Estimation of channel and transmission to a pilot OFDM system with spreading delay excessive

摘要

Estimation of channel and transmission to a pilot OFDM system with spreading delay excessive. Techniques are described for transmitting pilot and estimate the channel for OFDM system with application of excessive delay. To reduce the effects prejuciciais excess delay spread, the number of sub bands pilot is greater than the length of cyclic prefix.Such "over - sampling can be achieved by the use of more sub bands in each period of the pilot symbols or different sets of sub bands in different periods of pilot symbols.In a technique for estimation of channel, are obtained from a first and a second group of pilot symbols received for a first and second sets of sub bands pilot, respectively, which are used to derive a first and a second estimate of the frequency response, RA Ectivamente.A first and a second impulse response estimates are derived based on the first and second frequency response estimates, respectively, and are used to derive a third estimate impulse response having more branches than the number of sub band The pilot on any of the sets.