Noise-Robust Optimization of Impedance Loading for Single-RF MIMO Systems

Multiple-Input-Multiple-Output (MIMO) systems are widely used to enhance the system capacity in wireless communications systems. The complexity and the cost for implementing the multiple radio frequency-chain (RF-chain) increases proportional to the number of signal streams. Therefore, so-called load modulating single-RF MIMO system is one promising technology in the practical aspects. Load modulating single-RF MIMO can utilize two-port network for controlling the load and the desired signal can be generate by loading proper set of impedance. In this paper, the optimization method for choosing the two-port network impedance solution that is robust to the impedance noise is proposed and the simulations are conducted to verify the robustness.