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In the last years, the migration from analog to digital terrestrial television systems has favored the deployment of Single Frequency Networks (SFN), more efficient from a spectrum point of view, to provide DVB-T services in larger geographical areas through the reuse of frequencies. However, the planning of a SFN is not a trivial task, since the designer must find a trade-off between the quality...
This paper proposes a compensation scheme for both the time varying delay and the plant model uncertainty. As well known, time delay in feedback loop does not only weaken system performance, in worst-case situations it can cause system unstable. Conventional research treated the time varying delay as uncertain perturbation; however it restricts the performance of the system. In fact, the time delay...
The design and scaling of a 21 mm ?? 21 mm CMOS image sensor for charged-particle imaging, ??EM7,?? is presented and compared to its smaller prototype, EM5. The sensor contains ~50 million transistors spanning its 16 million pixels, and includes over 4,100 parallel analog processing and A/D conversion circuits, utilizing 12 parallel 10-bit readout busses for high data throughput. The clock distribution...
In this paper, the loop-delay analysis and the complexity consideration of the joint carrier synchronization and equalization algorithm for OFDM systems are presented. As a result, the loop-delay induces an additional phase lag and further gives rise to instability for the dual-loop carrier synchronization loop. In addition, the complexity consideration shows that the presented algorithm definitely...
Multicast parametric synchronous sampling (MPASS) architecture for real-time processing of optical signals based on parametric processes is reviewed. The processor uses parametric gates to obtain multiple sub-rate outputs. Operating principle and first demonstrations are described.
The frequency selectivity of wireless communication channels can be characterized by the delay spread Ds of the channel impulse response. If the delay spread is small compared to the bandwidth W of the input signal, that is, DsW ?? 1, the channel appears to be flat fading. For DsW ?? 1, the channel appears to be frequency selective, which is usually the case for wideband signals. In the first case,...
The implementation of complex functionality in low-power nano-CMOS technologies leads to enhance susceptibility to parametric disturbances (environmental, and operation-dependent). The purpose of this paper is to present recent improvements on a methodology to exploit power-supply voltage and temperature variations in order to produce fault-tolerant structural solutions. First, the proposed methodology...
The construction industry has been facing a paradigm shift to (i) increase; productivity, efficiency, infrastructure value, quality and sustainability, (ii) reduce; lifecycle costs, lead times and duplications, via effective collaboration and communication of stakeholders in construction projects. Digital construction is a political initiative to address low productivity in the sector. This seeks...
We propose and investigate a minimalistic model for distributed detection using a sensor network. The signal of interest is a priori unknown. When a signal is present, sensors receive scaled, delayed and noisy versions of it, and signal presence is decided solely based on the correlation between sensor observations. We obtain encouraging performance results for both centralized and distributed detection,...
The Niagara2 CMT system-on-chip incorporates many design-for-test features to achieve high test coverage for both arrays and logic. All the arrays are tested using memory built-in-self-test. This is supplemented with scan-based testing. Logic is tested with standard ATPG for slow-speed defects and extensive use of transition test, along with logic built-in-self-test for the SPARC cores, for at-speed...
In this paper, an energy efficient adaptive modulation scheme is proposed for a wireless cognitive radio ad hoc network, where each node is equipped with cognitive radio and the network is an OFDMA system operating on time slots. In each slot, the users with new traffic demand will sense the spectrum and locate the available subcarrier set. Then they choose subcarriers with favorable channel condition...
Timing-error detection and recovery circuits are implemented in a 65 nm resilient circuit test-chip to eliminate the clock frequency guardband from dynamic supply voltage (VCC) and temperature variations as well as to exploit path-activation probabilities for maximizing throughput. Two error-detection sequential (EDS) circuits are introduced to preserve the timing-error detection capability of previous...
Class D amplifiers are becoming the most feasible solution for embedded audio application. However, distortions due to the non-linear nature of switching stage are the main drawback for this amplifier topology. This paper discusses the design and implementation of high fidelity audio class D using sliding mode control scheme. This design method proves to be a cost effective solution for industrial...
In the context of networks providing QoS guarantees, the end-to-end delay experienced by a packet is an important parameter. In this paper, we show that network coding can be used to decrease worst case end-to-end bounds when compared to a classical routing strategy. This result can be explained by the fact that network coding can cope with congestion better that classical routing due to its property...
In this paper, we propose a robust STBC transmission scheme to combat the timing synchronization errors over frequency-selective multiple-access channels. First, the equivalent channel model in the presence of timing synchronization errors is derived and we find that the synchronization errors result in an equivalent channel model with larger number of correlated channel taps. Based on this correlated...
Li and Xia have recently investigated the design of space-time codes that achieve full spatial diversity for asynchronous cooperative communications. They show that certain of the binary space-time trellis codes derived from the Hammons-El Gamal stacking construction are delay tolerant and can be used in the multilevel code constructions by Lu and Kumar to produce delay tolerant space-time codes for...
Expected growth in use and implementation of wireless sensor networks (WSNs) in different environments and for different applications creates new security challenges. In WSNs, a malicious node may initiate incorrect path information, change the contents of data packets, and even hijack one or more genuine network nodes. As the network reliability completely depends on individual nodespsila presence...
Three applications in wireless networks where model-free stochastic learning is applicable, are discussed. The learning based optimization problems are formulated and simulation results are presented. Some open issues are also discussed.
We designed and built a novel all-optical re-timing, re-amplifying, and re-shaping (3R) regeneration system based on terahertz optical asymmetric demultiplexers (TOADs) developed in our laboratory. The system is capable of parallel processing multiple wavelengths, a feature which will significantly improve the scalability of current wavelength division multiplexing (WDM) networks. Performance against...
This contribution addresses the case when live packet-switched video is used to enrich circuit-switched speech calls in mobile telephony. Circuit-switched and packet-switched transmissions generally operate on completely different transmission paths resulting in different QoS in terms of delay and loss rates. In this case, video and audio data recorded at the same time are not multiplexed together...
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