Abstract: An estimation method of channel parameters for CDMA systems operating over channel with single or multiple propagation paths is proposed.This method exploits eigenstructure of thd received signal's sample correlation matrix in which the observation space can be partitioned into a signal subspace and a noise subspace.The channel estimation is formed by projecting a give user's spreading waveform into the estimated noise subspace and nulling the projection.Furthermore,a cost function which can null the noise compontnt of signal vector is presented.Compared with the method presented by S.E.Bensel et al (1996),this method can get the close-form solution which can be used for further analysis.Simulations state this estimation has strong ability against near-far effect and MAI.

Key words: code division multiple access, channel estimation, near-far, multiple access interference