Internet of Things(IoT) refers to an infrastructure which enables the forms of communication and collaboration between people and things,and between things themselves.In order to improve its performance,we present a t...Internet of Things(IoT) refers to an infrastructure which enables the forms of communication and collaboration between people and things,and between things themselves.In order to improve its performance,we present a tradeoff between bandwidth and energy consumption in the IoT in this paper.A service providing model is built to find the relationship between bandwidth and energy consumption using a cooperative differential game model.The game solution is gotten in the condition of grand coalition,feedback Nash equilibrium and intermediate coalitions and an allocation policy is obtain by Shapley theory.The results are shown as follows.Firstly,the performance of IoT decreases with the increasing of bandwidth cost or with the decreasing of energy cost;secondly,all the nodes in the IoT composing a grand coalition can save bandwidth and energy consumption;thirdly,when the factors of bandwidth cost and energy cost are equal,the obtained number of provided services is an optimised value which is the trade-off between energy and bandwidth consumption.展开更多
In this study,aiming at the characteristics of randomness and dynamics in Wearable Audio-oriented BodyNets(WA-BodyNets),stochastic differential game theory is applied to the investigation of the problem of transmitted...In this study,aiming at the characteristics of randomness and dynamics in Wearable Audio-oriented BodyNets(WA-BodyNets),stochastic differential game theory is applied to the investigation of the problem of transmitted power control inconsumer electronic devices.First,astochastic differential game model is proposed for non-cooperative decentralized uplink power control with a wisdom regulation factor over WA-BodyNets with a one-hop star topology.This model aims to minimize the cost associated with the novel payoff function of a player,for which two cost functions are defined:functions of inherent power radiation and accumulated power radiation damage.Second,the feedback Nash equilibrium solution of the proposed model and the constraint of the Quality of Service(QoS) requirement of the player based on the SIR threshold are derived by solving the Fleming-Bellman-Isaacs partial differential equations.Furthermore,the Markov property of the optimal feedback strategies in this model is verified.The simulation results show that the proposed game model is effective and feasible for controlling the transmitted power of WA-BodyNets.展开更多
Pilot contamination can spoil the accuracy of channel estimation and then has become one of the key problems influencing the performance of massive multiple input multiple output(MIMO)systems.This paper proposes a met...Pilot contamination can spoil the accuracy of channel estimation and then has become one of the key problems influencing the performance of massive multiple input multiple output(MIMO)systems.This paper proposes a method based on cell classification and users grouping to mitigate the pilot contamination in multi-cell massive MIMO systems and improve the spectral efficiency.The pilots of the terminals are allocated onebit orthogonal identifier to diminish the cell categories by the operation of exclusive OR(XOR).At the same time,the users are divided into edge user groups and central user groups according to the large-scale fading coefficients by the clustering algorithm,and different pilot sequences are assigned to different groups.The simulation results show that the proposed method can effectively improve the spectral efficiency of multi-cell massive MIMO systems.展开更多
基金ACKNOWLEDGEMENT We gratefully acknowledge anonymous revie- wers who read drafts and made many helpful suggestions. This work was supported by the National Natural Science Foundation of China under Grant No. 61202079 the China Post- doctoral Science Foundation under Grant No. 2013M530526+2 种基金 the Foundation of Beijing En- gineering the Fundamental Research Funds for the Central Universities under Grant No. FRF-TP-13-015A and the Technology Centre for Convergence Networks and Ubiquitous Services.
文摘Internet of Things(IoT) refers to an infrastructure which enables the forms of communication and collaboration between people and things,and between things themselves.In order to improve its performance,we present a tradeoff between bandwidth and energy consumption in the IoT in this paper.A service providing model is built to find the relationship between bandwidth and energy consumption using a cooperative differential game model.The game solution is gotten in the condition of grand coalition,feedback Nash equilibrium and intermediate coalitions and an allocation policy is obtain by Shapley theory.The results are shown as follows.Firstly,the performance of IoT decreases with the increasing of bandwidth cost or with the decreasing of energy cost;secondly,all the nodes in the IoT composing a grand coalition can save bandwidth and energy consumption;thirdly,when the factors of bandwidth cost and energy cost are equal,the obtained number of provided services is an optimised value which is the trade-off between energy and bandwidth consumption.
基金the National Natural Science Foundation of China under Grants No.61272506,No.61170014，the Foundation of Key Program of MOE of China under Grant No.311007，the Natural Science Foundation of Beijing under Grant No.4102041
文摘In this study,aiming at the characteristics of randomness and dynamics in Wearable Audio-oriented BodyNets(WA-BodyNets),stochastic differential game theory is applied to the investigation of the problem of transmitted power control inconsumer electronic devices.First,astochastic differential game model is proposed for non-cooperative decentralized uplink power control with a wisdom regulation factor over WA-BodyNets with a one-hop star topology.This model aims to minimize the cost associated with the novel payoff function of a player,for which two cost functions are defined:functions of inherent power radiation and accumulated power radiation damage.Second,the feedback Nash equilibrium solution of the proposed model and the constraint of the Quality of Service(QoS) requirement of the player based on the SIR threshold are derived by solving the Fleming-Bellman-Isaacs partial differential equations.Furthermore,the Markov property of the optimal feedback strategies in this model is verified.The simulation results show that the proposed game model is effective and feasible for controlling the transmitted power of WA-BodyNets.
基金supported by the Scientific and Technological Innovation Foundation of Shunde Graduate School,USTB(BK19CF002).
文摘Pilot contamination can spoil the accuracy of channel estimation and then has become one of the key problems influencing the performance of massive multiple input multiple output(MIMO)systems.This paper proposes a method based on cell classification and users grouping to mitigate the pilot contamination in multi-cell massive MIMO systems and improve the spectral efficiency.The pilots of the terminals are allocated onebit orthogonal identifier to diminish the cell categories by the operation of exclusive OR(XOR).At the same time,the users are divided into edge user groups and central user groups according to the large-scale fading coefficients by the clustering algorithm,and different pilot sequences are assigned to different groups.The simulation results show that the proposed method can effectively improve the spectral efficiency of multi-cell massive MIMO systems.
