一种改进的混合激励线性预测的基音周期估计算法

本文详细讨论了混合激励线性预测(MELP)的基音周期估计算法及其改进算法.该算法采用了分数基音周期、倍数检测等技术,保证了基音周期估计的精度.同时又采用了滑动窗的方法,使得对基音周期不规则的不平稳的语音段进行基音周期估计时的误差减小.本文最后给出了该算法的测试结果及优缺点.     

循环AMDF及其语音基音周期估计算法

基音周期是语音压缩、合成以及识别中的一个重要参数.传统的基于AMDF的基音估计算法容易导致估计的基音周期加倍.本文针对该现象,分析了AMDF函数的特性及其用于基音检测时存在的不足,提出了新的CAMDF函数.CAMDF有效地克服了AMDF函数的不足,简化了基音检测过程.在此基础上,本文给出了新的基于CAMDF的基音检测算法.该算法不仅简化了基音检测过程,而且降低了误判率,提高了估计精度.大量实验表明其性能优于其它AMDF或LVAMDF的方法.     

一种改进的正弦语音模型基音周期检测算法

分析了现有正弦语音模型基音周期检测算法的缺陷,提出一种改进算法。该算法改变了候选基音周期选择策略,大大降低了基音周期搜索时间;同时采用一种基于时域的前向滤波算法,解决了基音周期检测中的倍频问题。最后对实际采集的语音数据进行分析。     

面向移动应用的语音编解码开环基音搜索方法

基音周期搜索的准确性将直接影响到语音编码器的编码质量和效率。本文根据AMR—WB＋标准中基音周期搜索算法会发生检测基音倍频和半频错误,提出了开环基音搜索算法。该算法以白相关函数为基础,利用基音周期的平滑性,引入基音周期全局参考作为基音周期判断的辅助条件,有效解决了基音周期加倍的问题并在基音周期预测中体现基音周期的平滑性,实验结果表明本文算法性能优于AMR—WB＋中的算法性能。该算法已应用到AVS—P10移动音频编解码框架中。     

基于ACF和AMDF的基音检测改进算法

自相关函数法和平均幅度差函数法是基音周期检测的两种常用方法,两者具有独立且相似的统计特性。在讨论了传统基音周期检测算法及其缺点后,提出了综合应用ACF和ANDF函数进行基音检测的算法。该算法简单可行,性能优于一般传统时域基音周期检测算法。从仿真结果可以看出,对于含噪语音信号,该算法具有较强的抗噪能力。     

噪声环境下语音信号的基音检测

研究和改进了一种基于归一化互相关系数的基音检测方法(NCCFPDA)。NCCFPDA算法利用归一化互相关系数、短时归一化能量和自适应门限来区分清/浊音和选取基音周期,计算量小,精度高。在NCCFPDA算法的基础上,采用动态规划的方法对检测出的基音周期进行平滑,并在噪声环境下与自相关法检测基音周期的检测结果进行了比较。实验表明NCCFPDA算法在基音轨迹的平滑和清/浊判别方面都具有令人满意的效果,能实现基音周期的鲁棒性检测。     

基于DCT分带谱熵与信号分解的高精度基音检测算法

本文就低速率WI语音编码中的基音检测技术进行研究,针对基音检测在不同噪声与信噪比下容易发生清浊误判的问题,在基音检测前端引入基于DCT分带谱熵的语音检测算法划分语音段与非语音段;为了向基音检测算法提供更能准确反映基音周期实际变化的输入语音,基于谐波-噪声模型提出了一种改进的DCT域语音分解算法.然后,根据变形的MCAMDF(Modified Circular Average Magnitude Difference Function)与NCCF(Normalized Cross-Correlation Function)的峰值共性,结合上述两项基音检测前端处理技术,提出了MCAMDF-NCCF基音检测组合算法.为了满足不同环境下WI编码器对基音检测高精度的要求,在合成端更准确地恢复相位轨迹,本文又基于MCAMDF-NCCF算法提出了高精度MCAMDF-NCCF-FRAC基音检测算法以计算分数基音.将算法应用与2kb/s WI编码器,主观A/B听力测试结果表明,本文提出的基音检测算法在低信噪比下明显抑制了基音加倍减半及清浊误判现象的发生,得到了优异的基音检测结果,合成语音质量完全满足低速率WI编码器对基音检测技术的要求.     

基于小波变换的语音基音周期鲁棒性检测

固定门限的小波变换基音检测算法,在浊音信号起始段和结束段的模极大值不能有效提取。文中提出一种基于小波变换模极大值的基音周期自适应前后向跟踪算法,并结合过零率检测,实现了弱浊音信号基音周期的鲁棒性检测。算法对浊音信号采用自适应帧长,对陡变的基音周期能够准确提取,对噪声有较强的鲁棒性。     

一种基于奇偶相关性网络的基音周期隐写分析方法

由于基音周期参数在语音编码过程中具有不可预测性,因此,很多隐写算法都将隐藏信息嵌入到基音周期中。目前已有多种基于基音周期的检测方法,但是如何准确的做到信息隐藏检测仍是一项挑战。文章提出了一种基于奇偶相关性网络的基因周期隐写分析方法。实验结果表明,该方法可以有效地检测基于基音周期的隐写术。实验结果表明,提出的方法可以有效地检测基于基音周期的隐写术,具有良好的实时性和健壮性。     

基于形态滤波和小波变换的基音检测新方法

提出了一种基于数学形态滤波和小波变换相结合的基音检测方法。检测前采用文中提出的形态滤波算法对噪声信号进行滤除，突出了基音周期。用小波变换对滤波后语音信号的突变点进行检测，进而提取出了基音周期。实验表明该方法对噪声有较强的鲁棒性，能够精确地检测出基音周期。     

A New Enhanced Fast Handover Algorithm in Hierarchical Mobile IPv6 Network

1　Introduction　MobileIPv6requirestheMobileNode (MN)toregisterwiththeHomeAgent (HA)andtheCorre spondentNode (CN)whenitchangesitspointofattachmentintheInternet[1～ 3] .Therefore ,thiscauseMobileIPv6toincurlongdelayintheregis tration process,andaddsignalingtraffictothebackbonenetworkespeciallywhentheHAandCNarefarawayfromtheMN .Inordertominimizethisdelay ,andthesignalingoverhead presentinMobileIPv6,literatures[4～7] proposeHierarchicalMobileIPv6(HMIPv6)architectureandafasthan dover…     

FRR for latency reduction and QoS provisioning in OBS networks

We propose a forward resource reservation (FRR) scheme to reduce the data burst delay at edge nodes in optical burst switching (OBS) systems. We also explore algorithms to implement the various intrinsic features of the FRR scheme. Linear predictive filter (LPF)-based methods are investigated and demonstrated to be effective for dynamic burst-length prediction. An aggressive resource reservation algorithm is proposed to deliver a significant performance improvement with controllable bandwidth cost. By reserving resources in an aggressive manner, an FRR system can reduce both the signaling retransmission probability and the bandwidth wastage as compared with a system without the aggressive reservation. An FRR-based QoS strategy is also proposed to achieve burst delay differentiation for different classes of traffic. Theoretical analysis and simulation results verify the feasibility of the proposed algorithms and show that our FRR scheme yields a significant delay reduction for time-critical traffic without incurring a deleterious bandwidth overhead.     

基于硬件任务顶点的可重构系统资源管理算法

可重构资源的管理是影响动态可重构系统性能的关键因素之一.本文提出了一种保持任务顶点信息的布局算法KTVP,并将其扩展为KTVS调度算法.KTVP/KTVS算法根据已接收硬件任务的顶点信息安排新到达的硬件任务,可通过对系统资源的编码迅速验证布局/调度的可行性,能有效减少系统资源浪费,提高系统内在的并行度.仿真实验表明,与已有算法相比,KTVP/KTVS算法具有更低的任务拒绝率和更小的运行开销.     

A Cross Layer Routing Protocol for Multihop Cellular Networks

We propose a cross-layer routing protocol for a Code Division Multiple Access (CDMA) Multihop Cellular Network (MCN). In designing the routing protocol for MCN, multiple constraints are imposed on intermediate relay node selection and end-to-end path selection. The constraints on relay nodes include willingness for cooperation, sufficient neighbourhood connectivity and the level of interference offered on the path. Path constraints include end-to-end throughput and end-to-end delay. A facile incentive mechanism is presented to motivate the cooperation between nodes in call forwarding. In addition, we present a route resilience scheme in the event of dynamic call dropping. In particular, a fast neighbour detection scheme for route resilience is proposed. Instead of using periodic HELLO messages as in traditional ad-hoc routing, the proposed neighbour detection scheme adopts an explicit handshake mechanism to reduce neighbour detection latency. We conclude the paper by demonstrating the superior performance of the proposed routing protocol compared with the other well known routing algorithms.     

一种基于多尺度边缘特征提取的基音检测算法

目前很多的基音检测算法抗噪性较差，针对这一问题，本文提出了一种基于多尺度边缘特征提取的基音检测算法(加权求和法)，该算法与传统的小波变换算法相比减少了局部极值的搜索次数，提高了检测精度，具有很好的抗噪性。     

Hierarchical addressing scheme for 6LoWPAN WSN

This paper proposes a hierarchical addressing scheme for 6LoWPAN WSN and aims to reduce the addressing cost and latency. The proposed scheme includes the address initialization and address maintenance algorithms. When the network starts, the address initialization algorithm is performed. Through the address initialization process, each node can be configured with a globally unique address without duplication address detection. The address maintenance algorithm is made up of the address configuration sub-algorithm and the address reclamation sub-algorithm. After the address initialization process ends, a new node performs the address configuration sub-algorithm to obtain a globally unique address from a neighbor. The address reclamation sub-algorithm is performed to reclaim the released addresses for reuse so that there is enough address resources available for assignment. Finally, the proposed scheme is evaluated, and the results show that this scheme effectively reduces the addressing delay and cost.     

A parallel shuffled paging strategy under delay bounds in wireless systems

In sequential paging schemes, the paging process is considered on per user basis. When an incoming call arrives to a mobile terminal (MT), the associated location area is divided into several paging areas (PAs) and PAs are paged one by one until the MT is found. Even though sequential paging algorithms can reduce the paging cost compared to the blanket-paging scheme, they introduce extra and unnecessary delay due to the fact that, during each paging cycle, unpaged cells are idle and unused in terms of paging. In this letter, a simple parallel shuffled paging strategy is proposed to reduce delay and improve performance. In the proposed scheme, multiple MTs can be paged in difference PAs in parallel. Our study shows that the proposed scheme outperforms both the sequential paging and the blanket paging in terms of discovery rate and queueing delay.     

一种动态子信道分配MIMO-OFDM波束成形系统的信号检测算法

基于动态子信道分配的MIMO-OFDM波束成形系统可以获得比传统系统更好的误码率性能。但由于处理或者反馈时延的影响,会使得发射机利用不准确的信道状态信息发射数据,从而在数据流之间引入干扰,导致系统性能下降。通过分析时延对系统的影响,该文提出了一种改进的检测算法:通过构建等效MIMO系统模型,采用最小均方误差MIMO检测算法抑制数据流之间的干扰,并利用等效MIMO信道矩阵的特征值分解白化噪声获得等效高斯信道模型,计算编码比特的对数似然比。仿真表明,该算法相对于现有算法有2.5～4 dB的性能增益。     

车联网中基于神经网络的入侵检测方案

车联网的入侵检测（IDS）可用于确认交通事件通知中描述的事件的真实性。当前车联网IDS多采用基于冗余数据的一致性检测方案,为降低IDS对冗余数据的依赖性,提出了一个基于神经网络的入侵检测方案。该方案可描述大量交通事件类型,并综合使用了反向传播（BP）和支持向量机（SVM）2种学习算法。这2种算法分别适用于个人安全驾驶速度快与高效交通系统检测率高的应用。仿真实验和性能分析表明,本方案具有较快的入侵检测速度,且具有较高的检测率和较低的虚警率。