{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9819456","patent":{"patent_number":"US-9819456","title":"Preamble detection and frequency offset determination","assignee":null,"inventors":[],"filing_date":"2016-10-17T00:00:00.000Z","publication_date":"2017-11-14T00:00:00.000Z","cpc_codes":["H04L","G11B","H04L","H04L","H04W","H04L"],"num_claims":20,"abstract":"Systems and methods are disclosed for detection of a selected signal pattern, such as a servo sector preamble, and for frequency offset determination. A circuit may be configured to divide a signal into detection windows of a selected size, and sample the signal a selected number of times within each detection window. The circuit may then determine an error value for each detection window based on values of the samples for each detection window, and determine the preamble is detected when a threshold number of most-recently sampled detection windows have error values below a threshold value. The circuit may then organize the sample values corresponding to the preamble into groups, and calculate phase estimates representing a phase at which the groups were sampled. The circuit may determine a frequency offset based on the phase estimates, and modulate the sampling frequency according to the frequency offset."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Preamble detection and frequency offset determination","description":"Systems and methods are disclosed for detection of a selected signal pattern, such as a servo sector preamble, and for frequency offset determination. A circuit may be configured to divide a signal in","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9819456","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-9819456","citation_suggestion":"Patentable. \"Preamble detection and frequency offset determination\" (US-9819456). https://patentable.app/patents/US-9819456","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9819456","json":"https://patentable.app/api/llm-context/US-9819456","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T05:15:15.855Z"}