TY - JOUR
T1 - Analysis of energy efficiency in fading channels under QoS constraints
AU - Gursoy, Mustafa Cenk
AU - Qiao, Deli
AU - Velipasalar, Senem
N1 - Funding Information:
Manuscript received August 15, 2008; revised February 2, 2009 and March 29, 2009; accepted April 5, 2009. The associate editor coordinating the review of this paper and approving it for publication was H. Dai. The authors are with the Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588 (e-mail: dqiao726@huskers.unl.edu, {gursoy, velipasa}@engr.unl.edu). The material in this paper was presented in part at the IEEE Global Communications Conference (Globecom), New Orleans, in Dec. 2008. This work was supported by the National Science Foundation under Grants CCF – 0546384 (CAREER) and CNS – 0834753. Digital Object Identifier 10.1109/TWC.2009.081105
PY - 2009/8
Y1 - 2009/8
N2 - Energy efficiency in fading channels in the presence of Quality of Service (QoS) constraints is studied. Effective capacity, which provides the maximum arrival rate that a wireless channel can sustain while satisfying statistical QoS constraints, is considered. Spectral efficiency-bit energy tradeoff is analyzed in the low-power and wideband regimes by employing the effective capacity formulation, rather than the Shannon capacity. Through this analysis, energy requirements under QoS constraints are identified. The analysis is conducted under two assumptions: perfect channel side information (CSI) available only at the receiver and perfect CSI available at both the receiver and transmitter. In particular, it is shown in the low-power regime that the minimum bit energy required under QoS constraints is the same as that attained when there are no such limitations. However, this performance is achieved as the transmitted power vanishes. Through the wideband slope analysis, the increased energy requirements at low but nonzero power levels in the presence of QoS constraints are determined. A similar analysis is also conducted in the wideband regime. The minimum bit energy and wideband slope expressions are obtained. In this regime, the required bit energy levels are found to be strictly greater than those achieved when Shannon capacity is considered. Overall, a characterization of the energy-bandwidth-delay tradeoff is provided.
AB - Energy efficiency in fading channels in the presence of Quality of Service (QoS) constraints is studied. Effective capacity, which provides the maximum arrival rate that a wireless channel can sustain while satisfying statistical QoS constraints, is considered. Spectral efficiency-bit energy tradeoff is analyzed in the low-power and wideband regimes by employing the effective capacity formulation, rather than the Shannon capacity. Through this analysis, energy requirements under QoS constraints are identified. The analysis is conducted under two assumptions: perfect channel side information (CSI) available only at the receiver and perfect CSI available at both the receiver and transmitter. In particular, it is shown in the low-power regime that the minimum bit energy required under QoS constraints is the same as that attained when there are no such limitations. However, this performance is achieved as the transmitted power vanishes. Through the wideband slope analysis, the increased energy requirements at low but nonzero power levels in the presence of QoS constraints are determined. A similar analysis is also conducted in the wideband regime. The minimum bit energy and wideband slope expressions are obtained. In this regime, the required bit energy levels are found to be strictly greater than those achieved when Shannon capacity is considered. Overall, a characterization of the energy-bandwidth-delay tradeoff is provided.
KW - Effective capacity
KW - Energy efficiency
KW - Energy-bandwidthdelay tradeoff
KW - Fading channels
KW - Minimum bit energy
KW - Spectral efficiency
KW - Statistical quality of service (QoS) constraints
KW - Wideband slope
UR - http://www.scopus.com/inward/record.url?scp=73049101310&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=73049101310&partnerID=8YFLogxK
U2 - 10.1109/TWC.2009.081105
DO - 10.1109/TWC.2009.081105
M3 - Article
AN - SCOPUS:73049101310
SN - 1536-1276
VL - 8
SP - 4252
EP - 4263
JO - IEEE Transactions on Wireless Communications
JF - IEEE Transactions on Wireless Communications
IS - 8
M1 - 5200985
ER -