{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-11945402","patent":{"patent_number":"US-11945402","title":"Method and system for relay attack prevention incorporating channel coherence","assignee":null,"inventors":[],"filing_date":"2020-09-23T00:00:00.000Z","publication_date":"2024-04-02T00:00:00.000Z","cpc_codes":["H04W","G07C","H04B","H04B","H04W","G07C","G07C","H04B","H04W"],"num_claims":9,"abstract":"A method/system of detecting if a relay is present in a vehicle PEPS system, including transmitting from antenna(s) of a vehicle, a first/second LF signals and determining a minimum time-gap between the signal transmissions so that the time-gap exceeds the channel-coherence-time of a high-frequency wireless-relay. A maximum time between the signals is determined by a timing requirement of the PEPS system and the maximum allowable change in a key-fob position. A time gap between the minimum/maximum times is determined. Depending on the time-gap, the system timing requirement is increased to provide a predetermined-time. At the predetermined-time, separately transmitting between the first/second LF signals, which have a known signal ratio, from a vehicle antenna to a key-fob as part of an LF challenge; measuring, at the key-fob, the signal-levels of the first/second LF signals; and determining if the ratio of the first/second LF signals are within a predefined range."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Method and system for relay attack prevention incorporating channel coherence","description":"A method/system of detecting if a relay is present in a vehicle PEPS system, including transmitting from antenna(s) of a vehicle, a first/second LF signals and determining a minimum time-gap between t","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-11945402","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-11945402","citation_suggestion":"Patentable. \"Method and system for relay attack prevention incorporating channel coherence\" (US-11945402). https://patentable.app/patents/US-11945402","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-11945402","json":"https://patentable.app/api/llm-context/US-11945402","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-05-31T00:14:13.670Z"}