Channel Estimation For Wireless Communication Systems Aided By Large Intelligent Reflecting Surface

In recent years, the advantages of wireless communication systems assisted by intelligent reflecting surface (IRS) have attracted great attention in the field of mobile communication. However, due to IRS is a passive device with a large number of reflecting array sources, channel estimation (CE) is somewhat challenging. To solve this problem, this paper designs a CE scheme for large IRS-assisted multi-user wireless communication systems. The main idea is to reduce training overhead for CE by exploiting the spatial correlation of IRS channels and the correlation between users' channels. The simulation results show that compared with the traditional CE scheme, proposed CE scheme requires fewer pilot symbols. And when users send pilot symbols of the same length, the mean square error (MSE) is smaller.