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61.
Ahmet Tekin Hassan Elwan Kenneth Pedrotti 《Analog Integrated Circuits and Signal Processing》2010,65(2):225-238
In this paper, a novel universal receiver baseband approach is introduced. The chain includes a post-mixer noise shaping blocker pre-filter, a programmable-gain post mixer amplifier (PMA) with blocker suppression, a differential ramp-based novel linear-in-dB variable gain amplifier and a Sallen–Key output buffer. The 1.2-V chain is implemented in a 65-nm CMOS process, occupying a die area of 0.45 mm2. The total power consumption of the baseband chain is 11.5 mW. The device can be tuned across a bandwidth of 700-KHz to 5.2-MHz with 20 kHz resolution and is tested for two distinct mobile-TV applications; integrated services digital broadcasting-terrestrial ISDB-T (3-segment f c = 700 kHz) and digital video broadcasting-terrestrial/handheld (DVB-T/H f c = 3.8 MHz). The measured IIP3 of the whole chain for the adjacent blocker channel is 24.2 and 24 dBm for the ISDB-T and DVB-T/H modes, respectively. The measured input-referred noise density is 10.5 nV/sqrtHz in DVB-T/H mode and 14.5 nV/sqrtHz in ISDB-T mode. 相似文献
62.
Rainfall propagation impairments for medium elevation angle satellite‐to‐earth 12 GHz in the tropics
J.S. Mandeep S.I.S. Hassan M.F. Ain K. Tanaka 《International Journal of Satellite Communications and Networking》2008,26(4):317-327
Rain attenuation is the dominant propagation impairment for satellite communication systems operating at frequencies above about 10 GHz. The rainfall path attenuation at 12.255 GHz measured at Universiti Sains Malaysia (USM) for 4 years (2 January to 5 December) is presented. This paper presents an empirical analysis of rain rate and rain attenuation cumulative distribution functions obtained using 1‐min integrated rainfall data and comparison of the measured data with data obtained from well‐established rain model attenuation predictions. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
63.
This paper proposes a novel method for camera calibration using images of a mirror symmetric object. Assuming unit aspect ratio and zero skew, we show that interimage homographies can be expressed as a function of only the principal point. By minimizing symmetric transfer errors, we thus obtain an accurate solution for the camera parameters. We also extend our approach to a calibration technique using images of a 1-D object with a fixed pivoting point. Unlike existing methods that rely on orthogonality or pole-polar relationship, our approach utilizes new inter-image constraints and does not require knowledge of the 3-D coordinates of feature points. To demonstrate the effectiveness of the approach, we present results for both synthetic and real images. 相似文献
64.
Hassan Faraji Baghtash 《Analog Integrated Circuits and Signal Processing》2017,92(1):115-129
A programmable high-speed source-series-terminated driver with signal boost capability is presented. The driver uses only one main input data tap and is divided into main units and auxiliary units. A passive high pass filter is utilized to detect data transitions and control the inputs of the auxiliary units to enable a programmable amplitude boost for the output signal. The corner frequency of the high pass filter is adjusted depending on the data rate. Further, the amount of the high frequency signal boost can be adjusted depending on the loss of the channel. HSPICE simulations are used to demonstrate the performance of the driver at 10, 20 and 40 Gbps data rates. At 40 Gbps, the driver is capable of equalizing a PRBS9 data pattern signal through a channel that has a loss of 9 dB. At worst case conditions and 40 Gbps date rate, the driver achieves a differential eye-opening amplitude of 201 mVppd and an eye-opening of 0.952 UI. The driver is designed using 28 nm CMOS process and uses a nominal 1 V supply voltage. It consumes a maximum of 12 mW of at-speed power. 相似文献
65.
Rashid. A. Saeed Aisha A. Hassan Raed A. Alsaqour 《International Journal of Communication Systems》2014,27(12):3855-3873
Integrating vehicular ad hoc network (VANET) and universal mobile telecommunication system (UMTS) could be a promising architecture for future machine‐to‐machine applications. This integration can help vehicles have steady Internet connection through the UMTS network and in communicating with other vehicles. However, dead spot areas and unsuccessful handoff processes caused by the high speed of vehicles can disrupt the implementation of this kind of architecture. In this paper, a new simplified gateway selection (SGS) scheme for multihop relay in a VANET‐UMTS integration network is proposed. The proposed scheme extends the coverage or/and calming of the frequent handoff process and allows vehicles to continue to be connected to the UMTS infrastructure network. An integrated simulation environment that combines VanetMobiSim and NS2 is used to simulate and evaluate the proposed scheme. The simulation results show that the SGS scheme performed better when it was implemented with ad hoc on a demand distance vector routing and destination‐sequenced distance vector routing protocols. Furthermore, the SGS scheme is compared with other cluster‐based gateway selections used in the previous works. The results show that our SGS scheme outperforms other cluster‐based gateway selections scheme in terms of selection delay, control packet overhead, packet delivery ratio, and overall throughput. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
66.
Isma Masood Yongli Wang Ali Daud Naif Radi Aljohani Hassan Dawood 《Telematics and Informatics》2018,35(4):677-701
Patient Physiological Parameters (PPPs) seem to be the most extensively accessed and utilized Personal Health Information (PHI) in hospitals, and their utilization by the various medical entities for treatment and diagnosis creates a real threat to patient privacy. This study aims to investigate whether PPPs access in a hospital environment violates patient privacy. If so, to what extent can we manage patient privacy while accessing PPPs in this environment? We investigated this question by analyzing questionnaire-based data from two Asian countries: Group A (China) and Group B (Pakistan). For data collection, we targeted those medical entities which were directly dealing with PPPs in their routine tasks. Results suggest that patient type directly influences the collection of PPPs: Group A (one-time?=?1.9, follow-up?=?1.06) and Group B (one-time?=?2.0 and follow-up?=?1.9). Both groups agreed that patients have the right to control their own PPPs. In both, doctors are the most trusted entity: for Group A, the Pearson Chi-Square with one degree of freedom is 1.414, p?=?0.234, whereas for Group B, the Pearson Chi-Square with three degrees of freedom is 4.511, p?=?0.11. Most of the Group A entities (92%) are familiar with unauthorized access of PPPs, while in Group B the level was only 35%. In Group B, only 35% of entities stated the purpose, specification and use limitations of PPPs. Doctors in both groups showed a high utilization of PPPs read authorization rights. This empirical evidence about PPPs usage in both countries will benefit health technology and improve policy on patient privacy. 相似文献
67.
Ahmad Khasawneh Muhammad Shafie Bin Abd Latiff Omprakash Kaiwartya Hassan Chizari 《Wireless Networks》2018,24(6):2061-2075
Recently, Underwater Wireless Sensor Networks (UWSNs) has witnessed significant attention from both academia and industries in research and development, due to the growing number of applications for wide range of purposes including commercial, scientific, environmental and military. Some of the major applications include pollution monitoring, tactical surveillance, tsunami warnings and offshore exploration. Efficient communication among sensors in UWSNs is a challenging task due to the harsh environments and peculiar characteristics of UWSNs. Therefore, design of routing protocol for efficient communication among sensors and sink is one of the fundamental research themes in UWSNs. In this context, this paper proposes a location-free Reliable and Energy efficient Pressure-Based Routing (RE-PBR) protocol for UWSNs. RE-PBR considers three parameters including link quality, depth and residual energy for balancing energy consumption and reliable data delivery. Specifically, link quality is estimated using triangle metric method. A light weight information acquisition algorithm is developed for efficient knowledge discovery of the network. Multi-metric data forwarding algorithm is designed based on route cost calculation which utilizes residual energy and link quality. Simulations are carried out in NS-2 with Aqua-Sim package to evaluate the performance of RE-PBR. The performance of the proposed protocol is compared with the stat-of-the-art techniques: DBR and EEDBR. The comprehensive performance evaluation attests the benefit of RE-PBR as compared to the state-of-the-art techniques in terms of network lifetime, energy consumption, end-to-end delay and packet delivery ratio. 相似文献
68.
Hassan Faraji Baghtash Khalil Monfaredi Ahmad Ayatollahi 《Analog Integrated Circuits and Signal Processing》2012,70(1):103-112
A current operational amplifier (COA) with very high current drive capability is presented in this paper. The principle of
operation of this unique structure is discussed, its most important formulas are derived and its outstanding performance is
verified by HSPICE simulation in TSMC 0.18 μm CMOS, BSIM3, and Level49 technology. Owing to the elaborately arranged components,
the proposed circuit demonstrates very high frequency bandwidth, extremely high CMRR, high output impedance, and true rail
to rail output voltage swing range while operating at very low power supply of ±0.5 V. The interesting results such as current
drive capability of ±1 mA, high output impedance of 5 GΩ, wide gain bandwidth of 220 MHz, extremely high output voltage swing
of ±0.45 V, which interestingly provides the highest yet reported output voltage compliance for current mode building blocks
implemented by regular CMOS technology, low static power consumption of 159 μW, and very high CMRR of 155 dB is achieved utilizing
standard CMOS technology. Full process, voltage, and temperature variation analysis of the circuit is also investigated in
order to approve the well robustness of the structure. The transient stepwise and sinusoidal response analysis is also done
to verify the proposed COA stability. 相似文献
69.
Hassan Motallebi 《ETRI Journal》2020,42(3):388-398
We herein propose a heuristic redundancy selection algorithm that combines resubmission, replication, and checkpointing redundancies to reduce the resiliency overhead in fault‐tolerant workflow scheduling. The appropriate combination of these redundancies for workflow tasks is obtained in two consecutive phases. First, to compute the replication vector (number of task replicas), we apportion the set of provisioned resources among concurrently executing tasks according to their needs. Subsequently, we obtain the optimal checkpointing interval for each task as a function of the number of replicas and characteristics of tasks and computational environment. We formulate the problem of obtaining the optimal checkpointing interval for replicated tasks in situations where checkpoint files can be exchanged among computational resources. The results of our simulation experiments, on both randomly generated workflow graphs and real‐world applications, demonstrated that both the proposed replication vector computation algorithm and the proposed checkpointing scheme reduced the resiliency overhead. 相似文献
70.
Hassan Mona Bakri Alsharif Sameer Alhumyani Hesham Ali Elmustafa Sayed Mokhtar Rania A. Saeed Rashid A. 《Wireless Personal Communications》2021,116(3):2367-2390
Wireless Personal Communications - Smart Home is one of the most established applications of the Internet of Things. Almost every equipment we use in our daily life—appliances, electric... 相似文献