3-20 Predictions of Soft Error Rates in Space for the VATA160 Chip

VATA160 is a low-noise, low-power commercial Application Specific Integrated Circuit (ASIC) chip designed by IDEAS (Norway). It is a core device in the electronics system of the sub-detectors on the scientific satellite Dark Matter Particle Explorer (DAMPE)[1]. During its service period, DAMPE will encounter energetic and high flux protons from the space radiation environments.

Symbol Error Rate Performance Analysis of Non-Orthogonal Multiple Access for Visible Light Communications

Non-orthogonal multiple access(NOMA) is considered as one of promising radio access techniques for visible light communications(VLC) in next-generation wireless communications systems.In order to provide theoretical support for designing VLC-NOMA,we derive its analytic expressions for the symbol error rate(SER).Specifically,NOMA is first incorporated with appropriate VLC to establish a VLC-NOMA framework.Afterwards,mathematical expressions of the SER for the VLC-NOMA are developed.Moreover,numerical results are provided carefully to demonstrate that the proposed VLC-NOMA scheme outperforms than state-of-the-art orthogonal frequency division multiple access(OFDMA) one in terms of SER performance.Finally,relationships between the SER performance and the number of users,power allocation coefficient and semi-angle are well investigated,which can give us a scientific guide to devise the VLC-NOMA system for achieving better SER performance.

基于定向天线的DF协作通信系统SER性能分析

针对使用定向天线的协作通信系统,对固定译码转发协议(decode-and-forward protocol,DF)的误符号率(symbol error rate,SER)性能进行探索性研究。首先建立了基于定向天线的DF协作通信系统模型,从理论上推导出该模型下的SER闭式表达式,确定SER上界,并以SER为优化目标分析最优功率分配问题,最后结合具体的数值仿真对所建立模型的SER性能进行详细分析比较。结果表明,在使用定向天线的条件下,DF协作通信系统的SER更小,系统性能优劣与各节点定向增益、信道质量和功率分配方式密切相关,最优功率分配比平均功率分配性能更优。

相关衰落信道上M进制信号的SER近似计算

研究相关Nakagami-m衰落信道上采用最大比合并分集接收的M进制相移键控,M进制差分相移键控的平均误符号率性能,采用互补误差函数的方法来计算平均误符号率的上下限。数值计算结果表明该平均误符号率性能上限和下限能够较好地表征相关Nakagami-m衰落信道上M进制相移键控和M进制差分相移键控的平均误符号率性能。

AWGN信道高阶调制物理层网络编码的SER性能

扩展了最近邻近似方法使之能描述物理层网络编码的误符号率,并用该方法分析了双向中继网络中物理层网络编码在高阶调制下的误符号率.以8PSK为例,推导了高阶调制下PNC在AWGN信道中误符号率的闭式表达.研究发现,固定一个源节点的发射功率时,系统的SER并不会随着另一端源节点功率的提高而单调递减.蒙特卡罗仿真结果表明,所得表达式能正确刻画8PSK调制下物理层网络编码的误符号率.

SER-Tvpack:基于软错误率评估的SRAM型FPGA的装箱算法

为了提高基于SRAM的FPGA(SFPGA)上的容软错误能力,提出了一种基于软错误率(soft error rate,SER)评估的装箱算法SER-Tvpack.通过结合软错误率的两个组成部分错误传播率(error propagation probability,EPP)和节点错误率(node error rate,NER),得到软错误评估标准SER的估算值,并将该值作为可靠性因子加入到代价函数中指导装箱过程,以减少装箱后可编程逻辑块(configuration logic block,CLB)之间互连的软错误率,从而提高设计的可靠性.对20个MCNC基准电路(最大基准电路集)进行实验,结果表明,与基准时序装箱算法T-Vpack及已有的容错装箱算法FTvpack相比较,软故障率分别减少了14.5%和4.11%.而且,与F-Tvpack比较,在仅增加0.04%的面积开销下,减少了2.31%的关键路径的时延,提供了较好的时序性能.

SER analysis and power allocation for hybrid cooperative transmission system

The symbol-error-rate（SER） and power allocation for hybrid cooperative（HC） transmission system are investigated.Closed-form SER expression is derived by using the moment generating function（MGF）-based approach.However,the resultant SER contains an MGF of the harmonic mean of two independent random variables（RVs）,which is not tractable in SER analysis.We present a simple MGF expression of the harmonic mean of two independent RVs which avoids the hypergeometric functions used commonly in previous studies.Using the simple MGF,closed-form SER for HC system with M-ary phase shift keying（M-PSK） signals is provided.Further,an approximation as well as an upper bound of the SER is presented.It is shown that the SER approximation is asymptotically tight.Based on the tight SER approximation,the power allocation of the HC system is investigated.It is shown that the optimal power allocation does not depend on the fading parameters of the source-destination（SD） channel and it only depends on the source-relay（SR） and relay-destination（RD） channels.Moreover,the performance gain of the power allocation depends on the ratio of the channel quality between RD and SR.With the increase of this ratio,more performance gain can be acquired.

OPTIMAL POWER ALLOCATION WITH AF AND SDF STRATEGIES IN DUAL-HOP COOPERATIVE MIMO NETWORKS

Dual-hop cooperative Multiple-Input Multiple-Output (MIMO) network with multi-relay cooperative communication is introduced. Power allocation problem with Amplify-and-Forward (AF) and Selective Decode-and-Forward (SDF) strategies in multi-node scenario are formulated and solved respectively. Optimal power allocation schemes that maximize system capacity with AF strategy are presented. In addition, optimal power allocation methods that minimize asymptotic Symbol Error Rate (SER) with SDF cooperative protocol in multi-node scenario are also proposed. Furthermore, performance comparisons are provided in terms of system capacity and approximate SER. Numerical and simulation results confirm our theoretical analysis. It is revealed that, maximum system capacity could be obtained when powers are allocated optimally with AF protocol, while minimization of system's SER could also be achieved with optimum power allocation in SDF strategy. In multi-node scenario, those optimal power allocation algorithms are superior to conventional equal power allocation schemes.

Analysis of asymptotically tight approximation SER for cooperative NOMA systems

The closed-form formula derivation of the power domain cooperative non-orthogonal multiple access(NOMA)system is of great significance for further improving the performance of the system.However,the system performance formulas of the channel capacity and the paired bit error rate pairwise error probability(PEP)are too complicated,which have increased the difficulty in system performance optimization.Therefore,based on the amplify forward(AF)relay cooperative NOMA model,the signal interference noise ratio(SINR)formulas of the two user nodes are constructed.Through the assumption of that,the symbol error rate(SER)of each user is fair,the simplification condition of moment generating function(MGF)with the harmonic mean form is satisfied.Combined with the SER calculation formula of MGF,the system SER asymptotically tight approximation formula with simple structure is derived at high signal-to-noise ratio(SNR).The Monte Carlo simulation results show that,the formula can accurately describe the SER performance of the power domain cooperative NOMA system with the non-ideal successive interference cancellation(SIC)system when SNR is high.Under the condition of certain total power,the optimal power allocation factor is solved in order to minimize the total system SER.

PIPBQ Effect Aware SER Analysis for Combinational Logic Circuits

Technology scaling results in the propagation-induced pulse broadening and quenching（PIPBQ） effect become more noticeable.In order to effectively evaluate the soft error rate for combinational logic circuits,a soft error rate analysis approach considering the PIPBQ effect is proposed.As different original pulse propagating through logic gate cells,pulse broadening and quenching are measured by HSPICE.After that,electrical effect look-up tables（EELUTs） for logic gate cells are created to evaluate the PIPBQ effect.Sensitized paths are accurately retrieved by the proposed re-convergence aware sensitized path search algorithm.Further,by propagating pulses on these paths to simulate fault injection,the PIPBQ effect on these paths can be quantified by EELUTs.As a result,the soft error rate of circuits can be effectively computed by the proposed technique.Simulation results verify the soft error rate improvement comparing with the PIPBQ-not-aware method.

FinFET器件单粒子翻转物理机制研究评述

鳍式场效应晶体管(FinFET)器件由于其较高的集成度以及运算密度,已成为未来航天应用领域的重要选择。FinFET器件的辐射敏感性与其制作工艺和工作条件息息相关。为了解FinFET器件的单粒子翻转(SEU)敏感机制,文章结合国内外开展的相关研究,从SEU机理出发,分析了器件特征尺寸、电源电压和入射粒子的线性能量传输(LET)值等不同条件对器件SEU敏感性的影响,最后结合实际对FinFET器件SEU的研究发展方向进行展望。

空间混合辐射环境器件单粒子在轨错误率预估及不确定度分析方法

针对空间混合辐射对器件单粒子在轨错误率的影响,基于典型静态随机存储器利用中国原子能科学研究院HI-13串列加速器以及钴源总剂量模拟辐照试验装置开展协合效应研究,发展了一种器件在混合辐射环境下的单粒子在轨错误率计算方法。并利用该方法计算了协合效应影响下的航天器典型任务周期器件的在轨错误率,同时分析了器件在轨错误率计算中的不确定度来源并计算了在轨错误率不确定度。结果表明,对于该类型器件,空间混合辐射场导致的协合效应将降低器件单粒子在轨错误率。

基于CP重构的高时间传输效率CP-UFMC接收方法

针对循环前缀(cyclic prefix,CP)不足的情况对循环前缀通用滤波多载波(cyclic prefix-universal filtered multi-carrier,CP-UFMC)系统的影响进行了数学推导,提出了一种基于CP重构的高时间传输效率CP-UFMC接收方法来改善系统性能,并进一步研究了选择性重构方法的性能。之后仿真研究了不同CP长度,不同载波频率偏移和不同正交振幅调制阶数时的系统误符号率(symbol error rate,SER)表现。仿真结果表明,基于CP重构的CP-UFMC接收方法可以改善CP不足导致的系统SER恶化问题,使其接近CP充足时的SER,并优于对比的其他通用滤波多载波系统接收方法。

Application Specified Soft-Error Failure Rate Analysis Using Sequential Equivalence Checking Techniques

Soft errors have become a critical challenge as a result of technology scaling. Existing circuit-hardening techniques are commonly associated with prohibitive overhead of performance, area, and power. However,evaluating the influence of soft errors in Flip-Flops(FFs) on the failure of circuit is a difficult verification problem.Here, we proposed a novel flip-flop soft-error failure rate analysis methodology using a formal method with respect to application behaviors. Approach and optimization techniques to implement the proposed methodology based on the given formula using Sequential Equivalence Checking(SEC) are introduced. The proposed method combines the advantage of formal technique-based approaches in completeness and the advantage of application behaviors in accuracy to differentiate vulnerability of components. As a result, the FFs in a circuit are sorted by their failure rates, and designers can use this information to perform optimal hardening of selected sequential components against soft errors. Experimental results of an implementation of a SpaceWire end node and the largest ISCAS’89 benchmark sequential circuits indicate the feasibility and potential scalability of our approach. A case study on an instruction decoder of a practical 32-bit microprocessor demonstrates the applicability of our method.

基于虚拟MIMO的协作通信节点选择算法

针对一种新的协作通信方式O-DSTC(Opportunistic Distributed Space-Time Coding),该文在保证误码率的前提下,基于"效益函数"和"后悔函数",提出了均衡剩余能量的协作节点选择算法。在只能得到信道的统计特性并考虑距离信息的情况下,由于O-DSTC的平均误码率无法计算,所以该文提出并简化了协作中继的平均误码率逼近公式。根据该逼近公式选择满足误码率要求的协作节点集合,集合中的节点通过"后悔函数"分布式地设置延迟时间,并采用竞争方式成为协作节点。仿真结果验证了该文提出的误码率逼近公式的有效性和可靠性。实验结果也表明,协作节点选择算法可以保证误码率,提高最小剩余能量,同时减少竞争接入时间。

考虑偏置温度不稳定性的软差错率分析

纳米工艺下,老化效应与软差错共同引发的集成电路可靠性问题至关重要。该文分析偏置温度不稳定性(BTI),包括负偏置温度不稳定性(NBTI)和正偏置温度不稳定性(PBTI)对软差错率的影响,提出从关键电荷值和延迟两个因素综合考虑。首先分析BTI效应下两个因素如何变化,推导了延迟受BTI影响的变化模型,介绍关键电荷的变化机理。然后探讨将两个因素结合到软差错率(SER)评估中,推导了融入关键电荷值的SER计算模型,提出将延迟的变化导入到电气屏蔽中的方法。基于ISCAS89基准电路上的实验验证了综合两种因素考虑BTI效应评估SER的有效性和准确性。

Gamma-Gamma模型下采用PPM调制的MIMO-FSO系统误时隙率分析

分析了在Gamma-Gamma分布下基于脉冲位置调制(pulse position modulation,PPM)方式的多输入输出自由空间光学(multiple input multiple output free space optics,MIMO-FSO)通信系统模型。首先推导了单输入单输出(single input single output,SISO)-PPM系统的误时隙率(slot error rate,SER)计算公式,以此作为参考,在独立同分布和独立分布参数不同情况下,分别推导出MISO-PPM、SIMO-PPM和MIMO-PPM系统的平均SER计算公式,并用数值仿真的方法,分析了它们的平均SER性能。仿真结果表明,在Gamma-Gamma分布模型下,采用多发多收的方法确实能有效提高FSO系统的平均SER性能,如在误时隙率为10-4时,M=2、N=2的MIMO-PPM系统在信道分布参数相同和不同时,与SISO-PPM相比,分别能节省信噪比50dB和65dB左右。实际应用中,M和N分别取3或4就基本足够,对无线光通信系统的理论分析和系统设计具有一定的指导意义。

65nm工艺SRAM低能质子单粒子翻转实验研究

基于北京HI-13串列加速器质子源及技术改进工作,获得2~15 MeV低能质子束流。针对商业级65nm工艺4M×18bit大容量随机静态存储器（SRAM）,开展了质子单粒子翻转实验研究。实验结果表明,低能质子通过直接电离机制可在存储器中引起显著的单粒子翻转,其翻转截面较核反应机制引起的翻转截面大2~3个数量级。结合实验数据分析了质子翻转机制、LET值及射程、临界电荷及空间软错误率等,分析结果表明,实验器件翻转临界电荷约为0.97fC,而低能质子超过高能质子成为质子软错误率的主要贡献因素。

继电保护装置单粒子效应的测试方法与失效率研究

单粒子效应引发的存储器软错误对微机继电保护具有不可忽略的影响。介绍了α粒子和高能中子的来源,以及中国部分城市的大气中子通量。讨论了对继电保护装置进行中子辐照试验的方案细节,以及根据实验数据求取现场环境下单粒子失效率的方法。从现有可靠性指标出发,推导得到继电保护装置单粒子效应的可接受失效率。将该指标和辐照试验得出的失效率相比较,可以判断装置是否满足现场运行要求。该方法对评价继电保护装置的单粒子失效率具有一定的参考意义。

一种基于混合模拟的计算组合电路中软错误率的方法与工具

随着工艺尺寸的不断缩小,组合电路引起的SER(Soft Error Rates)越来越严重。针对使用HSPICE计算组合电路软错误率速度较慢以及使用传统的组合电路软错误率分析工具在对待重汇聚时计算精度不高的问题,本文提出了一种混合模拟的方法,并基于该方法实现了组合电路软错误率分析工具。该混合模拟方法使用HSPICE模拟发生重汇聚的逻辑门;使用快速的脉冲传播算法模拟其他逻辑门。模拟结果表明,该方法可以在速度和精度上达到很好的折中。通过与国际上常用的组合电路软错误率分析工具进行比较发现,在重汇聚发生较多的电路中,该混合模拟方法更能真实地反应组合逻辑中的软错误率。