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《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2008,16(9):1240-1243
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Gjendemsjo A. Hong-Chuan Yang Oien G.E. Alouini M.-S. 《Vehicular Technology, IEEE Transactions on》2008,57(4):2145-2152
We consider the problem of finding low-complexity, bandwidth-efficient, and processing-power-efficient transmission schemes for a downlink scenario under the framework of diversity combining. Capitalizing on recent results for joint adaptive modulation and diversity combining (AMDC) schemes, we design and analyze two AMDC schemes that utilize power control to reduce the radiated power and, thus, the potential interference to other systems/users. Based on knowledge of channel fading, the proposed schemes adaptively select the signal constellation, diversity combiner structure, and transmit power level. We show that the novel schemes also provide significant average transmit power gains compared to existing joint adaptive quadratic-amplitude modulation (QAM) and diversity schemes. In particular, over a large signal-to-noise ratio (SNR) range, the transmitted power is reduced by 30%-50%, yielding a substantial decrease in interference to coexisting systems/users, while maintaining high average spectral efficiency, low combining complexity, and compliance with bit-error-rate constraints. 相似文献
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《Microwave and Wireless Components Letters, IEEE》2006,16(11):615-617
A 2.4-GHz Doherty power amplifier (PA) is developed in 0.18-mum CMOS technology. An automatic adaptive bias control circuit is integrated with the auxiliary PA to improve the overall performance of the PA. Operated at 3V, the P1 dB and associated power-added-efficiency (PAE) of the PA are 21dBm and 33%, respectively. At the output power 6-dB backoff from P1 dB, the PAE remains 21%. The limited PAE degradation at backoff power levels makes the PA suitable for the applications with high peak-to-average power ratio 相似文献
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在全面梳理现有寄生供电系统的基础上,提出一种无需特殊工艺支持、可兼顾高速充电和低压差供电的智能多通路自适应调控寄生供电系统.该方案利用充放电控制状态机,协同双器件并行控制结构,对三条供电线路进行自适应调控切换,在提升充电速度和效率的同时,进一步模糊功耗信息.该方案可用于1-Wire芯片、高要求的光电等信息的采集以及实时监控等功能芯片的供电,并提升芯片的抗侧信道攻击能力.基于华虹宏利0.35 μm体硅CMOS工艺完成了该方案的仿真,结果表明,该系统能够将芯片内外供电压差降低到0.1 V以下,充电速度提升32%. 相似文献
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提出了一种新颖的脉宽调制(PWM)控制技术,该技术将误差放大器和PWM比较器归结为一个求和比较器来实现对电流模开关稳压器的自适应控制,使系统变得简洁,降低了成本,有利于集成.成功将该求和比较器应用于一款典型输入为5 V典型输出为15 V的升压型开关稳压器中,且稳压器采用低损耗的电流检测网络对峰值电流进行采样,减小了功耗.采用0.6 μm 30 V Bi CMOS工艺,经Hspice仿真验证,结果表明稳压器的输出电压纹波在±7 mV之间摆动,输出电压精度为±1.5%. 相似文献
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包络跟踪技术已经成为提高功率放大器效率的重要研究方向,其中高效率、高功率开关电源调制器是研究重点.对实际的开关电源调制电路以及相应的参数进行了分析,提出了适用于包络跟踪技术的开关电源调制电路.利用Spice软件对设计的电路进行了电路仿真,利用Cadence软件进行了印制电路板(PCB)电路的设计.经过实际测试,该开关电源调制器的输出电压达到48 V,电流约为0.9A,整个功能模块效率接近96%.该开关电源调制电路不仅具有高效率高功率输出脉冲信号,还可以根据设计需求改变NMOS管型号,并设计出不同开关频率、不同功率输出的开关电源调制电路. 相似文献
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Youngsoo Shin Sewan Heo Hyung-Ock Kim Jung Yun Choi 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2007,15(7):758-766
Power gating has been widely used to reduce subthreshold leakage. However, the efficiency of power gating degrades very fast with technology scaling, which we demonstrate by experiment. This is due to the gate leakage of circuits specific to power gating, such as storage elements and output interface circuits with a data-retention capability. A new scheme called supply switching with ground collapse is proposed to control both gate and subthreshold leakage in nanometer-scale CMOS circuits. Compared to power gating, the leakage is cut by a factor of 6.3 with 65-nm and 8.6 with 45-nm technology. Various issues in implementing the proposed scheme using standard-cell elements are addressed, from register transfer level to layout. These include the choice of standby supply voltage with circuits that support it, a power network architecture for designs based on standard-cell elements, a current switch design methodology, several circuit elements specific to the proposed scheme, and the design flow that encompasses all the components. The proposed design flow is demonstrated on a commercial design with 90-nm technology, and the leakage saving by a factor of 32 is observed with 3% and 6% of increase in area and wirelength, respectively. 相似文献
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Efficient resource management is a major challenge in the operation of wireless systems, especially energy-constrained ad hoc networks. In this paper, we propose a cross-layer optimization framework to jointly design the scheduling and power control in wireless ad hoc networks. We study the system performance by combining scheduling, power control, and adaptive modulation. Specifically, the transmitted power and constellation size are dynamically adapted based on the packet arrival, quality of service (QoS) requirements, power limits, and channel conditions. A key feature of the proposed method is that it facilitates a distributed implementation, which is desirable in wireless ad hoc networks. The performance of our proposed methodology will be investigated in ad hoc networks supporting unicast as well as multicast traffic. Simulation results will show that the proposed scheme achieves significant gains in both the single-hop throughput and power efficiency compared with the existing method, which implements the scheduling through a central controller, and adopts power control with fixed modulation 相似文献
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SG32525芯片在开关(逆变)电源中的应用 总被引:3,自引:0,他引:3
在研制开关电源和后备式UPS(不间断电源)的工程实践中,为提高其转换效率,减少外围元器件,减小体积,并提高长时间工作的可靠性与PWM(脉宽调制)的控制精度,对新型PWM集成芯片SG3525的功能特点、控制特性及外围电路进行了研究。讨论了该芯片在UPS逆变电源和开关稳压电源中的应用,利用该芯片设计并制作了高效率的开关电源与UPS逆变电源。 相似文献
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Kichon Han Bumman Kim 《Microwave and Wireless Components Letters, IEEE》2008,18(3):200-202
Two parallel operating power amplifiers (PAs) are controlled by a novel mode switch for high efficiencies at both the back-off power region and high power region. The mode switch is realized by the base-collector (BC) junction diode which reuses the dc current of the low power mode amplifier. A 836 MHz CDMA PA has been demonstrated using InGaP/GaAs heterojunction bipolar transistor with fully integrated matching component for small package and low cost. It shows a 13 mA idle current, 15.4% power added efficiency (PAE), ACPR1 at 16 dBm of the low power mode operation and a 40.5% PAE, ACPR1 at 28 dBm of the high power mode operation. 相似文献
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在分析开关电源脉冲序列(Pulse Train,PT)控制方法的原理和工作过程的基础上,设计了一种简单实用的脉冲序列控制电路。利用PSpice对PT控制DCM Buck变换器进行了仿真研究,并通过实验验证了脉冲序列控制器的可行性和正确性,为PT控制开关电源提供了一种有效的实施方案。 相似文献
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A 25 dBm Digitally Modulated CMOS Power Amplifier for WCDMA/EDGE/OFDM With Adaptive Digital Predistortion and Efficient Power Control 总被引:1,自引:0,他引:1
《Solid-State Circuits, IEEE Journal of》2009,44(7):1883-1896
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Cheng Shilun Yang Zhen Zhang Hui 《电子科学学刊(英文版)》2008,25(1):65-69
To regulate the transmit-power and enhance the total throughput, a novel Transmit Power Control Game (TPCG) algorithm and an adaptive Modulation TPCG (M-TPCG) algorithm which combine bandwidth allocation, adaptive modulation and transmit-power control based on Space Time Block Coding (STBC) OFDM-CDMA system are designed and a cross-layer framework of database sharing is proposed. Simulation results show that the TPCG algorithm can regulate their transmitter powers and enhance the total throughput effectively, M-TPCG algorithm can achieve maximal system throughput. The performance of the cognitive radio system is improved obviously. 相似文献
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With recent advances in power electronics, dual converter power supply based electric variable-speed drives are significantly used in many industries uses. Power electronic motor drivers are becoming able to efficiently read the inflexible characteristics of DC motor to prerequisites the load. By controlling the input armature voltage, the DC motor speed automatically changed. Half-bridge converter, semi converter, full bridge converter and dual converter are some of the thyristor controlled rectifier circuits are widely used in variable speed drives. In This work presents single phase dual converter power supply system based on adaptive inverse dynamic mode control (AIDMC) technique. The efficient dual converter control solution for industrial network control system (NCS) is proposed based on the industrial grade requirements, designed for low to high voltage operation. As the era of connecting the devices with the cloud is being increased gradually, the proposed method uses an NCS protocol for monitoring as well as controlling the dual converter system. The proposed method provides us the control over forward and reverse rotation, forward and reverse regeneration. From the simulation results, the proposed result offers variable DC voltage which is capable of four quadrant operation of the drive in a speed-torque plane by using MATLAB Simulink environment. A hardware setup also developed to validate the simulation. Over 96% accuracy achieved full load condition for proposed dual converter power supply system based on AIDMC controller. 相似文献
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开关电源的可靠性直接影响到电子产品系统的可靠性。文中从相关数控系统开关电源的各种保护电路着手,分析设计了数控开关电源的软启动电路,过压保护、过流保护、欠压保护等电路的工作原理和具体设计方法,解决了数控开关电源的工作可靠性问题,为数控系统的批量生产提供了保障。 相似文献