Title :
Adaptive data rate using ARQ and nonuniform constellations
Author :
Otnes, Roald ; Maseng, Torleiv
Author_Institution :
UniK-Center for Technol., Kjeller, Norway
Abstract :
We introduce an automatic repeat request (ARQ) scheme that uses nonuniform signal constellations in order to adapt the data rate to the received signal-to-noise ratio (SNR) in a fading channel without using channel state feedback or incremental redundancy. We have defined nonuniform phase shift key (PSK) and quadrature amplitude modulation (QAM) constellations with an arbitrary number of classes of bits. These constellations may also be of interest for further research into unequal error protection. We present simulations of the throughput in Rayleigh fading and lognormal shadowing, and discuss the cases where our proposed scheme may improve the throughput compared to standard ARQ using uniform signal constellations
Keywords :
AWGN; Rayleigh channels; automatic repeat request; error statistics; feedback; phase shift keying; quadrature amplitude modulation; ARQ; AWGN; BER perforinance; PSK constellations; QAM constellations; SNR; adaptive data rate; additive white Gaussian noise; automatic repeat request; channel state feedback; error probability; fading channel; incremental redundancy; lognormal shadowing; nonuniform PSK; nonuniform QAM; nonuniform signal constellations; phase shift keying; quadrature amplitude modulation; received signal-to-noise ratio; throughput; Automatic repeat request; Constellation diagram; Error correction codes; Fading; Phase shift keying; Quadrature amplitude modulation; Redundancy; Signal to noise ratio; State feedback; Throughput;
Conference_Titel :
Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd
Conference_Location :
Rhodes
Print_ISBN :
0-7803-6728-6
DOI :
10.1109/VETECS.2001.944576
