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In order to understand the competition and interactions between different technologies, it is of fundamental importance to study how users select these technologies operated by different network service providers (NSPs) . In this paper, we study the dynamics of user subscription by users in a wireless communication market that includes a continuum of users. First, we focus on a monopoly market with...
Multi-band orthogonal frequency division multiplexing (MB-OFDM) is an efficient approach for ultra-wideband (UWB). However, MB-OFDM is characterized by poor spectral properties that cause a high degree of spectral leakage and cyclic prefix symbol extension leads to a reduction of the bandwidth efficiency. Multicarrier transmission schemes without cyclic symbol extension require a good time-frequency...
Passive RFID technology has been widely applied, but mainly for an automatic identification of objects like in logistics applications. In this paper, as a novel approach the passive RFID system is applied to stream data transmission, where the RFID reader sends stream data and tags receive them. The extremely low power consumption of the passive tag system relieves a limited battery lifetime problem...
Hierarchical modulation (HM) offers an important coverage/throughput tradeoff for wireless communication, which involves a “base-layer” (BL) and an “enhancement-layer” (EL) bit streams. Generally, HM suffers from the severe performance degradation of the less protected EL stream. In this paper, HM with vector rotation operation introduced to EL stream is proposed, in order to improve the performance...
The following topics are dealt with: mobile computing; wireless communications; database and data mining; grid and cloud computing; ubiquitous computing; intelligent and bio-inspired computing; advanced networking; security; distributed and parallel computing; data management; workflow management; quality of services and scientific computing.
The direction of cross-layer wireless research has been prominently bottom-up, i.e., optimizing higher layer protocols based on the characteristics of the underlying wireless communication medium. Though this approach has been essential for efficient use of scarce wireless connectivity and bandwidth, there is a recent trend for massive availability of wireless resources through initiatives such as...
Traffic congestion wastes time, energy, and causes pollution. In this paper, We propose an application taking advantage of vehicular communications, namely dynamic route planning. In dynamic route planning, the route from a travel origin to its destination, instead of being statically determined at the travel starting time, is periodically recomputed according to real-time traffic information. Estimating...
Contrast to the adaptive equalization method, which need a training period, blind equalization technique, which only the output signal is known, is needed in many communication systems, such as multipoint data network or wireless communication systems. In this paper, a new blind equalization approach, called expectation maximization blind equalization (EM-BE), is proposed. First, transform the convolution...
The demand for longer battery life and faster speeds for communications circuits coupled with the exponential expansion of wireless communications devices is creating increasingly serious noise problems for communications circuits. Longer battery life means lower power consumption usually obtained by reduced noise margins that can only be achieved by better circuit design, but at least this under...
One major Disadvantage of OFDM is the high peak-to-average Power ratios (PAPR). There is a procedure for Selected Mapping (SLM) is PAPR reduction techniques for Orthogonal Frequency Division Multiplexing (OFDM). But these reduction techniques produce high computation complexity which is costly and time consuming. In this paper we proposed a scheme to reduce the computational complexity of SLM technique...
This paper presents a brief chronology of the origin and developments of wireless (or radio) communications, according to the following pattern: it gives credit to some of the scientists who performed the initial observations and the understanding of electric and magnetic phenomena; it mentions the experiments and inventions carried out towards the evolution of scientific and engineering models; and...
Mónico Sánchez Moreno (Piedrabuena (Spain) 1881, 1960) was radiology and electrotherapy pioneer who worked in New York for The Collins Wireless Telephone between 1909 and 1910. He invented a High Frequency and X-Ray Apparatus. The Collins Co. and his merged The Continental Wireless and Telegraph, Co. was involved in a worthless stocks sell campaign and many others. It describes the Collins' wireless...
Protocols such as TCP depend on loss detection and recovery algorithms to provide a reliable data delivery service. TCP detects loss events using either retransmission timeout or receipt of duplicate acknowledgements. Since, TCP does not have any explicit knowledge about the cause of packet loss, it always treats it as a congestion indication and then adjusts sending rate conservatively to maintain...
Implementation of a low cost wideband multi-channel up-convertor for future wireless communication System is reported in this paper. The up-convertor converts the IF signal of 1.45 GHz to the RF signal of 6 GHz-6.5 GHz, the channel bandwidth is 100 MHz. In order to obtain wideband LO and reduce the cost, the scheme of frequency multiplication is employed in the design of the LO. System block diagram...
This paper proposes the use of sub-GHz impulse radio Ultra-Wideband (UWB) communication for implantable medical devices. This new concept can offer a more reliable, safer and lower power consuming wireless link compared to other biomedical communications today. An operating frequency below 1 GHz is required to minimize the dielectric absorption of the human tissue and simultaneously allows for low...
Future semiconductor technologies will suffer from reliability issues, which requires a paradigm shift from the assumption of 100% reliable computations to fault-tolerant signal-processing systems. In this paper, we illustrate how the impact of unreliable circuits can be taken into account in the performance analysis of wireless communication systems. To this end, we consider the example of a multiple-input...
An modified estimation algorithm for radio communication distance along random rough surfaces (RRS) is proposed in this paper. RRSs are generated by the convolution method, and its density functions are selected Gaussian, n-th order power law and exponential spectrum. First, electromagnetic fields are calculated numerically by using the Discrete Ray-Tracing Method (DRTM). Next, the conventional estimation...
This paper studies the design of hardware system and implementation of program algorithm for emotion robot, then focuses on the specific of wireless communication subsystem and related key technique.
In this paper, a pattern reconfigurable printed quasi-Yagi antenna with slots in the directors is presented. The simulation results show that the impedance bandwidth of the proposed antenna is excellent, and the gain variation within operating bandwidth is relatively small. By controlling the states of the switches, the main beam of the proposed antenna in the xoy plane can be shifted to the one of...
An ultra low-power intelligent sensing platform has been developed by the authors. The platform is based on a novel single chip solution, designed and fabricated using a 0.18 μm CMOS technology. To that end, quad-channel low-power sensor front end sections composed of event-driven amplifiers and ADCs have been integrated with a custom low-power microcontroller and a wireless interface on...
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