{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:D2RVMRIGAQA5OXSC7X4ALICNS7","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"910470391cad2b035958f848baa718f5e3d17cd1ca33f305ae132612b9fa8361","cross_cats_sorted":["cs.SD","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2016-03-04T03:57:31Z","title_canon_sha256":"520360df2330c263720da5320027ce3b1231dc6d8ae6dbf747119f0c96e07c22"},"schema_version":"1.0","source":{"id":"1603.01340","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1603.01340","created_at":"2026-05-18T01:19:37Z"},{"alias_kind":"arxiv_version","alias_value":"1603.01340v1","created_at":"2026-05-18T01:19:37Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1603.01340","created_at":"2026-05-18T01:19:37Z"},{"alias_kind":"pith_short_12","alias_value":"D2RVMRIGAQA5","created_at":"2026-05-18T12:30:09Z"},{"alias_kind":"pith_short_16","alias_value":"D2RVMRIGAQA5OXSC","created_at":"2026-05-18T12:30:09Z"},{"alias_kind":"pith_short_8","alias_value":"D2RVMRIG","created_at":"2026-05-18T12:30:09Z"}],"graph_snapshots":[{"event_id":"sha256:de587e3758f28b43ea8cc292b036e023b3639a939783e4a7d5596515dee95e38","target":"graph","created_at":"2026-05-18T01:19:37Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"The extremely long underwater channel delay spread causes severe inter-symbol interference (ISI) for underwater acoustic communications. Passive time reversal processing (PTRP) can effectively reduce the channel time dispersion in a simple way via convolving the received packet with a time reversed probe signal. However the probe signal itself may introduce extra noise and interference (self-correlation of the probe signal). In this paper, we propose a virtual time reversal processing (VTRP) for single input single output (SISO) Orthogonal Frequency Division Multiplexing (OFDM) systems. It con","authors_text":"Gang Qiao, Songzuo Liu, Yanling Yin, Yue Yang","cross_cats":["cs.SD","math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2016-03-04T03:57:31Z","title":"OFDM demodulation using virtual time reversal processing in underwater acoustic communication"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1603.01340","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:01075ea153acef64706a8908927a658b3728b9a4682b3b40a8b119eb47420cf3","target":"record","created_at":"2026-05-18T01:19:37Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"910470391cad2b035958f848baa718f5e3d17cd1ca33f305ae132612b9fa8361","cross_cats_sorted":["cs.SD","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2016-03-04T03:57:31Z","title_canon_sha256":"520360df2330c263720da5320027ce3b1231dc6d8ae6dbf747119f0c96e07c22"},"schema_version":"1.0","source":{"id":"1603.01340","kind":"arxiv","version":1}},"canonical_sha256":"1ea35645060401d75e42fdf805a04d97f904f48cc295c74f5f6c824eeeb74133","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1ea35645060401d75e42fdf805a04d97f904f48cc295c74f5f6c824eeeb74133","first_computed_at":"2026-05-18T01:19:37.864915Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:19:37.864915Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"qzGcywdd+78QpgaD2U63asIIBwahTpAMXxQwg2EQmSes4wnNV4QAhz38tGwNCOw1MW61zTwfvrdQHreNncLxBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T01:19:37.865567Z","signed_message":"canonical_sha256_bytes"},"source_id":"1603.01340","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:01075ea153acef64706a8908927a658b3728b9a4682b3b40a8b119eb47420cf3","sha256:de587e3758f28b43ea8cc292b036e023b3639a939783e4a7d5596515dee95e38"],"state_sha256":"0fe24fd73e22d37eefe77cd0b785ef768baea1ff35d641f70d6cb28f35a973b3"}