The present invention provides a method and an apparatus may increase or
extend the range of wireless communication cells for a given throughput
in a downlink of a wireless communication system. When transmitting data
in a downlink of a plurality of access point cells in a wireless local
area network (WLAN), the range of the downlink may be increased for a
given throughput under one or more radiated power constraints. The method
includes providing a plurality of antennas at an access point to transmit
the data to a wireless unit under at least one of a first and a second
radiated power constraints. The method further includes using the
plurality of antennas for beamforming over a group of sub-carriers
subject to the first and/or second radiated power constraints. Under one
or more radiated power constraints, a multiple antenna based beamforming
may extend the range of a wireless communication for a user of a wireless
unit that may be located within a coverage area across the plurality of
access point cells of a Wi-Fi network associated with the WLAN. A joint
beamforming optimized over all of sub-carriers may account for a European
regulation restriction into at least one of an averaged and a spectral
density Equivalent Isotropic Radiated Power (EIRP) constraint. In this
way, an Orthogonal Frequency-Division Multiplexing (OFDM) based joint
beamformer may provide a significant performance improvement and range
extension.