Abstract: A blind identification process of each user' multipath channel using a subspace method for antenna arrays CDMA systems is presented.It is shown that based on the identified channel and combined with the knowledgeof the desired user' spreading sequence, multiuser detector can be constructedin closed form, at almost no extra computational cost. Because the computing of some high-dimension matrices has been avoided directly, the computation complexity becomes lower. By using antenna arrays, the proposed method can be applied to overload systems, where the number of users may exceed the processing gain.

Key words: code division multiple access, subspace decomposition, blind channel identification, multiuser detection