Method and/or system for reduction of PAPR

1. A method of transmitting a signal comprising:

preparing an orthogonal frequency-division multiplex (OFDM) sequence for transmission using a multi-input multi-output (MIMO) scheme using space-frequency block coding (SFBC), including performing rotation among transmit channels, wherein said rotation among transmit channels comprises a shifting of one or more sub-blocks in the time domain, and phase rotation of polyphase sequences of at least some sub-blocks of said OFDM sequence, based on a peak-to-average-power ratio (PAPR) reduction criterion, to thus obtain a prepared OFDM sequence; and

transmitting the prepared OFDM sequence.

2. The method of claim 1 , wherein the sub-blocks of the OFDM sequence having polyphase sequences that are channel-rotated and phase-rotated so that out of the possible combinations of channel-rotation and phase-rotation of polyphase sequences of sub-blocks that combination of channel-rotation and phase-rotation that reduces PAPR the most is selected for transmission.

3. The method of claim 1 , wherein preparing further comprises performing rotation in time based on a further partition of at least one sub-block.

4. An apparatus comprising:

a transmitter employing a multi-input multi-output orthogonal frequency-division multiplex (MIMO-OFDM) scheme using space-frequency block coding (SFBC);

said transmitter adapted to transmit an OFDM sequence in which polyphase sequences of at least some sub-blocks of said OFDM sequence have been rotated among transmit channels, wherein said rotation among transmit channels comprises a shifting of one or more sub-blocks in the time domain, and phase-rotated according to a peak-to-average-power ratio (PAPR) reduction criterion, so as to reduce PAPR.

5. The apparatus of claim 4 , wherein the transmitter is adapted to select the sub-blocks of the OFDM sequence having polyphase sequences that are channel-rotated and phase-rotated so that out of the possible combinations of channel-rotation and phase-rotation of polyphase sequences of sub-blocks that combination of channel-rotation and phase-rotation that reduces PAPR the most is selected for transmission.

6. The apparatus of claim 4 , wherein the transmitter is adapted to perform rotation in time based on a further partition of at least one sub-block.

7. An apparatus comprising:

a computing device;

said computing device adapted to:

prepare an orthogonal frequency-division multiplex (OFDM) sequence for transmission using a multi-input multi-output (MIMO) scheme using space-frequency block coding (SFBC), including performing rotation among transmit channels, wherein said rotation among transmit channels comprises a shifting of one or more sub-blocks in the time domain, and phase-rotating of polyphase sequences of at least some sub-blocks of said OFDM sequence, based on a peak-to-average-power ratio (PAPR) reduction criterion, to thus obtain a prepared OFDM sequence; and transmit the prepared OFDM sequence.

8. The apparatus of claim 7 , wherein said computing device is adapted to select the sub-blocks of the OFDM sequence having polyphase sequences that are channel-rotated and phase-rotated so that out of the possible combinations of channel-rotation and phase-rotation of polyphase sequences of sub-blocks that combination of channel-rotation and phase-rotation that reduces PAPR the most is selected for transmission.

9. The apparatus of claim 7 , wherein said computing device is further adapted to perform rotation in time based on a further partition of at least one sub-block.

10. An article comprising a non-transitory computer-readable storage medium containing instructions that, upon execution by a system, result in operations comprising:

preparing an orthogonal frequency-division multiplex (OFDM) sequence for transmission using a multi-input multi-output (MIMO) scheme using space-frequency block coding (SFBC), including performing rotation among transmit channels, wherein said rotation among transmit channels comprises a shifting of one or more sub-blocks in the time domain, and phase rotation of polyphase sequences of at least some sub-blocks of said OFDM sequence, based on a peak-to-average-power ratio (PAPR) reduction criterion, to thus obtain a prepared OFDM sequence; and transmitting the prepared OFDM sequence.

11. The article of claim 10 , wherein the sub-blocks of the OFDM sequence having polyphase sequences that are channel-rotated and phase-rotated so that out of the possible combinations of channel-rotating and phase-rotating ofpolyphase sequences of sub-blocks that combination of channel-rotating and phase-rotating that reduces PAPR the most is selected for transmission.

12. The article of claim 10 , wherein preparing further comprises performing rotation in time based on a further partition of at least one sub-block.