Spatial and polarisation correlation characteristics for UWB impulse radio

Correlation between diversity branches is the key parameter in determining the diversity performance of wireless systems. In this paper, measurements in a temporally and spatially stationary indoor environment are carried out to obtain the channel impulse responses for the UWB impulse radio using receivers with different positions or different polarisation states. A two-dimension (2D) RAKE receiver with post-detection equal gain combining (EGC) diversity is assumed to be used. Three definitions of correlation coefficients of the diversity branches are considered: correlation coefficient, normalized correlation and channel profile correlation, are analysed in this paper. The results show that the normalised correlation is more effective to ascertain the degree of similarity of the correlated diversity branches where medium scale fading dominates.