Method and apparatus for combining space-frequency block coding, spatial multiplexing and beamforming in a MIMO-OFDM system
A method and apparatus for combining space-frequency block coding (SFBC), spatial multiplexing (SM) and beamforming in a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system. The system includes a transmitter with a plurality of transmit antennas and a receiver with a plurality of receive antennas. The transmitter generates at least one data stream and a plurality of spatial streams. The number of generated spatial streams is based on the number of the transmit antennas and the number of the receive antennas. The transmitter determines a transmission scheme in accordance with at least one of SFBC, SM and beam forming. The transmitter transmits data in the data stream to the receiver based on the selected transmission scheme.
1. A transmitting device comprising:
a circuit configured to select to transmit data symbols between at least a closed loop mode and an open loop mode using four antenna outputs; wherein each antenna output is operatively coupled to at least one antenna;
wherein in the open loop mode, the circuit is further configured to process data symbols to be output to the four antenna outputs for one orthogonal frequency division multiplex (OFDM) symbol; wherein the one OFDM symbol has K subcarriers and the K subcarriers are divided into L groups of subcarriers; wherein L is greater than one; wherein for each of the L groups, four data symbols are space frequency block coded; wherein a first pair of the four symbols is space frequency block coded to produce four SFBC symbols outputted to a first and second antenna output for transmission and not a third and forth antenna output of the four antenna outputs; wherein a second pair of the four data symbols is space frequency block coded to produce four SFBC symbols outputted to a third and forth antenna output for transmission and not a first and second antenna output of the four antenna outputs; and
wherein in the closed loop mode, the circuit is further configured to receive information transmitted by a receiving device; wherein the received information includes at least a channel quality indicator (CQI) indicating a modulation and coding set; wherein data is transmitted using spatial multiplexing as data symbols; wherein each data symbol is transmitted using a plurality of subcarriers; wherein the data symbols are provided to the four antenna outputs for transmission using a number of streams and a modulation and coding set derived at least in part from the received information.
2. A receiving device comprising:
a circuit configured to recover data from transmit data symbols; wherein the circuit is configured to operate in a closed loop mode and an open loop mode;
wherein in the open loop mode, the circuit is further configured to receive and recover data symbols transmitted in each of a plurality of orthogonal frequency division multiplex symbols; wherein each of the OFDM symbols has K subcarriers and the K subcarriers are divided into L groups of subcarriers; wherein L is greater than one; wherein for each of the L groups, four data symbols are space frequency block coded; wherein a first pair of the four symbols was space frequency block coded to produce four SFBC symbols transmitted by a first and second antennas and not a third and forth antennas of four transmission antennas; wherein a second pair of the four data symbols was space frequency block coded to produce four SFBC symbols transmitted by the third and forth antenna antennas and not the first and second antennas of the four transmission antennas; and
wherein in the closed loop mode, the circuit is further configured to transmit information including at least a channel quality indicator (CQI) indicating a modulation and coding set; wherein the circuit is further configured to receive and recover data symbols transmitted using spatial multiplexing; wherein each data symbol was transmitted using a plurality of subcarriers by the four transmitting antennas using a number of streams and a modulation and coding set derived at least in part from the transmitted information.
3. A method comprising:
selecting, by a transmitting device, to transmit data symbols between at least a closed loop mode and an open loop mode using four antenna outputs; wherein each antenna output is operatively coupled to at least one antenna;
in the open loop mode, processing data symbols to be output to the four antenna outputs for one orthogonal frequency division multiplex (OFDM) symbol; wherein the one OFDM symbol has K subcarriers and the K subcarriers are divided into L groups of subcarriers; wherein L is greater than one; wherein for each of the L groups, four data symbols are space frequency block coded; wherein a first pair of the four symbols is space frequency block coded to produce four SFBC symbols outputted to a first and second antenna output for transmission and not a third and forth antenna output of the four antenna outputs; wherein a second pair of the four data symbols is space frequency block coded to produce four SFBC symbols outputted to a third and forth antenna output for transmission and not a first and second antenna output of the four antenna outputs; and
in the closed loop mode, receiving information transmitted by a receiving device; wherein the received information includes at least a channel quality indicator (CQI) indicating a modulation and coding set; wherein data is transmitted using spatial multiplexing as data symbols; wherein each data symbol is transmitted using a plurality of subcarriers; wherein the data symbols are provided to the four antenna outputs for transmission using a number of streams and a modulation and coding set derived at least in part from the received information.
4. A method comprising:
selectively recovering, by a receiving device, data from transmitted data symbols between a closed loop mode and an open loop mode;
wherein in the open loop mode, receiving and recovering, by the receiving device, data symbols transmitted in each of a plurality of orthogonal frequency division multiplex symbols; wherein each of the OFDM symbols has K subcarriers and the K subcarriers are divided into L groups of subcarriers; wherein L is greater than one; wherein for each of the L groups, four data symbols are space frequency block coded; wherein a first pair of the four symbols was space frequency block coded to produce four SFBC symbols transmitted by a first and second antennas and not a third and forth antennas of four transmission antennas; wherein a second pair of the four data symbols was space frequency block coded to produce four SFBC symbols transmitted by the third and forth antenna antennas and not the first and second antennas of the four transmission antennas; and
wherein in the closed loop mode, transmitting, by the receiving device, information including at least a channel quality indicator (CQI) indicating a modulation and coding set in the closed loop mode and receiving and recovering data symbols, by the receiving device, transmitted using spatial multiplexing in the closed loop mode; wherein each data symbol was transmitted using a plurality of subcarriers by the four transmitting antennas using a number of streams and a modulation and coding set derived at least in part from the transmitted information.