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介绍了语音通信声学回声产生模型和自适应AEC回声消除算法原理,分析了AEC应用于VoIP语音通信中存在的问题,设计了一种基于短时能量的非线性回声消除方法,在NGN网络的VoIP通信中,使用该方法实现了极高的回声抑制比。测试结果表明该方法的消回声效果、算法稳定性和实现复杂度等指标明显优于自适应AEC算法,适合于嵌入式VoIP通信终端设备的开发。 相似文献
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在全双工通信系统中,声学回声会降低用户的体验,针对在双向通话场景下自适应滤波算法消除声学回声效果不理想以及非线性声学回声难以消除的问题,提出一种注意力机制与BiLSTM网络相结合的CS-BiLSTM深度声学回声消除算法。首先通过构建BiLSTM网络提取语音的时序特征,之后引入通道和空间注意力机制提取回声信号的空间特征信息,并融合均方根误差与平均绝对误差提出一种新的损失函数,提高模型的鲁棒性。改进后的CS-BiLSTM网络模型能够获得清晰的语音信号,具有更好的回声消除性能。仿真结果表明,在非线性回声和双向通话环境下,与其他几种参考算法相比,所提出的CS-BiLSTM算法在感知语音质量评价方面明显优于其他算法,更有效地实现了回声消除,此外,该算法结构简单且模型参数量更少。 相似文献
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提出了一种回声消除和噪声抑制算法,采用改进的自适应步长非线性滤波技术,用单芯片对该算法进行了实现.用180nm 3.3V/1.8V 6层金属混合信号CMOS工艺流片,可达70dB的声学回声消除性能,噪音消除达20dB,侧音消除达30dB.该芯片包含1个16位DSP、3个14位Σ-Δ ADC、2个16位Σ-Δ DAC、 以及内置ROM和RAM等,并集成有USB、UART、I2C和PCM等接口.测试结果表明该芯片具有全双工和远距离免提的功能,支持双路麦克风输入,技术规范符合G.165国际标准.该芯片功耗低,外围电路简单,自适应能力强,可广泛应用于蓝牙车载免提通信、GPS和即时通讯等领域. 相似文献
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回声问题是蓝牙免提应用系统中最常见而且无法避免的问题之一。通过对回声的产生和消除原理进行分析,研究了用于回声消除的自适应滤波算法。最后,利用BlueCore3-Multimedia蓝牙芯片内置的DSP实现了该算法,并根据车载应用环境的特点来调节算法参数,以使回声消除的效果达到最佳。 相似文献
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随着无线通信技术的迅猛发展,以手机为代表的无线通信终端已经成为大众应用最为广泛的通信工具。这其中语音通话功能是非常重要的用途,通话质量的优劣直接影响着用户感受。而通话回声问题是最难解决的部分,因为回声产生途径多样、软件处理算法复杂、回声调试参数众多,因此给研发工程师调试带来很大困难。文章介绍NXP平台回声消除算法的原理及其应用,旨在帮助工程师较快理解此平台回声消除算法机理并运用介绍的思路进行软件音频调试系统的开发和应用,从而达到改善无线通信终端回声效果的目的。 相似文献
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VoIP声学回声消除算法研究 总被引:2,自引:0,他引:2
对回声消除技术原理进行了阐述,介绍自适应回声消除器基本结构,并分析了speex中的频域回声消除算法MDF,针对MDF算法提出了一种使估计回声和录音输入之间进行的同步方法;最后,以Speex开源项目为基础进行了测试.结果表明,该方法比现有的双段讲话检测(DTD)算法效果更好,实现也更为简单. 相似文献
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《现代电子技术》2020,(3):22-26
声学回声消除(AEC)系统依赖于自适应滤波器的回声路径估计,当麦克风接收的信号存在回声和近端信号时,可能出现模拟回声路径的自适应滤波器发散,导致回声消除性能下降,严重时影响双端通话质量。一个成熟的声学回声消除器应该包含有双端通话检测算法,针对该问题,提出一种准确度高、性能稳定的基于信号包络检测(Env)和归一化互相关(NCC)估计相结合的双端通话检测(DTD)算法。该算法先使用远端信号与麦克风信号的能量包络来判断双端通话是否发生,当包络检测不能准确地判断双端通话时,再使用远端信号与麦克风信号的互相关估计对双端通话进行最终判断,保证双端通话检测的准确性。仿真实验表明,提出的算法可以准确判断双端通话的开始与结束,并且受回声路径变化的影响较小,提升了AEC系统的性能。 相似文献
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考虑到非线性回声和非平稳噪声对智能设备回声消除算法的影响,论文提出一种基于双向长短时记忆(Bidirectional Long Short-Term Memory,BLSTM)神经网络的回声和噪声抑制算法。该算法首先采用多目标预处理模型,同步估计出回声和噪声信号的幅度谱;然后将其作为回声和噪声抑制模型的输入特征,进而估计出目标语音信号的理想比例掩模;最后通过联合训练两个模型得到最优回声和噪声抑制模型。实验结果表明,在非线性回声和非平稳噪声的环境下,该算法均取得了较好的回声和噪声抑制效果,语音失真较小。 相似文献
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文中提出了一种新的多相位子带自适应回声消除系统。在子带内进行自适应滤波对建模长度比较长的脉冲响应特别有效,同时由于仿射投影算法具有预白化的作用,它同样也具有改善滤波器收敛性能的功能。该系统集中了多相子带自适应滤波和仿射投影算法的优点,结合了子带内的双端检测算法,使得系统在临界采样的情况下能进行稳定有效的工作。实验表明:该系统对于语音信号和强相关信号都表现出了良好的性能。 相似文献
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Acoustic echo cancellation (AEC) in voiced communication systems is used to eliminate the echo which corrupts the speech signal and reduces the efficiency of signal transmission. Usually, the performance of AEC system based on the adaptive filtering degrades seriously in the presence of speech issued from the near-end speaker (double-talk). In typical AEC scenarios, double-talk detector (DTD) must be added to AEC for improving speech quality. One of the main problems in AEC with DTD is that the DTD errors can result in either large residual echo or distorting the near-end input speech. Considering the strong correlation property of speech signals, this paper presents a novel proportionate decorrelation normalized least-mean-square (PDNLMS) adaptive AEC without DTD for echo cancellation as an interesting alternative to the typical AEC with DTDs. Unlike traditional AEC with a DTD, the proposed PDNLMS uses the difference of near-end speech as the residual error to update adaptive echo channel filter during the periods of double-talk, which can efficiently reduce the double-talk influence on the AEC adaptation process. The experimental results show that not only the proposed PDNLMS without DTD illustrate better stability and faster convergence rate, but it is also of a lower steady-state misalignment and better residual signal than current methods with DTDs at a lower computational cost. 相似文献
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Toon van Waterschoot Geert Rombouts Piet Verhoeve Marc Moonen 《Signal Processing, IEEE Transactions on》2007,55(3):846-858
The performance of an acoustic echo canceller may be severely degraded by the presence of a near-end signal. In such a double-talk situation, the variance of the echo path estimate typically increases, resulting in slow convergence or even divergence of the adaptive filter. This problem is usually tackled by equipping the echo canceller with a double-talk detector that freezes adaptation during near-end activity. Nevertheless, there is a need for more robust adaptive algorithms since the adaptive filter's convergence may be affected considerably in the time interval needed to detect double-talk. Moreover, in some applications, near-end noise may be continuously present and then the use of a double-talk detector becomes futile. Robustness to double-talk may be established by taking into account the near-end signal characteristics, which are, however, unknown and time varying. In this paper, we show how concurrent estimation of the echo path and an autoregressive near-end signal model can be performed using prediction error (PE) identification techniques. We develop a general recursive prediction error (RPE) identification algorithm and compare it to three existing algorithms from adaptive feedback cancellation. The potential benefit of the algorithms in a double-talk situation is illustrated by means of computer simulations. It appears that especially in the stochastic gradient case a huge improvement in convergence behavior can be obtained 相似文献
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利用连续可变学习速率处理回声抵消双话情况时,随着近端语音能量的提高,学习速率的估计偏差增大,导致残留回声增加.提出了一种利用短时能量比显示检测与连续学习速率相结合的改进双话处理算法.该算法利用近端与远端语音的短时能量比,对学习速率估计中的泄露因子参数进行自适应修正,从而调整连续学习速率.实验证明,该算法使得回声抵消双话情况下,自适应滤波器发散程度下降,语音质量得到提升.在近远端能量比-6~6dB范围内,回声返回损失增加度(ERLE)提高0~11 dB,平均意见得分(MOS)提高0.02~ 0.45分. 相似文献
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基于相关函数的递推最小二乘算法及其在回波消除中的应用 总被引:7,自引:0,他引:7
本文给出一种新的类似于RLS(recursive least squares)算法的递推最小二乘算法,该算法直接对输入信号的相关函数进行处理而不是对输入信号本身进行处理,理论分析表明了该算法的收敛性。该算法应用于回波消除问题中,克服了常规自适应滤波算法在出现双方对讲的情况下需停止调节自适应滤波器系数这一不足。计算机模拟仿真表明该算法在双方对讲的情况下有良好的收敛性能。 相似文献
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A new subband echo canceler (SBEC) structure is proposed to reduce the transmission delay introduced by conventional SBEC structures, without distorting the near-end signal. The proposed structure is based on computing two output errors, one for using during single-talk and the other one for using during double-talk periods. With the SBEC structure we propose a double-talk detector with a subband configuration which allows a fast and accurate detection of double-talk periods, enabling the SBEC algorithm to track changes in the echo path impulse response when the near-end signal is absent. Computer simulations using actual speech signals, and subjective evaluation tests are given to show the convergence performance, tracking and double-talk detection ability, of the proposed scheme 相似文献