DCT-based channel estimation for single- and multicarrier communications

摘要

We present a novel channel estimation technique based on discrete cosine transforms (DCT) for multi-carrier and single carrier communications. Channel estimation is essential in communication systems, but especially in DCT-based transceivers for designing a front-end prefilter that must be included at the receiver to force the channel impulse response to be symmetric. The new technique is derived from the symmetric convolution-multiplication properties of discrete trigonometric transforms, and it is thus particularly suitable for DCT-based transceivers. The proposed channel estimation method is based on the use of training symbols, symmetric in time-domain, known by both transmitter and receiver. We demonstrate that by imposing a whole-sample symmetry condition in the training symbol, the channel impulse response can be estimated in a straightforward way. The analytical expressions to obtain the channel impulse response from the training symbol are also derived. Finally, this study is completed with several computer simulations to demonstrate the validity of the estimation technique.