{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:N7JCD2GLPKOELH45KN4COX726E","short_pith_number":"pith:N7JCD2GL","canonical_record":{"source":{"id":"1905.05906","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-05-15T01:25:12Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"8828b717f8eda808c9839d5b2423802f99b109c6b19b19e56b13ad7cfaa1b7af","abstract_canon_sha256":"ba6327ff958d0c056cd33afb29c4cfa5b60048108a4e798121bd8488bffaaf87"},"schema_version":"1.0"},"canonical_sha256":"6fd221e8cb7a9c459f9d5378275ffaf11e1edee52920c894a7eaa33ac2408ac8","source":{"kind":"arxiv","id":"1905.05906","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1905.05906","created_at":"2026-05-17T23:46:08Z"},{"alias_kind":"arxiv_version","alias_value":"1905.05906v1","created_at":"2026-05-17T23:46:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1905.05906","created_at":"2026-05-17T23:46:08Z"},{"alias_kind":"pith_short_12","alias_value":"N7JCD2GLPKOE","created_at":"2026-05-18T12:33:24Z"},{"alias_kind":"pith_short_16","alias_value":"N7JCD2GLPKOELH45","created_at":"2026-05-18T12:33:24Z"},{"alias_kind":"pith_short_8","alias_value":"N7JCD2GL","created_at":"2026-05-18T12:33:24Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:N7JCD2GLPKOELH45KN4COX726E","target":"record","payload":{"canonical_record":{"source":{"id":"1905.05906","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-05-15T01:25:12Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"8828b717f8eda808c9839d5b2423802f99b109c6b19b19e56b13ad7cfaa1b7af","abstract_canon_sha256":"ba6327ff958d0c056cd33afb29c4cfa5b60048108a4e798121bd8488bffaaf87"},"schema_version":"1.0"},"canonical_sha256":"6fd221e8cb7a9c459f9d5378275ffaf11e1edee52920c894a7eaa33ac2408ac8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:46:08.144758Z","signature_b64":"+JXPqR5SazuVi82F+tYEiWH8I1a3/3/yvAdRki1R4d6tuCsI1UeIGCpM5hdIJC2k+tP2/u1Y5XBfwF7EN0QZCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"6fd221e8cb7a9c459f9d5378275ffaf11e1edee52920c894a7eaa33ac2408ac8","last_reissued_at":"2026-05-17T23:46:08.144182Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:46:08.144182Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1905.05906","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":"2026-05-17T23:46:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VG7R6qXnWOEWwxPu8XO2HlIz6sV3w/DNDNyxAr4nXPtf/0M2co54RpTph/cVsZAB+7pN1manD/4UQL7odfVcAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T00:24:31.151560Z"},"content_sha256":"c6b00502c067afc152452279ddaa330e13a1ee4f87dd8f808df601de0ae44d32","schema_version":"1.0","event_id":"sha256:c6b00502c067afc152452279ddaa330e13a1ee4f87dd8f808df601de0ae44d32"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:N7JCD2GLPKOELH45KN4COX726E","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Time-Varying Downlink Channel Tracking for Quantized Massive MIMO Networks","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Feifei Gao, Hongyan Li, Jianpeng Ma, Shun Zhang, Zhu Han","submitted_at":"2019-05-15T01:25:12Z","abstract_excerpt":"This paper proposes a Bayesian downlink channel estimation algorithm for time-varying massive MIMO networks. In particular, the quantization effects at the receiver are considered. In order to fully exploit the sparsity and time correlations of channels, we formulate the time-varying massive MIMO channel as the simultaneously sparse signal model. Then, we propose a sparse Bayesian learning (SBL) framework to learn the model parameters of the sparse virtual channel. To reduce complexity, we employ the expectation maximization (EM) algorithm to achieve the approximated solution. Specifically, th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1905.05906","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":"2026-05-17T23:46:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"cBuHf1eUeXnxKE8W7gTbtGVfse3Mkdl8zzwLDqRSAk1IXtjl8O+sEo+tR8Z51rXe582bgSpmzyFU3P0kj8zrAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T00:24:31.151910Z"},"content_sha256":"e07c50d3f2ba7fc92ba4d8bf75574b4f95d1cc425157df6d0d59ba0a34961a1b","schema_version":"1.0","event_id":"sha256:e07c50d3f2ba7fc92ba4d8bf75574b4f95d1cc425157df6d0d59ba0a34961a1b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/N7JCD2GLPKOELH45KN4COX726E/bundle.json","state_url":"https://pith.science/pith/N7JCD2GLPKOELH45KN4COX726E/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/N7JCD2GLPKOELH45KN4COX726E/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":"2026-06-03T00:24:31Z","links":{"resolver":"https://pith.science/pith/N7JCD2GLPKOELH45KN4COX726E","bundle":"https://pith.science/pith/N7JCD2GLPKOELH45KN4COX726E/bundle.json","state":"https://pith.science/pith/N7JCD2GLPKOELH45KN4COX726E/state.json","well_known_bundle":"https://pith.science/.well-known/pith/N7JCD2GLPKOELH45KN4COX726E/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:N7JCD2GLPKOELH45KN4COX726E","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":"ba6327ff958d0c056cd33afb29c4cfa5b60048108a4e798121bd8488bffaaf87","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-05-15T01:25:12Z","title_canon_sha256":"8828b717f8eda808c9839d5b2423802f99b109c6b19b19e56b13ad7cfaa1b7af"},"schema_version":"1.0","source":{"id":"1905.05906","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1905.05906","created_at":"2026-05-17T23:46:08Z"},{"alias_kind":"arxiv_version","alias_value":"1905.05906v1","created_at":"2026-05-17T23:46:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1905.05906","created_at":"2026-05-17T23:46:08Z"},{"alias_kind":"pith_short_12","alias_value":"N7JCD2GLPKOE","created_at":"2026-05-18T12:33:24Z"},{"alias_kind":"pith_short_16","alias_value":"N7JCD2GLPKOELH45","created_at":"2026-05-18T12:33:24Z"},{"alias_kind":"pith_short_8","alias_value":"N7JCD2GL","created_at":"2026-05-18T12:33:24Z"}],"graph_snapshots":[{"event_id":"sha256:e07c50d3f2ba7fc92ba4d8bf75574b4f95d1cc425157df6d0d59ba0a34961a1b","target":"graph","created_at":"2026-05-17T23:46:08Z","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 proposes a Bayesian downlink channel estimation algorithm for time-varying massive MIMO networks. In particular, the quantization effects at the receiver are considered. In order to fully exploit the sparsity and time correlations of channels, we formulate the time-varying massive MIMO channel as the simultaneously sparse signal model. Then, we propose a sparse Bayesian learning (SBL) framework to learn the model parameters of the sparse virtual channel. To reduce complexity, we employ the expectation maximization (EM) algorithm to achieve the approximated solution. Specifically, th","authors_text":"Feifei Gao, Hongyan Li, Jianpeng Ma, Shun Zhang, Zhu Han","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-05-15T01:25:12Z","title":"Time-Varying Downlink Channel Tracking for Quantized Massive MIMO Networks"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1905.05906","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:c6b00502c067afc152452279ddaa330e13a1ee4f87dd8f808df601de0ae44d32","target":"record","created_at":"2026-05-17T23:46:08Z","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":"ba6327ff958d0c056cd33afb29c4cfa5b60048108a4e798121bd8488bffaaf87","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2019-05-15T01:25:12Z","title_canon_sha256":"8828b717f8eda808c9839d5b2423802f99b109c6b19b19e56b13ad7cfaa1b7af"},"schema_version":"1.0","source":{"id":"1905.05906","kind":"arxiv","version":1}},"canonical_sha256":"6fd221e8cb7a9c459f9d5378275ffaf11e1edee52920c894a7eaa33ac2408ac8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"6fd221e8cb7a9c459f9d5378275ffaf11e1edee52920c894a7eaa33ac2408ac8","first_computed_at":"2026-05-17T23:46:08.144182Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:46:08.144182Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"+JXPqR5SazuVi82F+tYEiWH8I1a3/3/yvAdRki1R4d6tuCsI1UeIGCpM5hdIJC2k+tP2/u1Y5XBfwF7EN0QZCQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:46:08.144758Z","signed_message":"canonical_sha256_bytes"},"source_id":"1905.05906","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c6b00502c067afc152452279ddaa330e13a1ee4f87dd8f808df601de0ae44d32","sha256:e07c50d3f2ba7fc92ba4d8bf75574b4f95d1cc425157df6d0d59ba0a34961a1b"],"state_sha256":"55b060444e47eac913c77acd974d3296507b32ab8be30a561d9b83522a40c0e7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SXqDo4AfudNzKgYXRFFT36/mbsx0tcJ9PrGNlZc22ikc/ypLXuJRgos45C0N815mUUaczdbbrn1eQ5yC0Cn1CA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-03T00:24:31.153964Z","bundle_sha256":"b508d19350e4d2c5e9ce2e537f150dbebb82812276fcd1a086a89d3b67f88782"}}