VoLTE语音端到端问题自动定位方法研究

本文主要介绍实现终端测试数据与核心网多种接口XDR数据进行同步关联的算法。利用对VoLTE通话异常原因的定位技术,指导VoLTE客户感知问题的发现、定界。研究成果可快速将VoLTE问题分配到归口部门进行解决,快速提升用户语音业务感知。     

Inter-layer correlation-based adaptive bit allocation for enhancement layer in scalable high efficiency video coding

To facilitate the diversity of network and end-user devices, bit allocation technology must be combined with scalable high efficiency video coding (SHVC) to achieve continuous bitrate variation. However, to date, the multilayer coding feature in SHVC has not been fully utilized. In this paper, a bit allocation algorithm is proposed for the enhancement layer in SHVC. The algorithm includes two parts: a bit allocation method for the initial frame and another for subsequent frames. The bit allocation method for the initial frame consists of a bit allocation factor model constructed based on investigation of the influence of the initial target bitrate on the overall coding performance. For the bit allocation of the subsequent frames, alternate GOP coding is designed and implemented to fully exploit the inter layer correlation. In addition, an adaptive frame layer bit allocation ratio model is deduced according to the rate distortion optimization theory. Experimental results show that the proposed algorithm can improve PSNR by 0.44 dB and 0.41 dB under low delay and random-access configurations, respectively, and achieve high bitrate control accuracy. The algorithm also outperforms the state-of-the-art algorithms in term of PSNR improvement.     

Globally coupled systems with prescribed synchronized dynamics

A system of globally coupled maps whose synchronized dynamics differs from the individual (chaotic) evolution is considered. For nonchaotic synchronized dynamics, the synchronized state becomes stable at a critical coupling intensity lower than that of the fully chaotic case. Below such critical point, synchronization is also stable in a set of finite intervals. Moreover, the system is shown to exhibit multistability, so that even when the synchronized state is stable not all the initial conditions lead to synchronization of the ensemble. Received 22 October 1999     

Effect of delay on phase locking in a pulse coupled neural network

Using a slightly simplified version of the integrate and fire model of a neural network with delay, I study the stability of the phase-locked state dependent on the coupling between the neurons and especially on a delay time. The coupling between neurons may be arbitrary. It is shown that the phase-locked state becomes less stable with increasing delay and that relaxation oscillations occur. Received 28 December 1999 and Received in final form 13 June 2000     

时间离散神经振子中的多吸引子共存

本文给出一类耦合时间离散神经网络振子动力学的理论分析和数值模拟结果,重点分析了多吸引子共存的震子及其吸引域的边界（不稳定的周期的周期不变坏）,研究了多上子共趣及耦合强度变化对于神经信号处理保,如受激盛同步和对模式形成有重要影响的锁频现象。     

Bit commitment using pseudo-random synthesizer

This paper presents two practical message commitment schemes: one is suitable for committing many bits, and another is useful for committing any bit-long message. They are provably secure based on pseudo-random synthesizers. In these schemes, the sender may be unbounded to polynomial time and the receiver is bounded. The advantage of these schemes is that the secure parameter may be small.     

长波红外无线激光通信脉冲宽度调制实验研究

为实现长波红外无线激光通信,建立了基于脉宽调制的长波红外无线激光通信系统模型,对系统性能进行了分析,给出了系统误码率的计算公式.搭建了实验系统,对CO_2激光器的平均输出光功率随占空比的变化情况进行了分析,对不同占空比条件下接收端对应的激光平均脉冲宽度以及脉冲宽度受噪声影响的随机变化情况进行了分析,得到了激光输出平均光功率、平均脉冲宽度与占空比之间的关系,以及脉宽的分布规律,并将实验结果与理论分析结果进行了对比,在此基础上得到了脉宽最佳判决门限和系统各类工作参数同误码率之间的关系.结果表明,基于CO_2激光器的脉冲宽度调制能够实现长波红外无线激光通信.     

Parameter-dependent synchronization of coupled neurons in cold receptor model

In this paper, synchronization in two coupled neurons with spiking, bursting and chaos firings is investigated as the coupling strength gets increased. Synchronization state can be identified by means of the bifurcation diagram, the correlation coefficient and ISI-distance. It is illustrated that the coupled neurons can exhibit different types of synchronization state when the coupling strength increases. The different synchronization processes appear similar, but their detailed processes are different depending on the parameter values. The synchronization of neuronal network with two different network connectivity patterns is also studied. It is shown that chaotic and high period pattern are more difficult to get complete synchronization than the situation in single spike and low period pattern. It is also demonstrated that the synchronization status of multiple neurons is dependent on the network connectivity patterns. These results may be instructive to understand synchronization in neuronal systems.     

Coupled van der Pol-Duffing oscillators: Phase dynamics and structure of synchronization tongues

Synchronization in the system of coupled non-identical non-isochronous van der Pol-Duffing oscillators with inertial and dissipative coupling is discussed. Generalized Adler’s equation is obtained and investigated in the presence of all relevant factors affecting the synchronization (non-isochronism of the oscillators, their non-identity, coupling of the dissipative and inertial types). Characteristic symmetries are revealed for the Adler’s equation responsible for equivalence of some of the factors. Numerical study of the parameters space of the initial differential equations is carried out using the method of charts of dynamic regimes in the parameter planes. Results obtained by both these approaches are compared and discussed.     

Synchronization analysis of delayed complex networks via adaptive time-varying coupling strengths

In this Letter, we study the synchronization for delayed complex networks by adjusting time-varying coupling strengths. Under some assumptions, the update laws of the coupling strengths are obtained to realize the synchronization based on Lassalle-Yoshizawa theorem. For the given delayed complex network, we can always find appropriate coupling strengths to achieve the synchronization. Compared with the existing results, the update laws don't need the information of the characteristics of the identical node and the coupling matrix. The state-dependencies of coupling strengths coupled to the dynamics of the nodes in a way to enhance synchronization. An example shows the proposed theoretical result is feasible and effective.