{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:LKRG4FUZAD2VL35KXXSIBIGWMP","short_pith_number":"pith:LKRG4FUZ","canonical_record":{"source":{"id":"1207.5483","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-23T18:56:40Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"c78db9f2838561fc4d7114f6284c5507a63d38cd1ef05c62bd6e281eee65dbf1","abstract_canon_sha256":"5629c0b236ff9afb489cdbe3472217e72d56f954cef2ac11dfc18954b242ef13"},"schema_version":"1.0"},"canonical_sha256":"5aa26e169900f555efaabde480a0d663f9e76191de6473b6e5b7527c878dfec0","source":{"kind":"arxiv","id":"1207.5483","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1207.5483","created_at":"2026-05-18T03:50:23Z"},{"alias_kind":"arxiv_version","alias_value":"1207.5483v1","created_at":"2026-05-18T03:50:23Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1207.5483","created_at":"2026-05-18T03:50:23Z"},{"alias_kind":"pith_short_12","alias_value":"LKRG4FUZAD2V","created_at":"2026-05-18T12:27:14Z"},{"alias_kind":"pith_short_16","alias_value":"LKRG4FUZAD2VL35K","created_at":"2026-05-18T12:27:14Z"},{"alias_kind":"pith_short_8","alias_value":"LKRG4FUZ","created_at":"2026-05-18T12:27:14Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:LKRG4FUZAD2VL35KXXSIBIGWMP","target":"record","payload":{"canonical_record":{"source":{"id":"1207.5483","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-23T18:56:40Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"c78db9f2838561fc4d7114f6284c5507a63d38cd1ef05c62bd6e281eee65dbf1","abstract_canon_sha256":"5629c0b236ff9afb489cdbe3472217e72d56f954cef2ac11dfc18954b242ef13"},"schema_version":"1.0"},"canonical_sha256":"5aa26e169900f555efaabde480a0d663f9e76191de6473b6e5b7527c878dfec0","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:50:23.319294Z","signature_b64":"bXPT+rgdBJtgZrH2bA8cDEHtWHU0Iq7WirqmGXJgg65/misAbHqeUFsgGvoX22Aef+JrY3VuBWknG1RW62I/Bg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"5aa26e169900f555efaabde480a0d663f9e76191de6473b6e5b7527c878dfec0","last_reissued_at":"2026-05-18T03:50:23.318563Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:50:23.318563Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1207.5483","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":"2026-05-18T03:50:23Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"krHv9N5KVmJXs/U3CQH/M07Zy7c/dJ0N7GnxvroryhndBZWg6xA4lBcQ3sm/8ozC8NlbsSQ7/l7YbuBuI0XRBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T23:28:49.681281Z"},"content_sha256":"069a7fb0963066abe4c2cfa7ae8cab91d8cc60e302ec0162c63ff5a90b7299b4","schema_version":"1.0","event_id":"sha256:069a7fb0963066abe4c2cfa7ae8cab91d8cc60e302ec0162c63ff5a90b7299b4"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:LKRG4FUZAD2VL35KXXSIBIGWMP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Exact Cramer-Rao Bounds for Semi-blind Channel Estimation in Amplify-and-Forward Two-Way Relay Networks","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Ioannis N. Psaromiligkos, Saeed Abdallah","submitted_at":"2012-07-23T18:56:40Z","abstract_excerpt":"In this paper, we derive for the first time the exact Cramer-Rao bounds (CRBs) on semi-blind channel estimation for amplify-and-forward two-way relay networks. The bounds cover a wide range of modulation schemes that satisfy a certain symmetry condition. In particular, the important classes of PSK and square QAM are covered. For the case square QAM, we also provide simplified expressions that lend themselves more easily to numerical implementation. The derived bounds are used to show that the semi-blind approach, which exploits both the transmitted pilots and the transmitted data symbols, can "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.5483","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":"2026-05-18T03:50:23Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"P2WLa1lA4fkfE/VHpVdbpbinT+tkjaBQPvMRBUyAH/qhL/vWNDeW3BI1xfVZ++4e4hWYgw7YdJ2kdH5jNVIBBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T23:28:49.681661Z"},"content_sha256":"f567e8d674457287f01959e1c40acaa8d38a7dc00222fccd76da8dbce397c0de","schema_version":"1.0","event_id":"sha256:f567e8d674457287f01959e1c40acaa8d38a7dc00222fccd76da8dbce397c0de"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/LKRG4FUZAD2VL35KXXSIBIGWMP/bundle.json","state_url":"https://pith.science/pith/LKRG4FUZAD2VL35KXXSIBIGWMP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/LKRG4FUZAD2VL35KXXSIBIGWMP/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":"2026-05-27T23:28:49Z","links":{"resolver":"https://pith.science/pith/LKRG4FUZAD2VL35KXXSIBIGWMP","bundle":"https://pith.science/pith/LKRG4FUZAD2VL35KXXSIBIGWMP/bundle.json","state":"https://pith.science/pith/LKRG4FUZAD2VL35KXXSIBIGWMP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/LKRG4FUZAD2VL35KXXSIBIGWMP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:LKRG4FUZAD2VL35KXXSIBIGWMP","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":"5629c0b236ff9afb489cdbe3472217e72d56f954cef2ac11dfc18954b242ef13","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-23T18:56:40Z","title_canon_sha256":"c78db9f2838561fc4d7114f6284c5507a63d38cd1ef05c62bd6e281eee65dbf1"},"schema_version":"1.0","source":{"id":"1207.5483","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1207.5483","created_at":"2026-05-18T03:50:23Z"},{"alias_kind":"arxiv_version","alias_value":"1207.5483v1","created_at":"2026-05-18T03:50:23Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1207.5483","created_at":"2026-05-18T03:50:23Z"},{"alias_kind":"pith_short_12","alias_value":"LKRG4FUZAD2V","created_at":"2026-05-18T12:27:14Z"},{"alias_kind":"pith_short_16","alias_value":"LKRG4FUZAD2VL35K","created_at":"2026-05-18T12:27:14Z"},{"alias_kind":"pith_short_8","alias_value":"LKRG4FUZ","created_at":"2026-05-18T12:27:14Z"}],"graph_snapshots":[{"event_id":"sha256:f567e8d674457287f01959e1c40acaa8d38a7dc00222fccd76da8dbce397c0de","target":"graph","created_at":"2026-05-18T03:50:23Z","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 derive for the first time the exact Cramer-Rao bounds (CRBs) on semi-blind channel estimation for amplify-and-forward two-way relay networks. The bounds cover a wide range of modulation schemes that satisfy a certain symmetry condition. In particular, the important classes of PSK and square QAM are covered. For the case square QAM, we also provide simplified expressions that lend themselves more easily to numerical implementation. The derived bounds are used to show that the semi-blind approach, which exploits both the transmitted pilots and the transmitted data symbols, can ","authors_text":"Ioannis N. Psaromiligkos, Saeed Abdallah","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-23T18:56:40Z","title":"Exact Cramer-Rao Bounds for Semi-blind Channel Estimation in Amplify-and-Forward Two-Way Relay Networks"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.5483","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":"sha256:069a7fb0963066abe4c2cfa7ae8cab91d8cc60e302ec0162c63ff5a90b7299b4","target":"record","created_at":"2026-05-18T03:50:23Z","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":"5629c0b236ff9afb489cdbe3472217e72d56f954cef2ac11dfc18954b242ef13","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2012-07-23T18:56:40Z","title_canon_sha256":"c78db9f2838561fc4d7114f6284c5507a63d38cd1ef05c62bd6e281eee65dbf1"},"schema_version":"1.0","source":{"id":"1207.5483","kind":"arxiv","version":1}},"canonical_sha256":"5aa26e169900f555efaabde480a0d663f9e76191de6473b6e5b7527c878dfec0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"5aa26e169900f555efaabde480a0d663f9e76191de6473b6e5b7527c878dfec0","first_computed_at":"2026-05-18T03:50:23.318563Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:50:23.318563Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"bXPT+rgdBJtgZrH2bA8cDEHtWHU0Iq7WirqmGXJgg65/misAbHqeUFsgGvoX22Aef+JrY3VuBWknG1RW62I/Bg==","signature_status":"signed_v1","signed_at":"2026-05-18T03:50:23.319294Z","signed_message":"canonical_sha256_bytes"},"source_id":"1207.5483","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:069a7fb0963066abe4c2cfa7ae8cab91d8cc60e302ec0162c63ff5a90b7299b4","sha256:f567e8d674457287f01959e1c40acaa8d38a7dc00222fccd76da8dbce397c0de"],"state_sha256":"73061e90b3b68bbdae88b79995ad98aca79b761dfdb1351428e03a6ba0ca108a"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ODTn3Ud0FGu7mLHxcvONQKKGF7sXOoiee1DZ7/VOhASHqNf85+8qb1V1V6CCOTJttT+nbfy3jdxzFO4kYwOsBQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T23:28:49.684012Z","bundle_sha256":"0ec6e83ceccfaf0259bedb0ed4915195ae0a7ea75eb98de8c4af572aed9063bb"}}