基于多尺度特征增强与注意力机制的调制识别算法
A Modulation Recognition Algorithm Based on Multi-Scale Feature Enhancement and Attention Mechanism
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摘要: 自动调制识别(Automatic Modulation Recognition,AMR)在非合作通信系统中具有重要作用。近年来,基于深度学习(Deep Learning,DL)的AMR(DL-AMR)方法在识别精度和鲁棒性方面相较传统方法已有显著提升。然而,现有DL-AMR方法普遍存在特征提取能力不足以及精度与复杂度难以平衡的问题。针对现有方法局限性,本文提出一种基于多尺度特征增强与注意力机制的调制识别网络MFEA-Net(Multi-Scale Feature Enhancement and Attention Mechanism Network)。该网络利用不同尺度的卷积核初步提取信号的多尺度特征,并通过卷积层对其进一步压缩与融合。在特征增强方面,采用深度卷积(Depthwise Convolution,DW-Conv)与膨胀卷积(Dilated Convolution, D-Conv)代替普通卷积对多尺度特征进一步增强的同时降低网络参数量与运算复杂度,并通过挤压与激励(Squeeze-and-Excitation, SE)注意力机制强化关键通道特征。此外,引入多头自注意力(Multi-Head Self-Attention,MHSA)机制在序列层面建模全局依赖关系,并结合全局最大池化与全局平均池化提取信号的全局统计特征,最终由全连接层输出识别结果。对比实验结果表明,本文提出的MFEA-Net在RML2016.10a与RML2016.10b数据集的信噪比≥0 dB区间内,对绝大多数调制类型的识别准确率超过了90%。此外,MFEA-Net在上述数据集中的整体准确率(Overall Accuracy,OA)分别达到63.01%、64.61%,且复杂度处于较低水平。同时,消融实验进一步验证了各模块对整体性能的贡献,证明了网络结构设计的合理性。综上,MFEA-Net在性能与复杂度之间取得了良好平衡,在资源受限场景中具备潜在的应用价值。Abstract: Automatic modulation recognition (AMR) plays an important role in noncooperative communication systems. In recent years, deep learning-based automatic modulation recognition (DL-AMR) methods have achieved notable improvements in recognition accuracy and robustness compared to traditional approaches. However, existing DL-AMR methods generally suffer from limited feature extraction capabilities and difficulty in balancing accuracy and the complexity of the computational model. To address these limitations, we propose a modulation recognition architecture referred to as a multi-scale feature enhancement and attention mechanism network (MFEA-Net). The proposed network employs convolution kernels with different receptive fields to extract multiscale signal features, which are then further compressed and fused through convolutional layers. For feature enhancement, depthwise convolution (DW-Conv) and dilated convolution (D-Conv) were used to replace standard convolutions to strengthen multiscale representations while reducing the number of parameters and computational cost. Squeeze-and-excitation (SE) attention was adopted to emphasize the informative channel features. Moreover, multi-head self-attention (MHSA) was introduced to model global dependencies at the sequence level. Global maximum pooling (GMP) and global average pooling (GAP) were combined to capture the global statistical features, and the final recognition results were produced through fully connected layers. Comparative experimental results show that, in the SNR≥0 dB range on both the RML2016.10a and RML2016.10b datasets, MFEA-Net achieves recognition accuracies exceeding 90% for the vast majority of modulation types. In addition, the overall accuracy (OA) of MFEA-Net respectively reached 63.01% and 64.61% on the two datasets despite the relatively low complexity of the model. Furthermore, the results of ablation studies verified the contributions of each module to the overall performance and thus demonstrate the rationality of the proposed architecture. Thus, the results demonstrate that MFEA-Net achieved a good balance between performance and complexity and showed promise for applications in resource-constrained scenarios.
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