Spatial multiplexing by decomposing the far-field of a compact ESPAR antenna

A framework for implementing spatial multiplexing using an electronically steerable parasitic array radiator (ESPAR) antenna is presented. While traditional multi-element arrays (MEA) show great potential for meeting the increasing demand for higher data rates, they come at the expense of computationally demanding signal processing, larger size, and higher consumption of DC power, making traditional MEA impractical at userspsila hand-held devices. In this work, we introduce a novel methodology for using ESPAR antennas as a compact, cheap and less power-hungry MEA, for spatially multiplexing BPSK symbols, while still providing comparable spectral efficiency and performance as traditional MEA. The main idea is to exploit the strong mutual coupling among the ESPAR antenna elements at the transmitter side to create a linear combination of orthogonal patterns (beams), onto which the symbols are directly mapped, instead of the traditional approach of sending the symbols toward different locations within the antenna domain. On the other side, the receiver (base-station (BS) or access point (AP)) is equipped with a traditional uniform linear array (ULA), and decodes the received signal using the Vertical Bell labs layered space time (VBLAST) algorithm.