MATLAB Implementation of Least Squares for OFDM Channel Estimation

In the field of communications, the least squares method is a widely used mathematical approach for estimating OFDM channel parameters. This technique finds optimal parameter estimates by minimizing the mean square error between predicted values and actual measurements. The MATLAB implementation typically involves matrix operations where the channel response is estimated using the pseudoinverse of the transmitted signal matrix. Key functions like `pinv()` for matrix inversion and element-wise operations are employed to solve the linear system H_est = Y * pinv(X), where Y represents the received signal and X is the known pilot matrix. This method enables more accurate characterization of channel properties, ultimately enhancing communication system performance through improved signal recovery and reduced interference. The code structure usually includes preprocessing of pilot symbols, computation of the least squares solution, and post-processing for channel interpolation across all subcarriers.