{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:WQ2YPPOWWMLLFVT43EML7IC7NH","short_pith_number":"pith:WQ2YPPOW","canonical_record":{"source":{"id":"1903.02077","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-03-05T22:02:10Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"80f413e4e5216ef78175c6fc63af9d5ad1b0761cfb3409572029c036eb950d63","abstract_canon_sha256":"8ffabc0e7ce4c134ae5c4c91c7f4c9abf9f84bc361dd9444c244cc4db4746489"},"schema_version":"1.0"},"canonical_sha256":"b43587bdd6b316b2d67cd918bfa05f69d4c4f13a465e739de7ce099a29a2122c","source":{"kind":"arxiv","id":"1903.02077","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1903.02077","created_at":"2026-05-17T23:51:56Z"},{"alias_kind":"arxiv_version","alias_value":"1903.02077v1","created_at":"2026-05-17T23:51:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1903.02077","created_at":"2026-05-17T23:51:56Z"},{"alias_kind":"pith_short_12","alias_value":"WQ2YPPOWWMLL","created_at":"2026-05-18T12:33:30Z"},{"alias_kind":"pith_short_16","alias_value":"WQ2YPPOWWMLLFVT4","created_at":"2026-05-18T12:33:30Z"},{"alias_kind":"pith_short_8","alias_value":"WQ2YPPOW","created_at":"2026-05-18T12:33:30Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:WQ2YPPOWWMLLFVT43EML7IC7NH","target":"record","payload":{"canonical_record":{"source":{"id":"1903.02077","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-03-05T22:02:10Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"80f413e4e5216ef78175c6fc63af9d5ad1b0761cfb3409572029c036eb950d63","abstract_canon_sha256":"8ffabc0e7ce4c134ae5c4c91c7f4c9abf9f84bc361dd9444c244cc4db4746489"},"schema_version":"1.0"},"canonical_sha256":"b43587bdd6b316b2d67cd918bfa05f69d4c4f13a465e739de7ce099a29a2122c","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:51:56.723840Z","signature_b64":"LinDpcK+t720YSXi4eVg5sPVqtPBd78PycgGVFSvtf8+X8gRY9lQj63668K1B9K7suRynYEVW4NdW76vb7eJBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b43587bdd6b316b2d67cd918bfa05f69d4c4f13a465e739de7ce099a29a2122c","last_reissued_at":"2026-05-17T23:51:56.723407Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:51:56.723407Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1903.02077","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":"2026-05-17T23:51:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SJ53Yj23HHi8zXN23g7VM8CMhUEwmYeRae3iZM2yOMVBxI7t2o9w+Rdg/KU2OxzCcxr4Zw/HlgZ5nmOw3sS9AQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T21:05:12.636186Z"},"content_sha256":"af9ce10f9b202c5541b33cb3c96f1b04a639c9454b5194aec0b687adfe060f20","schema_version":"1.0","event_id":"sha256:af9ce10f9b202c5541b33cb3c96f1b04a639c9454b5194aec0b687adfe060f20"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:WQ2YPPOWWMLLFVT43EML7IC7NH","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Generalized Approximate Message Passing for Massive MIMO mmWave Channel Estimation with Laplacian Prior","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Faouzi Bellili, Foad Sohrabi, Wei Yu","submitted_at":"2019-03-05T22:02:10Z","abstract_excerpt":"This paper tackles the problem of millimeter-Wave (mmWave) channel estimation in massive MIMO communication systems. A new Bayes-optimal channel estimator is derived using recent advances in the approximate belief propagation (BP) Bayesian inference paradigm. By leveraging the inherent sparsity of the mmWave MIMO channel in the angular domain, we recast the underlying channel estimation problem into that of reconstructing a compressible signal from a set of noisy linear measurements. Then, the generalized approximate message passing (GAMP) algorithm is used to find the entries of the unknown m"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1903.02077","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":"2026-05-17T23:51:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"wpWfy3rUxPNwESSe+ox36fx1yUR7q0/S/4I5BF8IjT8dAOJpDsNM11EbWXTeVc+heDhlYTJc7XS+ETIEXOIYCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T21:05:12.636942Z"},"content_sha256":"61fcc61d81943de79d9936a7008856df95e23df0c3cf0bec4d480a3ee702004e","schema_version":"1.0","event_id":"sha256:61fcc61d81943de79d9936a7008856df95e23df0c3cf0bec4d480a3ee702004e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/WQ2YPPOWWMLLFVT43EML7IC7NH/bundle.json","state_url":"https://pith.science/pith/WQ2YPPOWWMLLFVT43EML7IC7NH/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/WQ2YPPOWWMLLFVT43EML7IC7NH/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":"2026-05-31T21:05:12Z","links":{"resolver":"https://pith.science/pith/WQ2YPPOWWMLLFVT43EML7IC7NH","bundle":"https://pith.science/pith/WQ2YPPOWWMLLFVT43EML7IC7NH/bundle.json","state":"https://pith.science/pith/WQ2YPPOWWMLLFVT43EML7IC7NH/state.json","well_known_bundle":"https://pith.science/.well-known/pith/WQ2YPPOWWMLLFVT43EML7IC7NH/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:WQ2YPPOWWMLLFVT43EML7IC7NH","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":"8ffabc0e7ce4c134ae5c4c91c7f4c9abf9f84bc361dd9444c244cc4db4746489","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-03-05T22:02:10Z","title_canon_sha256":"80f413e4e5216ef78175c6fc63af9d5ad1b0761cfb3409572029c036eb950d63"},"schema_version":"1.0","source":{"id":"1903.02077","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1903.02077","created_at":"2026-05-17T23:51:56Z"},{"alias_kind":"arxiv_version","alias_value":"1903.02077v1","created_at":"2026-05-17T23:51:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1903.02077","created_at":"2026-05-17T23:51:56Z"},{"alias_kind":"pith_short_12","alias_value":"WQ2YPPOWWMLL","created_at":"2026-05-18T12:33:30Z"},{"alias_kind":"pith_short_16","alias_value":"WQ2YPPOWWMLLFVT4","created_at":"2026-05-18T12:33:30Z"},{"alias_kind":"pith_short_8","alias_value":"WQ2YPPOW","created_at":"2026-05-18T12:33:30Z"}],"graph_snapshots":[{"event_id":"sha256:61fcc61d81943de79d9936a7008856df95e23df0c3cf0bec4d480a3ee702004e","target":"graph","created_at":"2026-05-17T23:51:56Z","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":"This paper tackles the problem of millimeter-Wave (mmWave) channel estimation in massive MIMO communication systems. A new Bayes-optimal channel estimator is derived using recent advances in the approximate belief propagation (BP) Bayesian inference paradigm. By leveraging the inherent sparsity of the mmWave MIMO channel in the angular domain, we recast the underlying channel estimation problem into that of reconstructing a compressible signal from a set of noisy linear measurements. Then, the generalized approximate message passing (GAMP) algorithm is used to find the entries of the unknown m","authors_text":"Faouzi Bellili, Foad Sohrabi, Wei Yu","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-03-05T22:02:10Z","title":"Generalized Approximate Message Passing for Massive MIMO mmWave Channel Estimation with Laplacian Prior"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1903.02077","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:af9ce10f9b202c5541b33cb3c96f1b04a639c9454b5194aec0b687adfe060f20","target":"record","created_at":"2026-05-17T23:51:56Z","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":"8ffabc0e7ce4c134ae5c4c91c7f4c9abf9f84bc361dd9444c244cc4db4746489","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-03-05T22:02:10Z","title_canon_sha256":"80f413e4e5216ef78175c6fc63af9d5ad1b0761cfb3409572029c036eb950d63"},"schema_version":"1.0","source":{"id":"1903.02077","kind":"arxiv","version":1}},"canonical_sha256":"b43587bdd6b316b2d67cd918bfa05f69d4c4f13a465e739de7ce099a29a2122c","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b43587bdd6b316b2d67cd918bfa05f69d4c4f13a465e739de7ce099a29a2122c","first_computed_at":"2026-05-17T23:51:56.723407Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:51:56.723407Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"LinDpcK+t720YSXi4eVg5sPVqtPBd78PycgGVFSvtf8+X8gRY9lQj63668K1B9K7suRynYEVW4NdW76vb7eJBQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:51:56.723840Z","signed_message":"canonical_sha256_bytes"},"source_id":"1903.02077","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:af9ce10f9b202c5541b33cb3c96f1b04a639c9454b5194aec0b687adfe060f20","sha256:61fcc61d81943de79d9936a7008856df95e23df0c3cf0bec4d480a3ee702004e"],"state_sha256":"b7dcc372ed34316286607c36c2362fc0c0e1e4e5ad88529bbcdc1d8114f76a84"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Hc06kzr1ppL3RLa9ILTZmCu9cZT+TiitPRP7DIcBR3rV1m76nkrnut1ZOw0pCAnC/rSqcCVXQw5/g6tuuJjeCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T21:05:12.642035Z","bundle_sha256":"de723c4e8d4390465f796d6e6deae5b5f2321aec05fbd1986898501b43dd2601"}}