Channel estimation for orthogonal frequency division multiplexing uplinks in time-varying channels

This study deals with channel parameter based channel estimation in time-varying channels for orthogonal frequency division multiplexing in an uplink transmission. By modelling the uplink channel properly, the time-varying ‘channel response’ can be determined by estimating the corresponding ‘channel parameters’. A novel algorithm is proposed in this study to estimate the channel parameters by exploiting the time-frequency-representation of the time-varying channel response. Moreover, a decision-directed receiver structure is adopted to cancel the impact of residual Doppler shifts. Theoretical analysis on the performance is given as well. The optimum power allocation ratio of training signal power to data signal power is also discussed. Simulations are performed, demonstrating the effectiveness of the proposed algorithm.