Pilot tone selection for channel estimation in a mobile OFDM system

Channel estimation for mobile OFDM systems requires transmission of pilot tones. This paper addresses the important issue of selecting these pilot tones, so as to achieve a good quality estimate. It is shown that the best set of tones to be used are those which are equally spaced. Furthermore, it is shown using the case of a first order Markov channel, that it is more efficient to use a few pilot tones in all symbols, rather than use all tones as pilot tones in some symbols.