A CAD procedure for MIMO link estimation by the combination of nonlinear, electromagnetic and propagation analysis techniques

The paper demonstrates for the first time a CAD procedure for the circuit-level simulation of an entire MIMO link. The multiple transmitting and receiving antennas are treated as multiport radiating systems characterized by EM analysis. In this way the influence of mutual couplings on the frequency-dependent near-field and far-field performance of each element is fully accounted for. The set of transmitters is treated as a unique nonlinear system loaded by the multiport antenna, and is analyzed by nonlinear circuit techniques. In order to establish the connection between transmitters and receivers, the far fields incident on the receivers are evaluated by EM analysis and are combined by extending to the MIMO case an available ray tracing technique. EM theory is used to describe the receiving array as a linear active multiport network. The procedure is applied to several MIMO systems by varying antenna locations. The computation of BER performance at the circuit level is demonstrated.