Variable-rate incremental-redundancy HARQ for finite blocklengths

Incremental redundancy (IR) hybrid automatic repeat request (HARQ) is a staple component of modern wireless systems, instrumental for efficient and reliable low-latency communication. To further improve the performance, the blocklengths - and therefore the incremental rates - of the various transmis...

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Detalles Bibliográficos
Autores: Fu, Yu, Lozano Solsona, Angel, Yang, Hongwen
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Universitat Pompeu Fabra
Repositorio:Repositorio Digital de la UPF
OAI Identifier:oai:dnet:rdupf_______::fca396d8eaac155b8a626d9900fd7a08
Acceso en línea:https://hdl.handle.net/10230/73316
http://dx.doi.org/10.1109/OJCOMS.2025.3541238
Access Level:acceso abierto
Palabra clave:Blocklength allocation
Finite blocklength
Hybrid automatic repeat request
Incremental redundancy
Throughput
Descripción
Sumario:Incremental redundancy (IR) hybrid automatic repeat request (HARQ) is a staple component of modern wireless systems, instrumental for efficient and reliable low-latency communication. To further improve the performance, the blocklengths - and therefore the incremental rates - of the various transmissions can be released from being fixed. This paper optimizes these variable blocklengths in truncated IR-HARQ, with the goal of maximizing the overall throughput at any desired operating point (meaning any combination of signal-to-noise ratio and target error rate). The optimization relies on a finite-blocklength information-theoretical analysis, whereby the block error rate emerges as a function of the channel capacity and the channel dispersion. Numerical results confirm that the optimized variable-rate IR-HARQ significantly outperforms its fixed-rate counterpart, both with ideal codes and with a 5G commercial code. Additionally, a heuristic scheme that mimics the behavior of the optimized solution, but is simpler to implement, is set forth and shown to essentially attain the same performance.