Heuristic approach to construct three-dimensional codes for feedback-based MIMO-CDMA

We propose feedback-controlled code-division multiple access (FC-CDMA) using the multi-input multi-output (MIMO) technique. The proposed system generates a space-time-frequency (STF) code at the finite-duration impulse response (FIR) filter in the receiver. The proposed system obtains path diversity gain, frequency diversity gain, and space diversity gain, and increases the signal-to-interference plus noise ratio (SINR). It is shown that the proposed system provides us with a significant improvement in asynchronous MIMO multiple access performance over multipath channels.