{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9647865","patent":{"patent_number":"US-9647865","title":"Iterative-diversity COFDM broadcasting with improved shaping gain","assignee":null,"inventors":[],"filing_date":"2016-07-19T00:00:00.000Z","publication_date":"2017-05-09T00:00:00.000Z","cpc_codes":["H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L","H04L"],"num_claims":11,"abstract":"Transmitter apparatus to broadcast coded orthogonal frequency-division multiplexed (COFDM) radio-frequency carriers conveying low-density parity-check (LPDC) coding transmits the same coded DTV signals twice some time apart. The coded DTV signals of initial transmissions and of final transmissions are mapped to quadrature amplitude modulation (QAM) of the COFDM carriers according to first and second patterns, respectively. Bits that map to lattice points in the first mapping pattern more likely to experience error are mapped to lattice points in the second mapping pattern less likely to experience error. Bits that map to lattice points in the second mapping pattern more likely to experience error are mapped to lattice points in the first mapping pattern less likely to experience error. Receiver apparatus demaps QAM symbols in the earlier and later transmissions of twice-transmitted COFDM signals and maximal-ratio combines the de-mapping results at bit level, rather than symbol level."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Iterative-diversity COFDM broadcasting with improved shaping gain","description":"Transmitter apparatus to broadcast coded orthogonal frequency-division multiplexed (COFDM) radio-frequency carriers conveying low-density parity-check (LPDC) coding transmits the same coded DTV signal","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9647865","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-9647865","citation_suggestion":"Patentable. \"Iterative-diversity COFDM broadcasting with improved shaping gain\" (US-9647865). https://patentable.app/patents/US-9647865","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9647865","json":"https://patentable.app/api/llm-context/US-9647865","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T05:00:16.418Z"}