Quadrature cosine-basis beamforming in wireless networks using dual-polarized circular multimode antenna arrays

Co-channel interference in wireless networks has a spatial nature due to geographically distributed users in the coverage area and has to be suppressed using beamfoming techniques to achieve higher spectral and power efficiencies. Beamforming with conventional center-fed dipole arrays has several drawbacks such as low array gain, low spatial selectivity due to wide main beamwidths and possibility of occurence for grating lobes due to spatial aliasing. Motivated with these drawbacks of DPA-BMF, a conventional beamforming method using dual-polarized circular multimode microstrip antennas, denoted as quadrature cosine-basis beamforming (QCB-BMF), is proposed in this work that achieves much higher beamforming performance than DPA-BMF at comparable compactness and improved ergonomy with respect to DPA-BMF as well as higher spectral and power efficiency when used in interference-limited wireless communication networks.