Patent ID: 8243693

Claim:
For use in an orthogonal frequency division multiplexing (OFDM) wireless network that communicates with subscriber stations in a coverage area of the OFDM wireless network, a base station for transmitting broadcast data and unicast data to the subscriber stations from a plurality of antennas using multiple-input, multiple-output (MIMO) techniques, wherein the base station transmits in a first OFDM symbol a first broadcast pilot signal from a first antenna, a first unicast pilot signal transmitted from the first antenna, a second unicast pilot signal transmitted from a second antenna, and a second broadcast pilot signal transmitted from the second antenna; wherein the base station transmits in a second OFDM symbol superimposed broadcast data traffic and unicast data traffic transmitted from the first and second antennas, and wherein subcarriers in the first OFDM symbol used to carry each of the first broadcast pilot signal, the first unicast pilot signal, the second unicast pilot signal, and the second broadcast pilot signal are different than subcarriers in the second OFDM symbol used to carry each of the first broadcast pilot signal, the first unicast pilot signal, the second unicast pilot signal, and the second broadcast pilot signal.