# US 2023/0408664 A1 · Method for a one-sided radio-based distance measurement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0408664 A1 - Document ID: US20230408664A1 - Status: Published application - Kind: A1 - Application number: 18/250,835 - Filed: 2020-11-04 - Published: 2023-12-21 - Earliest claimed: 2020-11-04 - Assignees: Lambda:4 Entwicklungen GmbH - Applicants: Lambda:4 Entwicklungen GmbH - Inventors: Rönne REIMANN - Web page: https://patentgrep.com/patent/US20230408664A1 ## CPC - G01S 11/08: using synchronised clocks - 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 method for a one-sided radio-based distance measurement. The inventor has ascertained that, surprisingly, between time-synchronized objects, in particu-lar with a phase-coherent frequency change, it is possible to ob-viate the need for a transmission direction. This is achieved by a method for measuring distances between two objects, wherein the two objects are time-synchronized to IO ns or better, a first and/or second of the two objects emits signals at multiple frequen-cies, and the distance between the first and second object is deter-mined. The invention is characterized in that the method includes the process of deciding whether/which signals of the first object or the second object are used, in particular on the basis of at least one estimation or determination of the influence of interference on the reception of both objects. ## Claims ### Claim 1 A method for distance determination between two objects, wherein the two objects are time or clock-cycle-synchronized to 10 ns or better, and wherein one or both of a first object and a second object of the two objects emits signals at multiple frequencies, and the other of the one or both of the second object and the r first object of the two objects receives the signals at multiple frequencies, and the distance between the first object and the second object is determined therefrom as well as from knowledge of time-points at which features of the signals were emitted, wherein the method includes a decision whether the signals of the first object or the second object are used, or contains the decision as to which of the signals of the first object or the second object are used, wherein the decision rests in each case on the basis of at least one estimate or determination of effects of interferences on the reception at both of the two objects. ### Claim 2 (depends on 1) The method according to claim 1, wherein the one or both of the first object and the second object changes between at least two of the multiple frequencies. ### Claim 3 (depends on 1) The method according to claim 1, wherein for the distance determination, signal components of the one or both of the first object and the second object at frequencies with less than 40%, or at least signals with less than 20% of the mean energy of the signals, or signals with more than 140% of the mean energy, remain unconsidered. ### Claim 4 (depends on 1) The method according to claim 1, wherein the second object or the first object does not send any signals for distance determination, or the second object only sends signals for time or clock-cycle-synchronization. ### Claim 5 (depends on 1) The method according to claim 1, wherein the one or both of the first object and the second object of the two objects emits the signals at multiple frequencies successively or consecutively. ### Claim 6 (depends on 1) The method according to claim 1, wherein at least one time or clock-cycle synchronization or correction is carried out between the two objects before, after or while the method is carried out. ### Claim 7 (depends on 1) The method according to claim 1, wherein a frequency spacing between two consecutive frequencies of the multiple frequencies is one or both of at least 0.1 MHz and a maximum of 10 MHz. ### Claim 8 (depends on 1) The method according to claim 1, wherein accuracy of the distance determination lies in the range from 0.3 m to 3 m. ### Claim 9 (depends on 1) The method according to claim 1, wherein the distance determination is based on ascertaining a signal time-of-flight from the first object to the second object, or from the second object to the first object, or wherein the distance determination is based on ascertaining a phase shift of the signals from the first object to the second object, or from the second object to the first object. ### Claim 10 (depends on 1) The method according to claim 1, wherein a time drift of at least one of the two objects is determined or corrected or is considered in the calculation of the distance. ### Claim 11 (depends on 1) The method according to claim 1, wherein a mean value is determined from multiple spacing determinations. ### Claim 12 (depends on 1) The method according to claim 1, wherein signals received at the second object or the first object with a received power below a predetermined or calculated lower power limit, are not taken into consideration for the distance determination. ### Claim 13 (depends on 1) The method according to claim 1, carried out between a plurality of pairs of objects, and wherein ascertained distances of the pairs are used to carry out a mapping or position determination. ### Claim 14 (depends on 1) An object configured for carrying out the method according to claim 1. ### Claim 15 (depends on 1) The method according to claim 1, wherein at no time does the bandwidth of the signals exceed 50 MHz. ### Claim 16 (depends on 1) The method according to claim 1, wherein the multiple frequencies are at least five frequencies or a maximum of two hundred frequencies or both. ### Claim 17 (depends on 1) The method according to claim 1, wherein the multiple frequencies span a frequency band of at least 2 MHz or a maximum of 100 MHz or both. ### Claim 18 (depends on 1) The method according to claim 1, wherein signals received at the second object or the first object with a power above a predetermined or calculated upper power limit are not taken into consideration for the distance determination.