Soft GRAND under Channel Switching and Drift
Year: 2026
Type: article
Abstract: Under channel switching or drift, the posterior used to order soft GRAND queries can differ from the matched correction posterior, potentially increasing query rank and finite-budget decoding error. We bound log query rank using matched posterior self-information plus the positive part of the log-posterior mismatch; exact random-subset collision probabilities bound GRANDAB error. For switching among memoryless channels with capacity-achieving uniform input, a state-path mixture yields vanishing error uniformly over admissible paths below the minimum constituent capacity when log path-class size is sublinear in blocklength. For drift, pilot refresh bounds mismatch; the tracking upper bound yields a continuous-domain minimizer. Generalized-Gaussian BPSK simulations evaluate both regimes.
Source: IEEE Communications Letters
Author: Behrooz Razeghi
Institution: Harvard University
Language: English
Subfield: Computer Networks and Communications
Field: Computer Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,645
OpenAlex ID: W7204177565