SEP calculations for coherent M‐ary FSK in different fading channels with MRC diversity

In this paper, the authors derive symbol error probability (SEP) expressions for coherent M‐ary frequency shift keying (MFSK) modulation schemes in multipath fading channels. The multipath or small‐scale fading process is assumed to be slow and frequency non‐selective. In addition, the channel is also subjected to the usual degradation caused by the additive white Gaussian noise (AWGN). Different small‐scale fading statistics such as Rayleigh, Rician (Nakagami‐n), Hoyt (Nakagami‐q), and Nakagami‐m have been considered to portray diverse wireless environments. Further, to mitigate fading effects through space diversity, the receiver front‐end is assumed to be equipped with multiple antennas. Independent and identically distributed (IID) as well as uncorrelated signal replicas received through all these antennas are combined with a linear combiner before successive demodulation. As the detection is coherent in nature and thus involves phase estimation, optimum phase‐coherent combining algorithms, such as predetection maximal ratio combining (MRC), may be used without any added complexity to the receiver. In the current text, utilizing the alternate expressions for integer powers (1≤n≤4) of Gaussian Q function, SEP values of coherent MFSK are obtained through moment generating function (MGF) approach for all the fading models (with or without MRC diversity) described above. The derived end expressions are composed of finite range integrals, which can be numerically computed with ease, dispenses with the need of individual expressions for different M, and gives exact values up to M=5. When the constellation size becomes bigger (M≥6), the same SEP expressions provide a quite realistic approximation, much tighter than the bounds found in previous literatures. Error probabilities are graphically displayed for each fading model with different values of constellation size M, diversity order L, and for corresponding fading parameters (K, q, or m). To validate the proposed approximation method extensive Monte‐Carlo simulations were also performed, which show a close match with the analytical results deduced in the paper. Both these theoretical and simulation results offer valuable insight to assess the efficacy of relatively less studied coherent MFSK in the context of the optimum modulation choice in wireless communication. Copyright © 2010 John Wiley & Sons, Ltd.     

Multichannel Sonocatalysis Amplifiers Target IDH1-Mutated Tumor Plasticity and Attenuate Ros Tolerance to Repress Malignant Cholangiocarcinoma

Tumor adaptation-originated tumor tolerance that compensatory mechanisms (e.g., isocitrate dehydrogenase (IDH) mutation) jointly shape is the dominant obstacle of ROS therapy. Currently, targeting a single pathway fails to fundamentally reverse the complex milieu and diminish tumor adaptation. Herein, a multichannel sonocatalysis amplifier is engineered via one-pot gas diffusion method to attenuate IDH1-mutated cholangiocarcinoma plasticity and tolerance to ROS therapy, wherein triptolide and IR780 are co-loaded in DSPE-mPEG-modified CaCO₃ nanoparticles. Triptolide can blockade Nrf2 to cut off glutathione biosynthesis via blockading proteomic communication, and disrupt redox homeostasis to potentiate IR780-mediated sonocatalytic ROS production. ROS-induced mitochondria damages disrupt Ca²⁺ homeostasis and in turn aggravate ROS accumulation, which cooperates with sonocatalysis and Nrf2 blockade to reprogram mitochondrial energy and substance metabolism (e.g., adenosine triphosphatase and glutathione), hinder DNA self-repair, and impair IDH1-mutation-asired tolerance. Systematic experiments support that these actions in such multichannel sonocatalysis amplifiers indeed disrupt Ca²⁺/redox homeostasis to disarm robust tumor plasticity and IDH1-mutation-induced tolerance to sonocatalysis therapy against IDH1-mutated cholangiocarcinoma progression. Briefly, the sonocatalysis amplifiers pave a comprehensive avenue to reprogram tumor metabolism, target tumor vulnerability, and attenuate tumor plasticity against genomic instability-raised treatment adaptation.     

电镀均匀性影响因素探究及改善

通过研究电镀过程中浮架、钛篮、液位对电镀均匀性影响,合理布局电镀铜缸体,改善电镀均匀性。同时找出影响均匀性能力主要影响因素,为均匀性提升提供改善依据。并提出可行性建议,给整个电镀能力提升提供思路及方向。     

470-MHz–698-MHz IEEE 802.15.4m Compliant RF CMOS Transceiver

This paper proposes an IEEE 802.15.4m compliant TV white-space orthogonal frequency-division multiplexing (TVWS)-(OFDM) radio frequency (RF) transceiver that can be adopted in advanced metering infrastructures, universal remote controllers, smart factories, consumer electronics, and other areas. The proposed TVWS-OFDM RF transceiver consists of a receiver, a transmitter, a 25% duty-cycle local oscillator generator, and a delta-sigma fractional-N phase-locked loop. In the TV band from 470 MHz to 698 MHz, the highly linear RF transmitter protects the occupied TV signals, and the high-Q filtering RF receiver is tolerable to in-band interferers as strong as −20 dBm at a 3-MHz offset. The proposed TVWS-OFDM RF transceiver is fabricated using a 0.13-μm CMOS process, and consumes 47 mA in the Tx mode and 35 mA in the Rx mode. The fabricated chip shows a Tx average power of 0 dBm with an error-vector-magnitude of < 3%, and a sensitivity level of −103 dBm with a packet-error-rate of < 3%. Using the implemented TVWS-OFDM modules, a public demonstration of electricity metering was successfully carried out.     

Structural design of current-mode biquad filters

This work describes how to generate and design a novel current-mode biquad filter model using tunable multiple-output operational transconductance amplifiers and grounded capacitors (MO-OTA-Cs) for synthesizing both transmission poles and zeros. Transfer functions of low-pass, band-pass, high-pass, notch and all-pass are realized based on the filter model. The theory focuses mainly on establishing a relationship between the cascaded MO-OTA-Cs and the multiple-loop feedback matrix, which makes the structural generation and design formulas. All the filter architectures contain only grounded capacitors, which can absorb parasitic capacitances and require smaller chip areas than floating ones. The simulation results are also presented to confirm the theoretical analysis.     

An Efficient Architecture for a Lifted 2D Biorthogonal DWT

This paper presents a new algorithm for a 2D non-separable lifted bi-orthogonal wavelet transform. The algorithm is derived by factoring complementary pairs of wavelet transform 2D filters. The results are efficient architectures for real time signal processing, which do not require transpose memory for the 2D processing of data. The proposed architecture exploits in place implementation, inherit from the algorithm, and can take advantage of both vertical and horizontal parallelism in the direct implementation. The processing in our architecture is scheduled by carefully pipelining the lifted steps, which allows for up to four times faster processing than the direct implementation. The proposed architecture operates at high speed, consumes low power and has reduced computational complexity as compared to previously published filter and lifted based bi-orthogonal wavelet architectures.M. Alam (Student) is currently M.Sc. student in the Department of Electrical and Computer Engineering at University of Calgary. His research interest includes VLSI signal processing. He is recipient of iCORE International Graduate Scholarship.Wael Badawy (Ph.D. 00, M.Sc 98, 97; B.Sc. 94) is an associate professor in the Department of Electrical and Computer Engineering. He holds an adjunct professor in the Department of Mechanical Engineering, University of Alberta.Dr. Badawys research interests are in the areas of: Microelectronics, VLSI architectures for video applications with low-bit rate applications, digital video processing, low power design methodologies, and VLSI prototyping. His research involves designing new models, techniques, algorithms, architectures and low power prototype for novel system and consumer products. Dr. Badawy authored and co-authored more than 100 peer reviewed Journal and Conference papers and about 30 technical reports. He is the Guest Editor for the special issue on System on Chip for Real-Time Applications in the Canadian Journal on Electrical and Computer Engineering, the Technical Chair for the 2002 International Workshop on SoC for real-time applications, and a technical reviewer in several IEEE journals and conferences. He is currently a member of the IEEE-CAS Technical Committee on Communication. Dr. Badawy was honored with the 2002 Petro Canada Young Innovator Award, 2001 Micralyne Microsystems Design Award and the 1998 Upsilon Pi Epsilon Honor Society and IEEE Computer Society Award for Academic Excellence in Computer Disciplines. He is currently the Chairman of the Canadian Advisor Committee (CAC) and Head of the Canadian Delegation on ISO/IEC/JTC1/SC6 Telecommunications and Information Exchange Between Systems. Member, The Canadian Advisory Committee for the Standards Council of Canada-Subcommittee 29: Coding of Audio, Picture Multimedia and Hypermedia Information, and Canadian Delegate, The ISO/IEC MPEG standard committee. He is a voting Member on the VSI Alliance. He is also the Chair of the IEEE-Southern Alberta Society-Computer Chapter.Vassil S. Dimitrov was born in Plovdiv, Bulgaria, in 1964. He received his Ph.D. degree in mathematics in 1995 from the Mathematical Institute of the Bulgarian Academy of Sciences. Since then, he has spent two years as a postdocral fellow at the VLSI Research Group, University of Windsor, Canada, one year as a research scientist at the Reliable Software Technology Corporation, Virginia, USA, one year as a chief research scientist at the Signal Processing and Computer Technology Laboratory, Helsinki University of Technology, Finland, and one year as an Associate Professor at the University of Windsor, Canada. Since July 2001 he has held the position of Associate Professor at the Department of Electrical and Computer Engineering, University of Calgary, Canada. His main interests are in the area of number theoretic algorithms, computational complexity, cryptography, optimization theory, fast algorithms for digital signal processing and related topics. Dr. Dimitrov is a member of the New York Academy of Sciences.Graham Jullien (Fellow IEEE) was educated in the United Kingdom, receiving degrees, in Electrical Engineering, from the Universities of Loughborough, Birmingham and Aston (Ph.D., 1969). He was a student engineer and data processing engineer at English Electric Computers, UK, from 1961 to 1966, and a visiting senior research engineer at the Central Research Laboratories of EMI Ltd., UK, from 1975 to 1976. From 1969 until 2000 he was with the Department of Electrical and Computer Engineering at the University of Windsor, Ontario, Canada, where he held the rank of University Professor and was the Director of the VLSI Research Group. Since January 2001, he has been with the Department of Electrical and Computer Engineering at the University of Calgary, where he holds the iCORE Research Chair in Advanced Technology Information Processing Systems. He is a member of the Board of Directors of the Canadian Microelectronics Corporation (CMC) and is a member of the Steering Committee and Board of Directors of the Micronet Network of Centres of Excellence. He has published widely in the fields of Digital Signal Processing, Computer Arithmetic, Neural Networks and VLSI Systems, and teaches courses in related areas. He has served on the technical committees of many international conferences; he currently serves on the Editorial Board of the Journal of VLSI Signal Processing; and is a past Associate Editor of the IEEE Transactions on Computers. He hosted and was program co-chair of the 11th IEEE Symposium on Computer Arithmetic, was program chair for the 8th Great Lakes Symposium on VLSI, and was the technical program chair for the 1999 Asilomar Conference on Signals, Systems and Computers. He is general chair for the 2003 Asilomar Conference and general co-chair of the International Workshop on System-on-Chip for Real-Time Systems, Calgary, Alberta 2003.     

LD端面泵浦的1.57μm内腔式OPO

1.57 μm波长激光为人眼安全波长激光。将KTP晶体置于一个由LD端面泵浦、声光调Q的Nd:YVO4晶体双凹谐振腔内,利用KTP表面镀膜建立了内腔式OPO,实现了重复率在5～40 kHz范围内1.57 μm脉冲激光的稳定输出。实验结果表明,激光的阈值将随声光调Q器重复率的增加而升高,重复率为5 kHz时得到最低阈值1.52 W。重复率为15 kHz、泵浦功率为3.7 W时,输出光平均功率为305 mW,脉冲宽度50 ns,峰值功率400 W。     

基于VHDL可编程m序列发生器的研制

提出一种可实现周期／初相位编程控制的m序列发生器逻辑电路的设计方案。给出了VHDL与CPLD的实现方案。程序经编译、仿真、测试后，可以实现设计要求。该器件在MCS51的控制下，实现m序列的周期、初相位的编程变化．     

Local Electronic Structure Modulation Enables Fast-Charging Capability for Li-Rich Mn-Based Oxides Cathodes With Reversible Anionic Redox Activity

Anionic and cationic redox chemistries boost ultrahigh specific capacities of Li-rich Mn-based oxides cathodes (LRMO). However, irreversible oxygen evolution and sluggish kinetics result in continuous capacity decay and poor rate performance, restricting the commercial fast-charging cathodes application for lithium ion batteries. Herein, the local electronic structure of LRMO is appropriately modulated to alleviate oxygen release, enhance anionic redox reversibility, and facilitate Li⁺ diffusion via facile surface defect engineering. Concretely, oxygen vacancies integrated on the surface of LRMO reduce the density of states of O 2p band and trigger much delocalized electrons to distribute around the transition metal, resulting in less oxygen release, enhancing reversible anionic redox and the MnO₆ octahedral distortion. Besides, partially reduced Mn and lattice vacancies synchronously stimulate the electrochemical activity and boost the electronic conductivity, Li⁺ diffusion rate, and fast charge transfer. Therefore, the modified LRMO exhibits enhanced cyclic stability and fast-charging capability: a high discharging capacity of 212.6 mAh·g⁻¹ with 86.98% capacity retention after 100 cycles at 1 C is obtained and to charge to its 80%, SOC is shortened to 9.4 min at 5 C charging rate. This work will draw attention to boosting the fast-charging capability of LRMO via the local electronic structure modulation.     

压缩六角格子[A(BC)]m结构光子晶体禁带特性

通过引入缺陷和色散介质方法,调控光子的运动状态,研究一种压缩[A(BC)]m结构负折射率光子晶体的TE波和TM波的传输特性和色散特性,研究发现两种模的禁带特性随入射角和色散介质折射率的变化而变化,并且其带隙比普通光子晶体的大,而透射带要窄,这为高品质低损耗的谐振腔、微波天线、透射光栅、光波导等新器件的研制提供理论依据.