Method and arrangement in a wireless communication system

A transmitting unit for a wireless communication system, the transmitting unit being configured to transmit over at least two antennas pointing in different directions, each antenna providing a beam partially overlapping with at least one beam of at least one other of the antennas, the transmitting unit comprising:

• a signal processing unit adapted to transmit in a unicast mode over each of the at least two antennas and to transmit in a broadcast mode concurrently over all of the at least two antennas using a space time code to reduce directional nulls in overlapping radiation patterns of the at least two antennas, the space time code producing a magnitude of complex channel gain for each of the at least two antennas at a communication distance, and an effective signal to noise ratio (SNR) of the transmission in the broadcast mode is based on the magnitude of the complex channel gain as a function of the angle between the at least two antennas;
• and
• a control unit adapted to switch between transmitting in the unicast mode and in the broadcast mode,
• wherein switching occurs between symbols transmitted over the at least two antennas, transmitting in the unicast mode comprises transmitting parallel different streams of symbols over different ones of the at least two antennas, and transmitting in the broadcast mode using the space time code comprises transmitting multiple redundant copies of data over all of the at least two antennas with symbols mapped in a time and spatial transmit-antenna domain to capture transmit diversity provided by the at least two antennas.