{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:OQQQRBZ67OAA3VJ2EO734PIGO3","short_pith_number":"pith:OQQQRBZ6","canonical_record":{"source":{"id":"1402.5692","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-02-24T00:09:28Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"55b1b1bcb8be7c66ef6316aa26daf28094f1794f84994f3aaf1f262d77e35f00","abstract_canon_sha256":"0345cc37fddf74d2d0ab959b04324112b426bd39e75c3e8ee9631134aa6150d8"},"schema_version":"1.0"},"canonical_sha256":"742108873efb800dd53a23bfbe3d0676ef6376d1e0ebb6ea31966f1124d6e868","source":{"kind":"arxiv","id":"1402.5692","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1402.5692","created_at":"2026-05-18T02:58:13Z"},{"alias_kind":"arxiv_version","alias_value":"1402.5692v1","created_at":"2026-05-18T02:58:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1402.5692","created_at":"2026-05-18T02:58:13Z"},{"alias_kind":"pith_short_12","alias_value":"OQQQRBZ67OAA","created_at":"2026-05-18T12:28:43Z"},{"alias_kind":"pith_short_16","alias_value":"OQQQRBZ67OAA3VJ2","created_at":"2026-05-18T12:28:43Z"},{"alias_kind":"pith_short_8","alias_value":"OQQQRBZ6","created_at":"2026-05-18T12:28:43Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:OQQQRBZ67OAA3VJ2EO734PIGO3","target":"record","payload":{"canonical_record":{"source":{"id":"1402.5692","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-02-24T00:09:28Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"55b1b1bcb8be7c66ef6316aa26daf28094f1794f84994f3aaf1f262d77e35f00","abstract_canon_sha256":"0345cc37fddf74d2d0ab959b04324112b426bd39e75c3e8ee9631134aa6150d8"},"schema_version":"1.0"},"canonical_sha256":"742108873efb800dd53a23bfbe3d0676ef6376d1e0ebb6ea31966f1124d6e868","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:58:13.984135Z","signature_b64":"8UYtmAic6WfSh09A19ToR7KXA/+/KggDLWg/lwvut13CN8NoMDY2jERBT3wslkb2PADufjlDnCzre5uLAAdhBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"742108873efb800dd53a23bfbe3d0676ef6376d1e0ebb6ea31966f1124d6e868","last_reissued_at":"2026-05-18T02:58:13.983558Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:58:13.983558Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1402.5692","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":"2026-05-18T02:58:13Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"qwBFVq99Cp7pB8ZiV7aUv0fM26laIa5+GerLH+Dc7bsAFl0/C3M/IS4gjbK4g+8f/Ks/vV/HKBq8M+BRu+PjBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T05:23:35.700078Z"},"content_sha256":"bc71f4a16c9d18fab12e4cf43381bbff939bee1b80f7d2dadf6005b075435088","schema_version":"1.0","event_id":"sha256:bc71f4a16c9d18fab12e4cf43381bbff939bee1b80f7d2dadf6005b075435088"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:OQQQRBZ67OAA3VJ2EO734PIGO3","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Repeat Accumulate Based Designs for LDPC Codes on Fading Channels","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"A. G. D. Uchoa, C. T. Healy, R. C. de Lamare","submitted_at":"2014-02-24T00:09:28Z","abstract_excerpt":"Irregular repeat-accumulate Root-Check LDPC codes based on Progressive Edge Growth (PEG) techniques for block-fading channels are proposed. The proposed Root-Check LDPC codes are {both suitable for channels under $F = 2, 3$ independent fadings per codeword and} for fast fading channels. An IRA(A) Root-Check structure is devised for $F = 2, 3$ independent fadings. The performance of the new codes is investigated in terms of the Frame Error Rate (FER). Numerical results show that the IRAA LDPC codes constructed by the proposed algorithm {outperform by about 1dB the existing} IRA Root-Check LDPC "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1402.5692","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":"2026-05-18T02:58:13Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SFWO1CPL6fOI/YLUp5831T/qGK5jYysTxIlJp1mEqQ0ceE2JWbmuOBt5oCao6Q03MG3d5M5gFyNqlcAYq55TCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T05:23:35.700462Z"},"content_sha256":"aac6e57bc07d3f273a1eb33981d1f5ff17f578ea21e5dbcedd1ec99f7220a4bf","schema_version":"1.0","event_id":"sha256:aac6e57bc07d3f273a1eb33981d1f5ff17f578ea21e5dbcedd1ec99f7220a4bf"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OQQQRBZ67OAA3VJ2EO734PIGO3/bundle.json","state_url":"https://pith.science/pith/OQQQRBZ67OAA3VJ2EO734PIGO3/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OQQQRBZ67OAA3VJ2EO734PIGO3/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":"2026-05-28T05:23:35Z","links":{"resolver":"https://pith.science/pith/OQQQRBZ67OAA3VJ2EO734PIGO3","bundle":"https://pith.science/pith/OQQQRBZ67OAA3VJ2EO734PIGO3/bundle.json","state":"https://pith.science/pith/OQQQRBZ67OAA3VJ2EO734PIGO3/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OQQQRBZ67OAA3VJ2EO734PIGO3/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:OQQQRBZ67OAA3VJ2EO734PIGO3","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":"0345cc37fddf74d2d0ab959b04324112b426bd39e75c3e8ee9631134aa6150d8","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-02-24T00:09:28Z","title_canon_sha256":"55b1b1bcb8be7c66ef6316aa26daf28094f1794f84994f3aaf1f262d77e35f00"},"schema_version":"1.0","source":{"id":"1402.5692","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1402.5692","created_at":"2026-05-18T02:58:13Z"},{"alias_kind":"arxiv_version","alias_value":"1402.5692v1","created_at":"2026-05-18T02:58:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1402.5692","created_at":"2026-05-18T02:58:13Z"},{"alias_kind":"pith_short_12","alias_value":"OQQQRBZ67OAA","created_at":"2026-05-18T12:28:43Z"},{"alias_kind":"pith_short_16","alias_value":"OQQQRBZ67OAA3VJ2","created_at":"2026-05-18T12:28:43Z"},{"alias_kind":"pith_short_8","alias_value":"OQQQRBZ6","created_at":"2026-05-18T12:28:43Z"}],"graph_snapshots":[{"event_id":"sha256:aac6e57bc07d3f273a1eb33981d1f5ff17f578ea21e5dbcedd1ec99f7220a4bf","target":"graph","created_at":"2026-05-18T02:58:13Z","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":"Irregular repeat-accumulate Root-Check LDPC codes based on Progressive Edge Growth (PEG) techniques for block-fading channels are proposed. The proposed Root-Check LDPC codes are {both suitable for channels under $F = 2, 3$ independent fadings per codeword and} for fast fading channels. An IRA(A) Root-Check structure is devised for $F = 2, 3$ independent fadings. The performance of the new codes is investigated in terms of the Frame Error Rate (FER). Numerical results show that the IRAA LDPC codes constructed by the proposed algorithm {outperform by about 1dB the existing} IRA Root-Check LDPC ","authors_text":"A. G. D. Uchoa, C. T. Healy, R. C. de Lamare","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-02-24T00:09:28Z","title":"Repeat Accumulate Based Designs for LDPC Codes on Fading Channels"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1402.5692","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:bc71f4a16c9d18fab12e4cf43381bbff939bee1b80f7d2dadf6005b075435088","target":"record","created_at":"2026-05-18T02:58:13Z","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":"0345cc37fddf74d2d0ab959b04324112b426bd39e75c3e8ee9631134aa6150d8","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-02-24T00:09:28Z","title_canon_sha256":"55b1b1bcb8be7c66ef6316aa26daf28094f1794f84994f3aaf1f262d77e35f00"},"schema_version":"1.0","source":{"id":"1402.5692","kind":"arxiv","version":1}},"canonical_sha256":"742108873efb800dd53a23bfbe3d0676ef6376d1e0ebb6ea31966f1124d6e868","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"742108873efb800dd53a23bfbe3d0676ef6376d1e0ebb6ea31966f1124d6e868","first_computed_at":"2026-05-18T02:58:13.983558Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:58:13.983558Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"8UYtmAic6WfSh09A19ToR7KXA/+/KggDLWg/lwvut13CN8NoMDY2jERBT3wslkb2PADufjlDnCzre5uLAAdhBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T02:58:13.984135Z","signed_message":"canonical_sha256_bytes"},"source_id":"1402.5692","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:bc71f4a16c9d18fab12e4cf43381bbff939bee1b80f7d2dadf6005b075435088","sha256:aac6e57bc07d3f273a1eb33981d1f5ff17f578ea21e5dbcedd1ec99f7220a4bf"],"state_sha256":"250e3f78bd78a5a861aa2e312e05ffd492f5b1c6553fe64ba01616e689344756"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"gljMv6/fQ3hMTMIruaLHkHenV7zo2u2Icvbf+0xLQl8bKlnWLZ4fWmVC0K8/Wd5EUJ96idlHjFGl/6JliEqfDg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T05:23:35.702569Z","bundle_sha256":"b74bb8c852efa1d8e6b0fc4f017e5718202aaef05113c1bed572a609e978e5c4"}}