共查询到19条相似文献,搜索用时 171 毫秒
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当前,在较大区域下进行3D环绕声重放是个挑战,由于它要求巨大数量的扬声器。本文基于3D波场转换的研究提出一种高阶扬声器阵列,可以提供一种模式匹配的解决方案。对于一个给定的带宽,由于1/(L+1) 2的因素,Lth的使用使声源明显降低了对扬声器数量的要求。此外,音箱阵列有消弱外部声场影响的功能,可以提高它在回声环境中的表现力,应用于室内声场、室外声场和室内室外结合的声场重放系统中。 相似文献
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声场全息重构是通过近场声全息重构声源的声辐射特性的一种声场反演方法,是近年来的研究热点问题.基于近场声全息声场重构模型,研究声场全息重构方法;再运用LabVIEW虚拟仪器软件平台,开展了传声器阵列各通道标定校准、数据采集、全息面复声压的获取和声场可视化等声场全息重构实验研究.实验结果表明,声场全息重构实验具有较高的定位精度,同时也验证了声场全息重构方法的有效性和实用性. 相似文献
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在高精度的微弱光电信号检测系统中,存在信号被强噪声湮没的情况.针对这一问题,提出了一种基于改进高阶Vanderpol振子的微弱正弦信号定量检测方法.该方法利用改进高阶广义Vanderpol系统的高灵敏度与强抗噪性的特点提高了微弱信号检测的可靠性,再结合Lyapunov指数定量检测和90.移相补偿来实现混沌系统状态的量化判断和待测信号参数的高精度提取.仿真结果表明改进的Vanderpol振子比传统Vanderpol振子运算速度更快.与传统Duffing振子相比,在5%幅值检测误差范围内,改进的高阶广义Vanderpol系统可多获得37 dB的信噪比增益和60 dB的检测门限增益;与基于相轨迹突变定性检测待测信号幅相法相比,90°移相补偿幅相定量检测法在信噪比降低时其检测相对误差仍可控制在2%以内.改进算法实现了微弱正弦信号的高灵敏度和高精度的幅相检测. 相似文献
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提出一种利用非标准的扬声器布置重发双通路立体声的方法。理论和实验结果表明,通过虚拟声信号处理的方法,可在一定程度上改善扬声器的非标准布置所引起的声像位置畸变。 相似文献
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改进的后滤波波束形成器语音增强算法 总被引:1,自引:0,他引:1
该文提出了一种具有后滤波的波束形成器的语音增强改进算法。该算法主要解决维纳滤波器的理想信号功率谱估计,结合自功率谱减法和互功率谱减法计算出尽可能多的功率谱估计值,以使平均结果更接近于真实值,同时修正了声源移动引起的互功率谱变化。实验结果信噪比提高5dB以上,汽车环境中基于隐含马尔可夫模型(HMM)的小词汇量短语识别达到84%。从信噪比、平均谱距离和语音识别率可以看出该算法有效去除了原始算法中易残留的低频噪声,减少了语音信号失真。 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》1984,30(4):674-677
Robust Wiener filtering has previously been considered for the single-input (scalar) case where there is no channel distortion and where the signal to be estimated is the source signal itself. Here, these results are extended to the multiple-input (vector) case where linear channel distortion is allowed and the signal to be estimated is a linear-filtered version of the source signal. The results are obtained from those for the single-input ease by modifying the constraints on signal and noise characteristics. Such a modification is motivated by examining the expression of the mean-squared error for the optimum filter. 相似文献
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本文提出一种分频段数字音频动态范围处理器的设计方法。传统的分频段方法主要采用滤波器组,而本文则利用扬声系统中的LR分割器来分割频段。传统的动态范围处理器通常利用前馈包络法和低通滤波器来平滑增益曲线。但面对快速变化的信号或噪声,此类方法得到的结果可能会有较大的失真。针对此问题,本文提出了一种创新的时间幅度并行控制法,在时间和幅度域内同时对信号进行控制,能很好地降低噪声并改善输出信号的失真度。最后,本文给出了MATLAB仿真和基于ADSP21364的实测结果,验证了本方法的性能。 相似文献
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基于高阶累积量的近场通信波达方向估计算法 总被引:1,自引:0,他引:1
通过对近场通信波达方向准确估计,提高目标信源的定位能力.传统方法中对近场源通信信源的波达方向估计采用多普勒估计方法,由于近场通信的空间信源为窄带信号,多普勒估计会导致DOA估计频谱失真.提出一种基于高阶累积量的近场通信波达方向估计算法.采用均匀间隔线列阵构建近场通信的信号模型,进行近场源目标特征构建,提取近场源通信信号的斜度和峰度等特征,采用高阶累积量特征提取方法,分别求得对应近场通信信源的方位角、频率和距离三维参数,使得每个信源的参数自动配对,提高了近场通信DOA波达方向估计的效率和精度,实现近场源通信信号的波达方向估计算法改进.仿真实验结果表明,采用该方法进行近场方法波达方向估计的精度较高,对信源方位的定位准确,性能优越于传统方法,在近场通信中具有较好的应用价值. 相似文献
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A new technique of synthesis of near-field (NF) amplitude and phase patterns of linear, planar, of volume arrays of finite size or arrays located on a planar contour of finite size is presented. The array could consist of point dipoles or directive elements. The criterion for prescribing the NF (amplitude and phase) pattern information in the synthesis problem for unique determination of array excitation currents is also stated. The proposed near-field synthesis technique is based on the potential integral solution of source currents, Nyquist sampling of the near-field data and the technique of linear least square approximation (LLSA). The NF pattern synthesis technique is illustrated to synthesize a variety of NF patterns with a number of array configurations. Application of the proposed NF pattern synthesis technique to minimize distortion in far-field patterns of arrays mounted on a conducting platform and to realize array antennas with low sidelobes in the near and far field is also presented. 相似文献
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Statistical Model‐Based Noise Reduction Approach for Car Interior Applications to Speech Recognition
Sung Joo Lee Byung Ok Kang Ho‐Young Jung Yunkeun Lee Hyung Soon Kim 《ETRI Journal》2010,32(5):801-809
This paper presents a statistical model‐based noise suppression approach for voice recognition in a car environment. In order to alleviate the spectral whitening and signal distortion problem in the traditional decision‐directed Wiener filter, we combine a decision‐directed method with an original spectrum reconstruction method and develop a new two‐stage noise reduction filter estimation scheme. When a tradeoff between the performance and computational efficiency under resource‐constrained automotive devices is considered, ETSI standard advance distributed speech recognition font‐end (ETSI‐AFE) can be an effective solution, and ETSI‐AFE is also based on the decision‐directed Wiener filter. Thus, a series of voice recognition and computational complexity tests are conducted by comparing the proposed approach with ETSI‐AFE. The experimental results show that the proposed approach is superior to the conventional method in terms of speech recognition accuracy, while the computational cost and frame latency are significantly reduced. 相似文献
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介绍了扬声器阵列、扬声器线阵列、声柱的基本概念,以连续直线阵列为例,介绍其指向特性、波阵面传播特性、有效辐射率(ARF)概念及其估计方法,分析了点声源声柱和线声源声柱.提出了声梁的基本概念及一种利用二次剩余序列实现均匀声场的解决方案. 相似文献