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This article proposes a joint source-channel coding technique for two-dimensional (2D) binary Markov sources by using concatenated turbo block codes composed of two Bose, Chaudhuri, Hocquenghem (BCH) codes, of which output is followed by a rate-1 recursive systematic convolutional code. The source correlation of all rows and columns of the 2D source is well exploited by using a modified Bahl–Cocke–Jelinek–Raviv...
Software-defined radio (SDR) describes radio transceivers implemented in software that executes on general-purpose hardware. SDR combined with cloud computing technology will reshape the wireless access infrastructure, enabling computing resource sharing and centralized digital-signal processing (DSP). SDR clouds have different constraints than general-purpose grids or clouds: real-time response to...
This article presents a hybrid adaptive multi-carrier architecture that, according to the channel condition, wisely switches between orthogonal frequency division multiplexing (OFDM) and orthogonal filtered multitone (FMT) modulations. This new scheme is referred to as hybrid-FMT (H-FMT). For H-FMT, the problem of jointly allocating the sub-channels powers, the overhead duration, and the modulation...
We consider a multi-hop virtual multiple-input-multiple-output system, which uses the framed ALOHA technique to select the radio resource at each hop. In this scenario, the source, destination and relaying nodes cooperate with neighboring devices to exploit spatial diversity by means of the concept of virtual antenna array. We investigate both the optimum number of slots per frame in the slotted structure...
Users in a cellular network can move while their connections are handed off to different access points. Studies prove that the mobility pattern followed have a strong impact on performance metrics (i.e., handoff (HO) rate, cell residence time). Recently, some key aspects of the Random Waypoint mobility model have been studied in depth, but relating those studies with different cellular layouts has...
An easy-to-implement approach to allocate downlink data bursts in IEEE 802.16e (mobile WiMAX) frames is proposed. With the proposed allocation scheme, each mobile station can employ a decision-directed channel estimation method without demodulating data bursts destined for other stations. Three decision-directed channel estimation methods, each with different computational complexity, are suggested...
Estimating the spectrogram of non-stationary signal relates to many important applications in radar signal processing. In recent years, coprime sampling and array attract attention for their potential of sparse sensing with derivative to estimate autocorrelation coefficients with all lags, which could in turn calculate the power spectrum density. But this theoretical merit is based on the premise...
To solve the instant signal convergence of wireless sensing network transmission system, this study proposes an improved constant modulus algorithm. The improved constant modulus algorithm can quickly find the convergent direction by adding error functions and learning rates based on the reserved original cost functions. After processed by a matched filter, the received consecutive time signal can...
Blind recognition of space-time block codes (STBCs) used in multiple transmitter communication is an important research topic in the non-cooperative scenario, which has attracted more and more attention recently. However, all of the current recognition algorithms can only work well in multiple-input multiple-output system, i.e., the system employs multiple receive antennas. To our knowledge, there...
A conventional angle diversity receiver uses multiple receiving elements that are oriented in different directions, where each element employs its own filter and nonimaging concentrator, such as a compound parabolic concentrator (CPC) or hemispheric lens. In this paper, a study of the design of a conventional receiver structure using angle diversity that offers improved performance with respect to...
Broadcast is a fundamental operation in wireless networks. To this end, many past studies have studied the NP-hard, broadcast problem for always-on multi-hop networks. However, in wireless sensor networks, nodes are powered by batteries, meaning, they have finite energy. Consequently, nodes are required to have a low duty cycle, whereby they switch between active and sleep state periodically. This...
In some mobile wireless sensor network applications, it is not necessary to monitor the entire field all the time, and only a number of critical points or points of interest (POIs) need to be monitored periodically. In this paper, we address the minimum-delay POIs coverage in mobile wireless sensor networks problem with cost restriction, which is how to schedule the limited number of mobile sensors...
Intersession network coding (NC) can provide significant performance benefits via mixing packets at wireless routers; these benefits are especially pronounced when NC is applied in conjunction with intelligent scheduling. NC, however, imposes certain processing operations, such as encoding, decoding, copying, and storage. When not utilized carefully, all these operations can induce tremendous processing...
Rapidly rising energy costs and increasingly rigid environmental standards have led to an emerging trend of addressing “energy efficiency” aspect of wireless communication technologies. Cognitive radio can play an important role in improving energy efficiency in wireless networks, because from the green perspective, spectrum is a natural resource which should not be wasted but be shared. In this article,...
The ability to determine in real-time the geographic location of client nodes is an important tool in wireless networks, allowing instantaneous mobile tracking, implementation of location-aware services and also efficient channel and power allocation planning. Among existing classical cooperative localization techniques for wireless networks, the maximum likelihood estimator (MLE) is theoretically...
In this article, we present an intelligent context-aware energy management for saving home energy consumption using activities of daily living. In order to extract energy-consuming patterns, we analyze daily activities, which are collected from location sensors and electronic appliances. In addition, we construct an energy management model using the incremental statistical method, which is improved...
Alamouti space–frequency coding provides additional frequency diversity, especially in multipath propagation environments. This article addresses a new modeling of the Alamouti code multiple input single output (MISO) in a single frequency network(SFN) for two, three, and four transmitters, and different types of coding and modulations in the DVB-T2 (Digital Video Broadcasting Terrestrial second generation)...
The performance of multiple-input multiple-output systems using spatial multiplexing can be degraded when the spatial information channels are correlated. This work proposes a solution to this problem, which is based on a cooperative wireless communication system. Within the cooperative system, the relay is selected either randomly or using the smart selection scheme, a simple and distributed approach...
In this paper, a heterogeneous network composed of femtocells deployed within a macrocell network is considered, and a quality-of-service (QoS)-oriented fairness metric which captures important characteristics of tiered network architectures is proposed. Using homogeneous Poisson processes, the sum capacities in such networks are expressed in closed form for co-channel, dedicated channel, and hybrid...
Relayed transmission in a cognitive radio (CR) environment could be used to increase the coverage and capacity of communication system that benefits already from the efficient management of the spectrum developed by CR. Furthermore, there are many types of cooperative communications, including decode-and-forward (DAF) and amplify-and-forward (AAF). In this paper, these techniques are combined in an...
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