Efficient channel estimation based on discrete cosine transform

Abstract

Channel impairment caused by multi-path reflections can deeply degrade the transmission efficiency in wireless communication systems. Based on the property of the channel frequency response and the concept of interpolation, in this paper a DCT-based pilot-aided channel estimator for orthogonal frequency division multiplexing is proposed. This approach can mitigate the aliasing effect in the DFT-based channel estimator when there is nonsample-spaced path delay. Compared with DFT-based estimator, DCT-based estimator significantly improves the performance with a comparable complexity. In addition, a noise reduction scheme is introduced and combined with the estimator. In implementation, the DCT-based estimator has the advantages of utilizing mature fast DCT algorithms and compatible FFT algorithms, which is favorable to other matrix-based channel estimation methods.