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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
Achievable Throughput Regions Of Fading Broadcast And Interference Channels Under Qos Constraints, Deli Qiao, Mustafa Cenk Gursoy, Senem Velipasalar
Achievable Throughput Regions Of Fading Broadcast And Interference Channels Under Qos Constraints, Deli Qiao, Mustafa Cenk Gursoy, Senem Velipasalar
Department of Electrical and Computer Engineering: Faculty Publications
Transmission over fading broadcast and interference channels in the presence of quality of service (QoS) constraints is studied. Effective capacity, which provides the maximum constant arrival rate that a given service process can support while satisfying statistical QoS constraints, is employed as the performance metric. In the broadcast scenario, the effective capacity region achieved with superposition coding and successive interference cancellation is identified and is shown to be convex. Subsequently, optimal power control policies that achieve the boundary points of the effective capacity region are investigated, and an algorithm for the numerical computation of the optimal power adaptation schemes for …
Effective Capacity Of Two-Hop Wireless Communication Systems, Deli Qiao, Mustafa Cenk Gursoy, Senem Velipasalar
Effective Capacity Of Two-Hop Wireless Communication Systems, Deli Qiao, Mustafa Cenk Gursoy, Senem Velipasalar
Department of Electrical and Computer Engineering: Faculty Publications
A two-hop wireless communication link in which a source sends data to a destination with the aid of an intermediate relay node is studied. It is assumed that there is no direct link between the source and the destination, and the relay forwards the information to the destination by employing the decode-and-forward scheme. Both the source and intermediate relay nodes are assumed to operate under statistical quality of service (QoS) constraints imposed as limitations on the buffer overflow probabilities. The maximum constant arrival rates that can be supported by this two-hop link in the presence of QoS constraints are characterized …
Transmission Strategies In Multiple-Access Fading Channels With Statistical Qos Constraints, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
Transmission Strategies In Multiple-Access Fading Channels With Statistical Qos Constraints, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
Department of Electrical and Computer Engineering: Faculty Publications
Effective capacity, which provides the maximum constant arrival rate that a given service process can support while satisfying statistical queueing constraints, is analyzed in a multiuser scenario. In particular, the effective capacity region of fading multiple-access channels in the presence of quality of service (QoS) constraints is studied. Perfect channel side information is assumed to be available at both the transmitters and the receiver. It is initially assumed that the transmitters send the information at a fixed power level and, hence, do not employ power control policies. Under this assumption, the performance achieved by superposition coding with successive decoding techniques …
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 …
Performance Analysis Of Cognitive Radio Systems Under Qos Constraints And Channel Uncertainty, Sami Akin, Mustafa Cenk Gursoy
Performance Analysis Of Cognitive Radio Systems Under Qos Constraints And Channel Uncertainty, Sami Akin, Mustafa Cenk Gursoy
Department of Electrical and Computer Engineering: Faculty Publications
In this paper, performance of cognitive transmission over time-selective flat fading channels is studied under quality of service (QoS) constraints and channel uncertainty. Cognitive secondary users (SUs) are assumed to initially perform channel sensing to detect the activities of the primary users, and then attempt to estimate the channel fading coefficients through training. Energy detection is employed for channel sensing, and different minimum mean-square-error (MMSE) estimation methods are considered for channel estimation. In both channel sensing and estimation, erroneous decisions can be made, and hence, channel uncertainty is not completely eliminated. In this setting, performance is studied and interactions between …
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 …
Analysis Of Energy Efficiency In Fading Channels Under Qos Constraints, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
Analysis Of Energy Efficiency In Fading Channels Under Qos Constraints, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar
Department of Electrical and Computer Engineering: Faculty Publications
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 …
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 …