Efficient channel estimation based on discrete cosine transform

Abstract

Channel impairment caused by multipath 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, 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 non-sample-spaced path delay. Compared with a DFT-based estimator, the 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.