{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:572GPEIQHLEVO3X67AEBSQ2UUA","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":"6d09ef132f115805b94dcd78c2469067db280534488cca3a52e0e3a5b7558ead","cross_cats_sorted":["eess.SP","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2020-08-11T02:01:12Z","title_canon_sha256":"08f7071fc58fa557f024bdf9bd4558bbea55ef2c5bbc1d88193c981bc6afdeba"},"schema_version":"1.0","source":{"id":"2008.04476","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2008.04476","created_at":"2026-07-05T01:26:25Z"},{"alias_kind":"arxiv_version","alias_value":"2008.04476v1","created_at":"2026-07-05T01:26:25Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2008.04476","created_at":"2026-07-05T01:26:25Z"},{"alias_kind":"pith_short_12","alias_value":"572GPEIQHLEV","created_at":"2026-07-05T01:26:25Z"},{"alias_kind":"pith_short_16","alias_value":"572GPEIQHLEVO3X6","created_at":"2026-07-05T01:26:25Z"},{"alias_kind":"pith_short_8","alias_value":"572GPEIQ","created_at":"2026-07-05T01:26:25Z"}],"graph_snapshots":[{"event_id":"sha256:12f0658139d1a9c34aebae1b8b36bb9d5a69974a45b5a56d8b627ca7db83beee","target":"graph","created_at":"2026-07-05T01:26:25Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2008.04476/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"In this letter, we study efficient channel estimation for an intelligent reflecting surface (IRS)-assisted orthogonal frequency division multiplexing (OFDM) system to achieve minimum training time. First, a fast channel estimation scheme with reduced OFDM symbol duration is proposed for arbitrary frequency-selective fading channels. Next, under the typical condition that the IRS-user channel is line-of-sight (LoS) dominant, another fast channel estimation scheme based on the novel concept of sampling-wise IRS reflection variation is proposed. Moreover, the pilot signal and IRS training reflect","authors_text":"Beixiong Zheng, Changsheng You, Rui Zhang","cross_cats":["eess.SP","math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2020-08-11T02:01:12Z","title":"Fast Channel Estimation for IRS-Assisted OFDM"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2008.04476","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":"sha256:6a3213f6bbe4a97939950c906bf3d7b3682dba0b9af516d3e71efddd1ff5e85e","target":"record","created_at":"2026-07-05T01:26:25Z","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":"6d09ef132f115805b94dcd78c2469067db280534488cca3a52e0e3a5b7558ead","cross_cats_sorted":["eess.SP","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2020-08-11T02:01:12Z","title_canon_sha256":"08f7071fc58fa557f024bdf9bd4558bbea55ef2c5bbc1d88193c981bc6afdeba"},"schema_version":"1.0","source":{"id":"2008.04476","kind":"arxiv","version":1}},"canonical_sha256":"eff46791103ac9576efef808194354a01c4571e5420d1639c1528001428c6ca2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"eff46791103ac9576efef808194354a01c4571e5420d1639c1528001428c6ca2","first_computed_at":"2026-07-05T01:26:25.346534Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:26:25.346534Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"iaj5N2BALD6tlA0Unmr0QdG0QzFDdtfRRJ8MlAuw1imTN1veg2tWiUBBo9M323KipjiAw/Yea8ZXHOKYCJY9CQ==","signature_status":"signed_v1","signed_at":"2026-07-05T01:26:25.346947Z","signed_message":"canonical_sha256_bytes"},"source_id":"2008.04476","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:6a3213f6bbe4a97939950c906bf3d7b3682dba0b9af516d3e71efddd1ff5e85e","sha256:12f0658139d1a9c34aebae1b8b36bb9d5a69974a45b5a56d8b627ca7db83beee"],"state_sha256":"12a4d31ee27e743fc7bfc4c519fe64ef85cbfee418d00175caf1d3cbc2f6ea23"}