An Improved Channel Estimation and Coefficient of Smoothening Filtering based on BAT Optimization

The multiple-input multiple-output (MIMO) can be combined with orthogonal frequency division multiplexing (OFDM) to achieve better spectral efficiency and large data rates in advanced wireless communication systems. To reduce the system's complexity and estimate the characteristics of the channel, channel estimation algorithms play a significant role. It is an important factor to enhance the reliability and performance of the communication system. The channel estimation techniques are divided into three main categories, namely Pilot-aided Channel Estimation Techniques, Blind Channel Estimation, and Decision Directed Channel Estimation (DDCE) Techniques. In this paper, we have presented MIMO-OFDM system and channel estimation techniques followed by a literature survey conducted in order to better understand the channel estimation techniques. The performance of various channel estimation techniques presented by researchers in the literature survey is evaluated in terms of attenuation factor, delay, etc. The scope of advancements in these channel estimation algorithms is still there. These algorithms can be combined with advanced schemes in order to enhance their performance and improve the communication system.