Joint channel estimation and prediction for OFDM systems

Abstract

Adaptive OFDM improves the system throughput by adjusting transmission parameters based on channel state information (CSI) estimated at or received by the transmitter. The improvement, however, is conditioned on the quality of the CSI, which can be compromised by estimation and quantization errors, and more significantly by delay. Channel prediction has been previously proposed to combat feedback delay. In this paper, a novel OFDM channel prediction algorithm that uses a 2 times 1-dimensional frequency estimation to determine the time-delays and Doppler frequencies of each propagation path is investigated. The algorithm assumes a general far-field scatterer, frequency-selective wireless channel model and hence is applicable to a wide variety of wireless channel conditions. It is shown that the method requires less feedback information and has better mean-squared error performance than previous methods. We provide simulation results for IEEE 802.16e channels