Indoor radio impulse response measurements with polarization diversity

This paper deals with experimental results obtained for a wideband indoor radio channel by transmitting a 900 MHz vertically polarized signal modulated by a train of 2 ns pulses. The receiver is equipped with a two branch diversity system (cross-polarized antenna), which makes possible the application of polarization diversity in order to reduce the deep fades that affect the signal envelope. The observed wideband impulse response has delay spreads extending over a range up to 30 ns and a maximum rms value of about 12 ns. Time delay spread was found independent of the relative antenna polarization of the transmitter and receiver. The powers in the orthogonal polarizations have been shown to be uncorrelated to each other. This suggests the use of polarization diversity to combat Rayleigh fading