This paper theoretically analyzes the performance of RAKE combining (in time domain), maximal ratio combining (in spatial domain), and 2-dimensional RAKE combining (in spatial and time domains) techniques, applying a diversity combining theory, for multipath environments where multipath waves are distributed in spatial and time domains. The performance of fading suppression can be evaluated by use of eigen values obtained from a covariance matrix of branch signals, and can also be normalized by the beamwidth of an array antenna, for various parameters such as the number of antenna elements, angular spread, and angle of arrivals.