Astudy Of Novel Technology For Blind Identification And Equalization Of The Wireless Channel

The technique of blind channel identification and equalization is very attractive due to the pursuit of large capacities and high reliabilities in mobile communication systems. On the issue of the blind identification, some algorithms adopt the multiple antennas, while others use the fractional sampling, so as to form a SIMO structure. Early methods also used the higher order statistics. There are other techniques like pre coding and modulation induced cyclostationarity(MIC), where the induced spectral redundancy is utilized for blind channel identification.Firstly this thesis makes a brief introduction of some basic knowledge of blind identification and equalization, reviewing the definitions of cyclostationary signals and some related processing methods.Secondly the subspace method is described for Single Input Multiple Output(SIMO) system, applying the Second Order Statistics(SOS) in the identification of Channel Impulse Response(CIR). Then the Constant Modulus Complex Modulation(CMCM) is presented in the transmitter in order to introduce cyclostationarity, followed by the subspace method to identify the channel blindly. Another method is included which makes use of the repetition scheme to introduced spectral redundancy, by which the blind identification of the single carrier channel can be implemented.Finally, the blind fractionally spaced equalizer is designed for the SIMO model. As to the model of MIC , devises the cyclic Wiener filter. CMCM can maintains transmit power constant and generates spectral redundancy at the same time, for the receiver, by means of cyclic Wiener equalization to suppress interferences, repair the spectral damage.