC - G10K 11/17823: {Reference signals, e.g. ambient acoustic environment} - G10L 21/0208: Noise filtering - G10K 11/17873: {using a reference signal without an error signal, e.g. pure feedforward} - G10K 2210/3012: Algorithms - G10K 2210/505: Echo cancellation, e.g. multipath-, ghost- or reverberation-cancellation - G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING ## Abstract In at least one embodiment, an embedded Linux system is provided. The Linux system includes a memory, a system on a chip (SoC) device, and a first circuit. The SoC device includes the memory and is programmed to process at least a reference signal indicative of undesired audio content and a measured signal indicative of measured audio data in a listening environment. The first circuit is programmed to receive the reference signal and the measured signal. The first circuit is further programmed to merge the reference signal with the measured signal to provide a combined system input to the SoC device to prevent temporal misalignment between the reference signal and the measured signal caused by one or more software layers of the Linux system. ## Claims ### Claim 1 An embedded Linux system for an audio processing device, the system comprising: a memory; a system on a chip (SoC) device including the memory and being programmed to process at least a reference signal indicative of undesired audio content and a measured signal indicative of measured audio data in a listening environment; and a first circuit being programmed to: receive the reference signal; receive the measured signal; and merge the reference signal with the measured signal to provide a combined system input to a hardware layer of the SoC device prior to the combined system input being received at a plurality of software layers of the Linux system to prevent temporal misalignment between the reference signal and the measured signal caused by the plurality of software layers of the Linux system. ### Claim 2 (depends on 1) The system of claim 1 further comprising a mixer programmed to transmit the reference signal to the first circuit. ### Claim 3 (depends on 1) The system of claim 1 further comprising an input sensor programmed to transmit the reference signal to the first circuit. ### Claim 4 (depends on 1) The system of claim 1 further comprising an input sensor programmed to transmit the measured signal to the first circuit. ### Claim 5 (depends on 4) The system of claim 4, wherein the input sensor is one of a microphone or an acceleration sensor. ### Claim 6 (depends on 1) The system of claim 1, wherein the first circuit is further programmed to merge the reference signal with the measured signal prior to the combined system input being transmitted to the plurality of software layers of the Linux system. ### Claim 7 (depends on 1) The system of claim 1, wherein: a first software layer of the plurality of software layers includes at least one audio-based kernel, the at least one audio-based kernel includes a sound driver; a second software layer of the plurality of software layers includes an audio-based library; and a third software layer of the plurality of software layers includes a sound server to manage sound cards. ### Claim 8 (depends on 1) The system of claim 1, wherein the first circuit is further programmed to receive the reference signal as a plurality of N audio-based channels. ### Claim 9 (depends on 8) The system of claim 8, wherein the first circuit is further programmed to receive the measured signal as a plurality of M audio-based channels. ### Claim 10 (depends on 9) The system of claim 9, wherein the first circuit is further programmed to merge the reference signal with the measured signal to generate M+N audio-based channels to form a Time Division Multiplexing (TDM) data stream. ### Claim 11 A computer-program product embodied in a non-transitory computer readable medium that is programmed to prevent temporally misalignment between a reference signal and a measured signal for an embedded Linux system, the computer-program product comprising instructions to: receive the reference signal that is indicative of undesired audio content; receive the measured signal that is indicative of measured audio data in a listening environment; process the reference signal and the measured signal at a system on a chip (SoC) device; and merge the reference signal with the measured signal to provide a combined system input to a hardware layer of the SoC device prior to the combined system input being received at a plurality of software layers of the Linux system to prevent temporal misalignment between the reference signal and the measured signal caused by the plurality of software layers of the Linux system. ### Claim 12 (depends on 11) The computer-program product of claim 11 further comprising instructions to transmit the reference signal to the first circuit via a mixer. ### Claim 13 (depends on 11) The computer-program product of claim 11 further comprising instructions to transmit the reference signal to the first circuit via an input sensor. ### Claim 14 (depends on 11) The computer-program product of claim 11 further comprising instructions to transmit to transmit the measured signal to the first circuit. ### Claim 15 (depends on 11) The computer-program product of claim 11 further comprising instructions to merge the reference signal with the measured signal prior to the combined system input being transmitted to the plurality of software layers of the Linux system. ### Claim 16 (depends on 11) The computer-program product of claim 11, wherein a first software layer of the plurality of software layers includes at least one audio-based kernel, the at least one audio-based kernel includes a sound driver; a second software layer of the plurality of software layers includes an audio-based library; and a third software layer of the plurality of software layers includes a sound server to manage sound cards. ### Claim 17 (depends on 11) The computer-program product of claim 11 further comprising instructions to receive the reference signal as a plurality of N audio-based channels. ### Claim 18 (depends on 17) The computer-program product of claim 17 further comprising instructions to receive the measured signal as a plurality of M audio-based channels. ### Claim 19 (depends on 18) The computer-program product of claim 18 further comprising instructions to pack or add/merge the reference signal with the measured signal to generate an M+N audio-based channels to form a Time Division Multiplexing (TDM) data stream. ### Claim 20 A computer-program product embodied in a non-transitory computer readable medium that is programmed to prevent temporally misalignment between a reference signal and a measured signal for an embedded Linux system, the computer-program product comprising instructions to: receive the reference signal that is indicative of output data for an adaptive control system; receive the measured signal; process the reference signal and the measured signal at a system on a chip (SoC) device; and merge the reference signal with the measured signal to provide a combined system input to a hardware layer of the SoC device prior to the combined system input being received at a plurality of software layers of the Linux system to prevent temporal misalignment between the reference signal and the measured signal caused by the plurality of software layers of the Linux system.