{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2017:VBJ7LUK2IQ34FOUB3EDOR24DFQ","short_pith_number":"pith:VBJ7LUK2","canonical_record":{"source":{"id":"1709.02950","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-09-09T13:12:32Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"0b9d7ff27c4c2235e687c750984535dab3688c63d7743bcede96bc2447205c1f","abstract_canon_sha256":"f3fefb6152aecdd2bca6053e4df58f262df348cd136a6ff5fd564ebf08c7e8e2"},"schema_version":"1.0"},"canonical_sha256":"a853f5d15a4437c2ba81d906e8eb832c016a3b6add81708de115e231995c3ce9","source":{"kind":"arxiv","id":"1709.02950","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1709.02950","created_at":"2026-05-18T00:35:39Z"},{"alias_kind":"arxiv_version","alias_value":"1709.02950v1","created_at":"2026-05-18T00:35:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1709.02950","created_at":"2026-05-18T00:35:39Z"},{"alias_kind":"pith_short_12","alias_value":"VBJ7LUK2IQ34","created_at":"2026-05-18T12:31:49Z"},{"alias_kind":"pith_short_16","alias_value":"VBJ7LUK2IQ34FOUB","created_at":"2026-05-18T12:31:49Z"},{"alias_kind":"pith_short_8","alias_value":"VBJ7LUK2","created_at":"2026-05-18T12:31:49Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2017:VBJ7LUK2IQ34FOUB3EDOR24DFQ","target":"record","payload":{"canonical_record":{"source":{"id":"1709.02950","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-09-09T13:12:32Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"0b9d7ff27c4c2235e687c750984535dab3688c63d7743bcede96bc2447205c1f","abstract_canon_sha256":"f3fefb6152aecdd2bca6053e4df58f262df348cd136a6ff5fd564ebf08c7e8e2"},"schema_version":"1.0"},"canonical_sha256":"a853f5d15a4437c2ba81d906e8eb832c016a3b6add81708de115e231995c3ce9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:35:39.981494Z","signature_b64":"SvC1PVutH43IEiHjsODQukdKgpKemZJjy2ur+iBO4aWcxfQGWF3rn6WudDgyoUCURD1fNfwseAVD9T+CQgZBDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a853f5d15a4437c2ba81d906e8eb832c016a3b6add81708de115e231995c3ce9","last_reissued_at":"2026-05-18T00:35:39.980969Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:35:39.980969Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1709.02950","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":"2026-05-18T00:35:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"7zuyrN4GPq0Tbc+ZQCiH5ZD4Bd1Uai3h6gBxqnnFuM0+VECtVE4UVzXC0tYdK5jzmQruNksRkD7h8jPiM7H4AA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T03:19:42.799059Z"},"content_sha256":"b45c8432235db05d874f98ca4fcf022f6d4775d8cea660484547c637945af9b7","schema_version":"1.0","event_id":"sha256:b45c8432235db05d874f98ca4fcf022f6d4775d8cea660484547c637945af9b7"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2017:VBJ7LUK2IQ34FOUB3EDOR24DFQ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Spectral and Energy Efficiency of Cell-Free Massive MIMO Systems with Hardware Impairments","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Emil Bj\\\"ornson, Jiayi Zhang, Xu Li, Yinghua Wei, Yu Han","submitted_at":"2017-09-09T13:12:32Z","abstract_excerpt":"Cell-free massive multiple-input multiple-output (MIMO), with a large number of distributed access points (APs) that jointly serve the user equipments (UEs), is a promising network architecture for future wireless communications. To reduce the cost and power consumption of such systems, it is important to utilize low-quality transceiver hardware at the APs. However, the impact of hardware impairments on cell-free massive MIMO has thus far not been studied. In this paper, we take a first look at this important topic by utilizing well-established models of hardware distortion and deriving new cl"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1709.02950","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":"2026-05-18T00:35:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"v5XaJVHduSfHkSxFWTRU3OKONRoGnnj81lo+v6VQhftNYWrjh8NI3d/CaZ2QpqHMcvWVW5crIeyvmo0VvSuMAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T03:19:42.799420Z"},"content_sha256":"1fd584e5995688011bae80f017c40b677dc1c31f3e26cb0f7741450b614f67b0","schema_version":"1.0","event_id":"sha256:1fd584e5995688011bae80f017c40b677dc1c31f3e26cb0f7741450b614f67b0"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/VBJ7LUK2IQ34FOUB3EDOR24DFQ/bundle.json","state_url":"https://pith.science/pith/VBJ7LUK2IQ34FOUB3EDOR24DFQ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/VBJ7LUK2IQ34FOUB3EDOR24DFQ/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":"2026-06-03T03:19:42Z","links":{"resolver":"https://pith.science/pith/VBJ7LUK2IQ34FOUB3EDOR24DFQ","bundle":"https://pith.science/pith/VBJ7LUK2IQ34FOUB3EDOR24DFQ/bundle.json","state":"https://pith.science/pith/VBJ7LUK2IQ34FOUB3EDOR24DFQ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/VBJ7LUK2IQ34FOUB3EDOR24DFQ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:VBJ7LUK2IQ34FOUB3EDOR24DFQ","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":"f3fefb6152aecdd2bca6053e4df58f262df348cd136a6ff5fd564ebf08c7e8e2","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-09-09T13:12:32Z","title_canon_sha256":"0b9d7ff27c4c2235e687c750984535dab3688c63d7743bcede96bc2447205c1f"},"schema_version":"1.0","source":{"id":"1709.02950","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1709.02950","created_at":"2026-05-18T00:35:39Z"},{"alias_kind":"arxiv_version","alias_value":"1709.02950v1","created_at":"2026-05-18T00:35:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1709.02950","created_at":"2026-05-18T00:35:39Z"},{"alias_kind":"pith_short_12","alias_value":"VBJ7LUK2IQ34","created_at":"2026-05-18T12:31:49Z"},{"alias_kind":"pith_short_16","alias_value":"VBJ7LUK2IQ34FOUB","created_at":"2026-05-18T12:31:49Z"},{"alias_kind":"pith_short_8","alias_value":"VBJ7LUK2","created_at":"2026-05-18T12:31:49Z"}],"graph_snapshots":[{"event_id":"sha256:1fd584e5995688011bae80f017c40b677dc1c31f3e26cb0f7741450b614f67b0","target":"graph","created_at":"2026-05-18T00:35:39Z","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":"Cell-free massive multiple-input multiple-output (MIMO), with a large number of distributed access points (APs) that jointly serve the user equipments (UEs), is a promising network architecture for future wireless communications. To reduce the cost and power consumption of such systems, it is important to utilize low-quality transceiver hardware at the APs. However, the impact of hardware impairments on cell-free massive MIMO has thus far not been studied. In this paper, we take a first look at this important topic by utilizing well-established models of hardware distortion and deriving new cl","authors_text":"Emil Bj\\\"ornson, Jiayi Zhang, Xu Li, Yinghua Wei, Yu Han","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-09-09T13:12:32Z","title":"Spectral and Energy Efficiency of Cell-Free Massive MIMO Systems with Hardware Impairments"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1709.02950","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:b45c8432235db05d874f98ca4fcf022f6d4775d8cea660484547c637945af9b7","target":"record","created_at":"2026-05-18T00:35:39Z","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":"f3fefb6152aecdd2bca6053e4df58f262df348cd136a6ff5fd564ebf08c7e8e2","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-09-09T13:12:32Z","title_canon_sha256":"0b9d7ff27c4c2235e687c750984535dab3688c63d7743bcede96bc2447205c1f"},"schema_version":"1.0","source":{"id":"1709.02950","kind":"arxiv","version":1}},"canonical_sha256":"a853f5d15a4437c2ba81d906e8eb832c016a3b6add81708de115e231995c3ce9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a853f5d15a4437c2ba81d906e8eb832c016a3b6add81708de115e231995c3ce9","first_computed_at":"2026-05-18T00:35:39.980969Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:35:39.980969Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"SvC1PVutH43IEiHjsODQukdKgpKemZJjy2ur+iBO4aWcxfQGWF3rn6WudDgyoUCURD1fNfwseAVD9T+CQgZBDA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:35:39.981494Z","signed_message":"canonical_sha256_bytes"},"source_id":"1709.02950","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b45c8432235db05d874f98ca4fcf022f6d4775d8cea660484547c637945af9b7","sha256:1fd584e5995688011bae80f017c40b677dc1c31f3e26cb0f7741450b614f67b0"],"state_sha256":"d1be9728bca54d01d3864d8e0cef018d17dc300ab4e4885544ecf85dd2feee64"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"6qKFWbg56BmPFSARbxxj8BoiX7d0+zJg5cElBba5bLZ1mM47UQjSsAvA9ZsO0U8IznniU+kItSU0Jy/XkelaAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-03T03:19:42.801249Z","bundle_sha256":"fbb15f27e2ddd8db9350efed049ec163130a03c3a905399033c309c46278cd8a"}}