{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:PU4EWJDJOEGES2I22TZFTWCD6A","short_pith_number":"pith:PU4EWJDJ","canonical_record":{"source":{"id":"2107.06962","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2021-07-14T19:47:38Z","cross_cats_sorted":["cs.IT","math.IT"],"title_canon_sha256":"c3f0d23dc5ced8460bba13a4717632798df8831b3cbf3ddae62827c3864fb62a","abstract_canon_sha256":"d4147a25d3a74795ed483d222e6a1b289311f4d5d8184ae6e3f067bbedcb4fc5"},"schema_version":"1.0"},"canonical_sha256":"7d384b2469710c49691ad4f259d843f018e913638e087ff78e5125530394aa5c","source":{"kind":"arxiv","id":"2107.06962","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2107.06962","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"arxiv_version","alias_value":"2107.06962v1","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2107.06962","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"pith_short_12","alias_value":"PU4EWJDJOEGE","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"pith_short_16","alias_value":"PU4EWJDJOEGES2I2","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"pith_short_8","alias_value":"PU4EWJDJ","created_at":"2026-07-05T02:58:08Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:PU4EWJDJOEGES2I22TZFTWCD6A","target":"record","payload":{"canonical_record":{"source":{"id":"2107.06962","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2021-07-14T19:47:38Z","cross_cats_sorted":["cs.IT","math.IT"],"title_canon_sha256":"c3f0d23dc5ced8460bba13a4717632798df8831b3cbf3ddae62827c3864fb62a","abstract_canon_sha256":"d4147a25d3a74795ed483d222e6a1b289311f4d5d8184ae6e3f067bbedcb4fc5"},"schema_version":"1.0"},"canonical_sha256":"7d384b2469710c49691ad4f259d843f018e913638e087ff78e5125530394aa5c","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:58:08.648784Z","signature_b64":"wu3IujCU6p9LizYjdrNtJOMU090PofblhG4SkRg+8oHcxDNwfVTeVgRsWxHGESnEMwp/hkuG1MJu43vVV6tkBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7d384b2469710c49691ad4f259d843f018e913638e087ff78e5125530394aa5c","last_reissued_at":"2026-07-05T02:58:08.648344Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:58:08.648344Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2107.06962","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":"2026-07-05T02:58:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"9OvMQCn3mj71y2rLTr+b4FtDdqTMj5rFhH6GNngeZLhEcbgvh18IonPGzaVXBhKd+UH/xXwIZhHvPDRsF+RKAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T08:02:35.944253Z"},"content_sha256":"71e1625b0a1ee91ebbe535a04986cf48357293bd73b9c2d2b0603644cef0f1c8","schema_version":"1.0","event_id":"sha256:71e1625b0a1ee91ebbe535a04986cf48357293bd73b9c2d2b0603644cef0f1c8"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:PU4EWJDJOEGES2I22TZFTWCD6A","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Frequency-packed Faster-than-Nyquist Signaling via Symbol-level Precoding for Multi-user MISO Redundant Transmissions","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["cs.IT","math.IT"],"primary_cat":"eess.SP","authors_text":"Bj\\\"orn Ottersten, Symeon Chatzinotas, Wallace A. Martins","submitted_at":"2021-07-14T19:47:38Z","abstract_excerpt":"This work addresses the issue of interference generated by co-channel users in downlink multi-antenna multicarrier systems with frequency-packed faster-than-Nyquist (FTN) signaling. The resulting interference stems from an aggressive strategy for enhancing the throughput via frequency reuse across different users and the squeezing of signals in the time-frequency plane beyond the Nyquist limit. The error-free spectral efficiency is proved to be increasing with the frequency packing and FTN acceleration factors. The lower bound for the FTN sampling period that guarantees information losslesness"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2107.06962","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2107.06962/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T02:58:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"AC4WNkkTOp4t3vl1QBF3k9NCJAuqF93BUzTq7xr1aJ9NTXsznHsxxoj6Ad1qm3hISZD7gWevOrSC8vFXLVnxDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T08:02:35.944643Z"},"content_sha256":"439c5187e4fec8587394ce509f2d346d263695cd44db22d1bec9b2a6c439879e","schema_version":"1.0","event_id":"sha256:439c5187e4fec8587394ce509f2d346d263695cd44db22d1bec9b2a6c439879e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/PU4EWJDJOEGES2I22TZFTWCD6A/bundle.json","state_url":"https://pith.science/pith/PU4EWJDJOEGES2I22TZFTWCD6A/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/PU4EWJDJOEGES2I22TZFTWCD6A/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":"2026-07-07T08:02:35Z","links":{"resolver":"https://pith.science/pith/PU4EWJDJOEGES2I22TZFTWCD6A","bundle":"https://pith.science/pith/PU4EWJDJOEGES2I22TZFTWCD6A/bundle.json","state":"https://pith.science/pith/PU4EWJDJOEGES2I22TZFTWCD6A/state.json","well_known_bundle":"https://pith.science/.well-known/pith/PU4EWJDJOEGES2I22TZFTWCD6A/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:PU4EWJDJOEGES2I22TZFTWCD6A","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":"d4147a25d3a74795ed483d222e6a1b289311f4d5d8184ae6e3f067bbedcb4fc5","cross_cats_sorted":["cs.IT","math.IT"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2021-07-14T19:47:38Z","title_canon_sha256":"c3f0d23dc5ced8460bba13a4717632798df8831b3cbf3ddae62827c3864fb62a"},"schema_version":"1.0","source":{"id":"2107.06962","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2107.06962","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"arxiv_version","alias_value":"2107.06962v1","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2107.06962","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"pith_short_12","alias_value":"PU4EWJDJOEGE","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"pith_short_16","alias_value":"PU4EWJDJOEGES2I2","created_at":"2026-07-05T02:58:08Z"},{"alias_kind":"pith_short_8","alias_value":"PU4EWJDJ","created_at":"2026-07-05T02:58:08Z"}],"graph_snapshots":[{"event_id":"sha256:439c5187e4fec8587394ce509f2d346d263695cd44db22d1bec9b2a6c439879e","target":"graph","created_at":"2026-07-05T02:58:08Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2107.06962/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"This work addresses the issue of interference generated by co-channel users in downlink multi-antenna multicarrier systems with frequency-packed faster-than-Nyquist (FTN) signaling. The resulting interference stems from an aggressive strategy for enhancing the throughput via frequency reuse across different users and the squeezing of signals in the time-frequency plane beyond the Nyquist limit. The error-free spectral efficiency is proved to be increasing with the frequency packing and FTN acceleration factors. The lower bound for the FTN sampling period that guarantees information losslesness","authors_text":"Bj\\\"orn Ottersten, Symeon Chatzinotas, Wallace A. Martins","cross_cats":["cs.IT","math.IT"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2021-07-14T19:47:38Z","title":"Frequency-packed Faster-than-Nyquist Signaling via Symbol-level Precoding for Multi-user MISO Redundant Transmissions"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2107.06962","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":"sha256:71e1625b0a1ee91ebbe535a04986cf48357293bd73b9c2d2b0603644cef0f1c8","target":"record","created_at":"2026-07-05T02:58:08Z","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":"d4147a25d3a74795ed483d222e6a1b289311f4d5d8184ae6e3f067bbedcb4fc5","cross_cats_sorted":["cs.IT","math.IT"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2021-07-14T19:47:38Z","title_canon_sha256":"c3f0d23dc5ced8460bba13a4717632798df8831b3cbf3ddae62827c3864fb62a"},"schema_version":"1.0","source":{"id":"2107.06962","kind":"arxiv","version":1}},"canonical_sha256":"7d384b2469710c49691ad4f259d843f018e913638e087ff78e5125530394aa5c","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7d384b2469710c49691ad4f259d843f018e913638e087ff78e5125530394aa5c","first_computed_at":"2026-07-05T02:58:08.648344Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:58:08.648344Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"wu3IujCU6p9LizYjdrNtJOMU090PofblhG4SkRg+8oHcxDNwfVTeVgRsWxHGESnEMwp/hkuG1MJu43vVV6tkBA==","signature_status":"signed_v1","signed_at":"2026-07-05T02:58:08.648784Z","signed_message":"canonical_sha256_bytes"},"source_id":"2107.06962","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:71e1625b0a1ee91ebbe535a04986cf48357293bd73b9c2d2b0603644cef0f1c8","sha256:439c5187e4fec8587394ce509f2d346d263695cd44db22d1bec9b2a6c439879e"],"state_sha256":"c63410d518c0d9cdc290e91327d279f10a571b98dd2f2e463dd10d406ebb2c0b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"YhFftv6E7d12qNlmOFVMoTW5NsuYIOz50IGf8VQJeHDJaWfcrgGw72QDiB7Y3kPtY4yyA8qPi9MJHm4p79H9DA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-07T08:02:35.946765Z","bundle_sha256":"d106ed284f94f8d6943cc3cee5c6224fea204724bcf6951737859decfb4cb655"}}