{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:2LZS5JNBPETH5TNQHXTI6JYCIU","short_pith_number":"pith:2LZS5JNB","canonical_record":{"source":{"id":"1406.2897","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-06-11T13:22:36Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"ebad6182e2fbb6b185f8c9bb0cd99de52a5b17d064e0c67ac93df105e697abff","abstract_canon_sha256":"16de0efe270bcb525452a38ebdc5de5951e04eaa1d07a803e2cb747b2bb0cf91"},"schema_version":"1.0"},"canonical_sha256":"d2f32ea5a179267ecdb03de68f27024529cac67775043c56b0916ca57c7043e7","source":{"kind":"arxiv","id":"1406.2897","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1406.2897","created_at":"2026-05-18T01:44:11Z"},{"alias_kind":"arxiv_version","alias_value":"1406.2897v2","created_at":"2026-05-18T01:44:11Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1406.2897","created_at":"2026-05-18T01:44:11Z"},{"alias_kind":"pith_short_12","alias_value":"2LZS5JNBPETH","created_at":"2026-05-18T12:28:11Z"},{"alias_kind":"pith_short_16","alias_value":"2LZS5JNBPETH5TNQ","created_at":"2026-05-18T12:28:11Z"},{"alias_kind":"pith_short_8","alias_value":"2LZS5JNB","created_at":"2026-05-18T12:28:11Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:2LZS5JNBPETH5TNQHXTI6JYCIU","target":"record","payload":{"canonical_record":{"source":{"id":"1406.2897","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-06-11T13:22:36Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"ebad6182e2fbb6b185f8c9bb0cd99de52a5b17d064e0c67ac93df105e697abff","abstract_canon_sha256":"16de0efe270bcb525452a38ebdc5de5951e04eaa1d07a803e2cb747b2bb0cf91"},"schema_version":"1.0"},"canonical_sha256":"d2f32ea5a179267ecdb03de68f27024529cac67775043c56b0916ca57c7043e7","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:44:11.843610Z","signature_b64":"w65nXo29F3S2yPAgKTjHpL2IX9klqbcvn3OPOfiGIevtQFEvGZ7bryubImttw7kqseeCHpLag8wGA3KxsLacBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d2f32ea5a179267ecdb03de68f27024529cac67775043c56b0916ca57c7043e7","last_reissued_at":"2026-05-18T01:44:11.842840Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:44:11.842840Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1406.2897","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":"2026-05-18T01:44:11Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rwJstrpw+6yanyfRdbH5gxNvnS5YRB27JggBJFSn8ogGty9VvQovwY/K/vR7dLv1VLpGbDuCmtV+NpUDa2UMDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T16:35:35.222068Z"},"content_sha256":"8d9236e2d9dda87578046ef18f9125ccbdd472bdf4543cebda0287c6b17f5bbb","schema_version":"1.0","event_id":"sha256:8d9236e2d9dda87578046ef18f9125ccbdd472bdf4543cebda0287c6b17f5bbb"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:2LZS5JNBPETH5TNQHXTI6JYCIU","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Hadamard Coded Modulation for Visible Light Communications","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Maite Brandt-Pearce, Mohammad Noshad","submitted_at":"2014-06-11T13:22:36Z","abstract_excerpt":"Visible light communication (VLC) systems using the indoor lighting system to also provide downlink communications require high average optical powers in order to satisfy the illumination needs. This can cause high amplitude signals common in higher-order modulation schemes to be clipped by the peak power constraint of the light emitting diode (LED) and lead to high signal distortion. In this paper we introduce Hadamard coded modulation (HCM) to achieve low error probabilities in LED-based VLC systems needing high average optical powers. This technique uses a fast Walsh-Hadamard transform (FWH"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1406.2897","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":"2026-05-18T01:44:11Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"H70boNG1H5Ah/1LrLoVAobx0wXc0cvBjYl/IAbE2ZF3HBhN+ifCRTlHVdGu8aFmB31eNXs5hVQXW6xcB2hUXDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T16:35:35.222724Z"},"content_sha256":"238efc223bbc8bf57c5db175e3e6ddae5184af8fc81e343be77f0f083e52b686","schema_version":"1.0","event_id":"sha256:238efc223bbc8bf57c5db175e3e6ddae5184af8fc81e343be77f0f083e52b686"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/2LZS5JNBPETH5TNQHXTI6JYCIU/bundle.json","state_url":"https://pith.science/pith/2LZS5JNBPETH5TNQHXTI6JYCIU/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/2LZS5JNBPETH5TNQHXTI6JYCIU/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":"2026-05-27T16:35:35Z","links":{"resolver":"https://pith.science/pith/2LZS5JNBPETH5TNQHXTI6JYCIU","bundle":"https://pith.science/pith/2LZS5JNBPETH5TNQHXTI6JYCIU/bundle.json","state":"https://pith.science/pith/2LZS5JNBPETH5TNQHXTI6JYCIU/state.json","well_known_bundle":"https://pith.science/.well-known/pith/2LZS5JNBPETH5TNQHXTI6JYCIU/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:2LZS5JNBPETH5TNQHXTI6JYCIU","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":"16de0efe270bcb525452a38ebdc5de5951e04eaa1d07a803e2cb747b2bb0cf91","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-06-11T13:22:36Z","title_canon_sha256":"ebad6182e2fbb6b185f8c9bb0cd99de52a5b17d064e0c67ac93df105e697abff"},"schema_version":"1.0","source":{"id":"1406.2897","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1406.2897","created_at":"2026-05-18T01:44:11Z"},{"alias_kind":"arxiv_version","alias_value":"1406.2897v2","created_at":"2026-05-18T01:44:11Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1406.2897","created_at":"2026-05-18T01:44:11Z"},{"alias_kind":"pith_short_12","alias_value":"2LZS5JNBPETH","created_at":"2026-05-18T12:28:11Z"},{"alias_kind":"pith_short_16","alias_value":"2LZS5JNBPETH5TNQ","created_at":"2026-05-18T12:28:11Z"},{"alias_kind":"pith_short_8","alias_value":"2LZS5JNB","created_at":"2026-05-18T12:28:11Z"}],"graph_snapshots":[{"event_id":"sha256:238efc223bbc8bf57c5db175e3e6ddae5184af8fc81e343be77f0f083e52b686","target":"graph","created_at":"2026-05-18T01:44:11Z","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":"Visible light communication (VLC) systems using the indoor lighting system to also provide downlink communications require high average optical powers in order to satisfy the illumination needs. This can cause high amplitude signals common in higher-order modulation schemes to be clipped by the peak power constraint of the light emitting diode (LED) and lead to high signal distortion. In this paper we introduce Hadamard coded modulation (HCM) to achieve low error probabilities in LED-based VLC systems needing high average optical powers. This technique uses a fast Walsh-Hadamard transform (FWH","authors_text":"Maite Brandt-Pearce, Mohammad Noshad","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-06-11T13:22:36Z","title":"Hadamard Coded Modulation for Visible Light Communications"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1406.2897","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":"sha256:8d9236e2d9dda87578046ef18f9125ccbdd472bdf4543cebda0287c6b17f5bbb","target":"record","created_at":"2026-05-18T01:44:11Z","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":"16de0efe270bcb525452a38ebdc5de5951e04eaa1d07a803e2cb747b2bb0cf91","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-06-11T13:22:36Z","title_canon_sha256":"ebad6182e2fbb6b185f8c9bb0cd99de52a5b17d064e0c67ac93df105e697abff"},"schema_version":"1.0","source":{"id":"1406.2897","kind":"arxiv","version":2}},"canonical_sha256":"d2f32ea5a179267ecdb03de68f27024529cac67775043c56b0916ca57c7043e7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d2f32ea5a179267ecdb03de68f27024529cac67775043c56b0916ca57c7043e7","first_computed_at":"2026-05-18T01:44:11.842840Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:44:11.842840Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"w65nXo29F3S2yPAgKTjHpL2IX9klqbcvn3OPOfiGIevtQFEvGZ7bryubImttw7kqseeCHpLag8wGA3KxsLacBA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:44:11.843610Z","signed_message":"canonical_sha256_bytes"},"source_id":"1406.2897","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:8d9236e2d9dda87578046ef18f9125ccbdd472bdf4543cebda0287c6b17f5bbb","sha256:238efc223bbc8bf57c5db175e3e6ddae5184af8fc81e343be77f0f083e52b686"],"state_sha256":"1122d440539053f2222af7bca678bd882c53ef78c3d2b3d3feb5827b3b37ee49"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HsQevCIqeFjuHAxp7N2S2akJuZjtv44UiCS4BEOzmYjUhBhM55SLEYxiYmLt35QFMCvGv2cDqz+LaaM69xNVCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T16:35:35.225592Z","bundle_sha256":"cd79523436e3ac0ee7b36ed70a7c42d559ff591d772acbac330cba803fc1cfa0"}}