{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2009:255H7767HWODRE245INHUJKNHZ","short_pith_number":"pith:255H7767","canonical_record":{"source":{"id":"0904.1369","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2009-04-08T16:05:24Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"fcbb51f229511ad483cd813c62da62905b60114f2297e73c199cf55fd08f189f","abstract_canon_sha256":"d457f7b0685357e3a33d8a4ff995cfe2d3e00de77319066c44a7b9161d4badaf"},"schema_version":"1.0"},"canonical_sha256":"d77a7fffdf3d9c38935cea1a7a254d3e713161c994a6db1c3bab7da9b0082f50","source":{"kind":"arxiv","id":"0904.1369","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0904.1369","created_at":"2026-05-18T02:14:06Z"},{"alias_kind":"arxiv_version","alias_value":"0904.1369v2","created_at":"2026-05-18T02:14:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0904.1369","created_at":"2026-05-18T02:14:06Z"},{"alias_kind":"pith_short_12","alias_value":"255H7767HWOD","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"255H7767HWODRE24","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"255H7767","created_at":"2026-05-18T12:25:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2009:255H7767HWODRE245INHUJKNHZ","target":"record","payload":{"canonical_record":{"source":{"id":"0904.1369","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2009-04-08T16:05:24Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"fcbb51f229511ad483cd813c62da62905b60114f2297e73c199cf55fd08f189f","abstract_canon_sha256":"d457f7b0685357e3a33d8a4ff995cfe2d3e00de77319066c44a7b9161d4badaf"},"schema_version":"1.0"},"canonical_sha256":"d77a7fffdf3d9c38935cea1a7a254d3e713161c994a6db1c3bab7da9b0082f50","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:14:06.898493Z","signature_b64":"ps1qfWYlCQyd1kEAzNJHMl8HyZJU8cnXf/dX3oY0RjkaZRyEj9z/0CTVyIQzsjLNMp987+YUlOHqPYoHuD02Bw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d77a7fffdf3d9c38935cea1a7a254d3e713161c994a6db1c3bab7da9b0082f50","last_reissued_at":"2026-05-18T02:14:06.898024Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:14:06.898024Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0904.1369","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:14:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"yYDk6yqbcY1R/Adn0MkSaLn6N2CDphVdouIKFcaOWnP2baKxfV1oTiZHSAszvS0QuC3Z8X22r0AufoMm+0PZAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T17:42:43.913641Z"},"content_sha256":"c06097829ce45d15d4e406efef0115a30a458a61133d5f45072e947357071a90","schema_version":"1.0","event_id":"sha256:c06097829ce45d15d4e406efef0115a30a458a61133d5f45072e947357071a90"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2009:255H7767HWODRE245INHUJKNHZ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Cooperative Transmission for Wireless Relay Networks Using Limited Feedback","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Alex B. Gershman, Babak H. Khalaj, Javier M. Paredes","submitted_at":"2009-04-08T16:05:24Z","abstract_excerpt":"To achieve the available performance gains in half-duplex wireless relay networks, several cooperative schemes have been earlier proposed using either distributed space-time coding or distributed beamforming for the transmitter without and with channel state information (CSI), respectively. However, these schemes typically have rather high implementation and/or decoding complexities, especially when the number of relays is high. In this paper, we propose a simple low-rate feedback-based approach to achieve maximum diversity with a low decoding and implementation complexity. To further improve "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0904.1369","kind":"arxiv","version":2},"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":"2026-05-18T02:14:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"izKI48JbJtjsJdWriDRnYCvEkqqLpBKpRIPC6Yaflh4LAOzLZuufXGwbdsX3rKxt4NTEo9LiE2AYfszcVlRADQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T17:42:43.914293Z"},"content_sha256":"64acf639c57c8c3427610c8f33760d67a6b27171875a4b17a36636f80a19873b","schema_version":"1.0","event_id":"sha256:64acf639c57c8c3427610c8f33760d67a6b27171875a4b17a36636f80a19873b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/255H7767HWODRE245INHUJKNHZ/bundle.json","state_url":"https://pith.science/pith/255H7767HWODRE245INHUJKNHZ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/255H7767HWODRE245INHUJKNHZ/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":"2026-05-28T17:42:43Z","links":{"resolver":"https://pith.science/pith/255H7767HWODRE245INHUJKNHZ","bundle":"https://pith.science/pith/255H7767HWODRE245INHUJKNHZ/bundle.json","state":"https://pith.science/pith/255H7767HWODRE245INHUJKNHZ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/255H7767HWODRE245INHUJKNHZ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:255H7767HWODRE245INHUJKNHZ","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":"d457f7b0685357e3a33d8a4ff995cfe2d3e00de77319066c44a7b9161d4badaf","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2009-04-08T16:05:24Z","title_canon_sha256":"fcbb51f229511ad483cd813c62da62905b60114f2297e73c199cf55fd08f189f"},"schema_version":"1.0","source":{"id":"0904.1369","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0904.1369","created_at":"2026-05-18T02:14:06Z"},{"alias_kind":"arxiv_version","alias_value":"0904.1369v2","created_at":"2026-05-18T02:14:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0904.1369","created_at":"2026-05-18T02:14:06Z"},{"alias_kind":"pith_short_12","alias_value":"255H7767HWOD","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"255H7767HWODRE24","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"255H7767","created_at":"2026-05-18T12:25:58Z"}],"graph_snapshots":[{"event_id":"sha256:64acf639c57c8c3427610c8f33760d67a6b27171875a4b17a36636f80a19873b","target":"graph","created_at":"2026-05-18T02:14:06Z","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":"To achieve the available performance gains in half-duplex wireless relay networks, several cooperative schemes have been earlier proposed using either distributed space-time coding or distributed beamforming for the transmitter without and with channel state information (CSI), respectively. However, these schemes typically have rather high implementation and/or decoding complexities, especially when the number of relays is high. In this paper, we propose a simple low-rate feedback-based approach to achieve maximum diversity with a low decoding and implementation complexity. To further improve ","authors_text":"Alex B. Gershman, Babak H. Khalaj, Javier M. Paredes","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2009-04-08T16:05:24Z","title":"Cooperative Transmission for Wireless Relay Networks Using Limited Feedback"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0904.1369","kind":"arxiv","version":2},"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:c06097829ce45d15d4e406efef0115a30a458a61133d5f45072e947357071a90","target":"record","created_at":"2026-05-18T02:14:06Z","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":"d457f7b0685357e3a33d8a4ff995cfe2d3e00de77319066c44a7b9161d4badaf","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2009-04-08T16:05:24Z","title_canon_sha256":"fcbb51f229511ad483cd813c62da62905b60114f2297e73c199cf55fd08f189f"},"schema_version":"1.0","source":{"id":"0904.1369","kind":"arxiv","version":2}},"canonical_sha256":"d77a7fffdf3d9c38935cea1a7a254d3e713161c994a6db1c3bab7da9b0082f50","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d77a7fffdf3d9c38935cea1a7a254d3e713161c994a6db1c3bab7da9b0082f50","first_computed_at":"2026-05-18T02:14:06.898024Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:14:06.898024Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ps1qfWYlCQyd1kEAzNJHMl8HyZJU8cnXf/dX3oY0RjkaZRyEj9z/0CTVyIQzsjLNMp987+YUlOHqPYoHuD02Bw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:14:06.898493Z","signed_message":"canonical_sha256_bytes"},"source_id":"0904.1369","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c06097829ce45d15d4e406efef0115a30a458a61133d5f45072e947357071a90","sha256:64acf639c57c8c3427610c8f33760d67a6b27171875a4b17a36636f80a19873b"],"state_sha256":"ce484f4763ae874386a1d8cc2d989d25d0835264ac84f6bfd83a690d96f6f293"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ZG0UjKpUNzEV35Ea1QKqXhKCM/kj2om7h0UsYfrDDgO+peYX8R7FX4S+oSINiJbQ/DJctwKdXKSaNNIjwpoJDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T17:42:43.917707Z","bundle_sha256":"ecc801c5189518144fd5b78081555f1ce3a250f0a9d221a1becc38ed5e625f4a"}}