Effective Channel Estimation Method Research Articles

Review on Channel Estimation for Reconfigurable Intelligent Surface Assisted Wireless Communication System

With the dramatic increase in the number of mobile users and wireless devices accessing the network, the performance of fifth generation (5G) wireless communication systems has been severely challenged. Reconfigurable intelligent surface (RIS) has received much attention as one of the promising technologies for the sixth generation (6G) due to its ease of deployment, low power consumption, and low price. RIS is an electromagnetic metamaterial that serves to reconfigure the wireless environment by adjusting the phase, amplitude, and frequency of the wireless signal. To maximize channel transmission efficiency and improve the reliability of communication systems, the acquisition of channel state information (CSI) is essential. Therefore, an effective channel estimation method guarantees the achievement of excellent RIS performance. This survey presents a comprehensive study of existing channel estimation methods for RIS. Firstly, channel estimation methods in high and low frequency bands are overviewed and compared. We focus on channel estimation in the high frequency band and analyze the system model. Then, the comprehensive description of the different channel estimation methods is given, with a focus on the application of deep learning. Finally, we conclude the paper and provide an outlook on the future development of RIS channel estimation.

LTE Downlink Channel Estimation Base on DCT

The long term evolution (LTE) system is a high data rate transmission system. And the channel estimation is critical to it. In this paper, a novel channel estimator on the basis of Discrete Cosine Transform (DCT) method is presented for LTE. It can mitigate the aliasing error caused by spectral leakage well and is applicable for non-integer sampled channel because DCT can reduce the high frequency component. Its performance is much better than LS method and close to LMMSE method, and the complexity is much simpler than LMMSE. The simulation results show that the DCT-based method is superior to the traditional channel estimation algorithm in the multi-path Rayleigh fading channel which is a available and effective channel estimation method.

LTE-Advanced 상향 링크 시스템을 위한 적응적 채널 추정을 통한 고속 ICI 제거 방법 연구

In this paper, we propose a fast ICI suppression algorithm with adaptive channel estimation for the LTE-Advanced uplink system. In order to effectively remove phase noise and carrier frequency offset at time varying channel, we use the comb type pilot. The purpose is to improve performance by reducing computational complexity than conventional PNFS(Phase Noise & Frequency offset Suppression) algorithm. We reduce computational complexity by decreasing overlapping computation or unnecessary computation at conventional PNFS algorithm. Also, we propose an effective channel estimation method. We estimate and compensate multipath channel through the proposed adaptive channel estimation method. The BER performance of the proposed method is better about 0.5 dB than the conventional method at the Vehicular A channel.