{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:3HR6TU43KFXXCTMTMZ3R5SMKHP","short_pith_number":"pith:3HR6TU43","canonical_record":{"source":{"id":"1901.01425","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-01-05T14:50:21Z","cross_cats_sorted":["cs.IT","math.IT"],"title_canon_sha256":"7494a3239c6fc57e2d9c71d69307e62b5e038e0f793d9ebc633b2ea2aa495033","abstract_canon_sha256":"e5f357aa4b2da96a04facb25dd70b074760332904ea8857ff34feda082e5db93"},"schema_version":"1.0"},"canonical_sha256":"d9e3e9d39b516f714d9366771ec98a3be5c555c54e3c9f5933991abc8bb80822","source":{"kind":"arxiv","id":"1901.01425","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1901.01425","created_at":"2026-05-17T23:56:52Z"},{"alias_kind":"arxiv_version","alias_value":"1901.01425v1","created_at":"2026-05-17T23:56:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.01425","created_at":"2026-05-17T23:56:52Z"},{"alias_kind":"pith_short_12","alias_value":"3HR6TU43KFXX","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_16","alias_value":"3HR6TU43KFXXCTMT","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_8","alias_value":"3HR6TU43","created_at":"2026-05-18T12:33:07Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:3HR6TU43KFXXCTMTMZ3R5SMKHP","target":"record","payload":{"canonical_record":{"source":{"id":"1901.01425","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-01-05T14:50:21Z","cross_cats_sorted":["cs.IT","math.IT"],"title_canon_sha256":"7494a3239c6fc57e2d9c71d69307e62b5e038e0f793d9ebc633b2ea2aa495033","abstract_canon_sha256":"e5f357aa4b2da96a04facb25dd70b074760332904ea8857ff34feda082e5db93"},"schema_version":"1.0"},"canonical_sha256":"d9e3e9d39b516f714d9366771ec98a3be5c555c54e3c9f5933991abc8bb80822","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:56:52.051088Z","signature_b64":"B5+PrCN6hZODo2LGR+1LCS6nJA4S3axWCHXseS+R8MAtg22sYfbKDgfWfwnnjJtMco1Mt6nnYS/Ks1kywEuTBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d9e3e9d39b516f714d9366771ec98a3be5c555c54e3c9f5933991abc8bb80822","last_reissued_at":"2026-05-17T23:56:52.050616Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:56:52.050616Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1901.01425","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":"2026-05-17T23:56:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"odJWjAegfIg4af4GK80ESw+jhy8zaN9YWekgFdzjsvjE0KLqONt+GuBlr+603FeEsqwtVyPTVTyRrCcNHbk9CA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-22T13:36:53.206969Z"},"content_sha256":"b83e83f277daeebbf45473b4ccbb99d8a6400b72a87639b2b7be9397ec105ce3","schema_version":"1.0","event_id":"sha256:b83e83f277daeebbf45473b4ccbb99d8a6400b72a87639b2b7be9397ec105ce3"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:3HR6TU43KFXXCTMTMZ3R5SMKHP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Beam Training based on Dynamic Hierarchical Codebook for Millimeter Wave Massive MIMO","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.IT","math.IT"],"primary_cat":"eess.SP","authors_text":"Chenhao Qi, Kangjian Chen","submitted_at":"2019-01-05T14:50:21Z","abstract_excerpt":"Beam training based on hierarchical codebook for millimeter wave (mmWave) massive MIMO is investigated. Unlike the existing work using the same hierarchical codebook to estimate different multi-path components (MPCs), dynamic hierarchical codebooks which are updated according to the estimated MPCs are adopted. Firstly, a generalized hierarchical codebook design method is proposed. Then based on this method, a beam training method which dynamically updates the hierarchical codebook by removing the contribution of the estimated MPCs from the codebook is proposed. Simulation results verify the ef"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.01425","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":""},"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":"2026-05-17T23:56:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"XzmxVy0IZsSHqJ5dDFFWvjmitdaduzcBEx3XKQhsVRXin8SE/ER3Tm9duBAmEDrM6FjfkImMYN4e/PP6GylWDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-22T13:36:53.207337Z"},"content_sha256":"76f5450ba2a897a85500a9933dc1861969eba8e2576af9a5728f3bd1d8ea8b48","schema_version":"1.0","event_id":"sha256:76f5450ba2a897a85500a9933dc1861969eba8e2576af9a5728f3bd1d8ea8b48"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/3HR6TU43KFXXCTMTMZ3R5SMKHP/bundle.json","state_url":"https://pith.science/pith/3HR6TU43KFXXCTMTMZ3R5SMKHP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/3HR6TU43KFXXCTMTMZ3R5SMKHP/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":"2026-06-22T13:36:53Z","links":{"resolver":"https://pith.science/pith/3HR6TU43KFXXCTMTMZ3R5SMKHP","bundle":"https://pith.science/pith/3HR6TU43KFXXCTMTMZ3R5SMKHP/bundle.json","state":"https://pith.science/pith/3HR6TU43KFXXCTMTMZ3R5SMKHP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/3HR6TU43KFXXCTMTMZ3R5SMKHP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:3HR6TU43KFXXCTMTMZ3R5SMKHP","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":"e5f357aa4b2da96a04facb25dd70b074760332904ea8857ff34feda082e5db93","cross_cats_sorted":["cs.IT","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-01-05T14:50:21Z","title_canon_sha256":"7494a3239c6fc57e2d9c71d69307e62b5e038e0f793d9ebc633b2ea2aa495033"},"schema_version":"1.0","source":{"id":"1901.01425","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1901.01425","created_at":"2026-05-17T23:56:52Z"},{"alias_kind":"arxiv_version","alias_value":"1901.01425v1","created_at":"2026-05-17T23:56:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.01425","created_at":"2026-05-17T23:56:52Z"},{"alias_kind":"pith_short_12","alias_value":"3HR6TU43KFXX","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_16","alias_value":"3HR6TU43KFXXCTMT","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_8","alias_value":"3HR6TU43","created_at":"2026-05-18T12:33:07Z"}],"graph_snapshots":[{"event_id":"sha256:76f5450ba2a897a85500a9933dc1861969eba8e2576af9a5728f3bd1d8ea8b48","target":"graph","created_at":"2026-05-17T23:56:52Z","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":"Beam training based on hierarchical codebook for millimeter wave (mmWave) massive MIMO is investigated. Unlike the existing work using the same hierarchical codebook to estimate different multi-path components (MPCs), dynamic hierarchical codebooks which are updated according to the estimated MPCs are adopted. Firstly, a generalized hierarchical codebook design method is proposed. Then based on this method, a beam training method which dynamically updates the hierarchical codebook by removing the contribution of the estimated MPCs from the codebook is proposed. Simulation results verify the ef","authors_text":"Chenhao Qi, Kangjian Chen","cross_cats":["cs.IT","math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-01-05T14:50:21Z","title":"Beam Training based on Dynamic Hierarchical Codebook for Millimeter Wave Massive MIMO"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.01425","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:b83e83f277daeebbf45473b4ccbb99d8a6400b72a87639b2b7be9397ec105ce3","target":"record","created_at":"2026-05-17T23:56:52Z","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":"e5f357aa4b2da96a04facb25dd70b074760332904ea8857ff34feda082e5db93","cross_cats_sorted":["cs.IT","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-01-05T14:50:21Z","title_canon_sha256":"7494a3239c6fc57e2d9c71d69307e62b5e038e0f793d9ebc633b2ea2aa495033"},"schema_version":"1.0","source":{"id":"1901.01425","kind":"arxiv","version":1}},"canonical_sha256":"d9e3e9d39b516f714d9366771ec98a3be5c555c54e3c9f5933991abc8bb80822","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d9e3e9d39b516f714d9366771ec98a3be5c555c54e3c9f5933991abc8bb80822","first_computed_at":"2026-05-17T23:56:52.050616Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:56:52.050616Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"B5+PrCN6hZODo2LGR+1LCS6nJA4S3axWCHXseS+R8MAtg22sYfbKDgfWfwnnjJtMco1Mt6nnYS/Ks1kywEuTBw==","signature_status":"signed_v1","signed_at":"2026-05-17T23:56:52.051088Z","signed_message":"canonical_sha256_bytes"},"source_id":"1901.01425","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b83e83f277daeebbf45473b4ccbb99d8a6400b72a87639b2b7be9397ec105ce3","sha256:76f5450ba2a897a85500a9933dc1861969eba8e2576af9a5728f3bd1d8ea8b48"],"state_sha256":"24dbe6a293ada3674d14ecba129896769a07f1f301e422e44552400fcd5c0a7f"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"iRWBoBecKdFpHx+GoYa1Pc/Y3TzluJYFcSyfEJBL8MIEHWBS+TDEJeFR0GkRACNYmw0oQ4o+IYnthbU4pAAGDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-22T13:36:53.209305Z","bundle_sha256":"ad61e1319d7281f6fa8d5380e7ee5a49c49504902bc3966cc835c31a29bb4bfc"}}