{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:4HJ25HDIRIRGE6U2QHCJUZNC5K","short_pith_number":"pith:4HJ25HDI","canonical_record":{"source":{"id":"1907.07959","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-07-18T10:03:07Z","cross_cats_sorted":[],"title_canon_sha256":"6ecb42e6b5bf0bd62ff2ea18370153d413dc9607b0411094a96517b258f2245a","abstract_canon_sha256":"7fcab31663312278282c5fc37b237ddf19949134a979706a90b1c8323396c001"},"schema_version":"1.0"},"canonical_sha256":"e1d3ae9c688a22627a9a81c49a65a2eabe031cdb83db628206125ac5efca765b","source":{"kind":"arxiv","id":"1907.07959","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.07959","created_at":"2026-05-17T23:40:15Z"},{"alias_kind":"arxiv_version","alias_value":"1907.07959v1","created_at":"2026-05-17T23:40:15Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.07959","created_at":"2026-05-17T23:40:15Z"},{"alias_kind":"pith_short_12","alias_value":"4HJ25HDIRIRG","created_at":"2026-05-18T12:33:10Z"},{"alias_kind":"pith_short_16","alias_value":"4HJ25HDIRIRGE6U2","created_at":"2026-05-18T12:33:10Z"},{"alias_kind":"pith_short_8","alias_value":"4HJ25HDI","created_at":"2026-05-18T12:33:10Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:4HJ25HDIRIRGE6U2QHCJUZNC5K","target":"record","payload":{"canonical_record":{"source":{"id":"1907.07959","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-07-18T10:03:07Z","cross_cats_sorted":[],"title_canon_sha256":"6ecb42e6b5bf0bd62ff2ea18370153d413dc9607b0411094a96517b258f2245a","abstract_canon_sha256":"7fcab31663312278282c5fc37b237ddf19949134a979706a90b1c8323396c001"},"schema_version":"1.0"},"canonical_sha256":"e1d3ae9c688a22627a9a81c49a65a2eabe031cdb83db628206125ac5efca765b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:40:15.565393Z","signature_b64":"fJCesHvcTz1VYgOtPI5gOrjwEZjyDk67qUskX83XWAvEi65HMT89JrKIWH/ybqM2oEHmZ5ywhENWKmhqU6NxDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"e1d3ae9c688a22627a9a81c49a65a2eabe031cdb83db628206125ac5efca765b","last_reissued_at":"2026-05-17T23:40:15.564698Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:40:15.564698Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1907.07959","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":"2026-05-17T23:40:15Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"f7Tdgl7Dc2AexWgod9QQHSrWhS7kHlq3apMNv8Y1O3ZwAMp6P7QKGduynzs7BsY24HLZr5/Ci3amip72tELeCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T19:22:05.771361Z"},"content_sha256":"da883d9bb8d0ccb22ba0e93d166ca00da1d4fd837ea961609c50b50158c45116","schema_version":"1.0","event_id":"sha256:da883d9bb8d0ccb22ba0e93d166ca00da1d4fd837ea961609c50b50158c45116"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:4HJ25HDIRIRGE6U2QHCJUZNC5K","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Linearizing Active Antenna Arrays: Method and Measurements","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"eess.SP","authors_text":"Alberto Brihuega, Lauri Anttila, Mahmoud Abdelaziz, Matias Turunen, Mikko Valkama, Thomas Eriksson","submitted_at":"2019-07-18T10:03:07Z","abstract_excerpt":"In this paper, we provide a novel framework for efficient digital predistortion (DPD) based linearization of active antenna arrays with multiple and mutually different nonlinear power amplifiers. The proposed method builds on the use of a combined feedback signal essentially characterizing the observable nonlinear distortion at the receiving end. The proposed method is validated with extensive over-the-air RF measurements on a 64-element active antenna array transmitter operating at 28 GHz carrier frequency and transmitting a 200 MHz wide 5G New Radio (NR) waveform. The obtained results demons"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.07959","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":"2026-05-17T23:40:15Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"AuDRLuE+5p4coxCpoqCMzk0uxHp/8+xJod8D0wvqZmO8r5jkJwuVsEVMI+o4cCx7D6f+Wb3pjl8BlQRrTMTkAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T19:22:05.771695Z"},"content_sha256":"e67b094fa83f72ccb55f1f0f38aa6a83be27a65aa63fd2c6dd73637d2cb690b9","schema_version":"1.0","event_id":"sha256:e67b094fa83f72ccb55f1f0f38aa6a83be27a65aa63fd2c6dd73637d2cb690b9"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/4HJ25HDIRIRGE6U2QHCJUZNC5K/bundle.json","state_url":"https://pith.science/pith/4HJ25HDIRIRGE6U2QHCJUZNC5K/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/4HJ25HDIRIRGE6U2QHCJUZNC5K/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":"2026-06-23T19:22:05Z","links":{"resolver":"https://pith.science/pith/4HJ25HDIRIRGE6U2QHCJUZNC5K","bundle":"https://pith.science/pith/4HJ25HDIRIRGE6U2QHCJUZNC5K/bundle.json","state":"https://pith.science/pith/4HJ25HDIRIRGE6U2QHCJUZNC5K/state.json","well_known_bundle":"https://pith.science/.well-known/pith/4HJ25HDIRIRGE6U2QHCJUZNC5K/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:4HJ25HDIRIRGE6U2QHCJUZNC5K","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":"7fcab31663312278282c5fc37b237ddf19949134a979706a90b1c8323396c001","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-07-18T10:03:07Z","title_canon_sha256":"6ecb42e6b5bf0bd62ff2ea18370153d413dc9607b0411094a96517b258f2245a"},"schema_version":"1.0","source":{"id":"1907.07959","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.07959","created_at":"2026-05-17T23:40:15Z"},{"alias_kind":"arxiv_version","alias_value":"1907.07959v1","created_at":"2026-05-17T23:40:15Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.07959","created_at":"2026-05-17T23:40:15Z"},{"alias_kind":"pith_short_12","alias_value":"4HJ25HDIRIRG","created_at":"2026-05-18T12:33:10Z"},{"alias_kind":"pith_short_16","alias_value":"4HJ25HDIRIRGE6U2","created_at":"2026-05-18T12:33:10Z"},{"alias_kind":"pith_short_8","alias_value":"4HJ25HDI","created_at":"2026-05-18T12:33:10Z"}],"graph_snapshots":[{"event_id":"sha256:e67b094fa83f72ccb55f1f0f38aa6a83be27a65aa63fd2c6dd73637d2cb690b9","target":"graph","created_at":"2026-05-17T23:40:15Z","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 provide a novel framework for efficient digital predistortion (DPD) based linearization of active antenna arrays with multiple and mutually different nonlinear power amplifiers. The proposed method builds on the use of a combined feedback signal essentially characterizing the observable nonlinear distortion at the receiving end. The proposed method is validated with extensive over-the-air RF measurements on a 64-element active antenna array transmitter operating at 28 GHz carrier frequency and transmitting a 200 MHz wide 5G New Radio (NR) waveform. The obtained results demons","authors_text":"Alberto Brihuega, Lauri Anttila, Mahmoud Abdelaziz, Matias Turunen, Mikko Valkama, Thomas Eriksson","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-07-18T10:03:07Z","title":"Linearizing Active Antenna Arrays: Method and Measurements"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.07959","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:da883d9bb8d0ccb22ba0e93d166ca00da1d4fd837ea961609c50b50158c45116","target":"record","created_at":"2026-05-17T23:40:15Z","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":"7fcab31663312278282c5fc37b237ddf19949134a979706a90b1c8323396c001","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2019-07-18T10:03:07Z","title_canon_sha256":"6ecb42e6b5bf0bd62ff2ea18370153d413dc9607b0411094a96517b258f2245a"},"schema_version":"1.0","source":{"id":"1907.07959","kind":"arxiv","version":1}},"canonical_sha256":"e1d3ae9c688a22627a9a81c49a65a2eabe031cdb83db628206125ac5efca765b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e1d3ae9c688a22627a9a81c49a65a2eabe031cdb83db628206125ac5efca765b","first_computed_at":"2026-05-17T23:40:15.564698Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:40:15.564698Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"fJCesHvcTz1VYgOtPI5gOrjwEZjyDk67qUskX83XWAvEi65HMT89JrKIWH/ybqM2oEHmZ5ywhENWKmhqU6NxDA==","signature_status":"signed_v1","signed_at":"2026-05-17T23:40:15.565393Z","signed_message":"canonical_sha256_bytes"},"source_id":"1907.07959","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:da883d9bb8d0ccb22ba0e93d166ca00da1d4fd837ea961609c50b50158c45116","sha256:e67b094fa83f72ccb55f1f0f38aa6a83be27a65aa63fd2c6dd73637d2cb690b9"],"state_sha256":"e16d404d5a928f734eebd3a32fd51f6835b803f7850b67477f5b8dd6812833e1"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"z+O6T+ht1FMgL9wUBTyOskFxZ+/INQ/FRbLVBsajH/r9v3JyfhjBBV8vnTvJ7yZ+pyuiQIjK9wzVl+6zNfz8AQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-23T19:22:05.773490Z","bundle_sha256":"2f1be4399bb851f2dc4fba646cdd12f0aba5ab34cf74bd3d8c5dc8025fc66065"}}