On multistreaming with compact antenna arrays

We investigate the capability of compact antenna arrays to support the simultaneous transfer of several independent data streams over the same band of frequencies. It is shown that the near-field interaction of the closely spaced antennas inside the arrays accounts for a surprisingly good multistreaming capability, even for extremely compact arrays. This result is demonstrated for the case of a 2 × 2 system of thin half-wavelength dipoles in a multipath environment provided by two perfectly conducting reflector plates, and isotropic background noise. Decoupling/power-matching and decoupling/noise-matching networks are applied at the transmit side and the receive side arrays, respectively. The analysis is based on a circuit theoretic multiport model of the system which captures all relevant physics of antenna mutual coupling, the influence of the matching networks, and noise. It is shown that in the absence of heat loss in the matching networks and antenna wires, the simultaneous transfer of two data streams can work perfectly well even as the separation between the antennas inside the arrays approaches zero.