{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-11496174","patent":{"patent_number":"US-11496174","title":"Carrier and sampling frequency offset estimation for RF communication with crystal-less nodes","assignee":null,"inventors":[],"filing_date":"2021-01-29T00:00:00.000Z","publication_date":"2022-11-08T00:00:00.000Z","cpc_codes":["H04B","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L"],"num_claims":18,"abstract":"When the ultra-low power mm-scale sensor node does not have a crystal oscillator and phase-lock loop, it inevitably exhibits significant carrier frequency offset (CFO) and sampling frequency offset (SFO) with respect to the reference frequencies in the gateway. This disclosure enables efficient real-time calculation of accurate SFO and CFO at the gateway, thus the ultra-low power mm-scale sensor node can be realized without a costly and bulky clock reference crystal and also power-hungry phase lock loop. In the proposed system, the crystal-less sensor starts transmission with repetitive RF pulses with a constant interval, followed by the data payload using pulse-position modulation (PPM). A proposed algorithm uses a two-dimensional (2D) fast Fourier transform (FFT) based process that identifies the SFO and CFO at the same time to establish successful wireless communication between the gateway and crystal-less sensor nodes."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Carrier and sampling frequency offset estimation for RF communication with crystal-less nodes","description":"When the ultra-low power mm-scale sensor node does not have a crystal oscillator and phase-lock loop, it inevitably exhibits significant carrier frequency offset (CFO) and sampling frequency offset (S","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-11496174","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-11496174","citation_suggestion":"Patentable. \"Carrier and sampling frequency offset estimation for RF communication with crystal-less nodes\" (US-11496174). https://patentable.app/patents/US-11496174","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-11496174","json":"https://patentable.app/api/llm-context/US-11496174","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-05-31T04:21:13.301Z"}