{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:IT5HJNDOGJ3LN6DYWSHLLAR4YZ","short_pith_number":"pith:IT5HJNDO","canonical_record":{"source":{"id":"1806.02514","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2018-06-07T05:24:06Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"12f03b92bfae87eaf658c6a7729831b9a451a1c221fbd635d6a2ebeb773536d5","abstract_canon_sha256":"34213858565527f212dd4124220bd09cc6a8ebd34da95e7e0da8c936dd73537b"},"schema_version":"1.0"},"canonical_sha256":"44fa74b46e3276b6f878b48eb5823cc647077b6c3d645e9f5c84a9c0d727897e","source":{"kind":"arxiv","id":"1806.02514","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1806.02514","created_at":"2026-05-18T00:13:56Z"},{"alias_kind":"arxiv_version","alias_value":"1806.02514v1","created_at":"2026-05-18T00:13:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1806.02514","created_at":"2026-05-18T00:13:56Z"},{"alias_kind":"pith_short_12","alias_value":"IT5HJNDOGJ3L","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_16","alias_value":"IT5HJNDOGJ3LN6DY","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_8","alias_value":"IT5HJNDO","created_at":"2026-05-18T12:32:31Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:IT5HJNDOGJ3LN6DYWSHLLAR4YZ","target":"record","payload":{"canonical_record":{"source":{"id":"1806.02514","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2018-06-07T05:24:06Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"12f03b92bfae87eaf658c6a7729831b9a451a1c221fbd635d6a2ebeb773536d5","abstract_canon_sha256":"34213858565527f212dd4124220bd09cc6a8ebd34da95e7e0da8c936dd73537b"},"schema_version":"1.0"},"canonical_sha256":"44fa74b46e3276b6f878b48eb5823cc647077b6c3d645e9f5c84a9c0d727897e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:13:56.555375Z","signature_b64":"7LffGv20wTuwnHX/6d1kWTPnZmWIBa5Toprtagp1vPcASWwdpnnrd3xY3dhNwEroqS4EGidKkNpGyvQrMLziBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"44fa74b46e3276b6f878b48eb5823cc647077b6c3d645e9f5c84a9c0d727897e","last_reissued_at":"2026-05-18T00:13:56.554646Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:13:56.554646Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1806.02514","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":"2026-05-18T00:13:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"58U6ebiNZspjqGLZCZLf7kK5z16wqkzhoXZhGpy+EB/Uf52s+KS4ACCzVLTdI6BMdQEiq2GD+9EFXMf1CjThDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-28T06:04:19.535956Z"},"content_sha256":"d2889347cc33ad37ed4bc4a42007c853c96a45ae68a08151386db48c376cf14f","schema_version":"1.0","event_id":"sha256:d2889347cc33ad37ed4bc4a42007c853c96a45ae68a08151386db48c376cf14f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:IT5HJNDOGJ3LN6DYWSHLLAR4YZ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Multi-cell Hybrid Millimeter Wave Systems: Pilot Contamination and Interference Mitigation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Derrick Wing Kwan Ng, Jinhong Yuan, Lou Zhao, Mark C. Reed, Zhiqiang Wei","submitted_at":"2018-06-07T05:24:06Z","abstract_excerpt":"In this paper, we investigate the system performance of a multi-cell multi-user (MU) hybrid millimeter wave (mmWave) communications in a multiple-input multiple-output (MIMO) network. Due to the reuse of pilot symbols among different cells, the performance of channel estimation is expected to be degraded by pilot contamination, which is considered as a fundamental performance bottleneck of conventional multicell MU massive MIMO networks. To analyze the impact of pilot contamination to the system performance, we first derive the closed-form approximation of the normalized mean squared error (MS"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1806.02514","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":"2026-05-18T00:13:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sZeVPDlJc1lv6fgbY/hvDHv3augmQBrjsV2QKJAbiqUqOnS1sGbXu+wYTtW5B00/ZN4+KqHmJvXqiu3zO0kwBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-28T06:04:19.536304Z"},"content_sha256":"bdbf7ffe0b9a0c16bcb3f8b7a54b13b7d80b3053a609d3822f68927974f9557d","schema_version":"1.0","event_id":"sha256:bdbf7ffe0b9a0c16bcb3f8b7a54b13b7d80b3053a609d3822f68927974f9557d"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/IT5HJNDOGJ3LN6DYWSHLLAR4YZ/bundle.json","state_url":"https://pith.science/pith/IT5HJNDOGJ3LN6DYWSHLLAR4YZ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/IT5HJNDOGJ3LN6DYWSHLLAR4YZ/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":"2026-06-28T06:04:19Z","links":{"resolver":"https://pith.science/pith/IT5HJNDOGJ3LN6DYWSHLLAR4YZ","bundle":"https://pith.science/pith/IT5HJNDOGJ3LN6DYWSHLLAR4YZ/bundle.json","state":"https://pith.science/pith/IT5HJNDOGJ3LN6DYWSHLLAR4YZ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/IT5HJNDOGJ3LN6DYWSHLLAR4YZ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:IT5HJNDOGJ3LN6DYWSHLLAR4YZ","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":"34213858565527f212dd4124220bd09cc6a8ebd34da95e7e0da8c936dd73537b","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2018-06-07T05:24:06Z","title_canon_sha256":"12f03b92bfae87eaf658c6a7729831b9a451a1c221fbd635d6a2ebeb773536d5"},"schema_version":"1.0","source":{"id":"1806.02514","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1806.02514","created_at":"2026-05-18T00:13:56Z"},{"alias_kind":"arxiv_version","alias_value":"1806.02514v1","created_at":"2026-05-18T00:13:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1806.02514","created_at":"2026-05-18T00:13:56Z"},{"alias_kind":"pith_short_12","alias_value":"IT5HJNDOGJ3L","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_16","alias_value":"IT5HJNDOGJ3LN6DY","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_8","alias_value":"IT5HJNDO","created_at":"2026-05-18T12:32:31Z"}],"graph_snapshots":[{"event_id":"sha256:bdbf7ffe0b9a0c16bcb3f8b7a54b13b7d80b3053a609d3822f68927974f9557d","target":"graph","created_at":"2026-05-18T00:13:56Z","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":"In this paper, we investigate the system performance of a multi-cell multi-user (MU) hybrid millimeter wave (mmWave) communications in a multiple-input multiple-output (MIMO) network. Due to the reuse of pilot symbols among different cells, the performance of channel estimation is expected to be degraded by pilot contamination, which is considered as a fundamental performance bottleneck of conventional multicell MU massive MIMO networks. To analyze the impact of pilot contamination to the system performance, we first derive the closed-form approximation of the normalized mean squared error (MS","authors_text":"Derrick Wing Kwan Ng, Jinhong Yuan, Lou Zhao, Mark C. Reed, Zhiqiang Wei","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2018-06-07T05:24:06Z","title":"Multi-cell Hybrid Millimeter Wave Systems: Pilot Contamination and Interference Mitigation"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1806.02514","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:d2889347cc33ad37ed4bc4a42007c853c96a45ae68a08151386db48c376cf14f","target":"record","created_at":"2026-05-18T00:13:56Z","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":"34213858565527f212dd4124220bd09cc6a8ebd34da95e7e0da8c936dd73537b","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2018-06-07T05:24:06Z","title_canon_sha256":"12f03b92bfae87eaf658c6a7729831b9a451a1c221fbd635d6a2ebeb773536d5"},"schema_version":"1.0","source":{"id":"1806.02514","kind":"arxiv","version":1}},"canonical_sha256":"44fa74b46e3276b6f878b48eb5823cc647077b6c3d645e9f5c84a9c0d727897e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"44fa74b46e3276b6f878b48eb5823cc647077b6c3d645e9f5c84a9c0d727897e","first_computed_at":"2026-05-18T00:13:56.554646Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:13:56.554646Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"7LffGv20wTuwnHX/6d1kWTPnZmWIBa5Toprtagp1vPcASWwdpnnrd3xY3dhNwEroqS4EGidKkNpGyvQrMLziBA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:13:56.555375Z","signed_message":"canonical_sha256_bytes"},"source_id":"1806.02514","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d2889347cc33ad37ed4bc4a42007c853c96a45ae68a08151386db48c376cf14f","sha256:bdbf7ffe0b9a0c16bcb3f8b7a54b13b7d80b3053a609d3822f68927974f9557d"],"state_sha256":"51f8237c1d61eed37465bf8c289e25b26ee1cb41c04d8fe1024191cc95d952ec"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Ie2+pi1AzKA68XwwB1wTMkK3ej5SXy/0EF0vzVtjPgKeZsFBrb9uP46QdiNdyb+TB4uxqEGkieVYYBoQe71tDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-28T06:04:19.538225Z","bundle_sha256":"de2a532d1f9670d0f82a660de67ed721f0deda7fd0793d52742fbd9d5c271852"}}