可重构智能表面辅助的四元数调制无线通信系统

四元数调制(Quaternion Modulation,QMod)是一种新型高传输速率的极化调制(Polarized Modulation,PMod)技术,是未来卫星通信系统中极具潜力的多元调制方案之一。QMod将数据块分成4块,其中两块是传输数据信号,另外两块则映射到极化状态部分。每个极化状态块均有一位比特,那么它们可以产生4个极化状态组合。这些状态组合可以用来确定传输数据块在四元数4个不同维度中的位置,从而获得两位额外的传输比特。相比于传统的PMod技术,QMod有着更高的频谱效率。为了进一步挖掘QMod的潜力,介绍了由可重构智能表面(Reconfigurable Intelligent Surface,RIS)辅助的QMod系统,同时推导了该系统的平均误码率理论上界,并在瑞利信道下进行了BER性能仿真。仿真结果表明,RIS辅助的PMod或者QMod系统即便在较低的SNR情况下仍有良好的BER性能,并且随着RIS单元数的增多,其BER性能会逐步提升。     

Reconfigurable topology synthesis for application-specific NoC on partially dynamically reconfigurable systems

In this paper, a four-stage method for synthesizing reconfigurable ASNoC topology is proposed for partially dynamically reconfigurable systems, where the topology is reconfigured dynamically at run-time along with the application's execution. Firstly, a simulated annealing based topology-aware integrated optimization framework is proposed to generate the proper schedule and floorplan of task modules. Secondly, based on the schedule and floorplan of task modules, an Integer Linear Programming (ILP)-based method and a heuristic method, are proposed to partition the communication requirements of the application into $T$ time intervals. Thirdly, we explore the proper positions of switches in the floorplan for global communications. Finally, considering the reconfiguration costs between adjacent time intervals, the routing path allocation problem is solved for time intervals in an iterative procedure to generate fine-grained dynamically reconfigurable ASNoC topologies. Experimental results show that, compared to the random partition of communication requirements, the proposed heuristic method and ILP-based method can achieve 5.4% and 10.0% power consumption improvement, respectively. And, the reconfigurable ASNoC can achieve 31.6% power consumption improvement when compared with static ASNoC.     

Design of delayed reconfigurable manufacturing system based on part family grouping and machine selection

To improve the convertibility of reconfigurable manufacturing system (RMS), the concept of delayed reconfigurable manufacturing system (D-RMS) was proposed. RMS and D-RMS are both constructed around part family. However, D-RMS may suffer from ultra-long system problem with unacceptable idle machines using generic RMS part families. Besides, considering the complex basic system structure of D-RMS, machine selection of D-RMS should be addressed, including dedicated machine, flexible machine, and reconfigurable machine. Therefore, a system design method for D-RMS based on part family grouping and machine selection is proposed. Firstly, a part family grouping method is proposed for D-RMS that groups the parts with more former common operations into the same part family. The concept of longest relative position common operation subsequence (LPCS) is proposed. The similarity coefficient among the parts is calculated based on LPCS. The reciprocal value of the operation position of LPCS is adopted as the characteristic value. The average linkage clustering (ALC) algorithm is used to cluster the parts. Secondly, a machine selection method is proposed to complete the system design of D-RMS, including machine selection rules and the dividing point decision model. Finally, a case study is given to implement and verify the proposed system design method for D-RMS. The results show that the proposed system design method is effective, which can group parts with more former common operations into the same part family and select appropriate machine types.     

Design and investigations on a compact,UWB, monopole antenna with reconfigurable band notches for 5.2/5.8 GHz WLAN and 5.5 GHz Wi‐MAX bands

This article represents a microstrip line–fed novel circular monopole antenna with ultra‐wideband (UWB) characteristics. The compact antenna provides reconfigurable notches at WLAN (5.2/5.8 GHz) and Wi‐MAX (5.5 GHz) frequency bands. The band rejection is achieved by etching an open‐ended L‐shaped slot in the ground plane, which effectively mitigates the interference between WLAN, Wi‐MAX, and UWB systems with an effective patch area of 36.26%. The proposed antenna operates from 3.05 to 12.11 GHz with VSWR 2 except at stopband (3.89‐5.93 GHz) to filter the WLAN and Wi‐MAX signals. The simulated return loss, gain, and radiation pattern of the proposed antenna has been experimentally verified with the fabricated one which holds a good agreement.     

Optimal cost design of flow lines with reconfigurable machines for batch production

Modular reconfigurable machines offer the possibility to efficiently produce a family of different parts. This paper formalises a cost optimisation problem for flow lines equipped with reconfigurable machines which carry turrets, machining modules and single spindles. The proposed models take into account constraints related to: (i) design of machining modules, turrets, and machines, (ii) part locations, and (iii) precedence relations among operations. The goal is to minimise equipment cost while reaching a given output and satisfying all the constraints. A mixed integer programming model is developed for the considered optimisation problem. The approach is validated through an industrial case study and extensive numerical experiments.     

一种小型化八频段可重构手机天线设计

提出了一种新型频率可重构的手机天线,尺寸为43 mm×9 mm×3 mm.该天线由曲折馈电枝节、耦合枝节,以及多路射频开关(RF-Switch)组成.通过RF-Switch接入不同的电感改变天线的感抗值和带线的有效电长度,在低频段得到了四种不同的工作状态,天线的低频带宽显著增加.研究结果表明:所设计天线能够很好地覆盖长期演进(Long Term Evolution,LTE)、无线广域网(Wireless Wide Area Network,WWAN)八个频带且频段内回波损耗小于一6 dB.实测表明天线具有良好的辐射效率和辐射增益,能够实现全向覆盖,具有很好的应用前景.     

Silicon‐Based Current‐Controlled Reconfigurable Magnetoresistance Logic Combined with Non‐Volatile Memory

Silicon‐based complementary metal‐oxide‐semiconductor (CMOS) transistors have achieved great success. However, the traditional development pathway is approaching its fundamental limits. Magnetoelectronics logic, especially magnetic‐field‐based logic, shows promise for surpassing the development limits of CMOS logic and arouses profound attentions. Existing proposals of magnetic‐field‐based logic are based on exotic semiconductors and difficult for further technological implementation. Here, a kind of diode‐assisted geometry‐enhanced low‐magnetic‐field magnetoresistance (MR) mechanism is proposed. It couples p‐n junction's nonlinear transport characteristic and Lorentz force by geometry, and shows extremely large low‐magnetic‐field MR (>120% at 0.15 T). Further, it is applied to experimentally demonstrate current‐controlled reconfigurable magnetoresistance logic on the silicon platform at room temperature. This logic device could perform all four basic Boolean logic including AND, OR, NAND and NOR in one device. Combined with non‐volatile magnetic memory, this logic architecture with unique magnetoelectric properties has the advantages of current‐controlled reconfiguration, zero refresh consumption, instant‐on performance and would bridge the processor‐memory gap. Our findings would pave the way in silicon‐based magnetoelectronics and offer a route to make a new kind of microprocessor with potential of high performance.     

多轮分布式驱动车辆可重构集成协调控制方法

多轮分布式独立驱动平台运动控制技术的演进对提升特种无人车辆的快速机动性及操纵稳定性具有重要的战略意义,然而其底盘主动执行系统的故障率或相互干涉的可能性也大大增加。提出一种面向该平台的可重构集成协调控制方法,以实现车辆动力学性能的进一步提升。基于自顶向下的分层控制结构,在运动控制层引入考虑参数不确定性的自适应滑模控制器,以保证对车辆运动目标状态的准确跟踪,并生成所需的广义控制力;在控制分配层提出一种加权伪逆控制分配器,基于控制效率矩阵的零空间特性,在主动执行器饱和约束可行域内进行再分配修正,以完成从广义控制力到各车轮处轮胎力的优化分配,其中引入的配置矩阵与优化权重系数则分别实现对控制模型的重新配置以及分配目标的调节;通过设置主动执行器实现分配目标的执行。基于6×6分布式电驱动车辆原理样机,进行两种工况下的仿真和试验验证。研究结果表明,该控制器提升了多轮车辆在转向过程中的操纵稳定性,并获得了更高效更精准的多轮车辆驱动力分配控制效果。     

Metasurface based pattern reconfigurable antenna for 2.45 GHz ISM band applications

In this article, a Z‐shaped antenna is designed for 2.45 GHz ISM band applications. The proposed antenna is surrounded by metasurface‐based unit cells. The unit cells are designed to reflect for the proposed frequency. Each of this unit cells are activated with the help of a diode. Unit cell is considered active by switching on the diode of respective unit cell. According to the activation of unit cell the pattern of the antenna will be reconfigured. The 2.45 GHz ISM band pattern reconfigurable microstrip antenna is presented. The radiation pattern of the antenna can be steered toward a desired direction by activating appropriate metasurface unit cell, minimizing the interference and optimizing medium usage. The proposed antenna performance is presented with the help of reflection coefficient and the pattern steerable capability by activating metasurface unit cells. The proposed antenna is having azimuth‐pattern reconfigurable capability around 360°.