{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:ORUHIC3MSGQUHYHXPTYTJHMU2O","short_pith_number":"pith:ORUHIC3M","canonical_record":{"source":{"id":"2102.09871","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2021-02-19T11:17:52Z","cross_cats_sorted":[],"title_canon_sha256":"14de6c1b78c7b7a3edd4667206c5dacc68faade31eca74c08b03dd7dd1965213","abstract_canon_sha256":"5289591c499e605d0df13dd6a4c968882fc812b2c19f86c455f41e06a12758f3"},"schema_version":"1.0"},"canonical_sha256":"7468740b6c91a143e0f77cf1349d94d3a5dd46594efcbca0339b6d1adbbda4a8","source":{"kind":"arxiv","id":"2102.09871","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2102.09871","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"arxiv_version","alias_value":"2102.09871v1","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2102.09871","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"pith_short_12","alias_value":"ORUHIC3MSGQU","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"pith_short_16","alias_value":"ORUHIC3MSGQUHYHX","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"pith_short_8","alias_value":"ORUHIC3M","created_at":"2026-07-05T02:16:31Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:ORUHIC3MSGQUHYHXPTYTJHMU2O","target":"record","payload":{"canonical_record":{"source":{"id":"2102.09871","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2021-02-19T11:17:52Z","cross_cats_sorted":[],"title_canon_sha256":"14de6c1b78c7b7a3edd4667206c5dacc68faade31eca74c08b03dd7dd1965213","abstract_canon_sha256":"5289591c499e605d0df13dd6a4c968882fc812b2c19f86c455f41e06a12758f3"},"schema_version":"1.0"},"canonical_sha256":"7468740b6c91a143e0f77cf1349d94d3a5dd46594efcbca0339b6d1adbbda4a8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:16:31.828578Z","signature_b64":"om7RSok037pYOJyba1qBm29UqqAvPZLGGq46TkPYvA9r/GqNS5NSU8EIbrz9SCSArg3eAypGE6tdpGDrIWUlCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7468740b6c91a143e0f77cf1349d94d3a5dd46594efcbca0339b6d1adbbda4a8","last_reissued_at":"2026-07-05T02:16:31.828175Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:16:31.828175Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2102.09871","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:16:31Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rsV9XNnvujPuZYNd7HqGFovl8GC0a3MHdihxctd+WWOG9x65JMknVwNH7Z7TAnyrRCX7NcrRdWN77mK/SnVABg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T09:05:55.771075Z"},"content_sha256":"51502964b5dce5aa26ebdfb47a898e937bf679553a9f0fa391fe10d31f7842cc","schema_version":"1.0","event_id":"sha256:51502964b5dce5aa26ebdfb47a898e937bf679553a9f0fa391fe10d31f7842cc"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:ORUHIC3MSGQUHYHXPTYTJHMU2O","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Environment-Aware and Training-Free Beam Alignment for mmWave Massive MIMO via Channel Knowledge Map","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"eess.SP","authors_text":"Di Wu, Rui Zhang, Shi Jin, Yong Zeng","submitted_at":"2021-02-19T11:17:52Z","abstract_excerpt":"Millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) communication system is expected to achieve enormous transmission rate, provided that the transmit and receive beams are properly aligned with the MIMO channel. However, existing beam alignment techniques rely on either channel estimation or beam sweeping, which incur prohibitively high training overhead, especially for future wireless systems with further increased antenna dimensions and more stringent requirement on cost-effective hardware architectures. In this paper, we propose a new beam alignment technique, which is e"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2102.09871","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2102.09871/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:16:31Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"6GbD1Po/FUgNd+YRft9JMnrC3F2fLnc2jxyiuLEcof3W0V6V1dcr7D9Uyx/S7pzpbW8T73kvOKn2bGNAIn5vAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T09:05:55.771477Z"},"content_sha256":"442fa93815a94b03543b42f72730482f25d1f3fc2bb5c3af69b93d9a5b8f7916","schema_version":"1.0","event_id":"sha256:442fa93815a94b03543b42f72730482f25d1f3fc2bb5c3af69b93d9a5b8f7916"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ORUHIC3MSGQUHYHXPTYTJHMU2O/bundle.json","state_url":"https://pith.science/pith/ORUHIC3MSGQUHYHXPTYTJHMU2O/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ORUHIC3MSGQUHYHXPTYTJHMU2O/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-07T09:05:55Z","links":{"resolver":"https://pith.science/pith/ORUHIC3MSGQUHYHXPTYTJHMU2O","bundle":"https://pith.science/pith/ORUHIC3MSGQUHYHXPTYTJHMU2O/bundle.json","state":"https://pith.science/pith/ORUHIC3MSGQUHYHXPTYTJHMU2O/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ORUHIC3MSGQUHYHXPTYTJHMU2O/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:ORUHIC3MSGQUHYHXPTYTJHMU2O","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":"5289591c499e605d0df13dd6a4c968882fc812b2c19f86c455f41e06a12758f3","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2021-02-19T11:17:52Z","title_canon_sha256":"14de6c1b78c7b7a3edd4667206c5dacc68faade31eca74c08b03dd7dd1965213"},"schema_version":"1.0","source":{"id":"2102.09871","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2102.09871","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"arxiv_version","alias_value":"2102.09871v1","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2102.09871","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"pith_short_12","alias_value":"ORUHIC3MSGQU","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"pith_short_16","alias_value":"ORUHIC3MSGQUHYHX","created_at":"2026-07-05T02:16:31Z"},{"alias_kind":"pith_short_8","alias_value":"ORUHIC3M","created_at":"2026-07-05T02:16:31Z"}],"graph_snapshots":[{"event_id":"sha256:442fa93815a94b03543b42f72730482f25d1f3fc2bb5c3af69b93d9a5b8f7916","target":"graph","created_at":"2026-07-05T02:16:31Z","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/2102.09871/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) communication system is expected to achieve enormous transmission rate, provided that the transmit and receive beams are properly aligned with the MIMO channel. However, existing beam alignment techniques rely on either channel estimation or beam sweeping, which incur prohibitively high training overhead, especially for future wireless systems with further increased antenna dimensions and more stringent requirement on cost-effective hardware architectures. In this paper, we propose a new beam alignment technique, which is e","authors_text":"Di Wu, Rui Zhang, Shi Jin, Yong Zeng","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2021-02-19T11:17:52Z","title":"Environment-Aware and Training-Free Beam Alignment for mmWave Massive MIMO via Channel Knowledge Map"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2102.09871","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":"sha256:51502964b5dce5aa26ebdfb47a898e937bf679553a9f0fa391fe10d31f7842cc","target":"record","created_at":"2026-07-05T02:16:31Z","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":"5289591c499e605d0df13dd6a4c968882fc812b2c19f86c455f41e06a12758f3","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2021-02-19T11:17:52Z","title_canon_sha256":"14de6c1b78c7b7a3edd4667206c5dacc68faade31eca74c08b03dd7dd1965213"},"schema_version":"1.0","source":{"id":"2102.09871","kind":"arxiv","version":1}},"canonical_sha256":"7468740b6c91a143e0f77cf1349d94d3a5dd46594efcbca0339b6d1adbbda4a8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7468740b6c91a143e0f77cf1349d94d3a5dd46594efcbca0339b6d1adbbda4a8","first_computed_at":"2026-07-05T02:16:31.828175Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:16:31.828175Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"om7RSok037pYOJyba1qBm29UqqAvPZLGGq46TkPYvA9r/GqNS5NSU8EIbrz9SCSArg3eAypGE6tdpGDrIWUlCg==","signature_status":"signed_v1","signed_at":"2026-07-05T02:16:31.828578Z","signed_message":"canonical_sha256_bytes"},"source_id":"2102.09871","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:51502964b5dce5aa26ebdfb47a898e937bf679553a9f0fa391fe10d31f7842cc","sha256:442fa93815a94b03543b42f72730482f25d1f3fc2bb5c3af69b93d9a5b8f7916"],"state_sha256":"f29b18e92120a7e64a2b722ff884de4cbd0aabae11e1d5d1cad391138751cbb7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ZuXu2kjNvtixy2ZIv3mKWaWmJn+Zoxe1HwNW7BEtVGSyGvaJhB+/v/ZvFE0k2MD4OLb1YrIKZoHOboAslsP+AA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-07T09:05:55.773717Z","bundle_sha256":"4ab52ddcdeb38ce1660225e164c65d4358d10612abfc35d376d97cb4402bb2db"}}