Enhanced capacity using adaptive transmission and receive diversity

The use of multiple element antennas-both transmitting and receiving-has great potential for increasing the capacity of wireless systems. The capacity is derived as a function of the eigenvalues of the channel matrix and computed for an “edge-excited cell” with 3 base sites and a subscriber terminal with a 3 element array, for line-of-sight channels. In an attempt to approach this capacity, we use a blind source separation technique at the receiver, and in the case when the smallest eigenvalue makes a negligible contribution to the capacity, we propose a way of using different transmitting schemes through link adaptation. These techniques allow multiple co-channel signals to coexist within the cell and thus capacity is increased. We present simulation results to compare their performance to the great capacity announced by information theory