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Title: Effect of Feedback Delay on Adaptive LDPC Coding in a Fading Free-Space Optical Channel
Free-space optical (FSO) links are sensitive to channel fading caused by atmospheric turbulence, varying weather conditions, and changes in the distance between the transmitter and receiver. To mitigate FSO fading, this paper applies linear and quadratic prediction to estimate fading channel conditions and dynamically select the appropriate low-density parity check (LDPC) code rate. This adaptivity achieves reliable communication while efficiently utilizing the available channel mutual information. Protograph-based Raptor-like (PBRL) LDPC codes supporting a wide range of rates are designed, facilitating convenient rate switching. When channel state information (CSI) is known without delay, dynamically selecting LDPC code rate appropriately maximizes throughput. This work explores how such prediction behaves as the feedback delay is increased from no delay to a delay of 4 ms for a channel with a coherence time of 10 ms.  more » « less
Award ID(s):
1955660
PAR ID:
10540382
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
IEEE
Date Published:
ISSN:
1938-1883
ISBN:
978-1-7281-9054-9
Page Range / eLocation ID:
2420 to 2426
Subject(s) / Keyword(s):
Free-space optical communication Fading Channel Low Density Parity Check Codes PBRL Protograph-Based Raptor-Like Rate-Compatible Feedback Channel State Information Atmospheric Turbulence
Format(s):
Medium: X
Location:
Denver, CO, USA
Sponsoring Org:
National Science Foundation
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