Noncoherent eigenbeamforming and interference suppression for outdoor OFDM systems

Abstract--We investigate a new approach to uplink communications in wideband outdoor cellular systems that can take advantage of multiple antennas at the base station in a scalable manner, while eliminating or minimizing overhead for channel estimation. The proposed techniques, which focus on exploiting correlated channels with the use of closely spaced antenna arrays, are applicable to emerging Orthogonal Frequency Division Multiplexing (OFDM) based Wireless Metropolitan Area Network (WMAN) systems, such as those based on the IEEE 802.16/20 standards. Outdoor channels frequently have a small number of dominant spatial modes, which can be learned from overheadfree estimation of the spatial covariance matrix by averaging across subcarriers. We describe an eigenbeamforming receiver which projects the received signal along the dominant spatial modes, yielding a beamforming gain that scales up with the number of receive elements and a diversity level depending on the number of dominant spa...

• Type: Journal
• Year: 2008
• Where: TCOM
• Authors: Noah Jacobsen, Gwen Barriac, Upamanyu Madhow
• Keywords: Dominant Spatial Modes, Number Dominant Modes, Orthogonal Frequency Division Multiplexing, TCOM 2008