Stability analysis for cross-polar interference cancellers

Linear least-mean-square equalization theory is generalized to dual polarized fading radio channels and an analysis of the XPIC performance in radio relay links is presented. It is shown that fractionally-spaced structures generally exhibit long term instability, which could cause register overflows and consequent performance degradation. In order to counterbalance such degradation, suitable algorithms, usually adopted for stabilizing fractionally-spaced equalizers in channels without frequency reuse, can be effectively applied to fractionally-spaced XPICs