Lattice array receiver and sender for spatially orthonormal MIMO communication

In this paper, line-of-sight (LoS) oriented multiple input multiple output (MIMO) communication is examined. It is shown that two opposing rectangular (as well as square and linear) lattice antenna arrays achieve the maximum attainable channel capacity, when a certain distance-wavelength condition is fulfilled. A relationship for a large number of antenna elements is derived that connects LoS MIMO with LoS SISO channel capacity, through array aperture, wavelength and number of array antenna elements. Furthermore, a sensitivity study is performed for the proposed MIMO array arrangement that reveals high robustness against various array and antenna element position errors. Sensitivity against reflections is also examined, with the conclusion that the studied MIMO scheme appears less sensitive to reflections than a SISO system.