Advanced antenna test bed characterization for wideband wireless communication systems

This paper discusses an advanced antenna test bed (ATE) and the results of a wideband diversity experiment. The ATE consists of a multi-channel spread spectrum receiver, multiple spread spectrum transmitters, mobile units utilizing GPS navigation, mounting structures for antenna arrays and a well characterized RF environment consisting of two PCS cell sectors. This experiment utilized a 1920 MHz mobile transmitter and 4 stationary receiving antennas. Fast fading reduction using antenna diversity and increased channel bandwidth (19.6 kHz, 1.25 MHz, 5.0 MHz, 10.0 MHz) is examined. Three combining methods are considered: selection diversity, equal gain combining, and maximal ratio combining. Measurements indicate that increasing the number of diversity antennas or the channel bandwidth significantly reduces fading; however, little difference is found between the various combining techniques for these data. The results also provide a baseline characterization of propagation conditions at the ATE site. These data will enable future comparative testing of advanced antennas, systems and processing algorithms in a known environment