Indoor Wireless Reception Improvement Using Cross-polarized Multipath Signals

Abstract

Previous work has noted the distinct characteristics of vertically and horizontally polarized multipath components for indoor non-line-of-sight (NLOS) environments. Using measured data, the receiver signal-to-noise ratios (SNRs) for coherent and noncoherent combining of the co- and cross-polarized multipath components are compared to those obtained with omnidirectional reception for vertical or horizontal polarizations. It is seen that significant improvements in SNR can be achieved using intelligent combining with polarization diversity. Furthermore, it is observed that when the receiver is unable to resolve multipath components, coherent combination of both orthogonally polarized signals components provides a consistent advantage over vertically or horizontally polarized omnidirectional reception. At higher bandwidths, the increased resolution improves the performance of all techniques however the dual polarization multipath combining retains its relative advantage over the other techniques.