I. Introduction
CHANNEL depolarization in wireless communication systems has attracted considerable attention [1]– [7]. Depolarization degrades the performance of polarization multiplexing schemes, yet it provides for polarization diversity at the receiver. Multi-polarized antennas exploit polarization diversity caused by channel depolarization to increase channel capacity and reduce the required antenna spacing [8]– [12]. In practice, cellular land mobile radio systems have employed dual-polarized 45 slant antennas at the base stations to good benefit.