Title :
Performance of hybrid-ARQ in block-fading channels: A fixed outage probability analysis
Author :
Wu, Peng ; Jindal, Nihar
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Minnesota, Minneapolis, MN, USA
fDate :
4/1/2010 12:00:00 AM
Abstract :
This paper studies the performance of hybrid-ARQ (automatic repeat request) in Rayleigh block-fading channels. The long-term average transmitted rate is analyzed in a fast-fading scenario where the transmitter only has knowledge of channel statistics, and, consistent with contemporary wireless systems, rate adaptation is performed such that a target outage probability (after a maximum number of H-ARQ rounds) is maintained. H-ARQ allows for early termination once decoding is possible, and thus is a coarse, and implicit, mechanism for rate adaptation to the instantaneous channel quality. Although the rate with H-ARQ is not as large as the ergodic capacity, which is achievable with rate adaptation to the instantaneous channel conditions, even a few rounds of H-ARQ make the gap to ergodic capacity reasonably small for operating points of interest. Furthermore, the rate with H-ARQ provides a significant advantage compared to systems that do not use H-ARQ and only adapt rate based on the channel statistics.
Keywords :
Rayleigh channels; automatic repeat request; decoding; probability; Rayleigh channels; automatic repeat request; block fading channels; channel quality; channel statistics; decoding; ergodic capacity; fixed outage probability analysis; hybrid ARQ; transmitter; Automatic repeat request; Decoding; Fading; Feedback; Information rates; Performance analysis; Probability; Statistical analysis; Statistics; Transmitters; Fading channels; Information rates; automatic repeat request; channel coding;
Journal_Title :
Communications, IEEE Transactions on
DOI :
10.1109/TCOMM.2010.04.080622