Study Of OFDM Channel Estimate Technology

Providing more customers with better service in the more complicated environment is the requirement of the development of communication in the future, which will certainly raise higher requirement for the development of the communication technology. The Orthogonal Frequency Division Multiplexing (OFDM) is just the transmit technology which meet this requirement. It has been used in digital video and audio area and is part of the WLAN standard. It utilizes the technology of channel orthogonal and germination with high using rate. Therefore it can solve the problem of breaking up in wideband communication. With the CP technology, it can also reduce the ICI and ISI efficiently.Channel estimate is one of the key problems which need to be resolved by OFDM. Blind channel doesn't need send any training serial. It can realize channel estimation by using the channel information included in the signals received. In this way, transmitting rate can be improved greatly!On the base of deeply analyzing the theory of OFDM and arithmetic of it's key technology. We have done the work hereinafter:1,Study the recent blind identification methods systematically, especially the second order statistical subspace-based estimate method and power music method.2,Put forward a ST-OFDM blind channel estimate arithmetic of "two-send and one-receive" . It utilizes the characters of space time block code to carry out the blind channel estimation algorithm in constant modules modulation way. It doesn't need redundant pre-coding so it won't reduce the system coding rate. Channel estimate can be realized by adopting single received antenna. It doesn't need to change the construction of receiver so it can reduce the complication of system. What's more, it is impregnable to the state of the channel over-estimating.3,It makes concrete mathematic calculation for this arithmetic, emulate it. The outcome of emulation shows great improvement of the performance.