Channel estimation method for IRS assisted mine communication system based on self supervised learning

Abstract

A channel estimation method for intelligence reflecting surface (IRS) assisted mine communication system based on self supervised learning (SSL) is proposed to address the problems of multipath fading, non line of sight communication, and difficulty in obtaining true labels caused by complex mine environments. The method builds an underground communication system model based on the Nakagami-g fading channel model and IRS signal transmission model, and solves the problems of multipath fading and non line of sight communication through IRS technology. Preliminary channel estimation is performed using the least squares (LS) algorithm, and then the channel estimation results are optimized using octave convolution (OCT) neural network under the SSL framework. OCT directly processes both high-frequency and low-frequency components, capturing both the rough features and subtle differences of the channel, providing comprehensive channel information, and thus more accurately estimating the channel state. The SSL algorithm uses received signals and their noisy versions as training data to improve the precision and efficiency of IRS assisted channel estimation through the intrinsic structure of unlabeled data, thereby reducing reliance on manual labeling. The simulation results show the following points.① Introducing IRS technology can effectively reduce channel estimation errors. ② The loss value of OCT neural network is significantly lower than that of CNN, and the data fitting effect is better. OCT neural network has high computational efficiency and can improve the overall performance of channel estimation in communication systems. In environments with limited computing resources, OCT neural networks can maintain low parameter and memory usage.③ The SSL algorithm can maintain a low normalized mean square error under all signal-to-noise ratio conditions, verifying its efficiency and robustness in channel estimation.④ The channel estimation method for IRS assisted mine communication system based on SSL has good scalability and robustness in large-scale networks.

Abstract

摘要：针对矿井复杂环境导致的多径衰落、非视距通信及真实标签获取困难的问题, 提出一种基于自监督学 习(SSL)的智能反射面(IRS)辅助矿井通信系统信道估计方法。根据井下Nakagami-g衰落信道模型和IRS信号 传输模型搭建井下通信系统模型, 通过IRS技术解决多径衰落和非视距通信问题。通过最小二乘(LS)算法进行 初步信道估计, 再采用SSL框架下的八度卷积(OCT)神经网络优化信道估计结果。OCT直接对高频分量和低频 分量进行处理, 能同时捕捉信道的粗糙特征和细微差别, 提供全面的信道信息, 从而更准确地估计信道状态; SSL算法使用接收信号及其带噪版本作为训练数据, 通过未标注数据的内在结构提升IRS辅助信道估计的精度 和效率, 从而降低对人工标签的依赖。仿真结果表明：①引入IRS技术能有效降低信道估计误差。 ②OCT神经网络的损失值明显低于CNN, 数据拟合效果更好;OCT神经网络计算效率高, 可提高通信系统信道 估计的整体性能;在计算资源有限的环境下, OCT神经网络可保持较低参数量和内存使用量。③SSL算法在所 有信噪比条件下均能保持较低的归一化均方误差, 验证了其在信道估计中的高效性和鲁棒性。④基于SSL的 IRS辅助矿井通信系统信道估计方法在大规模网络中具有较好的扩展性和鲁棒性。