Channel Estimation Based on Linear Filtering Least Square in OFDM Systems

—Orthogonal Frequency Division Multiplexing (OFDM) has been a popular scheme for digital communication systems, which is widely used in digital television and audio broadcasting, wireless networks, powerline networks, and the Fourth Generation (4G) mobile communications. In OFDM scheme, channel estimation is a necessary technique for improving the system’s performance. Linear Least Square (LLS) and Linear Filtering LS (LFLS) channel estimation methods are proposed in this paper. The LLS channel estimation method can improve the accuracy of channel estimation based on timedomain threshold. The LFLS channel estimation method can effectively suppress the Additive White Gaussian Noise (AWGN) by the linear filter. Simulation results are shown to verify the effectiveness of the proposed LFLS channel estimation method. Compared with LS and LLS channel estimation methods in CP-OFDM system, the LFLS channel estimation method can suppress the noise effectively through the appropriate linear filter in time domain and provide superior system performance over multipath channel conditions.