共查询到20条相似文献,搜索用时 15 毫秒
1.
Helleseth T. Kholosha A. Ness G.J. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(6):2236-2245
Considered is the distribution of the cross correlation between in-sequences of length 22k -1, where m = 2k, and m-sequences of shorter length 2k -1. New pairs of m -sequences with three-valued cross correlation are found and the complete correlation distribution is determined. Finally, we conjecture that there are no more cases with a three-valued cross correlation apart from the ones proven here. 相似文献
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《IEEE transactions on circuits and systems. I, Regular papers》2009,56(1):60-73
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This letter presents the results of an enhancement mode metamorphic high-electron-mobility transistor device on a GaAs substrate with a 70% indium composition channel. A 35-nm gate length device exhibits a 490-GHz current gain cutoff frequency (fT), a transconductance (gm) of 2 S/mm, a threshold voltage (Vth) of 0.11 V (enhancement mode) and a low on- resistance of 0.37 Omega mm. These attributes make the device well- suited for millimeter-wave circuit applications. 相似文献
5.
Cornelissens K. Steyaert M. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2008,55(5):389-393
This brief discusses the design tradeoffs for cascaded delta-sigma (DeltaSigma) analog-to-digital converters. Increasing the order of the first loop allows a tradeoff between aggressive noise shaping and moderate operational transconductance amplifier (OTA) specifications. A comparison between fourth-order topologies indicates that for a cascade 3-1 topology, 55-dB OTA gain is sufficient for 96-dB signal-to-noise-distortion ratio while 5% coefficient mismatch results in less than 4-dB degradation. Dependent on the ratio between the power consumption of the digital recombination and decimation filter and that of the analog loop filter, the optimal topology can be chosen. A cascade 3-1 converter is most efficient when this ratio lies between 0.54 and 0.97. A design in a 65-nm CMOS technology demonstrates the performance of a cascade 3-1 converter. 相似文献
6.
A Design Approach for Power-Optimized Fully Reconfigurable $Delta Sigma$ A/D Converter for 4G Radios
Yi Ke Craninckx J. Gielen G. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2008,55(3):229-233
This paper presents a novel design approach for fully reconfigurable low-voltage delta-sigma analog-digital converters for next-generation wireless applications. This approach guides us to find the power-optimal solution corresponding to the specifications of various wireless standards by exploring single-loop feedback and feedforward topologies with different filter order, number of quantizer bits, and oversampling ratios. Unlike previous multimode designs, this approach provides a better power efficiency. Based on this approach, a system-level design of a digitally programmable delta-sigma modulator for 4G radios is presented. 相似文献
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《Electron Device Letters, IEEE》2008,29(11):1236-1238
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《Electron Device Letters, IEEE》2009,30(2):152-154
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《Electron Device Letters, IEEE》2009,30(1):5-7
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《Electron Device Letters, IEEE》2009,30(8):837-839
11.
Adachi S. Woonghee Lee Akahane N. Oshikubo H. Mizobuchi K. Sugawa S. 《Solid-State Circuits, IEEE Journal of》2008,43(4):823-830
A high-sensitivity CMOS image sensor keeping a high full-well capacity has been developed by introducing a new pixel having a small floating diffusion (FD) capacitance connected to a lateral overflow integration capacitor (LOFIC) through a MOS switch. The conceptual advantage of the small FD approach over conventional column amplifier approaches is compared and demonstrated. To ensure both the high sensitivity and the high full-well capacity, the low-light and the bright-light signals (S1 and S2) are output and reproduced without a visible SNR degradation at the S1/S2 switching point. As the most critical problem, the increase of the conversion gain variation in this approach is suppressed by applying a self-aligned offset structure to the small FD. A 1/4-in VGA format CMOS image sensor fabricated through 0.18-mum 2P3M process achieves 2.2-e- rms noise floor with 200-muV/e- conversion gain and 100-ke- full-well capacity. 相似文献
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《Electron Devices, IEEE Transactions on》2009,56(9):1897-1903
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Saab R. Yilmaz O. McKeown M.J. Abugharbieh R. 《Signal Processing, IEEE Transactions on》2007,55(8):4004-4017
In this paper, we address the problem of underdetermined blind source separation (BSS) of anechoic speech mixtures. We propose a demixing algorithm that exploits the sparsity of certain time-frequency expansions of speech signals. Our algorithm merges lscrq -basis-pursuit with ideas based on the degenerate unmixing estimation technique (DUET) [Yiotalmaz and Rickard, "Blind Source Separation of Speech Mixtures via Time-Frequency Masking," IEEE Transactions on Signal Processing, vol. 52, no. 7, pp. 1830-1847, July 2004]. There are two main novel components to our approach: 1, our algorithm makes use of all available mixtures in the anechoic scenario where both attenuations and arrival delays between sensors are considered, without imposing any structure on the microphone positions, and 2, we illustrate experimentally that the separation performance is improved when one uses lscrq-basis-pursuit with q < 1 compared to the q = 1 case. Moreover, we provide a probabilistic interpretation of the proposed algorithm that explains why a choice of 0.1 les q les 0.4 is appropriate in the case of speech. Experimental results on both simulated and real data demonstrate significant gains in separation performance when compared to other state-of-the-art BSS algorithms reported in the literature. 相似文献
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A combined k-out-of-n:F(G) & consecutive kc -out-of-n :F(G) system fails (functions) iff at least k components fail (function), or at least fcc consecutive components fail (function). Explicit formulas are given for the lifetime distribution of these combined systems whenever the lifetimes of components are exchangeable, and have an absolutely continuous joint distribution. The lifetime distributions of the aforementioned systems are represented as a linear combination of distributions of order statistics by using the concept of Samaniego's signature. Formulas for the mean lifetimes are given. Some numerical results are also presented. 相似文献
15.
Hoover R.C. Maciejewski A.A. Roberts R.G. 《IEEE transactions on image processing》2009,18(11):2562-2571
Eigendecomposition represents one computationally efficient approach for dealing with object detection and pose estimation, as well as other vision-based problems, and has been applied to sets of correlated images for this purpose. The major drawback in using eigendecomposition is the off line computational expense incurred by computing the desired subspace. This off line expense increases drastically as the number of correlated images becomes large (which is the case when doing fully general 3-D pose estimation). Previous work has shown that for data correlated on S 1 , Fourier analysis can help reduce the computational burden of this off line expense. This paper presents a method for extending this technique to data correlated on S 2 as well as SO(3) by sampling the sphere appropriately. An algorithm is then developed for reducing the off line computational burden associated with computing the eigenspace by exploiting the spectral information of this spherical data set using spherical harmonics and Wigner-D functions. Experimental results are presented to compare the proposed algorithm to the true eigendecomposition, as well as assess the computational savings. 相似文献
16.
The electrical characteristics of germanium p-metal-oxide-semiconductor (p-MOS) capacitor and p-MOS field-effect transistor (FET) with a stack gate dielectric of HfO2/TaOxNy are investigated. Experimental results show that MOS devices exhibit much lower gate leakage current than MOS devices with only HfO2 as gate dielectric, good interface properties, good transistor characteristics, and about 1.7-fold hole-mobility enhancement as compared with conventional Si p-MOSFETs. These demonstrate that forming an ultrathin passivation layer of TaOxNy on germanium surface prior to deposition of high-k dielectrics can effectively suppress the growth of unstable GeOx, thus reducing interface states and increasing carrier mobility in the inversion channel of Ge-based transistors. 相似文献
17.
Cheng C.H. Lin S.H. Jhou K.Y. Chen W.J. Chou C.P. Yeh F.S. Hu J. Hwang M. Arikado T. McAlister S.P. Chin A. 《Electron Device Letters, IEEE》2008,29(8):845-847
We report Ir/TiO2/TaN metal-insulator-metal capacitors processed at only 300degC, which show a capacitance density of 28 fF/mum2 and a leakage current of 3 times 10-8 (25degC) or 6 times 10-7 (125degC) A/cm2 at -1 V. This performance is due to the combined effects of 300degC nanocrystallized high-kappa TiO2, a high conduction band offset, and high work-function upper electrode. These devices show potential for integration in future very-large-scale-integration technologies. 相似文献
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《Electron Device Letters, IEEE》2009,30(1):39-41
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Pesenti S. Clement P. Kayal M. 《IEEE transactions on circuits and systems. I, Regular papers》2008,55(4):1011-1022
Multibit feedback, being one way of lowering DeltaSigma modulators power consumption, has a major obstacle: the number of components in the internal analog-to-digital converter (ADC) and digital-to-analog converter (DAC). Nevertheless, the number of comparators in the ADC can be significantly reduced depending on the order of noise-shaping and the oversampling ratio. In this paper, we propose an auto-ranging algorithm with a mechanism to keep the structure stable that emulates more quantization levels than that allowed by the number of comparators. As the recourse to segmented DACs allows lowering the complexity of the mismatch shaping encoder, the auto-ranging ADC brings the benefits of multibit feedback without the usual increase in size and power consumption. The internal number of bits in DeltaSigma modulators is no more restricted by the difficulty of building the flash ADC with a low voltage supply. 相似文献
20.
《IEEE transactions on circuits and systems. I, Regular papers》2008,55(9):2469-2482