A brief review of HF channel response estimation

Estimation of channel impulse response constitutes a first step in computation of scattering function. Due to spatial and temporal variations, HF channel impulse response has to be estimated adaptively. The channel impulse response can be estimated using various estimators. In this paper, a brief review of standard estimation algorithms such as Least Squares, Least Mean Squares, Recursive Least Squares, Kalman Filter is presented. Then, an alternative estimation algorithm for the channel modulation response is proposed as a solution to a least squares constraint optimization problem. The proposed computation constrains the unknown channel impulse response to be a bandlimited function of time for a fixed delay. The new method is simple and cost-effective due to the fact that numerical computation is based on the correlation of the samples of estimated channel impulse response. After finding the optimal channel response estimate, further processing for equalization and detection can be achieved successfully.