# US 11,994,608 B2 · Method and device for non-coherent distributed full-duplex transmission radar systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,608 B2 - Document ID: US11994608B2 - Status: Granted - Kind: B2 - Application number: 17/330,094 - Filed: 2021-05-25 - Published: 2022-02-10 - Granted: 2024-05-28 - Earliest claimed: 2018-11-26 - Assignees: Symeo GmbH - Applicants: Symeo GmbH - Inventors: Michael Gottinger; Igor Bilous; Peter Georg Gulden; Martin Vossiek - Web page: https://patentgrep.com/patent/US11994608B2 ## CPC - G01S 7/003: {Transmission of data between radar, sonar or lidar systems and remote stations} - G01S 7/006: {using shared front-end circuitry, e.g. antennas (G01S13/765, G01S13/825 take precedence)} - G01S 7/35: Details of non-pulse systems - G01S 13/825: {with exchange of information between interrogator and responder} - G01S 13/84: for distance determination by phase measurement - G01S 13/931: of land vehicles - G01S 13/933: of aircraft or spacecraft - G01S 2013/9316: {combined with communication equipment with other vehicles or with base stations} - 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 The invention relates to a radar method for exchanging signals between at least two non-coherent transceiver units which respectively have initially non-synchronous, in particular controllable, clock sources, having the following steps: a synchronization in which clock offsets and/or clock rates of the clock sources of the at least two transceiver units are adapted; a full-duplex measuring process in which a first transmission signal of the first transceiver unit is transmitted to the second transceiver unit and a second transmission signal of the second transceiver unit is transmitted to the first transceiver unit via a radio channel; with synchronization prior to the full-duplex measuring process being carried out in such a way that a time offset and/or a frequency offset between the transmission signals at least substantially remain(s) constant during a transmission time of the full-duplex measuring process. ## Claims ### Claim 1 A radar method for exchanging signals between at least two non-coherent transceiver units, the method comprising: aligning clock offsets and/or clock rates of respective clock sources of the at least two transceiver units; performing a full-duplex measuring process, in which a first transmit signal is transmitted from a first transceiver unit to a second transceiver unit and a second transmit signal is transmitted from the second transceiver unit to the first transceiver unit, the measuring process comprising generating a comparison signal in each of the first transceiver unit and the second transceiver unit by mixing and/or correlating the first transmit signal with a received second transmit signal and vice versa, respectively; and exchanging the comparison signals between the transceiver units as part of the full-duplex measuring process: wherein the alignment of clock offsets and/or clock rates is performed prior to the full-duplex measuring process, such that a time offset and/or a frequency offset between the transmit signals remains at least substantially constant during a transmission time of the full-duplex measuring process. ### Claim 2 (depends on 1) The method according to claim 1, wherein the aligning is performed by radio or by cable. ### Claim 3 (depends on 1) The method according to claim 1, wherein exchanged synchronization signals are used for the aligning. ### Claim 4 (depends on 3) The method according to claim 3, wherein the exchanged synchronization signals are modulated using frequency modulation, including an FMCW modulation or an FSK modulation. ### Claim 5 (depends on 1) The method according to claim 1, wherein for the aligning, individual synchronization values, in particular individual signal parameters such as preferably frequency and/or phase values are transmitted. ### Claim 6 (depends on 5) The method according to claim 5, wherein the individual synchronization values comprise a first global time of the first transceiver unit and/or a second global time of the second transceiver unit, wherein the first global time is determined based on the second global time and a first local time, and/or the second global time is determined based on the first global time and a second local time. ### Claim 7 (depends on 1) The method according to claim 1, wherein, for the aligning, a chronological drift between the clock rates of the clock sources is determined and exchanged, between the at least two transceiver units. ### Claim 8 (depends on 1) The method according to claim 1, wherein for the aligning the clock sources are controlled using corresponding control signals such that the clock rates of the clock sources are aligned. ### Claim 9 (depends on 1) The method according to claim 1, wherein in the full-duplex measuring process, a distance and/or a relative speed between the at least two transceiver units are determined based on a signal propagation time of the transmit signals. ### Claim 10 (depends on 1) The method according to claim 1, wherein in the full-duplex measuring process, transmit signals are exchanged, which comprise a sequence of alternating up and down chirps, a sequence of only up chirps, or a sequence of only down chirps. ### Claim 11 (depends on 1) The method according to claim 1, wherein, the full-duplex measuring process comprises, in at least one of the two transceiver units: determining and correcting a center frequency; and correcting a phase shift. ### Claim 12 (depends on 1) The method according to claim 1, wherein, in the full-duplex measuring process, evaluation parameters are determined based on comparison signals. ### Claim 13 (depends on 12) The method according to claim 12, wherein for each signal chirp, a comparison spectrum of the comparison signal is generated, and the evaluation parameters comprise a frequency value corresponding to a maximum magnitude in the comparison spectrum and a phase value corresponding to the maximum magnitude in the comparison spectrum. ### Claim 14 (depends on 12) The method according to claim 12, wherein a two-dimensional comparison signal spectrum is generated in each transceiver station, and the evaluation parameters comprise two frequency values per transceiver station, which are the frequency values of a maximum magnitude along each dimension of the two-dimensional comparison signal spectrum. ### Claim 15 A radar system for determining a distance and/or a relative speed, the system comprising: at least two non-coherent transceiver units, that respectively have non-synchronous clock sources; a synchronization device for aligning clock offsets and/or clock rates of the clock sources of the at least two transceiver units; wherein the transceiver units are configured to perform a full-duplex measuring process, in which a first transmit signal of a first transceiver unit is transmitted to a second transceiver unit and a second transmit signal of the second transceiver unit is transmitted to the first transceiver unit; wherein the synchronization device is configured to perform the alignment of clock offsets and/or clock rates prior to the full-duplex measuring process, such that a time offset and/or a frequency offset between the transmit signals remains at least substantially constant during a transmission time of the full-duplex measuring process; wherein the first transceiver unit is configured to generate a comparison signal by mixing and/or correlating the first transmit signal with a received second transmit signal and the second transceiver unit is configured to generate another comparison signal by mixing and/or correlating the second transmit signal with a received first transmit signal, and wherein the transceiver units are further configured to exchange the comparison signals as part of the full-duplex measuring process. ### Claim 16 (depends on 15) The radar system according to claim 15, wherein the clock sources are controllable oscillators. ### Claim 17 (depends on 1) The method according to claim 1, wherein the method is performed by a mobile apparatus, comprising a vehicle. ### Claim 18 (depends on 15) The system according to claim 15, wherein at least one of the transceiver units is associated with a vehicle.