Distributed Interference-Aware Energy-Efficient Resource Allocation for Device-to-Device Communications Underlaying Cellular Networks

The introduction of device-to-device (D2D) into cellular networks poses many new challenges in the resource allocation design due to the co-channel interference caused by spectrum reuse and limited battery life of user equipments (UEs). In this paper, we propose a distributed interference-aware energy-efficient resource allocation algorithm to maximize each UE's energy efficiency (EE) subject to its specific quality of service (QoS) and maximum transmission power constraints. We model the resource allocation problem as a noncooperative game, in which each player is self-interested and wants to maximize its own EE. The formulated EE maximization problem is a non-convex problem and is transformed into a convex optimization problem by exploiting the properties of the nonlinear fractional programming. An iterative optimization algorithm is proposed and verified through computer simulations.Comment: 6 pages, 3 figures, IEEE GLOBECOM 201

Energy Efficiency and Spectral Efficiency Tradeoff in Device-to-Device (D2D) Communications

In this letter, we investigate the tradeoff between energy efficiency (EE) and spectral efficiency (SE) in device-to-device (D2D) communications underlaying cellular networks with uplink channel reuse. The resource allocation problem is modeled as a noncooperative game, in which each user equipment (UE) is self-interested and wants to maximize its own EE. Given the SE requirement and maximum transmission power constraints, a distributed energy-efficient resource allocation algorithm is proposed by exploiting the properties of the nonlinear fractional programming. The relationships between the EE and SE tradeoff of the proposed algorithm and system parameters are analyzed and verified through computer simulations.Comment: 8 pages, 6 figures, long version paper of IEEE Wireless Communications Letters, accepted for publication. arXiv admin note: text overlap with arXiv:1405.196

Spectrum-Free Estimation of Doppler Velocities Using Ultra-Wideband Radar

A method for estimating Doppler velocities using ultra-wideband radar data is presented. Unlike conventional time-frequency analysis, the proposed method can directly obtain Doppler velocities without searching for peaks in a spectrum. By exploiting closed-form solutions for the Doppler velocities, it avoids the trade-off between time and frequency resolution, thus maintaining high time resolution. Both simulations and measurements are used to evaluate the proposed method versus conventional techniques

実際の遺伝的パラメータ，育種目標の変更を仮定した場合での３集団モデルの遺伝的有利性

Breeding efficiency was compared among three population schemes; a single population, a population with two sub-populations and a population with three sub-populations when sets of realistics genetic parameters were assumed, and when breeding objectives were changed in the middle of selection program. A simulation experiment of selection was carried out for 10 generations with 20 replications each by comparing average breeding values and inbreeding coefficients among the three population schemes. Genetic gain of growth trait was the largest, then that of meat quality trait was the second largest, and that of reproductive trait was the smallest. The amount of the genetic gain was dependent on their genetic variance. Among the three population schemes, the single population scheme had similar genetic level with the other two schemes under a selection with same economic weights for the traits, however, the multiple sub-populations scheme had the highest genetic level after crossbreeding between sub-populations when inbreeding depression was assumed. The population shceme with three sub-populations can enjoy full advantage of heterosis when different economic weights were applied to the traits. The change of breeding objective made impact on genetic gain of population scheme when different economic weights were applied to the traits, where the population scheme with three sub-populations had higher genetic than the older population schemes

A Game-Theoretic Approach to Energy-Efficient Resource Allocation in Device-to-Device Underlay Communications

Despite the numerous benefits brought by Device-to-Device (D2D) communications, the introduction of D2D into cellular networks poses many new challenges in the resource allocation design due to the co-channel interference caused by spectrum reuse and limited battery life of User Equipments (UEs). Most of the previous studies mainly focus on how to maximize the Spectral Efficiency (SE) and ignore the energy consumption of UEs. In this paper, we study how to maximize each UE's Energy Efficiency (EE) in an interference-limited environment subject to its specific Quality of Service (QoS) and maximum transmission power constraints. We model the resource allocation problem as a noncooperative game, in which each player is self-interested and wants to maximize its own EE. A distributed interference-aware energy-efficient resource allocation algorithm is proposed by exploiting the properties of the nonlinear fractional programming. We prove that the optimum solution obtained by the proposed algorithm is the Nash equilibrium of the noncooperative game. We also analyze the tradeoff between EE and SE and derive closed-form expressions for EE and SE gaps.Comment: submitted to IET Communications. arXiv admin note: substantial text overlap with arXiv:1405.1963, arXiv:1407.155