Threshold channel estimation for OFDM in wireless systems

Channel estimation is usually used in OFDM systems to achieve high performance. Interpolation-based algorithm is deployed in channel estimation for further improvement in performance. However the computation complexity for interpolation is high and it becomes one of the most power hungry modules for OFDM systems. In this paper, we put forward a threshold scheme which can pre-determine whether the channel has varied too small to do interpolation. When interpolation is really needed, for multipath channel, our proposed threshold scheme can also find those paths with little change so that no update on those paths is needed. With the help of the threshold scheme, compared with conventional method, significant amount of computation is reduced with little performance degradation. The simulation results show that 40% computation of interpolation can be reduced when the Doppler frequency is 50 Hz and the reduced ratio can be even as large as 80% when the Doppler frequency is 50 Hz.