{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2010:XO5XBU3773DNOO3AIX6SBI677O","short_pith_number":"pith:XO5XBU37","schema_version":"1.0","canonical_sha256":"bbbb70d37ffec6d73b6045fd20a3dffb9d7fc681d756f5b914ad079569c80c9a","source":{"kind":"arxiv","id":"1004.2844","version":2},"attestation_state":"computed","paper":{"title":"Minimizing the Complexity of Fast Sphere Decoding of STBCs","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"B. Sundar Rajan, G. R. Jithamithra","submitted_at":"2010-04-16T13:45:43Z","abstract_excerpt":"Decoding of linear space-time block codes (STBCs) with sphere-decoding (SD) is well known. A fast-version of the SD known as fast sphere decoding (FSD) has been recently studied by Biglieri, Hong and Viterbo. Viewing a linear STBC as a vector space spanned by its defining weight matrices over the real number field, we define a quadratic form (QF), called the Hurwitz-Radon QF (HRQF), on this vector space and give a QF interpretation of the FSD complexity of a linear STBC. It is shown that the FSD complexity is only a function of the weight matrices defining the code and their ordering, and not "},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1004.2844","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2010-04-16T13:45:43Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"bfe5dcbbd0d1401721ce6775e73e19e4f930d5e2761fc8a8760ae90beb7e5082","abstract_canon_sha256":"f1e28e1d6ee50252fdc8e0ba6b8e487f4a292411243e5928b18c5335d9b4ae6d"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:24:16.557937Z","signature_b64":"E2m0iQ2U9ZWQkPvpWiPgkCI5mUC2RvQGFu7ZnVO3v/099RjSSqoCVj7uaBX25j9wJoXEWKeE3Jdby11T4thhCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"bbbb70d37ffec6d73b6045fd20a3dffb9d7fc681d756f5b914ad079569c80c9a","last_reissued_at":"2026-05-18T02:24:16.557233Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:24:16.557233Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Minimizing the Complexity of Fast Sphere Decoding of STBCs","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"B. Sundar Rajan, G. R. Jithamithra","submitted_at":"2010-04-16T13:45:43Z","abstract_excerpt":"Decoding of linear space-time block codes (STBCs) with sphere-decoding (SD) is well known. A fast-version of the SD known as fast sphere decoding (FSD) has been recently studied by Biglieri, Hong and Viterbo. Viewing a linear STBC as a vector space spanned by its defining weight matrices over the real number field, we define a quadratic form (QF), called the Hurwitz-Radon QF (HRQF), on this vector space and give a QF interpretation of the FSD complexity of a linear STBC. It is shown that the FSD complexity is only a function of the weight matrices defining the code and their ordering, and not "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1004.2844","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"1004.2844","created_at":"2026-05-18T02:24:16.557353+00:00"},{"alias_kind":"arxiv_version","alias_value":"1004.2844v2","created_at":"2026-05-18T02:24:16.557353+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1004.2844","created_at":"2026-05-18T02:24:16.557353+00:00"},{"alias_kind":"pith_short_12","alias_value":"XO5XBU3773DN","created_at":"2026-05-18T12:26:17.028572+00:00"},{"alias_kind":"pith_short_16","alias_value":"XO5XBU3773DNOO3A","created_at":"2026-05-18T12:26:17.028572+00:00"},{"alias_kind":"pith_short_8","alias_value":"XO5XBU37","created_at":"2026-05-18T12:26:17.028572+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O","json":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O.json","graph_json":"https://pith.science/api/pith-number/XO5XBU3773DNOO3AIX6SBI677O/graph.json","events_json":"https://pith.science/api/pith-number/XO5XBU3773DNOO3AIX6SBI677O/events.json","paper":"https://pith.science/paper/XO5XBU37"},"agent_actions":{"view_html":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O","download_json":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O.json","view_paper":"https://pith.science/paper/XO5XBU37","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1004.2844&json=true","fetch_graph":"https://pith.science/api/pith-number/XO5XBU3773DNOO3AIX6SBI677O/graph.json","fetch_events":"https://pith.science/api/pith-number/XO5XBU3773DNOO3AIX6SBI677O/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O/action/timestamp_anchor","attest_storage":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O/action/storage_attestation","attest_author":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O/action/author_attestation","sign_citation":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O/action/citation_signature","submit_replication":"https://pith.science/pith/XO5XBU3773DNOO3AIX6SBI677O/action/replication_record"}},"created_at":"2026-05-18T02:24:16.557353+00:00","updated_at":"2026-05-18T02:24:16.557353+00:00"}