Low complexity channel estimation with pilot symbol assisted modulation

Pilot symbol assisted modulation (PSAM) allows the channel estimation in fast-fading channels. The approaches proposed up to now were mainly concerned with the robustness and simplicity of adaptation of the channel estimators. In this paper we analyze the techniques presented in the literature from the complexity and performance points of view. As a result, we show that using linear interpolation the complexity of the channel estimation may be straightforwardly reduced by order of magnitude without compromising the performance. For channels with very fast fading, we propose a new method which offers a simple trade-off between performance and complexity. Numerical simulations are shown to illustrate the analysis.