{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:JZNLPY2LI5OTYK7ITMHCYLU7R7","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":"1d2b68ebfa49a249c4093760f9c261b4194196a7c2a4327bbf9eaff69f6ccf41","cross_cats_sorted":["cs.PF"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-02-27T08:59:18Z","title_canon_sha256":"cd0a1314ba8712d1b8f0472f436fbc93986fc0e2816cefe75cd54731bb697e9d"},"schema_version":"1.0","source":{"id":"1802.10461","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1802.10461","created_at":"2026-05-18T00:22:17Z"},{"alias_kind":"arxiv_version","alias_value":"1802.10461v1","created_at":"2026-05-18T00:22:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1802.10461","created_at":"2026-05-18T00:22:17Z"},{"alias_kind":"pith_short_12","alias_value":"JZNLPY2LI5OT","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_16","alias_value":"JZNLPY2LI5OTYK7I","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_8","alias_value":"JZNLPY2L","created_at":"2026-05-18T12:32:33Z"}],"graph_snapshots":[{"event_id":"sha256:4aa4e05cb265192a1fa5c3b3811a640980d2413ea1bdfd7ccb6490d4249755fd","target":"graph","created_at":"2026-05-18T00:22:17Z","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 propose a channel tracking method for massive multi-input and multi-output systems under both time-varying and spatial-varying circumstance. Exploiting the characteristics of massive antenna array, a spatial-temporal basis expansion model is designed to reduce the effective dimensions of up-link and down-link channel, which decomposes channel state information into the time-varying spatial information and gain information. We firstly model the users movements as a one-order unknown Markov process, which is blindly learned by the expectation and maximization (EM) approach. The","authors_text":"Feifei Gao, Hai Lin, Hongxiang Xie, Jianwei Zhao, Shi Jin, Weimin Jia","cross_cats":["cs.PF"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-02-27T08:59:18Z","title":"Time Varying Channel Tracking with Spatial and Temporal BEM for Massive MIMO Systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1802.10461","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:f5563d0679bb10d09214dac64ff5a96adeb665d21d73e3f18eb955378da2675e","target":"record","created_at":"2026-05-18T00:22:17Z","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":"1d2b68ebfa49a249c4093760f9c261b4194196a7c2a4327bbf9eaff69f6ccf41","cross_cats_sorted":["cs.PF"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-02-27T08:59:18Z","title_canon_sha256":"cd0a1314ba8712d1b8f0472f436fbc93986fc0e2816cefe75cd54731bb697e9d"},"schema_version":"1.0","source":{"id":"1802.10461","kind":"arxiv","version":1}},"canonical_sha256":"4e5ab7e34b475d3c2be89b0e2c2e9f8ff05c180c4e541b41be72eb3e967658c0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"4e5ab7e34b475d3c2be89b0e2c2e9f8ff05c180c4e541b41be72eb3e967658c0","first_computed_at":"2026-05-18T00:22:17.085045Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:22:17.085045Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"lfcni34JI8cSqrnovVCp+ZKtjL60BBJvIkX8z+H4+cWfISE4yGlhJoIgy73hZnQRT/h2B9X8mdrvOrJqyg8XAw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:22:17.085692Z","signed_message":"canonical_sha256_bytes"},"source_id":"1802.10461","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f5563d0679bb10d09214dac64ff5a96adeb665d21d73e3f18eb955378da2675e","sha256:4aa4e05cb265192a1fa5c3b3811a640980d2413ea1bdfd7ccb6490d4249755fd"],"state_sha256":"bc50443a55e6ec94bd202f651cda1afb2dc3d04b35ec44543c238664c85eb75e"}