To overcome the limitations of conventional speech enhancement methods, such as inaccurate voice activity detector(VAD) and noise estimation, a novel speech enhancement algorithm based on the approximate message passi...To overcome the limitations of conventional speech enhancement methods, such as inaccurate voice activity detector(VAD) and noise estimation, a novel speech enhancement algorithm based on the approximate message passing(AMP) is adopted. AMP exploits the difference between speech and noise sparsity to remove or mute the noise from the corrupted speech. The AMP algorithm is adopted to reconstruct the clean speech efficiently for speech enhancement. More specifically, the prior probability distribution of speech sparsity coefficient is characterized by Gaussian-model, and the hyper-parameters of the prior model are excellently learned by expectation maximization(EM) algorithm. We utilize the k-nearest neighbor(k-NN) algorithm to learn the sparsity with the fact that the speech coefficients between adjacent frames are correlated. In addition, computational simulations are used to validate the proposed algorithm, which achieves better speech enhancement performance than other four baseline methods-Wiener filtering, subspace pursuit(SP), distributed sparsity adaptive matching pursuit(DSAMP), and expectation-maximization Gaussian-model approximate message passing(EM-GAMP) under different compression ratios and a wide range of signal to noise ratios(SNRs).展开更多
针对正交时频空(Orthogonal Time Frequency Space,OTFS)调制系统采用矩形窗函数时,信道矩阵结构复杂导致的鲁棒性差的问题,提出了一种基于时域处理和酉近似消息传递的检测算法。该算法首先添加循环前缀,将时域信道转换为分块对角矩阵;...针对正交时频空(Orthogonal Time Frequency Space,OTFS)调制系统采用矩形窗函数时,信道矩阵结构复杂导致的鲁棒性差的问题,提出了一种基于时域处理和酉近似消息传递的检测算法。该算法首先添加循环前缀,将时域信道转换为分块对角矩阵;然后应用酉变换和近似消息传递建立迭代检测算法。仿真结果表明,所提检测算法能够在不增加复杂度的条件下有效提升检测精度和鲁棒性,特别是存在信道编码的条件下表现出2 dB的性能增益,使得该算法更适用于杂散多径、高速移动等环境,具有较高的应用价值。展开更多
When estimating the direction of arrival (DOA) of wideband signals from multiple sources, the performance of sparse Bayesian methods is influenced by the frequency bands occupied by signals in different directions. Th...When estimating the direction of arrival (DOA) of wideband signals from multiple sources, the performance of sparse Bayesian methods is influenced by the frequency bands occupied by signals in different directions. This is particularly true when multiple signal frequency bands overlap. Message passing algorithms (MPA) with Dirichlet process (DP) prior can be employed in a sparse Bayesian learning (SBL) framework with high precision. However, existing methods suffer from either high complexity or low precision. To address this, we propose a low-complexity DOA estimation algorithm based on a factor graph. This approach introduces two strong constraints via a stretching transformation of the factor graph. The first constraint separates the observation from the DP prior, enabling the application of the unitary approximate message passing (UAMP) algorithm for simplified inference and mitigation of divergence issues. The second constraint compensates for the deviation in estimation angle caused by the grid mismatch problem. Compared to state-of-the-art algorithms, our proposed method offers higher estimation accuracy and lower complexity.展开更多
In this paper,a powerful model-driven deep learning framework is exploited to overcome the challenge of multi-domain signal detection in spacedomain index modulation(SDIM)based multiple input multiple output(MIMO)syst...In this paper,a powerful model-driven deep learning framework is exploited to overcome the challenge of multi-domain signal detection in spacedomain index modulation(SDIM)based multiple input multiple output(MIMO)systems.Specifically,we use orthogonal approximate message passing(OAMP)technique to develop OAMPNet,which is a novel signal recovery mechanism in the field of compressed sensing that effectively uses the sparse property from the training SDIM samples.For OAMPNet,the prior probability of the transmit signal has a significant impact on the obtainable performance.For this reason,in our design,we first derive the prior probability of transmitting signals on each antenna for SDIMMIMO systems,which is different from the conventional massive MIMO systems.Then,for massive MIMO scenarios,we propose two novel algorithms to avoid pre-storing all active antenna combinations,thus considerably improving the memory efficiency and reducing the related overhead.Our simulation results show that the proposed framework outperforms the conventional optimization-driven based detection algorithms and has strong robustness under different antenna scales.展开更多
正交时频空(Orthogonal Time Frequency Space,OTFS)调制技术和索引调制(Index Modulation,IM)技术适用于高移动性场景,具有高频谱效率等优势,在图像传输领域应用前景广泛。然而,结合索引调制的正交时频空(Orthogonal Time Frequency Sp...正交时频空(Orthogonal Time Frequency Space,OTFS)调制技术和索引调制(Index Modulation,IM)技术适用于高移动性场景,具有高频谱效率等优势,在图像传输领域应用前景广泛。然而,结合索引调制的正交时频空(Orthogonal Time Frequency Space with Index Modulation,OTFS-IM)调制技术的算法实现复杂度较高。对此,在广义近似消息传递(Generalized Approximate Message Passing,GAMP)的基础上改进,提出一种基于概率排序的阻尼广义消息传递算法。实验结果表明,在图像传输应用中,与传统的最小均方误差结合最大似然方案(Minimum Mean Squared Error with Maximum Likelihood,MMSEML)相比,所提的算法具有更低的复杂度,性能也优于传统的MMSE-ML传输方案。展开更多
期望最大化贝努利高斯（BG）近似信息传递（EM-BG-AMP）算法中的BG模型因为具有对称性,在逼近实际信号先验分布时会受到限制;而期望最大化高斯混合近似信息传递（EM-GM-AMP）算法中的GM模型是BG模型的高阶形式,复杂度较高。为了解决以...期望最大化贝努利高斯（BG）近似信息传递（EM-BG-AMP）算法中的BG模型因为具有对称性,在逼近实际信号先验分布时会受到限制;而期望最大化高斯混合近似信息传递（EM-GM-AMP）算法中的GM模型是BG模型的高阶形式,复杂度较高。为了解决以上问题,提出贝努利不对称高斯模型（BAG）,进而推导得到期望最大化贝努利不对称高斯近似信息传递（EM-BAG-AMP）算法。该算法的主要思路是假设输入信号服从BAG模型,然后使用广义近似信息传递（GAMP）重构信号并在算法迭代中同时更新模型参数。实验证明,在处理不同图像数据时,EM-BAG-AMP和EM-BG-AMP相比,时间增加了1.2%,峰值信噪比（PSNR）值提升了0.1~0.5 d B,尤其在处理纹理较少以及色差变化明显的图像时峰值信噪比（PSNR）值提升了0.4~0.5 d B。EM-BAG-AMP是对EM-BG-AMP算法的扩展和延伸,更适合实际信号的处理。展开更多
作为第5代(5G)移动通信系统更新换代的标志性技术——非正交多址接入(NOMA)技术相对于传统的正交技术能够大幅提高频谱效率和提升系统容量。接收机检测技术是非正交多址接入系统性能提高的关键技术,本文基于传统的消息传递算法(MPA)进...作为第5代(5G)移动通信系统更新换代的标志性技术——非正交多址接入(NOMA)技术相对于传统的正交技术能够大幅提高频谱效率和提升系统容量。接收机检测技术是非正交多址接入系统性能提高的关键技术,本文基于传统的消息传递算法(MPA)进行改进,在MPA算法的基础上加入Turbo译码后的先验信息进行连续迭代运算以进一步提高检测性能,称为MPA-Turbo译码联合迭代算法(MPA-TDJIA)。根据先验信息的加入方式提出4种实现方案,并在链路仿真中对其性能进行评估。仿真结果表明MPA-TDJIA相对于MPA最高可获得1. 67 d B的性能增益。展开更多
基金supported by National Natural Science Foundation of China(NSFC)(No.61671075)Major Program of National Natural Science Foundation of China(No.61631003)。
文摘To overcome the limitations of conventional speech enhancement methods, such as inaccurate voice activity detector(VAD) and noise estimation, a novel speech enhancement algorithm based on the approximate message passing(AMP) is adopted. AMP exploits the difference between speech and noise sparsity to remove or mute the noise from the corrupted speech. The AMP algorithm is adopted to reconstruct the clean speech efficiently for speech enhancement. More specifically, the prior probability distribution of speech sparsity coefficient is characterized by Gaussian-model, and the hyper-parameters of the prior model are excellently learned by expectation maximization(EM) algorithm. We utilize the k-nearest neighbor(k-NN) algorithm to learn the sparsity with the fact that the speech coefficients between adjacent frames are correlated. In addition, computational simulations are used to validate the proposed algorithm, which achieves better speech enhancement performance than other four baseline methods-Wiener filtering, subspace pursuit(SP), distributed sparsity adaptive matching pursuit(DSAMP), and expectation-maximization Gaussian-model approximate message passing(EM-GAMP) under different compression ratios and a wide range of signal to noise ratios(SNRs).
文摘针对正交时频空(Orthogonal Time Frequency Space,OTFS)调制系统采用矩形窗函数时,信道矩阵结构复杂导致的鲁棒性差的问题,提出了一种基于时域处理和酉近似消息传递的检测算法。该算法首先添加循环前缀,将时域信道转换为分块对角矩阵;然后应用酉变换和近似消息传递建立迭代检测算法。仿真结果表明,所提检测算法能够在不增加复杂度的条件下有效提升检测精度和鲁棒性,特别是存在信道编码的条件下表现出2 dB的性能增益,使得该算法更适用于杂散多径、高速移动等环境,具有较高的应用价值。
基金supported in part by the National Natural Science Foundation of China(Nos.6202780103 and 62033001)the Innovation Key Project of Guangxi Province(No.AA22068059)+2 种基金the Key Research and Development Program of Guilin(No.2020010332)the Natural Science Foundation of Henan Province(No.222300420504)Academic Degrees and Graduate Education Reform Project of Henan Province(No.2021SJGLX262Y).
文摘When estimating the direction of arrival (DOA) of wideband signals from multiple sources, the performance of sparse Bayesian methods is influenced by the frequency bands occupied by signals in different directions. This is particularly true when multiple signal frequency bands overlap. Message passing algorithms (MPA) with Dirichlet process (DP) prior can be employed in a sparse Bayesian learning (SBL) framework with high precision. However, existing methods suffer from either high complexity or low precision. To address this, we propose a low-complexity DOA estimation algorithm based on a factor graph. This approach introduces two strong constraints via a stretching transformation of the factor graph. The first constraint separates the observation from the DP prior, enabling the application of the unitary approximate message passing (UAMP) algorithm for simplified inference and mitigation of divergence issues. The second constraint compensates for the deviation in estimation angle caused by the grid mismatch problem. Compared to state-of-the-art algorithms, our proposed method offers higher estimation accuracy and lower complexity.
基金supported by the National Natural Science Foundation of China under Grant U19B2014the Sichuan Science and Technology Program under Grant 2023NSFSC0457the Fundamental Research Funds for the Central Universities under Grant 2242022k60006.
文摘In this paper,a powerful model-driven deep learning framework is exploited to overcome the challenge of multi-domain signal detection in spacedomain index modulation(SDIM)based multiple input multiple output(MIMO)systems.Specifically,we use orthogonal approximate message passing(OAMP)technique to develop OAMPNet,which is a novel signal recovery mechanism in the field of compressed sensing that effectively uses the sparse property from the training SDIM samples.For OAMPNet,the prior probability of the transmit signal has a significant impact on the obtainable performance.For this reason,in our design,we first derive the prior probability of transmitting signals on each antenna for SDIMMIMO systems,which is different from the conventional massive MIMO systems.Then,for massive MIMO scenarios,we propose two novel algorithms to avoid pre-storing all active antenna combinations,thus considerably improving the memory efficiency and reducing the related overhead.Our simulation results show that the proposed framework outperforms the conventional optimization-driven based detection algorithms and has strong robustness under different antenna scales.
文摘正交时频空(Orthogonal Time Frequency Space,OTFS)调制技术和索引调制(Index Modulation,IM)技术适用于高移动性场景,具有高频谱效率等优势,在图像传输领域应用前景广泛。然而,结合索引调制的正交时频空(Orthogonal Time Frequency Space with Index Modulation,OTFS-IM)调制技术的算法实现复杂度较高。对此,在广义近似消息传递(Generalized Approximate Message Passing,GAMP)的基础上改进,提出一种基于概率排序的阻尼广义消息传递算法。实验结果表明,在图像传输应用中,与传统的最小均方误差结合最大似然方案(Minimum Mean Squared Error with Maximum Likelihood,MMSEML)相比,所提的算法具有更低的复杂度,性能也优于传统的MMSE-ML传输方案。
文摘期望最大化贝努利高斯（BG）近似信息传递（EM-BG-AMP）算法中的BG模型因为具有对称性,在逼近实际信号先验分布时会受到限制;而期望最大化高斯混合近似信息传递（EM-GM-AMP）算法中的GM模型是BG模型的高阶形式,复杂度较高。为了解决以上问题,提出贝努利不对称高斯模型（BAG）,进而推导得到期望最大化贝努利不对称高斯近似信息传递（EM-BAG-AMP）算法。该算法的主要思路是假设输入信号服从BAG模型,然后使用广义近似信息传递（GAMP）重构信号并在算法迭代中同时更新模型参数。实验证明,在处理不同图像数据时,EM-BAG-AMP和EM-BG-AMP相比,时间增加了1.2%,峰值信噪比（PSNR）值提升了0.1~0.5 d B,尤其在处理纹理较少以及色差变化明显的图像时峰值信噪比（PSNR）值提升了0.4~0.5 d B。EM-BAG-AMP是对EM-BG-AMP算法的扩展和延伸,更适合实际信号的处理。
文摘作为第5代(5G)移动通信系统更新换代的标志性技术——非正交多址接入(NOMA)技术相对于传统的正交技术能够大幅提高频谱效率和提升系统容量。接收机检测技术是非正交多址接入系统性能提高的关键技术,本文基于传统的消息传递算法(MPA)进行改进,在MPA算法的基础上加入Turbo译码后的先验信息进行连续迭代运算以进一步提高检测性能,称为MPA-Turbo译码联合迭代算法(MPA-TDJIA)。根据先验信息的加入方式提出4种实现方案,并在链路仿真中对其性能进行评估。仿真结果表明MPA-TDJIA相对于MPA最高可获得1. 67 d B的性能增益。
