Title :
Delay performance optimization for multiuser diversity systems with bursty-traffic and heterogeneous wireless links
Author :
Harsini, Jalil S. ; Lahouti, Farshad
Author_Institution :
WMC Lab., Univ. of Tehran, Tehran, Iran
Abstract :
This paper presents a cross-layer approach for optimizing the delay performance of a multiuser diversity system with heterogeneous block-fading channels and a delay-sensitive bursty-traffic. We consider the downlink of a time-slotted multiuser system employing opportunistic scheduling with fair performance at the medium access (MAC) layer and adaptive modulation and coding (AMC) with power control at the physical layer. Assuming individual user buffers which temporarily store the arrival traffic of users at the MAC layer, we first present a large deviations based statistical model to evaluate the delay-bound violation of packets in the user buffers. Aiming at minimizing the delay probability of the individual users, we then optimize the AMC and power control module subject to a target packet-error rate constraint. In the case of a quantized feedback channel, we also present a constant-power AMC based opportunistic scheduling scheme. Numerical and simulation results are provided to evaluate the delay performance of the proposed adaptation schemes in a multiuser setup.
Keywords :
adaptive codes; adaptive modulation; diversity reception; fading channels; multiuser channels; numerical analysis; optimisation; radio links; scheduling; adaptive coding; adaptive modulation; cross-layer approach; delay performance optimization; delay sensitive bursty traffic; heterogeneous block-fading channels; heterogeneous wireless links; medium access layer; multiuser diversity systems; numerical simulation; opportunistic scheduling; power control module; quantized feedback channel; statistical model; time-slotted multiuser system; Adaptive control; Buffer storage; Delay; Downlink; Modulation coding; Optimization; Physical layer; Power control; Programmable control; Traffic control; Multiuser diversity; QoS optimization; adaptive transmission; cross-layer design;
Conference_Titel :
Signal Processing Advances in Wireless Communications, 2009. SPAWC '09. IEEE 10th Workshop on
Conference_Location :
Perugia
Print_ISBN :
978-1-4244-3695-8
Electronic_ISBN :
978-1-4244-3696-5
DOI :
10.1109/SPAWC.2009.5161783