Adaptive Polar-Linear Interpolation Aided Channel Estimation for Wireless Communication Systems

Channel Estimation (CE) is one of the key components in wireless communication systems employing coherent demodulation and interference cancellation. Among the numerous CE techniques in the literature, Pilot-Assisted Channel Estimation (PACE) has been widely used in many practical systems, thanks to its simplicity and efficiency for implementation. In order to minimise pilot overhead, interpolation is typically mandatory in PACE. Conventional linear and Polar-Linear Interpolation (PLI) methods are easy to implement, but naturally result in residual interpolation errors that can not be mitigated even at high Signal-to-Noise Ratios (SNRs). In this paper, we propose a CE scheme equipped with a novel interpolation method referred to as Adaptive Polar-Linear Interpolation (APLI). The proposed APLI-aided CE scheme can achieve a good performance, thanks to its capability of adaptively tracking the instantaneous variation of channel's fading coefficients, while maintaining a low complexity that is similar to the simple linear interpolation. The benefits of our proposal are demonstrated by a range of numerical illustrations and simulation results.