  Today, MIMO has become an indispensable scheme for providing significant
spectral efficiency in wireless communication and for future wireless system,
recently, it goes to two extremes: massive MIMO and single-RF MIMO. This paper,
which is put in the latter, utilizes load-modulated arrays with only reactance
loads for single-RF transmission of spatially multiplexed QAM signals. To
alleviate the need for iterative processes while considering mutual coupling in
the compact antenna, we present a novel design methodology for the loading
network, which enables the exact computation of the three reactance loads per
antenna element and also the perfect matching to the source with the
opportunity to select appropriate analog tunable loads. We verify the design
methodology by comparing the calculated values for some key parameters with the
values from the circuit simulation. In addition, as an evaluation of the
proposed architecture, we perform the bit error rate (BER) comparison which
shows that our scheme with ideal loading is comparable to the conventional
MIMO.
