{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:OKOP6ZONIJEC4QHIJ3QAIX3VHT","short_pith_number":"pith:OKOP6ZON","canonical_record":{"source":{"id":"1401.1138","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-01-06T17:01:25Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"235f1e06f912cabd5a639cc558331a153987ea651ce364ac2a5081372b8c939c","abstract_canon_sha256":"7902436cd19092e65d00b57bcfdac783765931f08c4751388448a39cf3052d81"},"schema_version":"1.0"},"canonical_sha256":"729cff65cd42482e40e84ee0045f753cf78a4d282d5c39005266074003251093","source":{"kind":"arxiv","id":"1401.1138","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1401.1138","created_at":"2026-05-18T02:42:37Z"},{"alias_kind":"arxiv_version","alias_value":"1401.1138v1","created_at":"2026-05-18T02:42:37Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1401.1138","created_at":"2026-05-18T02:42:37Z"},{"alias_kind":"pith_short_12","alias_value":"OKOP6ZONIJEC","created_at":"2026-05-18T12:28:41Z"},{"alias_kind":"pith_short_16","alias_value":"OKOP6ZONIJEC4QHI","created_at":"2026-05-18T12:28:41Z"},{"alias_kind":"pith_short_8","alias_value":"OKOP6ZON","created_at":"2026-05-18T12:28:41Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:OKOP6ZONIJEC4QHIJ3QAIX3VHT","target":"record","payload":{"canonical_record":{"source":{"id":"1401.1138","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-01-06T17:01:25Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"235f1e06f912cabd5a639cc558331a153987ea651ce364ac2a5081372b8c939c","abstract_canon_sha256":"7902436cd19092e65d00b57bcfdac783765931f08c4751388448a39cf3052d81"},"schema_version":"1.0"},"canonical_sha256":"729cff65cd42482e40e84ee0045f753cf78a4d282d5c39005266074003251093","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:42:37.236693Z","signature_b64":"CF/LIzGuNjj18gLLnSn+Pw8GK/W2S316tktTYb2lVly/licL7qGxVFd2Tmwv/HRXDNhKS3CpfhPdr/OunGV6Aw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"729cff65cd42482e40e84ee0045f753cf78a4d282d5c39005266074003251093","last_reissued_at":"2026-05-18T02:42:37.235386Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:42:37.235386Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1401.1138","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":"2026-05-18T02:42:37Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SZrfMou9SUuB38OTnVkmEH59VJaD4PgTL32tz2Yay/MfF9RsGSAc4fGJh+TTnPKQWnylWvT5iV5eFyy3hYGaCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-05T08:28:21.629207Z"},"content_sha256":"c2d4e7b998822635397437e4d212a2ac96d7b0524e09d296a04f98def6640b95","schema_version":"1.0","event_id":"sha256:c2d4e7b998822635397437e4d212a2ac96d7b0524e09d296a04f98def6640b95"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:OKOP6ZONIJEC4QHIJ3QAIX3VHT","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Analysis of the Local Quasi-Stationarity of Measured Dual-Polarized MIMO Channels","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Adrian Ispas, Christian Schneider, Gerd Ascheid, Reiner Thom\\\"a","submitted_at":"2014-01-06T17:01:25Z","abstract_excerpt":"It is common practice in wireless communications to assume strict or wide-sense stationarity of the wireless channel in time and frequency. While this approximation has some physical justification, it is only valid inside certain time-frequency regions. This paper presents an elaborate characterization of the non-stationarity of wireless dual-polarized channels in time. The evaluation is based on urban macrocell measurements performed at 2.53 GHz. In order to define local quasi-stationarity (LQS) regions, i.e., regions in which the change of certain channel statistics is deemed insignificant, "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1401.1138","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":"2026-05-18T02:42:37Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"qtvQx13LijckrLC9LVf2qS28IyjldvS8Yw2KIHJStWDEyaf+OPQh8RoQlU18KaC47kIM1NMFNoJG4udjRE19Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-05T08:28:21.629571Z"},"content_sha256":"f9d89f958d0bad9c6eefe4758baf62ca6e452d27e8fd718ad9930d92e3aaf989","schema_version":"1.0","event_id":"sha256:f9d89f958d0bad9c6eefe4758baf62ca6e452d27e8fd718ad9930d92e3aaf989"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OKOP6ZONIJEC4QHIJ3QAIX3VHT/bundle.json","state_url":"https://pith.science/pith/OKOP6ZONIJEC4QHIJ3QAIX3VHT/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OKOP6ZONIJEC4QHIJ3QAIX3VHT/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":"2026-06-05T08:28:21Z","links":{"resolver":"https://pith.science/pith/OKOP6ZONIJEC4QHIJ3QAIX3VHT","bundle":"https://pith.science/pith/OKOP6ZONIJEC4QHIJ3QAIX3VHT/bundle.json","state":"https://pith.science/pith/OKOP6ZONIJEC4QHIJ3QAIX3VHT/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OKOP6ZONIJEC4QHIJ3QAIX3VHT/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:OKOP6ZONIJEC4QHIJ3QAIX3VHT","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":"7902436cd19092e65d00b57bcfdac783765931f08c4751388448a39cf3052d81","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-01-06T17:01:25Z","title_canon_sha256":"235f1e06f912cabd5a639cc558331a153987ea651ce364ac2a5081372b8c939c"},"schema_version":"1.0","source":{"id":"1401.1138","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1401.1138","created_at":"2026-05-18T02:42:37Z"},{"alias_kind":"arxiv_version","alias_value":"1401.1138v1","created_at":"2026-05-18T02:42:37Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1401.1138","created_at":"2026-05-18T02:42:37Z"},{"alias_kind":"pith_short_12","alias_value":"OKOP6ZONIJEC","created_at":"2026-05-18T12:28:41Z"},{"alias_kind":"pith_short_16","alias_value":"OKOP6ZONIJEC4QHI","created_at":"2026-05-18T12:28:41Z"},{"alias_kind":"pith_short_8","alias_value":"OKOP6ZON","created_at":"2026-05-18T12:28:41Z"}],"graph_snapshots":[{"event_id":"sha256:f9d89f958d0bad9c6eefe4758baf62ca6e452d27e8fd718ad9930d92e3aaf989","target":"graph","created_at":"2026-05-18T02:42:37Z","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":"It is common practice in wireless communications to assume strict or wide-sense stationarity of the wireless channel in time and frequency. While this approximation has some physical justification, it is only valid inside certain time-frequency regions. This paper presents an elaborate characterization of the non-stationarity of wireless dual-polarized channels in time. The evaluation is based on urban macrocell measurements performed at 2.53 GHz. In order to define local quasi-stationarity (LQS) regions, i.e., regions in which the change of certain channel statistics is deemed insignificant, ","authors_text":"Adrian Ispas, Christian Schneider, Gerd Ascheid, Reiner Thom\\\"a","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-01-06T17:01:25Z","title":"Analysis of the Local Quasi-Stationarity of Measured Dual-Polarized MIMO Channels"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1401.1138","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:c2d4e7b998822635397437e4d212a2ac96d7b0524e09d296a04f98def6640b95","target":"record","created_at":"2026-05-18T02:42:37Z","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":"7902436cd19092e65d00b57bcfdac783765931f08c4751388448a39cf3052d81","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-01-06T17:01:25Z","title_canon_sha256":"235f1e06f912cabd5a639cc558331a153987ea651ce364ac2a5081372b8c939c"},"schema_version":"1.0","source":{"id":"1401.1138","kind":"arxiv","version":1}},"canonical_sha256":"729cff65cd42482e40e84ee0045f753cf78a4d282d5c39005266074003251093","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"729cff65cd42482e40e84ee0045f753cf78a4d282d5c39005266074003251093","first_computed_at":"2026-05-18T02:42:37.235386Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:42:37.235386Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"CF/LIzGuNjj18gLLnSn+Pw8GK/W2S316tktTYb2lVly/licL7qGxVFd2Tmwv/HRXDNhKS3CpfhPdr/OunGV6Aw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:42:37.236693Z","signed_message":"canonical_sha256_bytes"},"source_id":"1401.1138","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c2d4e7b998822635397437e4d212a2ac96d7b0524e09d296a04f98def6640b95","sha256:f9d89f958d0bad9c6eefe4758baf62ca6e452d27e8fd718ad9930d92e3aaf989"],"state_sha256":"3315b89a51f1d217caba332d6f40179036839ac21d893a9af9ef3369d03299b7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"44/FQG5e4iTLl//0W1e2MIGGiIcn2dBHi32qZ9He5WFvtL8B7Z/bZQ8mJiRKAsIYLkgSYKAjhHeViGwN0IvyCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-05T08:28:21.631832Z","bundle_sha256":"3beed7d4d358ee127a1bc7554115473ce6fd621f8ba12cc78413f09f0a2b79d2"}}