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University of Nebraska - Lincoln
Department of Electrical and Computer Engineering: Faculty Publications
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Full-Text Articles in Engineering
Energy Efficiency In Multiaccess Fading Channels Under Qos Constraints, Deli Qiao, Mustafa Cenk Gursoy, Senem Velipasalar
Energy Efficiency In Multiaccess Fading Channels Under Qos Constraints, Deli Qiao, Mustafa Cenk Gursoy, Senem Velipasalar
Department of Electrical and Computer Engineering: Faculty Publications
In this article, transmission over multiaccess fading channels under quality-of-service (QoS) constraints is studied in the low-power and wideband regimes. QoS constraints are imposed as limitations on the buffer violation probability. The effective capacity, which characterizes the maximum constant arrival rates in the presence of such statistical QoS constraints, is employed as the performance metric. A two-user multiaccess channel model is considered, and the minimum bit energy levels and wideband slope regions are characterized for different transmission and reception strategies, namely time-division multiple-access (TDMA), superposition coding with fixed decoding order, and superposition coding with variable decoding order. It is shown …
Mimo Wireless Communications Under Statistical Queueing Constraints, M. Cenk Gursoy
Mimo Wireless Communications Under Statistical Queueing Constraints, M. Cenk Gursoy
Department of Electrical and Computer Engineering: Faculty Publications
The performance of multiple-input multiple-output (MIMO) wireless systems is investigated in the presence of statistical queueing constraints. Queuing constraints are imposed as limitations on buffer violation probabilities. The performance under such constraints is captured through the effective capacity formulation. A detailed analysis of the effective capacity is carried out in the low-power, wideband, and high signal-to-noise ratio (SNR) regimes. In the low-power analysis, expressions for the first and second derivatives of the effective capacity with respect to SNR at SNR = 0 are obtained under various assumptions on the degree of channel state information at the transmitter. Transmission strategies that …
Energy Efficiency In The Low-Snr Regime Under Queueing Constraints And Channel Uncertainty, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
Energy Efficiency In The Low-Snr Regime Under Queueing Constraints And Channel Uncertainty, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
Department of Electrical and Computer Engineering: Faculty Publications
Energy efficiency of fixed-rate transmissions is studied in the presence of queueing constraints and channel uncertainty. It is assumed that neither the transmitter nor the receiver has channel side information prior to transmission. The channel coefficients are estimated at the receiver via minimum mean-square-error (MMSE) estimation with the aid of training symbols. It is further assumed that the system operates under statistical queueing constraints in the form of limitations on buffer violation probabilities. The optimal fraction of power allocated to training is identified. Spectral efficiency–bit energy tradeoff is analyzed in the low-power and wideband regimes by employing the effective capacity …
The Impact Of Qos Constraints On The Energy Efficiency Of Fixed-Rate Wireless Transmissions, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
The Impact Of Qos Constraints On The Energy Efficiency Of Fixed-Rate Wireless Transmissions, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
Department of Electrical and Computer Engineering: Faculty Publications
Transmission over wireless fading channels under quality of service (QoS) constraints is studied when only the receiver has channel side information. Being unaware of the channel conditions, transmitter is assumed to send the information at a fixed rate. Under these assumptions, a two-state (ON-OFF) transmission model is adopted, where information is transmitted reliably at a fixed rate in the ON state while no reliable transmission occurs in the OFF state. QoS limitations are imposed as constraints on buffer violation probabilities, and effective capacity formulation is used to identify the maximum throughput that a wireless channel can sustain while satisfying statistical …