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Network bandwidth and server capacity are gradually becoming overloaded due to high demand and rapid evolution of high quality multimedia services over the Internet. Internet Protocol Television (IPTV) is among the multimedia services that demand more of network and server resources, especially with the emergence of Mobile IPTV. It is imperative for service providers to maintain good quality management...
Physical-layer network coding (PNC) can significantly improve the throughput of wireless communication systems by exploiting signal superimposition at relays. It is practically challenging to achieve symbol alignment in PNC. In this paper, we study the impact of the signal power loss and the inter-symbol-interference (ISI) on the system performance when the symbols are not aligned. We show that when...
Spurred by the industrial demands for terabyte/s bandwidth graphics module, high bandwidth memory (HBM) has been emerged to overcome the limitations of conventional DRAMs. Additionally, due to the fine pitch and high density interconnect routing between GPU and 4 HBMs in 2.5D terabyte/s bandwidth graphics module, HBM interposer has also been to the force. However, several signal integrity issues of...
System-on-Chip (SOC) designs composed of many embedded cores are ubiquitous in today's integrated circuits. Each of these cores requires to be tested separately after manufacturing of the SoC. That's why, modular testing is adopted for core-based SoCs, as it promotes test reuse and permits the cores to be tested without comprehensive knowledge about their internal structural details. Such modular...
Graphene has become a hot topic since it was discovered. However, articles about using graphene in passive devices, especially the GHz band antennas for modern communication application, have been less reported so far. In this work, a dipole antenna printed on a substrate is proposed and experimentally investigated, where the graphene sheet is connected to the ends of the dipole. This dipole is designed...
The next generation of mobile communication can increase the data transfer rate in the limited bandwidth of high-capacity transmission. The space-time coding technique is the important technology to solve the bandwidth problem based on OFDM (orthogonal frequency division multiplexing), it can take full advantage of multi-scattering wireless channel which caused by multipath environment by enhancing...
In this paper, a novel autonomous antenna-beamwidth control is proposed for safety applications operating in vehicular ad hoc networks that typically rely on periodical single-hop broadcast transmissions. Specifically, in our proposed scheme, the antenna beamwidth is varied according to the vehicular speed. Varying the beamwidth allows us to attain a higher quality of service, because the effective...
Transmitting multi-sine signals with high peak-to-average power ratio (PAPR) has emerged as an efficient solution to improve the power conversion efficiency (PCE) of wireless power transfer (WPT). This paper analyzes the radio frequency (RF) PCE as a function of the number of tones (Nt) and signal bandwidth (BW) in multi-sine based WPT networks. We show how the energy harvesting efficiency depends...
A two-stage Miller-compensated amplifier with Gm-boosting (MCG) is introduced in this paper. The design involves the conventional two-stage amplifier and a proposed wide-bandwidth scalar circuit that amplifies the output signal voltage at the first stage of the conventional two-stage amplifier. The wide-bandwidth scalar circuit has very short delay so that the non-dominant pole and right-half-plane...
Among various protection and restoration schemes it is hard to decide which is the best to be used in a certain situation. First, we propose a method to find the best possible shared protection scheme among all possible shared protection schemes. We provide optimisation and simulation results. Second, we prove the optimality of the proposed method in terms of minimal resource usage for any single...
Spurred by the industrial demands for terabyte/s bandwidth graphics module, high bandwidth memory (HBM) has been emerged to overcome the limitations of conventional DRAMs. Additionally, due to the fine pitch and high density interconnect routing between GPU and 4 HBMs in 2.5D terabyte/s bandwidth graphics module, HBM interposer has also been to the force. However, several signal integrity issues of...
Recently, there is an increasing interest for operating long term evolution (LTE) in unlicensed bands (i.e., LTE-U). Up to date, only a few studies have been reported to show the performance of LTE-U. In this work, we first modify the LENA LTE module in the ns-3 simulator and present extensive simulation results in terms of TCP goodput under LTE-U handover scenarios. Simulation results reveal that...
To reduce an adjacent channel interference (ACI) by sharpening the spectrum edges of the orthogonal frequency division multiplexing (OFDM) signal in the frequency domain, an windowing function is applied to the individual OFDM symbols in time domain. A commonly used windowing function is the raised cosine function with a roll-off factor. In this paper, the spectrum of an OFDM signal and −45 dB bandwidth...
This paper analyzes delays and resource efficiency when DASH segment files are transmitted through IP-based next-generation broadcasting systems such as ATSC 3.0. DASH segment files are designed to support media content of various qualities in the DASH system. The size of a DASH segment file can vary even though they may have the same quality and playback time. As the quantity of media content such...
In order to integrate renewable energy into the utility grid with high penetration, AC/DC hybrid microgrids have obtained much attentions in recent years since they feature both advantages of AC microgrids and DC microgrids. In an AC/DC hybrid microgrid, the parallel-operated AC/DC bi-directional interfacing converters (IFCs) are key elements to connect AC bus and DC bus. When unbalanced grid faults...
Today's scientific applications increasingly involve large amounts of input/output data that must be moved among multiple computing facilities via wide-area networks (WANs). The bandwidth of WANs, however, is growing at a much smaller rate and thus becoming a bottleneck. Moreover, the network bandwidth has not been viewed as a limited resource, and thus coordinated allocation is lacking. Uncoordinated...
In order to estimate the DL cell average throughput of LTE network, the paper proposes an algorithm of LTE throughput based on MCS level distribution which can be used to estimate the DL cell capacity under different load conditions. The algorithm is convenient for operation and useful in guiding network planning and optimization, the simulation results show that the algorithm is effective and the...
In this paper, we study joint topology management and energy cooperation in cellular networks. The topology management scheme transfers users (traffic) from one base station (BS) to another BS by adjusting the cell- size of the BSs, and the energy cooperation scheme transfers harvested energy from one BS to another BS. We first formulate a joint topology management and energy cooperation problem which...
This paper proposes a frequency selective surface (FSS) design to be used in Wi-Fi applications as either a reject or pass band single-layer filter. This design consists of a combination of canonical elements, i.e. ring loops/slots, and is tuned for both 2.4 and 5.2 GHz Wi-Fi frequency bands. It has a stable frequency response in the aforementioned Wi-Fi bands for incidence angles ranging from 0°...
X-band reconfigurable reflectarray (RRA) cells having two, three, and four discrete reflection phase states are presented in this paper. The cell topology enables independent dynamic reflection phase control of each linear component of a dual-polarized wave. The reflection phase step deviation is smaller than the quantization error in 12.5% bandwidth for the two and three states designs and in 6.5%...
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