{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:6URJ5XCIGTI6RWIREJ42QUU3XG","short_pith_number":"pith:6URJ5XCI","canonical_record":{"source":{"id":"1310.1806","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2013-10-07T14:52:24Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"0765d37fc3fe52b0f3ac58fb078917fbe50ae3dc2b7338ec52212f02b599f49d","abstract_canon_sha256":"b486cd730ce6748b9b907f57254be8c948f646570a530febfafb79a6fa4a2b85"},"schema_version":"1.0"},"canonical_sha256":"f5229edc4834d1e8d9112279a8529bb99a0449756a0698605e9b739f89c259db","source":{"kind":"arxiv","id":"1310.1806","version":4},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1310.1806","created_at":"2026-05-18T02:46:39Z"},{"alias_kind":"arxiv_version","alias_value":"1310.1806v4","created_at":"2026-05-18T02:46:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1310.1806","created_at":"2026-05-18T02:46:39Z"},{"alias_kind":"pith_short_12","alias_value":"6URJ5XCIGTI6","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_16","alias_value":"6URJ5XCIGTI6RWIR","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_8","alias_value":"6URJ5XCI","created_at":"2026-05-18T12:27:36Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:6URJ5XCIGTI6RWIREJ42QUU3XG","target":"record","payload":{"canonical_record":{"source":{"id":"1310.1806","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2013-10-07T14:52:24Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"0765d37fc3fe52b0f3ac58fb078917fbe50ae3dc2b7338ec52212f02b599f49d","abstract_canon_sha256":"b486cd730ce6748b9b907f57254be8c948f646570a530febfafb79a6fa4a2b85"},"schema_version":"1.0"},"canonical_sha256":"f5229edc4834d1e8d9112279a8529bb99a0449756a0698605e9b739f89c259db","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:46:39.367497Z","signature_b64":"sVHhafQX+FDhxuLzTp+cf4atwZyjYFSo6huXP+XOAniWObVk3Al/eUW/SJryrI4bAPO1NOLCy4x+y26AejYBAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f5229edc4834d1e8d9112279a8529bb99a0449756a0698605e9b739f89c259db","last_reissued_at":"2026-05-18T02:46:39.367063Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:46:39.367063Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1310.1806","source_version":4,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:46:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bArmsS+Htu9FjP40mIZjeX6LBXv59K+8Aif70/2i2ZoHOqdT1AIRgsLKSupWD9vfp/gvXytn+nXS/Bq9Nz0vCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T11:02:05.647998Z"},"content_sha256":"9408d050623f180e2514dd060f7aff0bfacc324f5e67b5492e4bdd0865be2836","schema_version":"1.0","event_id":"sha256:9408d050623f180e2514dd060f7aff0bfacc324f5e67b5492e4bdd0865be2836"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:6URJ5XCIGTI6RWIREJ42QUU3XG","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Linear Precoding Based on Polynomial Expansion: Reducing Complexity in Massive MIMO","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Abla Kammoun, Axel M\\\"uller, Emil Bj\\\"ornson, M\\'erouane Debbah","submitted_at":"2013-10-07T14:52:24Z","abstract_excerpt":"Large-scale multi-user multiple-input multiple-output (MIMO) techniques have the potential to bring tremendous improvements for future communication systems. Counter-intuitively, the practical issues of having uncertain channel knowledge, high propagation losses, and implementing optimal non-linear precoding are solved more-or-less automatically by enlarging system dimensions. However, the computational precoding complexity grows with the system dimensions. For example, the close-to-optimal regularized zero-forcing (RZF) precoding is very complicated to implement in practice, since it requires"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1310.1806","kind":"arxiv","version":4},"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":"2026-05-18T02:46:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"YF4Es5nwgZfRW7kPqzGmYPYEeddxWNNETRbo6U1+HcL8ORV6t2y6TP5fCrMuyavYrRm3OUW7pCBIUHIs8r2ZDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T11:02:05.648682Z"},"content_sha256":"ea39eebf72239ef60b10a63b890be6ea439b419a743808d8f08aed6eb5870e75","schema_version":"1.0","event_id":"sha256:ea39eebf72239ef60b10a63b890be6ea439b419a743808d8f08aed6eb5870e75"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/6URJ5XCIGTI6RWIREJ42QUU3XG/bundle.json","state_url":"https://pith.science/pith/6URJ5XCIGTI6RWIREJ42QUU3XG/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/6URJ5XCIGTI6RWIREJ42QUU3XG/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":"2026-05-27T11:02:05Z","links":{"resolver":"https://pith.science/pith/6URJ5XCIGTI6RWIREJ42QUU3XG","bundle":"https://pith.science/pith/6URJ5XCIGTI6RWIREJ42QUU3XG/bundle.json","state":"https://pith.science/pith/6URJ5XCIGTI6RWIREJ42QUU3XG/state.json","well_known_bundle":"https://pith.science/.well-known/pith/6URJ5XCIGTI6RWIREJ42QUU3XG/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:6URJ5XCIGTI6RWIREJ42QUU3XG","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":"b486cd730ce6748b9b907f57254be8c948f646570a530febfafb79a6fa4a2b85","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2013-10-07T14:52:24Z","title_canon_sha256":"0765d37fc3fe52b0f3ac58fb078917fbe50ae3dc2b7338ec52212f02b599f49d"},"schema_version":"1.0","source":{"id":"1310.1806","kind":"arxiv","version":4}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1310.1806","created_at":"2026-05-18T02:46:39Z"},{"alias_kind":"arxiv_version","alias_value":"1310.1806v4","created_at":"2026-05-18T02:46:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1310.1806","created_at":"2026-05-18T02:46:39Z"},{"alias_kind":"pith_short_12","alias_value":"6URJ5XCIGTI6","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_16","alias_value":"6URJ5XCIGTI6RWIR","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_8","alias_value":"6URJ5XCI","created_at":"2026-05-18T12:27:36Z"}],"graph_snapshots":[{"event_id":"sha256:ea39eebf72239ef60b10a63b890be6ea439b419a743808d8f08aed6eb5870e75","target":"graph","created_at":"2026-05-18T02:46:39Z","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":"Large-scale multi-user multiple-input multiple-output (MIMO) techniques have the potential to bring tremendous improvements for future communication systems. Counter-intuitively, the practical issues of having uncertain channel knowledge, high propagation losses, and implementing optimal non-linear precoding are solved more-or-less automatically by enlarging system dimensions. However, the computational precoding complexity grows with the system dimensions. For example, the close-to-optimal regularized zero-forcing (RZF) precoding is very complicated to implement in practice, since it requires","authors_text":"Abla Kammoun, Axel M\\\"uller, Emil Bj\\\"ornson, M\\'erouane Debbah","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2013-10-07T14:52:24Z","title":"Linear Precoding Based on Polynomial Expansion: Reducing Complexity in Massive MIMO"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1310.1806","kind":"arxiv","version":4},"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":"sha256:9408d050623f180e2514dd060f7aff0bfacc324f5e67b5492e4bdd0865be2836","target":"record","created_at":"2026-05-18T02:46:39Z","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":"b486cd730ce6748b9b907f57254be8c948f646570a530febfafb79a6fa4a2b85","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2013-10-07T14:52:24Z","title_canon_sha256":"0765d37fc3fe52b0f3ac58fb078917fbe50ae3dc2b7338ec52212f02b599f49d"},"schema_version":"1.0","source":{"id":"1310.1806","kind":"arxiv","version":4}},"canonical_sha256":"f5229edc4834d1e8d9112279a8529bb99a0449756a0698605e9b739f89c259db","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f5229edc4834d1e8d9112279a8529bb99a0449756a0698605e9b739f89c259db","first_computed_at":"2026-05-18T02:46:39.367063Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:46:39.367063Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"sVHhafQX+FDhxuLzTp+cf4atwZyjYFSo6huXP+XOAniWObVk3Al/eUW/SJryrI4bAPO1NOLCy4x+y26AejYBAw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:46:39.367497Z","signed_message":"canonical_sha256_bytes"},"source_id":"1310.1806","source_kind":"arxiv","source_version":4}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9408d050623f180e2514dd060f7aff0bfacc324f5e67b5492e4bdd0865be2836","sha256:ea39eebf72239ef60b10a63b890be6ea439b419a743808d8f08aed6eb5870e75"],"state_sha256":"611d0c4edf4e757569b70a6f4504af596a95db282ccef6574f0cefe0a0860356"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"0eZF1uRCYBxgHFL1XJizHne2dwIa2UpvYxjr0H0pdEik9TUAtLG+zkOw7MmLkjADZo6SlHjh+KQTvnKZIKKkAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T11:02:05.653420Z","bundle_sha256":"b7c2417d3d87efa9fc19c28778ef846175fcd1fcd0383679ac5c3b26ee744882"}}