MIMO Channel - Symbol Estimation Duality

This paper presents a novel method to estimate the channel matrix of MIMO systems. It uses the same mathematical framework that is employed for symbol estimation, when precoders and decoders are used. This was made possible, after the proof that channel and symbol estimation are dual problems. The duality channel-symbol estimation proved to be a very powerful tool for channel estimation. Two examples are presented to illustrate the duality: one using SVD decomposition and another one using optimal precoder and decoder. For the last one, dimension reduction is illustrated and numerical results are given.