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WSN routing performance can be affected by how nodes are placed in the given network surface. This paper presents a performance study of geographic routing in WSNs when different network topologies are employed for a forest fire prevention application scenario. A MATLAB simulation script has been developed for this research. Packet forwarding employs geographic routing based on progress towards destination...
In this paper we discuss the implementation of a Single Carrier Frequency Division Multiple Access (SC-FDMA) transceiver running over the Universal Software Radio Peripheral 2 (USRP2). SC-FDMA is the air interface which has been selected for the uplink in the latest Long Term Evolution (LTE) standard. In this paper we derive an AWGN channel model for SC-FDMA transmission, which is useful for benchmarking...
Nonlinear interference cancellation has been successful as a low-complexity iterative detection strategy for multiple-input, multiple-output channels. However, such strategies are generally difficult to analyze. Here we develop a connection to constrained optimization through the use of penalty functions. The resulting framework provides a means of analysis, and includes known nonlinear cancellation...
We endeavor to improve compressed sensing reconstruction performance of parallel pursuit algorithms. In an iteration, standard parallel pursuit algorithms use a support-set expansion by a fixed number of coefficients, leading to restricted performance. To achive a better performance, we develop a look ahead strategy that adaptively chooses the best number of coefficients. We develop a new algorithm...
In single-user transmission, the receive antennas should preferably be used to enable multiplexing. The situation is different under multiuser transmission, where only the number of transmit antennas limits the multiplexing gain. The system therefore has the choice between sending one stream per scheduled user (i.e., combining receive antennas for diversity) or selecting a smaller number of users...
Two blind algorithms that are developed with the intention of improving the symbol detection of Orthogonal Frequency Division Multiplexing (OFDM) techniques are proposed in this paper. OFDM systems are easy to equalize in implementations. The schemes are based on the theories of blind source separation (BSS). They are among the premier mechanisms used for extracting unobserved signals from observed...
We propose a jamming attacks detection algorithm based on Support Vector Machine (SVM) at the base station in wireless cellular networks. The proposed jamming detection process uses only inherent information which is available in common receivers and does not need excessive hardware requirements for external information. Using SVM based jamming detection algorithms not only improves the performance...
We propose a new bandwidth allocation scheme for two-hop transmission. The fixed relay network is modeled as a virtual oligopoly market, and the Cournot game model is exploited in order to solve the resource allocation problem. Two different types of Cournot competition, namely static and dynamic, are discussed. For the latter case, the stability conditions are analyzed. By using the proposed scheme,...
In this work, we first provide an exact closed-form expression for the packet drop probability (PDP) in incremental redundancy (IR) based hybrid automatic repeat request (HARQ) schemes with a limit on the maximum number of transmissions. In the later part, we extend our work in [5], and consider the optimal resource allocation problem of minimizing the PDP under the constraints of an average transmit...
This paper elaborates on the performance of orthogonal space-time block codes (STBCs) for multiple-input multiple-output (MIMO) systems operating in generalized-K fading conditions. The considered fading model is generic since it intimately encompasses both small-scale fading (modeled via the Nakagami-m distribution) and large-scale fading (modeled via the gamma distribution). In the following, new...
Market research reports by In-Stat, Gartner, and the Swedish Post and Telecom Agency (PTS) reveal a growing worldwide demand for Voice over IP (VoIP) and smartphones. This trend is expected to continue over the coming years and there is wide scope for mobile VoIP solutions. With this growth in VoIP adoption come challenges related with quality of service and security. Most consumer VoIP solutions,...
In this paper, we investigate the performance of multiple-input multiple-output (MIMO) systems deploying maximum ratio transmission (MRT). Our analysis takes into account not only imperfect channel estimation at the receiver and feedback delay at the transmitter, but also includes co-channel interference (CCI). In particular, we first derive the statistical properties of the signal-to-interference-plus-noise...
This paper introduces a multi-cell transmission scheme for High-Speed Downlink Packet Access (HSDPA) networks, called High-Speed Single-Frequency Network (HS-SFN). While existing multi-point transmission features for WCDMA have concentrated on soft/softer handover (HO) mechanisms and are applicable only for Rel-99 based networks, HS-SFN brings an over-the-air combining approach to multi-cell transmissions...
The maximum reach of the Dense Wavelength-Division-Multiplexed Passive Optical Network (DWDM-PON) system can be severely limited by chromatic dispersion (CD). This paper contains the investigation of long-reach high speed 16-channel DWDM-PON system with efficient CD compensation methods. It is shown that chromatic dispersion compensation has a crucial role for guaranteed downstream optical link performance...
Currently, considerable interest has been shown in the research and standardization communities in multicell transmission schemes for HSPA, with a number of possible schemes under discussion that include Multiflow, Fast Cell Switching (FCS) and High-Speed Single Frequency Network (HS-SFN). In particular, HS-SFN is a promising technique that not only combines received energy from participating cells,...
With the launch of flat-rate mobile broadband Internet access, wireless service providers (WSP) have faced a fierce competition for users. This became even more challenging issue with the expansion of smartphones and cloud computing applications driving the demand for mobile broadband access. Allowing users to get service offers freely from any wireless service provider, some aspects should be considered...
The authors have studied the possibilities to obtain the maximum spectral efficiency for a combined wavelength division multiplexing (WDM) system by minimizing the channel spacing. The fiber optic transmission systems under study can be considered in the context of next generation optical networks and is offered as a model for designing the future backbone networks. In the case of different telecom...
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