In this paper,we study the system performance of mobile edge computing(MEC)wireless sensor networks(WSNs)using a multiantenna access point(AP)and two sensor clusters based on uplink nonorthogonal multiple access(NOMA)...In this paper,we study the system performance of mobile edge computing(MEC)wireless sensor networks(WSNs)using a multiantenna access point(AP)and two sensor clusters based on uplink nonorthogonal multiple access(NOMA).Due to limited computation and energy resources,the cluster heads(CHs)offload their tasks to a multiantenna AP over Nakagami-m fading.We proposed a combination protocol for NOMA-MEC-WSNs in which the AP selects either selection combining(SC)or maximal ratio combining(MRC)and each cluster selects a CH to participate in the communication process by employing the sensor node(SN)selection.We derive the closed-form exact expressions of the successful computation probability(SCP)to evaluate the system performance with the latency and energy consumption constraints of the considered WSN.Numerical results are provided to gain insight into the system performance in terms of the SCP based on system parameters such as the number of AP antennas,number of SNs in each cluster,task length,working frequency,offloading ratio,and transmit power allocation.Furthermore,to determine the optimal resource parameters,i.e.,the offloading ratio,power allocation of the two CHs,and MEC AP resources,we proposed two algorithms to achieve the best system performance.Our approach reveals that the optimal parameters with different schemes significantly improve SCP compared to other similar studies.We use Monte Carlo simulations to confirm the validity of our analysis.展开更多
This paper investigates a Multiple-Input Multiple-Output (MIMO) scheme combining Transmit Antenna Selection and receive Maximal-Ratio Combining (TAS/MRC) in time-varying Rayleigh fading channels. We first present new ...This paper investigates a Multiple-Input Multiple-Output (MIMO) scheme combining Transmit Antenna Selection and receive Maximal-Ratio Combining (TAS/MRC) in time-varying Rayleigh fading channels. We first present new closed-form expressions for optimal received Signal-to-Noise Ratio (SNR),which is expressed in polynomial form. These are used to analyze ergodic capacity,outage probability and Bit Error Rate (BER) of TAS/MRC systems. Numerical results are presented to validate the theoretical analysis.展开更多
<正> Let X be an alphabet. The measure on the language family monoid 2~x which consist,of all languages over X is introduced by [1] as follows. Let π be a probability distribution on X, and be homomorphically e...<正> Let X be an alphabet. The measure on the language family monoid 2~x which consist,of all languages over X is introduced by [1] as follows. Let π be a probability distribution on X, and be homomorphically extended, still denoted by π, to a function from the monoid X into the monoid [0,1] with the usual multiplication of real numbers.展开更多
We investigate the secrecy outage performance of maximal ratio combining(MRC) in cognitive radio networks over Rayleigh fading channels. In a single-input multiple-output wiretap system, we consider a secondary user(S...We investigate the secrecy outage performance of maximal ratio combining(MRC) in cognitive radio networks over Rayleigh fading channels. In a single-input multiple-output wiretap system, we consider a secondary user(SU-TX) that transmits confidential messages to another secondary user(SU-RX) equipped with M(M ≥ 1)antennas where the MRC technique is adopted to improve its received signal-to-noise ratio. Meanwhile, an eavesdropper equipped with N(N ≥ 1) antennas adopts the MRC scheme to overhear the information between SU-TX and SU-RX. SU-TX adopts the underlay strategy to guarantee the service quality of the primary user without spectrum sensing. We derive the closed-form expressions for an exact and asymptotic secrecy outage probability.展开更多
In the paper, the author addresses the Lyapunov characteristic spectrum of an ergodic autonomous ordinary differential system on a complete riemannian manifold of finite dimension such as the d-dimensional euclidean s...In the paper, the author addresses the Lyapunov characteristic spectrum of an ergodic autonomous ordinary differential system on a complete riemannian manifold of finite dimension such as the d-dimensional euclidean space Rd, not necessarily compact, by Liaowise spectral theorems that give integral expressions of Lyapunov exponents. In the context of smooth linear skew-product flows with Polish driving systems, the results are still valid. This paper seems to be an interesting contribution to the stability theory of ordinary differential systems with non-compact phase spaces.展开更多
本文研究了非理想信道状态信息(channel state information,CSI)下经典4点(信源、信宿、中继、窃密者)模型的物理层保密中断性能.在此模型中,考虑窃密信道为单输入多输出,也就是信源、中继均为单天线,信宿、窃密者均为多天线.信宿和窃...本文研究了非理想信道状态信息(channel state information,CSI)下经典4点(信源、信宿、中继、窃密者)模型的物理层保密中断性能.在此模型中,考虑窃密信道为单输入多输出,也就是信源、中继均为单天线,信宿、窃密者均为多天线.信宿和窃密者均采用最大比合并分集策略处理接收到的多径信号,中继分别采用解码放大转发(decode-and-forward,DF)和随机放大转发(randomize-andforward,RF)两种方式向信宿转发信息.信源通过中继向信宿发送信息时,信源与中继、中继与信宿两跳通信过程均遭到窃密者的窃听.在非理想CSI下,本文分别推导出了DF与RF中继转发下保密中断概率的闭式表达式及渐近表达式,并通过Monte Carlo仿真验证了理论模型的正确性.展开更多
基金supported in part by Thailand Science Research and Innovation(TSRI)and National Research Council of Thailand(NRCT)via International Research Network Program(IRN61W0006)Thailand+1 种基金by Khon Kaen University,ThailandDuy Tan University,Vietnam。
文摘In this paper,we study the system performance of mobile edge computing(MEC)wireless sensor networks(WSNs)using a multiantenna access point(AP)and two sensor clusters based on uplink nonorthogonal multiple access(NOMA).Due to limited computation and energy resources,the cluster heads(CHs)offload their tasks to a multiantenna AP over Nakagami-m fading.We proposed a combination protocol for NOMA-MEC-WSNs in which the AP selects either selection combining(SC)or maximal ratio combining(MRC)and each cluster selects a CH to participate in the communication process by employing the sensor node(SN)selection.We derive the closed-form exact expressions of the successful computation probability(SCP)to evaluate the system performance with the latency and energy consumption constraints of the considered WSN.Numerical results are provided to gain insight into the system performance in terms of the SCP based on system parameters such as the number of AP antennas,number of SNs in each cluster,task length,working frequency,offloading ratio,and transmit power allocation.Furthermore,to determine the optimal resource parameters,i.e.,the offloading ratio,power allocation of the two CHs,and MEC AP resources,we proposed two algorithms to achieve the best system performance.Our approach reveals that the optimal parameters with different schemes significantly improve SCP compared to other similar studies.We use Monte Carlo simulations to confirm the validity of our analysis.
文摘This paper investigates a Multiple-Input Multiple-Output (MIMO) scheme combining Transmit Antenna Selection and receive Maximal-Ratio Combining (TAS/MRC) in time-varying Rayleigh fading channels. We first present new closed-form expressions for optimal received Signal-to-Noise Ratio (SNR),which is expressed in polynomial form. These are used to analyze ergodic capacity,outage probability and Bit Error Rate (BER) of TAS/MRC systems. Numerical results are presented to validate the theoretical analysis.
文摘<正> Let X be an alphabet. The measure on the language family monoid 2~x which consist,of all languages over X is introduced by [1] as follows. Let π be a probability distribution on X, and be homomorphically extended, still denoted by π, to a function from the monoid X into the monoid [0,1] with the usual multiplication of real numbers.
基金Project supported in part by the National Natural Science Foundation of China(Nos.61401372 and 61531016)the Research Fund for the Doctoral Program of Higher Education of China(No.20130182120017)+1 种基金the Natural Science Foundation of CQ CSTC(No.cstc2013jcyj A40040)the Fundamental Research Funds for the Central Universities,China(No.XDJK2015B023)
文摘We investigate the secrecy outage performance of maximal ratio combining(MRC) in cognitive radio networks over Rayleigh fading channels. In a single-input multiple-output wiretap system, we consider a secondary user(SU-TX) that transmits confidential messages to another secondary user(SU-RX) equipped with M(M ≥ 1)antennas where the MRC technique is adopted to improve its received signal-to-noise ratio. Meanwhile, an eavesdropper equipped with N(N ≥ 1) antennas adopts the MRC scheme to overhear the information between SU-TX and SU-RX. SU-TX adopts the underlay strategy to guarantee the service quality of the primary user without spectrum sensing. We derive the closed-form expressions for an exact and asymptotic secrecy outage probability.
基金supported by the National Natural Science Foundation of China (Grant No. 10671088)the Major State Basic Research Development Program of China (Grant No. 2006CB805903)
文摘In the paper, the author addresses the Lyapunov characteristic spectrum of an ergodic autonomous ordinary differential system on a complete riemannian manifold of finite dimension such as the d-dimensional euclidean space Rd, not necessarily compact, by Liaowise spectral theorems that give integral expressions of Lyapunov exponents. In the context of smooth linear skew-product flows with Polish driving systems, the results are still valid. This paper seems to be an interesting contribution to the stability theory of ordinary differential systems with non-compact phase spaces.
文摘本文研究了非理想信道状态信息(channel state information,CSI)下经典4点(信源、信宿、中继、窃密者)模型的物理层保密中断性能.在此模型中,考虑窃密信道为单输入多输出,也就是信源、中继均为单天线,信宿、窃密者均为多天线.信宿和窃密者均采用最大比合并分集策略处理接收到的多径信号,中继分别采用解码放大转发(decode-and-forward,DF)和随机放大转发(randomize-andforward,RF)两种方式向信宿转发信息.信源通过中继向信宿发送信息时,信源与中继、中继与信宿两跳通信过程均遭到窃密者的窃听.在非理想CSI下,本文分别推导出了DF与RF中继转发下保密中断概率的闭式表达式及渐近表达式,并通过Monte Carlo仿真验证了理论模型的正确性.
