Non-Intrusive Objective Speech Quality Measurement Based on Fuzzy GMM and SVR for Narrowband Speech

Based on fuzzy Gaussian mixture model (FGMM) and support vector regression (SVR),an improved version of non-intrusive objective measurement for assessing quality of output speech without inputting clean speech is proposed for narrowband speech.Its perceptual linear predictive (PLP) features extracted from clean speech and clustered by FGMM are used as an artificial reference model.Input speech is separated into three classes,for each a consistency parameter between each feature pair from test speech signals...     

利用FPGA技术实现数字通信中的交织器和解交织器

介绍用FPGA实现数字通信中的交、解交织器的一种比较通用的方案,详细说明了设计中的一些问题及解决办法.还介绍了一种实现FPGA中信号延时的方法.     

基于LDPC码的部分增量冗余型HARQ优化

提出了一种适用于高码率低密度奇偶校验(LDPC)编码的部分增量冗余(PIR)型混和自动重发请求(HARQ)优化方案.该方案结合不等差错保护和星座图重排技术(CoRe)的优点,能够有效地平均多次重传后不同编码比特之间的可靠性,降低误块率(BLER),提高LDPC译码性能,可应用于改善移动通信系统的链路适配性能.     

Bark-Band Residual Noise Model for Parametric Audio Coding

A Bark-band residual noise model integrated with the human hearing mechanism is proposed to efficiently complement sinusoidal model in parametric audio coding. The time-varying spectrum of the residual noise is retrieved by Bark-scale piecewise constant magnitude estimates along with random phases. In the proposed noise model, Bark bands information is obtained by short-time FFT method and window overlap-add technique is exploited to remove boundary discontinuities. SVQ is also incorporated into parameter quantization process for the low bit-rate coding demand. Simulation results and informal listening tests show that when the sinusoidal model is combined with the Bark-band noise model, better synthesis audio quality can be achieved compared with the original sinusoidal modeling audio codec.     

建设“国内一流 国际知名”高水平研究型大学

在2003年1月5日召开的教育部直属高校工作咨询委员会第十三次会议上，周济部长明确指出．各高校要“思考两个问题”，制定“三个规划”。两个问题：一是建设一个什么样的大学?即战略目标和发展理念问题；二是怎样建设这样的大学?即创新思路和战     

Novel Mapping Design Criterion for BICM-ID with Square QAM Constellations

Mapping design criteria of bit-interleaved coded modulation with iterative decoding (BICM-ID) with square 16QAM are analyzed. Three of the existing criteria are analyzed and compared with each other. Through the comparison, two main characters of the mapping design criteria are found. They are the harmonic mean of the minimum squared Euclidean distance and the average of Hamming distances with the nearest Euclidean distance.Based on these two characters, a novel mapping design criterion is proposed and a label mapping named mixed mapping is searched according to it. Simulation results show that mixed mapping performs better than the other mappings in BICM-ID system.     

一种基于空域的MIMO系统链路自适应策略研究

提出基于空域上联合SM和TD的LA策略。该策略通过检测后的符号SNR来自适应搜寻满足服务质量要求的最优空间分组方案,天线组内部使用空时分组编码(STBC),组间进行复用。仿真结果表明,同基于时域的LA策略相比,该策略能充分利用SM与TD在时域及空域的性能折中,具有更优的吞吐量性能,且复杂度较低。     

一种新的基于进化规划方法的盲CMA快速收敛算法

本文把改进的进化规划方法引进到解决均衡问题中,定义以代价函数为自变量的一种新的函数作为高斯随机化算子的标准差,来控制算法的收敛,提出了一种新的基于进化规划的CMA算法(QEPCMA),该方法应用进化规划来估计均衡器的系数,进一步提高了文献[5]中改进的CMA算法的收敛速度。通过Monte—Carlo仿真,比较了这两种算法和标准 CMA算法的性能,验证了所提算法的有效性。     

基于小波变换的2.4kbit/s波形内插语音编码算法

基于双正交小波滤波器组对波形内插编码中提取的特征波进行多级分解与重构，提出了一种基于小波变换（WT）的2．4kbit／s特征波形内插（CWI）语音编码算法。编码端去除了特征波对齐运算，并对幅度谱进行多级分解，相位谱不传输，鉴于小波变换对信号的压缩特性，仅传输对人耳感知起主要贡献的最后一级特征波幅度谱；解码端对各尺度空间采用单独重建的方法，相位信息在重构的末级与幅度谱结合，并由浊音度标志选择固定或随机相位。此外，根据语音信号的时变特性，由基于子帧的浊音度标志选择需要传输的幅度谱及量化模式。主观R-A／B测试表明，这种基于小波变换的2．4kbit／s编码算法的合成语音质量明显优于标准的2．4kbit／s的MELP编码器及FS1016的4．8kbit／sCELP编码器，亦优于3．8kbit／s的传统CWI编码框架下的合成语音效果。