提出一种基于盲信号分离的方法对MIMO信号进行调制识别.该方法对接收信号的相关矩阵作奇异值分解,用于估算发射天线数目,并对信号进行白化.采用特征值矩阵的联合近似对角化(joint approximate diagonalisation of eigen-matrices,JADE)...提出一种基于盲信号分离的方法对MIMO信号进行调制识别.该方法对接收信号的相关矩阵作奇异值分解,用于估算发射天线数目,并对信号进行白化.采用特征值矩阵的联合近似对角化(joint approximate diagonalisation of eigen-matrices,JADE)算法对接收信号进行分离,恢复发送端信号.通过分析信号的频谱特征,提出4个新的特征参数,并结合四阶累积量实现对MIMO体制下6种信号调制方式的识别.识别过程中无需估计载波频率和符号率等参数,具有较强的实用性.仿真结果表明文中提出的方法具有良好的性能.展开更多
Infrared target detection models are more required than ever before to be deployed on embedded platforms,which requires models with less memory consumption and better real-time performance while considering accuracy.T...Infrared target detection models are more required than ever before to be deployed on embedded platforms,which requires models with less memory consumption and better real-time performance while considering accuracy.To address the above challenges,we propose a modified You Only Look Once(YOLO)algorithm PF-YOLOv4-Tiny.The algorithm incorpo-rates spatial pyramidal pooling(SPP)and squeeze-and-excitation(SE)visual attention modules to enhance the target localization capability.The PANet-based-feature pyramid networks(P-FPN)are proposed to transfer semantic information and location information simultaneously to ameliorate detection accuracy.To lighten the network,the standard convolutions other than the backbone network are replaced with depthwise separable convolutions.In post-processing the images,the soft-non-maximum suppression(soft-NMS)algorithm is employed to subside the missed and false detection problems caused by the occlusion between targets.The accuracy of our model can finally reach 61.75%,while the total Params is only 9.3 M and GFLOPs is 11.At the same time,the inference speed reaches 87 FPS on NVIDIA GeForce GTX 1650 Ti,which can meet the requirements of the infrared target detection algorithm for the embedded deployments.展开更多
针对单一卷积神经网络对多种复杂背景下手势图像识别准确率较低等问题,提出一种基于改进Xception网络的手势图像识别方法。该方法使用密集连接代替残差连接,在保留跳跃连接效果的同时减少深度可分离卷积模块和网络通道数量,不仅有效利...针对单一卷积神经网络对多种复杂背景下手势图像识别准确率较低等问题,提出一种基于改进Xception网络的手势图像识别方法。该方法使用密集连接代替残差连接,在保留跳跃连接效果的同时减少深度可分离卷积模块和网络通道数量,不仅有效利用了网络参数,而且降低了模型大小;其还融合SE模块强化重要特征,采用特征金字塔结构获得包含多尺度语义的特征张量,有助于网络分类。验证实验结果表明,改进网络的计算参数量为原始Xception网络的1/5,对NUS-Ⅱ手势数据集的识别准确率达到99.64%,比原始Xception网络提高了1.09%;对Sign Language for Numbers手势数据集的识别准确率达到99.7%,比原始Xception网络提高了0.15%。与ResNet50、DenseNet121和InceptionV3等常用手势识别网络进行比较,改进网络在训练时间、模型大小、计算参数量和识别准确率方面均表现更优。基于改进Xception网络的手势识别方法在多种复杂背景因素干扰下仍具有较高的识别准确率,其泛化性强、参数量少,综合性能优于许多常用网络。展开更多
文摘提出一种基于盲信号分离的方法对MIMO信号进行调制识别.该方法对接收信号的相关矩阵作奇异值分解,用于估算发射天线数目,并对信号进行白化.采用特征值矩阵的联合近似对角化(joint approximate diagonalisation of eigen-matrices,JADE)算法对接收信号进行分离,恢复发送端信号.通过分析信号的频谱特征,提出4个新的特征参数,并结合四阶累积量实现对MIMO体制下6种信号调制方式的识别.识别过程中无需估计载波频率和符号率等参数,具有较强的实用性.仿真结果表明文中提出的方法具有良好的性能.
基金supported by The Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grants No.19JKB520031).
文摘Infrared target detection models are more required than ever before to be deployed on embedded platforms,which requires models with less memory consumption and better real-time performance while considering accuracy.To address the above challenges,we propose a modified You Only Look Once(YOLO)algorithm PF-YOLOv4-Tiny.The algorithm incorpo-rates spatial pyramidal pooling(SPP)and squeeze-and-excitation(SE)visual attention modules to enhance the target localization capability.The PANet-based-feature pyramid networks(P-FPN)are proposed to transfer semantic information and location information simultaneously to ameliorate detection accuracy.To lighten the network,the standard convolutions other than the backbone network are replaced with depthwise separable convolutions.In post-processing the images,the soft-non-maximum suppression(soft-NMS)algorithm is employed to subside the missed and false detection problems caused by the occlusion between targets.The accuracy of our model can finally reach 61.75%,while the total Params is only 9.3 M and GFLOPs is 11.At the same time,the inference speed reaches 87 FPS on NVIDIA GeForce GTX 1650 Ti,which can meet the requirements of the infrared target detection algorithm for the embedded deployments.
文摘针对单一卷积神经网络对多种复杂背景下手势图像识别准确率较低等问题,提出一种基于改进Xception网络的手势图像识别方法。该方法使用密集连接代替残差连接,在保留跳跃连接效果的同时减少深度可分离卷积模块和网络通道数量,不仅有效利用了网络参数,而且降低了模型大小;其还融合SE模块强化重要特征,采用特征金字塔结构获得包含多尺度语义的特征张量,有助于网络分类。验证实验结果表明,改进网络的计算参数量为原始Xception网络的1/5,对NUS-Ⅱ手势数据集的识别准确率达到99.64%,比原始Xception网络提高了1.09%;对Sign Language for Numbers手势数据集的识别准确率达到99.7%,比原始Xception网络提高了0.15%。与ResNet50、DenseNet121和InceptionV3等常用手势识别网络进行比较,改进网络在训练时间、模型大小、计算参数量和识别准确率方面均表现更优。基于改进Xception网络的手势识别方法在多种复杂背景因素干扰下仍具有较高的识别准确率,其泛化性强、参数量少,综合性能优于许多常用网络。
