Increasing spectrum-efficiency (SE) as well energy-efficiency (EE) has attracted much attention recently due to the fact that future wireless networks need address issues of high throughput and low power consumption. However, objective for optimizing SE sometimes conflicts with one EE, methods improving EE may result in a decrease SE. In this paper, we consider SE-EE tradeoff cognitive radio (CR) co-operative spectrum sensing (CSS). First, formulate general problem, analyze two special...

An excellent routing protocol is important for wireless sensor network (WSN) construction and efficient data transmission. With the continuous expansion of application scenarios scopes Internet Things, existing WSN protocols are no longer suitable complex structure huge demands communications. Aiming at these issues protocols, such as short lifetime caused by high energy consumption uneven distribution surviving nodes, this article proposes an energy-saving clustering based on adaptive...

Android root is the voluntary and legitimate process of gaining highest privilege full control over a user's device. To facilitate popular demand, unique ecosystem has formed where variety providers begin to offer as service. Even though legitimate, many convenient one-click methods operate by exploiting vulnerabilities in system. If not carefully controlled, such exploits can be abused malware author gain unauthorized privilege. understand risks, we undertake study on number yet mysterious...

Nonparametric regression analysis has broad applications. In some cases, the function with jumps (i.e., curve is discontinuous) seems to be more appropriate describe related phenomena. Existing a number of methods for estimating discontinuous curve, most which are based on data complete, unrealistic in many practical situations. this paper, we consider nonparametric model missing covariate data. Based inverse selection probability weighted and jump-preserving techniques, estimation procedure...

Co-frequency and co-time full-duplex (CCFD) technique claims to be the most potential duplex scheme for next generation system, since it can double spectral efficiency. The challenge of CCFD wireless communication systems lies in mitigating self-interference (SI). In this paper, we focus on digital SI cancellation (SIC) systems. performance traditional techniques is mainly limited by nonlinearity components local transmitter. Aiming at issue an auxiliary receive chain employed paper....

Unmanned Aerial Vehicle (UAV) aided communication has the potential to provide on-demand wireless services and improve outdoor link throughput. Applications for UAVs are rapidly growing with development of Internet Things. Because limited battery energy, need time-limited spectrum access complete data transmission. Hence there two challenges UAV-based communication: 1) Spectrum-efficient design; 2) Energy-efficient design. In this paper, we investigate optimization efficiency (SE) energy...

Time series is traditionally treated with two main approaches, i.e., the time domain approach and frequency approach. These approaches must rely on a sliding window so that time-shift versions of periodic subsequence can be measured to similar. Coupled use root point-to-point measure, existing methods often have quadratic complexity. We offer third R It begins an insight subsequences in as sets independent identically distributed (iid) points generated from unknown distribution R. This...

The deployment of unmanned aerial vehicle (UAV)-enabled cognitive radio system in the area covered by primary network is studied this letter. UAV shares spectrum with user (PU) and aims to maximize transmitted bits limited battery capacity. When flies towards transmitter, sensing performance throughput will be improved. However, energy consumption increases linearly flying distance. goal letter find optimal position optimize as well power allocation such that maximized while PU sufficiently...

To improve the utilisation efficiency of licensed spectrum in cognitive radio network, two new channel selection strategies are proposed for secondary user (SU) this paper. The solution tries its best to reduce collision and switching probabilities SU during data transmission. By using historical information spectrum, chooses with lowest busy probability within service time Time series prediction is employed forecast near future units, a novel method named distance factor recursive least...

Fifth-generation (5G) wireless networks are expected to achieve 1000 times higher capacity compared with fourth-generation networks. Thus, improving the spectrum efficiency (SE) is a crucial problem, which must be considered. Cognitive radio (CR) considered an effective approach alleviate scarcity problem. In this paper, based on location information of primary transmitter (PT) and CR network, we estimate distance between PT secondary (ST) then propose joint sensing power allocation (JSS-PA)...

In cognitive radio networks, a secondary user (SU) equipped with frequency (RF) energy-harvesting circuits can not only harvest the RF energy from primary transmitter, but also recycle its self-power when transmitting. this paper, we are concerned following design metrics: SU's harvested energy, efficiency, and harvesting which is defined as ratio of average by SU over consumption. We interested in two tradeoff designs: one between efficiency other efficiency. Multiobjective optimization...

The unmanned aerial vehicle (UAV) assisted communication can significantly improve the coverage and spectrum efficiency of Internet Things (IoT). One main feature IoT is short packet (SPC), in which data transmission uses finite block-length codewords. rate error will affect effective throughput IoT. In this paper, we investigate impact SPC on performance UAV-enabled sharing network. Specifically, optimization energy (EE) UAV system considered since battery usually limited. We design rate,...

The authors investigate the problem of blind multi-user detection (MUD) for uplink asynchronous direct-sequence code-division multiple access (DS-CDMA) systems with hostile jamming. To cope lack prior knowledge spread signals, jamming and channel state information, propose a scheme based on source separation (BSS) to solve this problem. Dual receive antennas are used in proposed scheme. By exploiting structure two received BSS model dependent sources is formed, then cancellation MUD obtained...

ION is a unified memory management interface for Android that widely used on virtually all ARM based devices. attempts to achieve several ambitious goals have not been simultaneously achieved before (not even Linux). Different from managing regular in the system, designed share and manage with special constraints, e.g., physically contiguous memory. Despite great flexibility performance benefits offered, such critical subsystem, as we discover, unfortunately has flawed security assumptions...

Static analysis is known to yield numerous false alarms when used in bug finding, especially for complex vulnerabilities large code bases like the Linux kernel. One important class of such what we call "high-order taint style vulnerability", where flow from user input vulnerable site crosses boundary a single entry function invocation (i.e., syscall). Due scope and high precision requirement, few have attempted solve problem. In this paper, present SUTURE, highly precise scalable static tool...

As known, receivers with in-phase and quadrature-phase (I/Q) down conversion, especially direct-conversion architectures' always suffer from I/Q imbalance. imbalance is caused by amplitude phase mismatch between paths. The performance degradation resulting can not be mitigated simply higher signal to noise ratio (SNR). Thus, compensation in digital domain critical. There are two main contributions this paper. Firstly, we proposed a blind estimation algorithm for parameters based on joint...

In this paper, the fundamental problem for full-duplex communication systems, i.e., self-interference cancellation (SIC), is investigated, and a novel digital-domain SIC method based on blind source separation proposed. This achieves by has two prominent characteristics that are: 1) it method, no training sequence or time needed 2) unaffected nonlinear components of signal. Meanwhile, critical factors spectral efficiency (SE) are fully analyzed herein. simulations, performances proposed...

Green energy powered cognitive radio is proposed as a promising method to improve the efficiency (EE) and spectrum (SE). We consider green power farms that harvest from solar wind, which used for primary transmitter sensor network (CSN). The has priority utilize energy, then CSN may not be sufficient. Both management harvesting process will affect throughput of sensors (CSs). In this paper, we aim design system parameters in (including sensing threshold, time, final decision threshold fusion...

A hybrid spectrum access strategy which is different from traditional underlay or overlay proposed for cognitive radio networks. In strategy, the secondary users (SU) cooperatively sense state of primary user (PU) in a given band. Based on sensing results and an additional requirement bit error rate, SU adapts its transmit power modulation level. Specifically, if PU inactive, allocates subject to peak constraint. Else active, average interference constraint would be further imposed protect...