Exploiting the spatial domain for high bit rate indoor communications

The ACTS AWACS (ATM Wireless Access Communications Systems) project is considering the feasibility of supporting ATM compatible bit rates over the wireless bearer for low mobility terminals using directional antenna technology. The viability of directional antennas as an alternative to equalisation and multicarrier techniques is studied by employing pre-prototype hardware supplied by NTT Wireless Research Labs (Japan). This The paper presents the results of an investigation into the effects of spatial filtering on the performance of high bit rate wireless ATM systems. Various combinations of directional and omni antennas have been considered in a number of indoor environments. The scenarios studied range from short and long multipath variation (from a few centimetres to 25 m), LOS, partial-LOS and obstructed-LOS situations.