Liu Xin, Zhao Shanghong, Liang Yanxia, Karim Shahid
School of Information Engineering, Xi'an Eurasia University, Xi'an, China.
School of Information and Navigation, Air Force Engineering University, Xi'an, China.
PeerJ Comput Sci. 2025 May 8;11:e2852. doi: 10.7717/peerj-cs.2852. eCollection 2025.
In contemporary wireless communication systems, channel estimation and optimization have become increasingly pivotal with the growing number and complexity of devices. Communication systems frequently encounter multiple challenges, such as multipath propagation, signal fading, and interference, which may result in the degradation of communication quality, a reduction in data transmission rates, and even communication interruptions. Therefore, effective estimation and optimization of channels in complex communication environments are of paramount importance to ensure communication quality and enhance system performance. In this article, we address the intelligent, reflective surface (IRS)-assisted channel estimation problem and propose an intelligent channel estimation model based on the fusion of convolutional neural network (CNN) and gated recurrent unit (GRU) row features, utilizing the reinforcement learning Deep Deterministic Policy Gradient (DDPG) strategy for Channel Reconstruction Prediction and Generation Network (CRPG-Net). The framework initially acquires the received signal by converting the guide-frequency symbols at the transmitter into time-domain sequences to be transmitted, and after propagating through the direct channel and the IRS reflection channel, processes the data at the receiver. Subsequently, the spatial and temporal features in the received signal are extracted using the CRPG-Net model, with the adaptive optimization capability of the model enhanced by deep reinforcement learning. The introduction of reinforcement learning enables the model to continuously optimize decisions in dynamic channel environments, improve the robustness of channel estimation, and quickly adjust the IRS reflection parameters when the channel state changes to adapt to complex communication conditions. Experimental results demonstrate that the framework achieves significant channel estimation accuracy and robustness across several public datasets and real test scenarios, with the channel estimation error markedly smaller than that of traditional least squares (LS) and linear minimum mean square error (LMMSE) methods. This method introduces innovative techniques for channel estimation in intelligent communication systems, playing a crucial role in enhancing communication quality and overall system performance.
在当代无线通信系统中,随着设备数量的增加和复杂性的提升,信道估计与优化变得愈发关键。通信系统经常面临多种挑战,如多径传播、信号衰落和干扰,这些可能导致通信质量下降、数据传输速率降低,甚至通信中断。因此,在复杂通信环境中对信道进行有效的估计和优化对于确保通信质量和提升系统性能至关重要。在本文中,我们解决了智能反射面(IRS)辅助的信道估计问题,并提出了一种基于卷积神经网络(CNN)和门控循环单元(GRU)行特征融合的智能信道估计模型,利用强化学习深度确定性策略梯度(DDPG)策略用于信道重构预测与生成网络(CRPG-Net)。该框架首先通过将发射端的导频符号转换为时域序列进行传输来获取接收信号,该信号在经过直接信道和IRS反射信道传播后,在接收端进行数据处理。随后,使用CRPG-Net模型提取接收信号中的时空特征,并通过深度强化学习增强模型的自适应优化能力。强化学习的引入使模型能够在动态信道环境中不断优化决策,提高信道估计的鲁棒性,并在信道状态变化时快速调整IRS反射参数以适应复杂的通信条件。实验结果表明,该框架在多个公共数据集和实际测试场景中均实现了显著的信道估计精度和鲁棒性,其信道估计误差明显小于传统的最小二乘法(LS)和线性最小均方误差法(LMMSE)。该方法为智能通信系统中的信道估计引入了创新技术,在提升通信质量和整体系统性能方面发挥了关键作用。