{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:JVWXCISY7BQPCJOBW7OE3TL5XL","short_pith_number":"pith:JVWXCISY","canonical_record":{"source":{"id":"1203.5924","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-03-27T10:37:55Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"e09fe79a0656febb37205f24ced5c14694a007a0d6aaef7674054fac6e129327","abstract_canon_sha256":"84bd0a7ae781819d85fdc3bf84a3a185432f4476832190ceb07e2e221701c875"},"schema_version":"1.0"},"canonical_sha256":"4d6d712258f860f125c1b7dc4dcd7dbad7ff238ddc710a7c23fe53281eab9888","source":{"kind":"arxiv","id":"1203.5924","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1203.5924","created_at":"2026-05-18T00:59:09Z"},{"alias_kind":"arxiv_version","alias_value":"1203.5924v2","created_at":"2026-05-18T00:59:09Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1203.5924","created_at":"2026-05-18T00:59:09Z"},{"alias_kind":"pith_short_12","alias_value":"JVWXCISY7BQP","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_16","alias_value":"JVWXCISY7BQPCJOB","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_8","alias_value":"JVWXCISY","created_at":"2026-05-18T12:27:11Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:JVWXCISY7BQPCJOBW7OE3TL5XL","target":"record","payload":{"canonical_record":{"source":{"id":"1203.5924","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-03-27T10:37:55Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"e09fe79a0656febb37205f24ced5c14694a007a0d6aaef7674054fac6e129327","abstract_canon_sha256":"84bd0a7ae781819d85fdc3bf84a3a185432f4476832190ceb07e2e221701c875"},"schema_version":"1.0"},"canonical_sha256":"4d6d712258f860f125c1b7dc4dcd7dbad7ff238ddc710a7c23fe53281eab9888","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:59:09.732015Z","signature_b64":"UA/gb0KUIJLgQKDzQHinkxFmAyfVO4iCvA/F1RMEEkFkXLDu6nB4JHf5p5wAaZtK9cMlE+2+Sjp7sClqYJ93Bg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"4d6d712258f860f125c1b7dc4dcd7dbad7ff238ddc710a7c23fe53281eab9888","last_reissued_at":"2026-05-18T00:59:09.731292Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:59:09.731292Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1203.5924","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:59:09Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"V8YdxD/Zxq5qiktLFKPmi49GCNkkqmKrWSRq2PIhMer12mM5s939NCKvuNaevIXUtSJaVv1Gp48YPccE/GBiBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-12T00:41:14.570909Z"},"content_sha256":"28e8cc1de8cbd4db674935e132da11323b588c4e19caf4a54fdd89a5960697fe","schema_version":"1.0","event_id":"sha256:28e8cc1de8cbd4db674935e132da11323b588c4e19caf4a54fdd89a5960697fe"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:JVWXCISY7BQPCJOBW7OE3TL5XL","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A Coordinated Approach to Channel Estimation in Large-scale Multiple-antenna Systems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"David Gesbert, Haifan Yin, Miltiades Filippou, Yingzhuang Liu","submitted_at":"2012-03-27T10:37:55Z","abstract_excerpt":"This paper addresses the problem of channel estimation in multi-cell interference-limited cellular networks. We consider systems employing multiple antennas and are interested in both the finite and large-scale antenna number regimes (so-called \"massive MIMO\"). Such systems deal with the multi-cell interference by way of per-cell beamforming applied at each base station. Channel estimation in such networks, which is known to be hampered by the pilot contamination effect, constitute a major bottleneck for overall performance. We present a novel approach which tackles this problem by enabling a "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1203.5924","kind":"arxiv","version":2},"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":"2026-05-18T00:59:09Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"s/2cNhZWvyz+0M1HeQ77T8hoLW+G7H9lrCuFxue9nIVYs2JFAoO/qeiSMmW/zs6rnglf7b9ljlEz68cuBE5vBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-12T00:41:14.571724Z"},"content_sha256":"42af268eaae02d6c31b58da4900fae325b5bafa1452ef8150ee84552e6f47777","schema_version":"1.0","event_id":"sha256:42af268eaae02d6c31b58da4900fae325b5bafa1452ef8150ee84552e6f47777"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/JVWXCISY7BQPCJOBW7OE3TL5XL/bundle.json","state_url":"https://pith.science/pith/JVWXCISY7BQPCJOBW7OE3TL5XL/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/JVWXCISY7BQPCJOBW7OE3TL5XL/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":"2026-06-12T00:41:14Z","links":{"resolver":"https://pith.science/pith/JVWXCISY7BQPCJOBW7OE3TL5XL","bundle":"https://pith.science/pith/JVWXCISY7BQPCJOBW7OE3TL5XL/bundle.json","state":"https://pith.science/pith/JVWXCISY7BQPCJOBW7OE3TL5XL/state.json","well_known_bundle":"https://pith.science/.well-known/pith/JVWXCISY7BQPCJOBW7OE3TL5XL/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:JVWXCISY7BQPCJOBW7OE3TL5XL","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":"84bd0a7ae781819d85fdc3bf84a3a185432f4476832190ceb07e2e221701c875","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-03-27T10:37:55Z","title_canon_sha256":"e09fe79a0656febb37205f24ced5c14694a007a0d6aaef7674054fac6e129327"},"schema_version":"1.0","source":{"id":"1203.5924","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1203.5924","created_at":"2026-05-18T00:59:09Z"},{"alias_kind":"arxiv_version","alias_value":"1203.5924v2","created_at":"2026-05-18T00:59:09Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1203.5924","created_at":"2026-05-18T00:59:09Z"},{"alias_kind":"pith_short_12","alias_value":"JVWXCISY7BQP","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_16","alias_value":"JVWXCISY7BQPCJOB","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_8","alias_value":"JVWXCISY","created_at":"2026-05-18T12:27:11Z"}],"graph_snapshots":[{"event_id":"sha256:42af268eaae02d6c31b58da4900fae325b5bafa1452ef8150ee84552e6f47777","target":"graph","created_at":"2026-05-18T00:59:09Z","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":"This paper addresses the problem of channel estimation in multi-cell interference-limited cellular networks. We consider systems employing multiple antennas and are interested in both the finite and large-scale antenna number regimes (so-called \"massive MIMO\"). Such systems deal with the multi-cell interference by way of per-cell beamforming applied at each base station. Channel estimation in such networks, which is known to be hampered by the pilot contamination effect, constitute a major bottleneck for overall performance. We present a novel approach which tackles this problem by enabling a ","authors_text":"David Gesbert, Haifan Yin, Miltiades Filippou, Yingzhuang Liu","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-03-27T10:37:55Z","title":"A Coordinated Approach to Channel Estimation in Large-scale Multiple-antenna Systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1203.5924","kind":"arxiv","version":2},"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":"sha256:28e8cc1de8cbd4db674935e132da11323b588c4e19caf4a54fdd89a5960697fe","target":"record","created_at":"2026-05-18T00:59:09Z","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":"84bd0a7ae781819d85fdc3bf84a3a185432f4476832190ceb07e2e221701c875","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-03-27T10:37:55Z","title_canon_sha256":"e09fe79a0656febb37205f24ced5c14694a007a0d6aaef7674054fac6e129327"},"schema_version":"1.0","source":{"id":"1203.5924","kind":"arxiv","version":2}},"canonical_sha256":"4d6d712258f860f125c1b7dc4dcd7dbad7ff238ddc710a7c23fe53281eab9888","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"4d6d712258f860f125c1b7dc4dcd7dbad7ff238ddc710a7c23fe53281eab9888","first_computed_at":"2026-05-18T00:59:09.731292Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:59:09.731292Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"UA/gb0KUIJLgQKDzQHinkxFmAyfVO4iCvA/F1RMEEkFkXLDu6nB4JHf5p5wAaZtK9cMlE+2+Sjp7sClqYJ93Bg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:59:09.732015Z","signed_message":"canonical_sha256_bytes"},"source_id":"1203.5924","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:28e8cc1de8cbd4db674935e132da11323b588c4e19caf4a54fdd89a5960697fe","sha256:42af268eaae02d6c31b58da4900fae325b5bafa1452ef8150ee84552e6f47777"],"state_sha256":"71f281225c229156fe465a94170218ea0a2c106cd0b0891918b15f7cdc5a9478"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MMeZQ8DrlsosEuCUm/iKSFY85qf77i3nCuX+eBMPC23EKibjGlgM5E03Xv+eTmQg8M6q33lo059IvSiqhcLFBg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-12T00:41:14.576141Z","bundle_sha256":"8b2d5342c0c40c506c909d38d0dd4cb6a67f00bf6a9bd8c96218f257a4200ab3"}}