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Cloud computing provides utility-oriented IT services for users worldwide, and it enables offering various kinds of applications to consumer in scientific or business field based on a pay-as-you-go model. Although cloud computing is still in its infancy, the scale of cloud infrastructure is expanding fast, which result in huge energy consumption and operating costs. Due to the complex architecture...
Golay complementary code pairs have the advantage of being biphase, available at a variety of lengths as long as desired, with complete sidelobe cancellation. But, they have the disadvantage of requiring two frequencies/channels with the possibility of inexact sidelobe cancellation due to frequency selective fading. In this paper, the complementary code pair are transmitted at the same frequency band,...
In this paper, we propose a frequency coding waveform with segment linear frequency modulation (LFM) signal for the multiple-input multiple-output (MIMO) radar. This new waveform is modified from the discrete frequency coding waveform with LFM (DFC-LFM) by changing the subpulse from the LFM signal to segment LFM and extending the contiguous waveform to a pulse train. Compared to the existing frequency...
The safety of on-duty firefighters in indoor environments could be increased by ensuring reliable, high-data rate communication in potentially life-threatening situations. This increases their situational awareness, strengthens their decision making and decreases response time by ensuring efficient indoor communication of sensor data, biometric data, pictures or videos. Therefore, a real-life rescue...
In this contribution we present the results of a channel measurement campaign carried out in indoor hall scenarios with 2 GHz bandwidth centered at 72 GHz. Horn antennas of the same type were employed at both the transmitter and the receiver. Frequency responses have been captured when the Rx horn antenna swept at 36 azimuth and 3 elevation angles with 10° interval. Then, coherence bandwidths are...
This paper deals with experimental results of Multiple-Input Multiple-Output (MIMO)-Ultra Wide Band (UWB) system. Measurement campaigns under line-of-sight (LOS) scenario using two different antenna configurations have been made in underground mine environment. Results, suggest that the channel transfer matrix depends not only on the propagation environment but also on the MIMO array configuration...
Can thermal light be represented by a mixture of single pulses? It cannot; only a modified mixture can yield the correct first-order correlation function at equal space-points. Still, this fails to reproduce higher orders.
Dynamic flows may lead to congestion, deadlock, packet loss and forwarding loops in a dedicated network. The update process is sensitive to the steps it took. Given the initial and final states of traffic distribution, diverse update strategies will generate unpredictable results, not to mention the unknown final state situations. Currently, most methods only consider about migration process. However,...
Ultra-wideband (UWB) communication techniques are highly interesting because they seek to rearrange the huge spectrum of UWB for diverse applications. Therefore, UWB is the main technique employed in communication systems for 4G wireless networks. However, several issues in UWB technology, such as interference with various existing civil and military communication systems, require resolution. In this...
The use of correlation matrices to estimate the number of uncorrelated frequency steps of the reverberation chamber field is presented and discussed. Finite-difference time-domain simulations of an actual reverberation facility are performed through an in-house parallel code. The efficiency of this code allows for capturing the field behavior through large spatial volumes. Spatial field samples are...
We discuss the use of a metric based on the amplitude variation of a channel in the signal bandwidth to predict whether or not a digital wireless communication test system receiver will be able to demodulate a test signal. This metric is compared to another method consisting of the correlation calculated across the channel. A logistic regression analysis is used to provide a normalized assessment...
Delay performance is crucial in distributed storage systems and it can greatly impact user experience. Both direct and k-access reads are common in storage systems. However, much of previous research only considers k-access reads and many schemes, such as Redundant Scheme, are only shown to reduce delay for k-access reads. We have no idea whether those existing schemes can also work for direct reads...
The paper presents methodology for analyzing compliance of Impulse Radio Ultra-Wideband (IR-UWB) communications systems with regulatory limits specified by US Federal Communications Commission (FCC). First, discrete spectral component that reduce Effective Isotropic Radiated Power (EIRP) in IR-UWB spectrum are analyzed in an exemplary IRUWB system. After that, a minimal Pulse Repetition Frequency...
In this paper, the on-body performance of three quasi-static channels was evaluated, when the human body undergoes certain typical movements. The main contribution of this work is the analysis of the impact of body movements on the performance of the on-body system in a mine environment. The quasi-static channels parameters were determined and compared to those of a corresponding static channel.
A multiple element antenna (MEA) concept is presented which is suitable for a spherical propagation scenario. The MEA structure is based on three orthogonal circular ground planes which form 8 right-angled 3D sectors and support 48 elements comprising 24 monopoles and 24 slots. It offers a benchmark performance for compact, wideband diversity/MIMO in a spherical scenario.
Massive multiple-input multiple-output (MEMO) is a potential key technology for the 5th generation (5G) of wireless communication systems. A reliable and realistic channel model serves as the enabling foundation for practical design and testing of the massive MIMO communication systems. In this paper, based on the realistic measurement conducted in open stadium environments, the frequency correlation...
The power attack protection of encryption engines often comes at the expense of area, power, and/or performance overheads making the design of a low-power and compact but secure encryption engine challenging. This paper explores the feasibility of using an on-chip low dropout regulator (LDO) as a countermeasure to power attack of low-power and compact encryption engine. We design an area minimized...
This paper presents an approach to optimizing CDMA signatures for multiple correlated sources in a sensor network when the common receiver is equipped with multiple antennas. An algorithm for determining optimal CDMA signatures under individual transmitter power constrains is presented. The numerical results show that the optimum signatures outperform orthogonal signatures by exploiting the inter-source...
We present the design and implementation of a custom GPU-based compute cluster that provides the correlation X-engine of the CHIME Pathfinder radio telescope. It is among the largest such systems in operation, correlating 32,896 baselines (256 inputs) over 400MHz of radio bandwidth. Making heavy use of consumer-grade parts and a custom software stack, the system was developed at a small fraction of...
In many radar applications, including marine, automotive and MIMO, there is a need for orthogonal transmission from different radar sets to mitigate mutual interference; the same applies to the different channels in a MIMO radar. New techniques, belonging to the cyclic algorithm family, might be used to generate orthogonal signals with, in addition, low sidelobes in their autocorrelation function...
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