Patent ID: 8917694

Claim:
A method of receiving a plurality of acknowledgement (ACK)/negative acknowledgement (NAK) signals at a base station (BS) in a wireless communication system utilizing an orthogonal frequency division multiplexing (OFDM) scheme, the method comprising: transmitting, by the BS, a plurality of data packets to a plurality of mobile stations; receiving, by the BS, a plurality of first ACK/NAK signals from the plurality of mobile stations, wherein the plurality of first ACK/NAK signals are multiplexed on a first set of orthogonal frequency tones using a plurality of sequences corresponding to the plurality of mobile stations; receiving, by the BS, a plurality of second ACK/NAK signals from the plurality of mobile stations, wherein the plurality of second ACK/NAK signals are multiplexed on a second set of orthogonal frequency tones, wherein the plurality of second ACK/NAK signals carry the same information as the plurality of first ACK/NAK signals; and determining, by the BS, whether the plurality of data packets are successfully received by the plurality of mobile stations based on the plurality of first ACK/NAK signals and the plurality of second ACK/NAK signals, wherein the first set of orthogonal frequency tones are different from the second set of orthogonal frequency tones over two transmission instants, and wherein the plurality of sequences are generated from a single sequence.