Electronically tunable current-mode instrumentation amplifier with high CMRR and wide bandwidth

A current-mode instrumentation amplifier consists of only two current follower differential input transconductance amplifiers is proposed in this paper. The proposed circuit of instrumentation amplifier is realized without using any passive components. Thus, the proposed circuit structure is very simple and suitable to the integrated circuit technology. The input impedance is low and output impedance is high, therefore the proposed circuit is easily cascadable. The gain of the proposed instrumentation amplifier is electronically controllable. The proposed circuit also enjoys the features of high common mode rejection ratio, wide bandwidth and low power consumption. Additionally, performance of the proposed circuit is tested under process, supply voltage and temperature variations. Furthermore, another circuit of instrumentation amplifier, which is capable of providing higher differential mode gain is also shown. The non-ideal and parasitic studies are included. HSPICE simulations are performed to validate the proposed circuits of instrumentation amplifier.     

Low-complexity adaptive decision-feedback equalization of MIMO channels

A new adaptive MIMO channel equalizer is proposed based on adaptive generalized decision-feedback equalization and ordered-successive interference cancellation. The proposed equalizer comprises equal-length subequalizers, enabling any adaptive filtering algorithm to be employed for coefficient updates. A recently proposed computationally efficient recursive least squares algorithm based on dichotomous coordinate descents is utilized to solve the normal equations associated with the adaptation of the new equalizer. Convergence of the proposed algorithm is examined analytically and simulations show that the proposed equalizer is superior to the previously proposed adaptive MIMO channel equalizers by providing both enhanced bit error rate performance and reduced computational complexity. Furthermore, the proposed algorithm exhibits stable numerical behavior and can deliver a trade-off between performance and complexity.     

基于块对角化和服务公平性的次最优用户选择方案

该文基于块对角化的思想提出了一种次最优用户选择方案。首先推导出一个和速率容量的上界公式,将其作为该文提出算法的选择准则;然后用此上界公式代替瞬时和容量公式作为自适应准则,得到了所提出算法的简化算法;最后考虑到用户之间服务公平性的因素,把该文的提出算法与比例公平调度机制相结合,使得系统既能获得一定的信道容量增益又能让所有用户均得到公平的服务。仿真结果表明,该文所提出算法具有接近最优的性能,与比例公平调度机制相结合后可以达到系统和容量与服务公平性的折衷。     

Method for Enhancing the Accuracy of Frequency Offset Estimation in OFDM Modulation Based Communication Systems

The paper proposes a method for enhancing the accuracy of estimation of frequency offset for OFDM modulation based communication systems. An increase accuracy of the proposed method is achieved at the expense of combined use of pilot and information symbols of OFDM signal. The main factors determining the accuracy of proposed method were identified. Mathematical simulation of the proposed method was performed for a multipath radio wave propagation channel. The proposed method efficiency was shown in comparison with existing methods for the estimation of frequency offset. Advantages and disadvantages of existing and proposed methods were described. The relationships of the root-mean-square error of frequency offset estimation as a function of the signal-to-noise ratio were built for the proposed and existing methods. The attainable high accuracy of frequency offset estimation by employing the proposed method makes its use expedient in control and measuring equipment. Conclusions have been made regarding the simulation results obtained and the expediency of proposed method applications.     

Efficient and secure message authentication scheme for VANET

A new efficient identity-based message authentication scheme for VANET was proposed. The proposed scheme decreased the complexity of cryptographic operations on signature by using elliptic curve cryptosystem (ECC) to construct authentication protocol without bilinear pairing and provided the function of conditional privacy-preserving. Security analysis demonstrated that the proposed scheme satisfies all security and privacy requirements for VANET. Per-formance analysis show that compared with the most recent proposed schemes the proposed scheme decreases the com-putation cost and communication cost.     

梯度向量正交的相关函数自适应滤波算法

该文把Asharif(1999)定义的相关函数均方误差(MSE)准则Jr(n)=E「eT(n)Ce(n)」改为时变的遗忘因子指数加权最小二乘误差(LSE)准则Jr(n)=nt=0 n-teT(n)Ce(n),对这一准则利用梯度法,使当前时刻的梯度向量正交于前一时刻的梯度向量而得到一种新的相关函数自适应滤波算法.计算机仿真结果表明新算法的收敛性能优于Asharif提出的ECLMS算法.     

A simple snubber configuration for three-level GTO inverters

A simple snubber configuration for three-level gate turn-off thyristor (GTO) inverters is proposed. The proposed snubber has a single resistor per arm for stored energy dissipation, while the conventional RLD/RCD snubber contains six. This implies that the proposed snubber needs only one chopper circuit per arm for snubber energy recovery. This helps reduce the size, cost, and number of components. Besides the single resistor, the proposed snubber requires two less diodes per arm than the RLD/RCD snubber. Furthermore, the proposed snubber resolves the voltage imbalance problem between inner and outer GTOs without additional components. We have analyzed the proposed circuits and proven its performance through simulations and experiments     

用于CMOS图像传感器的12位低功耗单斜坡模数转换器设计

 本文提出了一种应用于CMOS图像传感器中的高精度低功耗单斜坡模数转换器(single slope analog-to-digital converter)设计方案.该ADC方案由可变增益放大器、前置预放大器和动态锁存比较器组成.相比现有的设计方案,本文提出的电路在不牺牲噪声性能的前提下,具有更低的功耗和更小的芯片面积.通过集成列并行的单斜坡模数转换器在最新设计的高精度高速CMOS图像传感器设计中,实验结果证明了设计的有效性.     

Cooperative Learning Algorithms for Data Fusion Using Novel $L_{1}$ Estimation

Two novel L₁ estimation methods for multisensor data fusion are developed, respectively in the case of known and unknown scaling coefficients. Two discrete-time cooperative learning (CL) algorithms are proposed to implement the two proposed methods. Compared with the high-order statistical method and the entropy estimation method, the two proposed estimation methods can minimize a convex cost function of the linearly fused information. Furthermore, the proposed estimation method can be effectively used in the blind fusion case. Compared with the minimum variance estimation method and linearly constrained least square estimation method, the two proposed estimation methods are suitable for non-Gaussian noise environments. The two proposed CL algorithms are guaranteed to converge globally to the optimal fusion solution under a fixed step length. Unlike existing CL algorithms, the proposed two CL algorithms can solve a more complex L₁ estimation problem and are more suitable for weight learning. Illustrative examples show that the proposed CL algorithms can obtain more accurate solutions than several related algorithms.     

基于深度学习的快速QTMT划分

与之前的编码标准相比,多功能视频编码(versatile video coding,VVC)进一步提高了压缩效率。嵌套多类树的四叉树(quadtree with nested multi-type tree,QTMT)结构是提高编码增益的关键之一,同时极大地增加了编码复杂度。为降低VVC编码复杂度,提出了一种基于深度学习的快速QTMT划分方法。首先,提出了注意力?非对称卷积结构来预测划分模式的概率。然后,基于阈值提出了快速划分模式决策。最后,提出了编码性能与时间的代价函数来求解最优阈值,提出了阈值决策方法。实验表明,算法在不同档次下的时间节省分别为48.62%、52.93%、62.01%,BDBR分别为1.05%、1.33%、2.38%。结果表明,算法的时间节省和率失真性能优于其他快速算法。     

一种新型OFDM系统频率和时间同步算法

提出了一种正交频分复用(OFDM)系统的频率和时间同步算法。该算法利用未经过前一个符号的延迟扩展干扰的循环前缀部分来进行频率偏移和时间偏移的估计。因此,该算法有效地降低了ISI的影响。最后,该算法在存在高斯白噪声和多径信道的条件下进行了仿真,仿真结果表明这种算法有很好的估计性能。     

基于双曲线特征的浅地层探地雷达杂波抑制与合成孔径成像研究

本文根据浅地层探地雷达图像的特点,提出了一种基于图像处理技术的杂波抑制方法。并在此基础上,进而提出了一种实现探地雷达合成孔径成像的快速方法。通过对实测数据进行处理,结果表明,所提杂波抑制方法取得了很好的效果,且通用性强;所提的快速合成孔径成像方法与普通合成孔径成像方法相比,所得图像的分辨力相当,且所提方法减少了杂波成分的影响,使处理速度得到了极大的提高,成像的效果更好。     

一种高效快速的高密度椒盐噪声消除算法

本文提出了一个简单高效的消除高密度椒盐噪声的算法,在该算法中,对于图像中的每一个椒盐像素,计算以该像素为中心的窗口内非椒盐像素的平均值,并且在不同的阶段对其更新,实验结果表明,对于污染度为10％到90％的图像,本文的算法都有良好的噪声消除能力,所得到的恢复图像能够较好地保持原始图像的细节.另外,本文的算法计算时间较少,...     

A Simplified Control Method for the Grid-Connected Inverter With the Function of Islanding Detection

In this paper, a novel method for the voltage-controlled grid-connected inverter with the function of islanding detection is proposed for the distribution power generation system. The salient features of the proposed voltage-controlled grid-connected inverter are simple control circuit and fast transient response. Besides, an islanding detection method is proposed and incorporated into the controller of a voltage-controlled grid-connected inverter. The proposed islanding detection method will cause variation in amplitude and frequency of the load voltage when the utility is interrupted so as to immediately detect the islanding operation. A prototype is developed and tested to demonstrate the performance of the proposed voltage-controlled grid-connected inverter. The experimental results show that the performance of the proposed voltage-controlled grid-connected inverter is as expected.      

Multi-objective data collecting strategies for wireless sensor network based on the time variable multi-salesman problem and genetic algorithm

Comparing to the traditional data collecting method with data route,the technology of wireless mobile nodes has gradually became a new technique in the wireless sensor network.As the solution to the visiting order of the static nodes was an intrinsic NP-hard problem,a more general multi-objective data colleting strategies based on multi-mobile nodes was proposed.The proposed data collecting technique was abstracted as a model of time variable multiple traveling salesman problem.Belonging to a discrete optimal problem,the proposed model was solved by with a proposed hybrid genetic algorithm to determine the paths of the multi-mobile nodes.The convergence analysis of the proposed algorithm was given.With the experiment of open dataset,the proposed model based on the time variable multiple traveling salesman problem and the proposed hybrid genetic algorithm certify a certain improvement to the efficiency and real-time ability.     

New basic unit and cascaded multilevel inverters with reduced power electronic devices

ABSTRACT

In this paper, a new cascade multilevel inverter based on series connection of several basic units is proposed. The basic topology consists of 5 dc voltage sources and 12 switches. The required mathematical analysis consisting of voltage on switches, power losses and the values of dc voltage sources is provided. To verify the advantages of proposed topology, the suggested structure is compared with other multilevel inverter topologies in terms of used dc voltage sources, switches, voltage on switches and the number of on-state switches. The proposed structure uses the least numbers of dc voltage sources and switches compared to other multilevel inverters for the same number of levels. Also, voltage rating on the switches in the proposed topology is less than other topologies. These characteristics cause the weight, size and cost of proposed topology to be reduced. The proposed inverter is implemented using experimental setup. The experimental results verify the performance of proposed structure.     

A New Bidirectional Switch With Regenerative Snubber to Realize a Simple Series Connection for Matrix Converters

A new bidirectional switch and snubber circuit are proposed for medium-voltage AC/AC converters. The proposed switch can be constructed using 2-in-1 insulated-gate bipolar transistor and 2-in-1 diode modules, and can reduce the voltage stress of the switching device by series connection. The proposed snubber configuration is very simple and can regenerate absorbed energy. On the other hand, timing errors in the switching between the series-connected switches cause a voltage imbalance in the snubber circuit. Therefore, a simple method is proposed for reducing the voltage imbalance that uses one voltage sensor for each switch circuit. This proposed method controls the snubber voltages by adjusting the switch timings. Furthermore, application of the proposed switch circuit to a matrix converter is discussed and is confirmed by experiment.     

Novel MOS-C oscillators using the current feedback op-amp

Three new MOS-C oscillators using the current feedback op-amp are presented. The proposed oscillators have the advantage of independent control of the oscillation frequency and the condition of oscillation. Two of the proposed MOS-C oscillators provide two outputs in phase quadrature. The third proposed oscillator provides two outputs in the balanced form. PSpice simulation results for the proposed oscillators are given.     

Design of a CMOS low-power and low-voltage four-quadrant analog multiplier

A New CMOS four-quadrant analog multiplier is presented in this paper. The proposed multiplier is suitable for low supply-voltage operation and its power consumption is also very low. The proposed circuit has been simulated with the HSPICE and simulation results are given to confirm the feasibility of the proposed analog multiplier. According to the simulation results, under the supply voltage of 1.5 V, the input range of the proposed multiplier can be 120 mV and the corresponding maximum linearity error is less than 3.2%. Moreover, the power dissipation of the proposed circuit is only 6.7 μW. The proposed circuit is expected to be useful in analog signal processing applications.     

基于Lawson范数的通用lncosh稀疏自适应算法

该文提出一种通用稀疏系统识别Lawson-lncosh自适应滤波算法,该算法采用系数向量的Lawson范数和误差的lncosh函数构建代价函数。Lawson范数约束引入参数p,实现稀疏约束滤波动态调整,所提算法可以提高稀疏系统识别时的收敛速度,减小了稳态误差。误差的lncosh函数具有良好的抗脉冲噪声性能。然后,算法分析了步长参数的取值范围和参数p对算法性能的影响。计算机仿真结果表明,在高斯信号输入和色信号输入情况下,所提算法的性能要明显优于其他现存算法,且具备稀疏约束可控特性。