Study on MIMO transmission using orthogonal directivities obtained from higher order microstrip antenna modes

A simpler MIMO transmission method using orthogonal directivities is proposed. In future wireless communication systems, higher data rates will be required since large amounts of data will be transmitted and received. MIMO technology is useful for achieving higher data rates. However, since MIMO detection becomes complicated when the number of antennas becomes large, a simpler method should be considered. To solve this problem, the present authors proposed a spatial division method using orthogonal directivities. This previously proposed method to N streams is expanded transmission for application to much higher data rate systems. Furthermore, using higher order antenna modes at the same frequency to more easily obtain orthogonal directivities is proposed. To evaluate the proposed method, it is confirmed by numerical analysis that the capacity of the proposed method increases without MIMO detection when the number of antennas becomes large.