{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:S53OOUFNT2WLJDKBDALXIUYRUP","short_pith_number":"pith:S53OOUFN","canonical_record":{"source":{"id":"1207.6862","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-30T08:12:02Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"2fac3392dcbd35ea0cfec6156c1c45279f2910b6080a4350a6ff743c8e3fb453","abstract_canon_sha256":"305b20f5bfe778973247a761de723e4a3755d2e0640f2944eee230f9016d880e"},"schema_version":"1.0"},"canonical_sha256":"9776e750ad9eacb48d411817745311a3d1fc9b0162f52174863b88cda48017c0","source":{"kind":"arxiv","id":"1207.6862","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1207.6862","created_at":"2026-05-18T03:49:48Z"},{"alias_kind":"arxiv_version","alias_value":"1207.6862v1","created_at":"2026-05-18T03:49:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1207.6862","created_at":"2026-05-18T03:49:48Z"},{"alias_kind":"pith_short_12","alias_value":"S53OOUFNT2WL","created_at":"2026-05-18T12:27:20Z"},{"alias_kind":"pith_short_16","alias_value":"S53OOUFNT2WLJDKB","created_at":"2026-05-18T12:27:20Z"},{"alias_kind":"pith_short_8","alias_value":"S53OOUFN","created_at":"2026-05-18T12:27:20Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:S53OOUFNT2WLJDKBDALXIUYRUP","target":"record","payload":{"canonical_record":{"source":{"id":"1207.6862","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-30T08:12:02Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"2fac3392dcbd35ea0cfec6156c1c45279f2910b6080a4350a6ff743c8e3fb453","abstract_canon_sha256":"305b20f5bfe778973247a761de723e4a3755d2e0640f2944eee230f9016d880e"},"schema_version":"1.0"},"canonical_sha256":"9776e750ad9eacb48d411817745311a3d1fc9b0162f52174863b88cda48017c0","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:49:48.413384Z","signature_b64":"dWq3mS1mlx2EV74cuhl1AWMRkwVD0L5e0NwQlDkhDHZTZMcm61Q0ieCAt2MyQy6lmxHTPRLw9fztlsOUwEjuDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"9776e750ad9eacb48d411817745311a3d1fc9b0162f52174863b88cda48017c0","last_reissued_at":"2026-05-18T03:49:48.412696Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:49:48.412696Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1207.6862","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":"2026-05-18T03:49:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"TVHywskWGgTJkIrUECUXxrRVVd5j2SP8ymHFyot3rXvaT6MpOnh04HUMQ5OGCP2V41TimS9AuBJ1U3BJv8AaDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T07:29:40.404330Z"},"content_sha256":"0d440909ab77ffd0d881ac604a895409cdb83c431454ea6f346b1bfc59457b0b","schema_version":"1.0","event_id":"sha256:0d440909ab77ffd0d881ac604a895409cdb83c431454ea6f346b1bfc59457b0b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:S53OOUFNT2WLJDKBDALXIUYRUP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Improved Channel Estimation with Partial Sparse Constraint for AF Cooperative Communication Systems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Guan Gui, Wei Peng","submitted_at":"2012-07-30T08:12:02Z","abstract_excerpt":"Accurate channel state information (CSI) is necessary for coherent detection in amplify and forward (AF) broadband cooperative communication systems. Based on the assumption of ordinary sparse channel, efficient sparse channel estimation methods have been investigated in our previous works. However, when the cooperative channel exhibits partial sparse structure rather than ordinary sparsity, our previous method cannot take advantage of the prior information. In this paper, we propose an improved channel estimation method with partial sparse constraint on cooperative channel. At first, we formu"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.6862","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":"2026-05-18T03:49:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"I37UWzYAOnTuFoaVFro91OMHor7b5mAnXNNV/7d7cBK45EBswJvy+6MlOG3mt/rnyndbH6KM1pehrMpPr6avAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T07:29:40.404690Z"},"content_sha256":"07855845f194290c71345f55ea19b2658cdf2e5b5a825f76e4d9dbea816f4d2c","schema_version":"1.0","event_id":"sha256:07855845f194290c71345f55ea19b2658cdf2e5b5a825f76e4d9dbea816f4d2c"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/S53OOUFNT2WLJDKBDALXIUYRUP/bundle.json","state_url":"https://pith.science/pith/S53OOUFNT2WLJDKBDALXIUYRUP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/S53OOUFNT2WLJDKBDALXIUYRUP/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":"2026-06-03T07:29:40Z","links":{"resolver":"https://pith.science/pith/S53OOUFNT2WLJDKBDALXIUYRUP","bundle":"https://pith.science/pith/S53OOUFNT2WLJDKBDALXIUYRUP/bundle.json","state":"https://pith.science/pith/S53OOUFNT2WLJDKBDALXIUYRUP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/S53OOUFNT2WLJDKBDALXIUYRUP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:S53OOUFNT2WLJDKBDALXIUYRUP","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":"305b20f5bfe778973247a761de723e4a3755d2e0640f2944eee230f9016d880e","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-30T08:12:02Z","title_canon_sha256":"2fac3392dcbd35ea0cfec6156c1c45279f2910b6080a4350a6ff743c8e3fb453"},"schema_version":"1.0","source":{"id":"1207.6862","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1207.6862","created_at":"2026-05-18T03:49:48Z"},{"alias_kind":"arxiv_version","alias_value":"1207.6862v1","created_at":"2026-05-18T03:49:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1207.6862","created_at":"2026-05-18T03:49:48Z"},{"alias_kind":"pith_short_12","alias_value":"S53OOUFNT2WL","created_at":"2026-05-18T12:27:20Z"},{"alias_kind":"pith_short_16","alias_value":"S53OOUFNT2WLJDKB","created_at":"2026-05-18T12:27:20Z"},{"alias_kind":"pith_short_8","alias_value":"S53OOUFN","created_at":"2026-05-18T12:27:20Z"}],"graph_snapshots":[{"event_id":"sha256:07855845f194290c71345f55ea19b2658cdf2e5b5a825f76e4d9dbea816f4d2c","target":"graph","created_at":"2026-05-18T03:49:48Z","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":"Accurate channel state information (CSI) is necessary for coherent detection in amplify and forward (AF) broadband cooperative communication systems. Based on the assumption of ordinary sparse channel, efficient sparse channel estimation methods have been investigated in our previous works. However, when the cooperative channel exhibits partial sparse structure rather than ordinary sparsity, our previous method cannot take advantage of the prior information. In this paper, we propose an improved channel estimation method with partial sparse constraint on cooperative channel. At first, we formu","authors_text":"Guan Gui, Wei Peng","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-30T08:12:02Z","title":"Improved Channel Estimation with Partial Sparse Constraint for AF Cooperative Communication Systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.6862","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":"sha256:0d440909ab77ffd0d881ac604a895409cdb83c431454ea6f346b1bfc59457b0b","target":"record","created_at":"2026-05-18T03:49:48Z","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":"305b20f5bfe778973247a761de723e4a3755d2e0640f2944eee230f9016d880e","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-30T08:12:02Z","title_canon_sha256":"2fac3392dcbd35ea0cfec6156c1c45279f2910b6080a4350a6ff743c8e3fb453"},"schema_version":"1.0","source":{"id":"1207.6862","kind":"arxiv","version":1}},"canonical_sha256":"9776e750ad9eacb48d411817745311a3d1fc9b0162f52174863b88cda48017c0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"9776e750ad9eacb48d411817745311a3d1fc9b0162f52174863b88cda48017c0","first_computed_at":"2026-05-18T03:49:48.412696Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:49:48.412696Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"dWq3mS1mlx2EV74cuhl1AWMRkwVD0L5e0NwQlDkhDHZTZMcm61Q0ieCAt2MyQy6lmxHTPRLw9fztlsOUwEjuDA==","signature_status":"signed_v1","signed_at":"2026-05-18T03:49:48.413384Z","signed_message":"canonical_sha256_bytes"},"source_id":"1207.6862","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0d440909ab77ffd0d881ac604a895409cdb83c431454ea6f346b1bfc59457b0b","sha256:07855845f194290c71345f55ea19b2658cdf2e5b5a825f76e4d9dbea816f4d2c"],"state_sha256":"feb40d8134f62fc94da585e6a3b897d8fb53725979ee7b81fe2fbc1d8487cc9d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"9UxKdC2jK44fvPvFL2CzZJv2R8atyNDvI0yKYdwyx4DYY0ksews2oiDuWg6M2hBpvNOQssuyx1DQ4rQUCHeIAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-03T07:29:40.406611Z","bundle_sha256":"f1d68167e4d8cfe7f1cacc60337f891f10949ea6e52c81d4e6327811f1261588"}}