On the Use of Distributed Directive Antenna Arrays in Mobile OFDMA Networks

Distributed Omni Antenna Systems (OASs) have been proposed to increase the capacity of Broadband Wireless Access (BWA) systems. We investigate the extension of such systems by employing distributed Directive Antenna Arrays (DAAs) to support high speed users also employing multiple antenna configurations. The problem of beamforming in a single sector is considered where remote Base Stations (BS´s) equipped with multiple antennas attempt to serve a separate user. Different positions of distributed BS´s in the sector are studied. The beamforming design is based on partial Channel State Information (CSI). The case study for a WiMAX system show that DAAs using beamforming techniques significantly improve performance compared to OASs and lead to an optimum network infrastructure in BWA with high mobile users systems where high - bandwidth radio services are required.