A novel low-complexity power allocation algorithm based on the NOMA system in a low-speed environment

For future wireless communication systems, Power Domain Non-Orthogonal Multiple Access (PD-NOMA) using an advanced receiver has been considered as a promising radio access technology candidate. Power allocation plays an important role in the PD-NOMA system because it considerably affects the total throughput and Geometric Mean User Throughput (GMUT) performance. However, most existing studies have not completely accounted for the computational complexity of the power allocation process when the User Terminals (UTs) move in a slow fading channel environment. To resolve such problems, a power allocation method is proposed to considerably reduce the search space of a Full Search Power (FSP) allocation algorithm. The initial power reallocation coefficients will be set to start with former optimal values by the proposed Lemma before searching for optimal power reallocation coefficients based on total throughput performance. Step size and correction granularity will be adjusted within a much narrower power search range while invalid power combinations may be reasonably discarded during the search process. The simulation results show that the proposed power reallocation scheme can greatly reduce computational complexity while the total throughput and GMUT performance loss are not greater than 1.5% compared with the FSP algorithm.     

超宽带低噪声放大器的计算机辅助设计

叙述了超宽带低噪声放大器的计算机辅助设计方法，提出了利用普通微带混合集成电路．工艺设计超宽带低噪声放大器的方法和关键技术，并且用带封装的ＢＪＴ和ＦＥＴ实现了两个超宽带低噪声放大器。实验结果和设计结果吻合较好。一个利用２ＳＣ３３５８，放大器为三级，频带为３０ｋＨＺ～１６００ＭＨＺ，增益Ｇ＝２０±１ｄＢ，噪声系数ＮＦ≤３．５ｄＢ；另一个利用ＡＴＦ１０２３５（６），放大器为二级，频带为５００ｋＨＺ～６０００ＭＨＺ，增益Ｇ＝２０±２ｄＢ，噪声系数ＮＦ≤２ｄＢ。     

Low complexity encoder optimization for HEVC

High Efficiency Video Coding (HEVC) improved the coding efficiency significantly. Compared to its predecessor H.264/AVC, it can provide equivalent subjective quality with more than 57% bit rate reduction. However, the improvement on coding efficiency is obtained at the expense of much more intensive computation complexity. In this paper, based on an overall analysis of computation complexity at the HEVC encoder, a low complexity encoder optimization scheme is proposed by reducing the number of available candidates for evaluation in terms of the intra prediction mode decision, early termination of coding unit (CU) splitting and adaptive reference frame selection. With the proposed scheme, the rate distortion optimization (RDO) technique of HEVC can be implemented in a low-complexity way for complexity-constrained encoders. Experimental results demonstrate that, compared with the original HEVC reference encoder implementation, the proposed optimization scheme can achieve more than 40% complexity reduction on average with coding performance degradation as only 0.43% which can be ignorable.     

Sub-Wavelength Virtual Imaging Using a Pair of 2-D L Loaded and C Loaded Transmission-Line Metamaterial Slabs

The dispersion relations and impedance expressions for both two-dimensional （2-D）/μ-negative and e-negative transmission line metamaterials, which may be paired to form a virtual image of the object, are presented. Under the conjugate matched condition, the voltage distri-butions inside and outside such paired slabs are derived for a plane-wave excitation. Green＇s functions corresponding to the voltages by a y directed elementary current source excitation are utilized to computed voltage phase and mag-nitude in all regions. The 2-D plots show that the voltage waves, the propagating waves and the evanescent waves, can pass through the conjugate matched slabs and so sub-wavelength virtual imaging has been achieved.     

EFFECT OF INCORPORATING ADDITIONAL OLEIC ACID INTO THE PLASMA MEMBRANE OF BAKER'S YEAST ON THE PERMEATION OF PYRUVIC ACID

Addition of Tween 80 to the growth medium of baker's yeast (Saccharomyces cerevisiae) under anaerobic conditions resulted in an increased content of 9-cis-octadecenoic acid (oleic acid) in a membrane preparation consisting mainly of plasma membrane. There was no significant effect on the pyruvate decarboxylation capacity of disintegrated cells, but that of intact cells was significantly enhanced, presumably because of an oleate-induced increase in the permeability of the plasma membrane to pyruvate.     

土石坝应用土工膜防渗设计的几个问题

本文就土石坝应用土工膜进行坝体防渗，对其透水性及渗漏量、土工膜防渗层与坝体间的作用、土工膜厚度的计算方法作了介绍，可供土石坝应用土工膜防渗设计参考。     

基于SOC的PAGER控制芯片设计

文章讨论了PAGER控制器芯片（ZQD021）的系统设计，该控制器内部集成了FLASH，SRAM，POCSAG协议解码器和嵌入式MCU CORE。重点分析了芯片的可测性设计（DFT），内嵌FLASH设计，低功耗设计，其设计方法和思路对消费类和嵌入式控制芯片的设计有一定的借鉴意义。     

可调谐双耦合场作用下的电磁诱导负折射特性

建立了可调谐双耦合场作用下的A型四能级系统模型,研究了系统的介电常数和磁导率随耦合场参数的变化规律,并由此探讨了满足负折射的条件.结果表明,固定耦合场的拉比频率,当两个耦合场中的一个共振、另一个失谐,或两个耦合场均失谐时满足负折射条件,但它们呈现不同的负折射特性.