Mixed mode preamble for MIMO wireless communications

A radio frequency (RF) transmitter comprises:

• a baseband processing module that is operably coupled to:
• generate a first frame for transmission from a first antenna over a wireless channel for a multiple input multiple output (MIMO) wireless communication, wherein the first frame includes:
• a legacy preamble portion in accordance with a legacy standard wireless communication protocol, wherein the legacy preamble portion includes at least a first training sequence and a second training sequence and a signal field,
• wherein the signal field is formatted in accordance with the legacy wireless communication protocol and includes information that is interpretable by a legacy device to determine a specific period of time that the wireless channel is in use for avoiding a collision with the MIMO communication;
• and
• a current protocol preamble portion in accordance with a second current standard wireless communication protocol of the MIMO wireless communication;
• and
• generate a second frame for transmission from a second antenna over a wireless channel for the MIMO wireless communication, wherein the second frame includes:
• a cyclically shifted legacy preamble portion in accordance with the legacy standard wireless communication protocol, wherein the cyclically shifted legacy preamble portion includes a cyclically shifted first training sequence, a cyclically shifted second training sequence and a cyclically shifted signal field, wherein the cyclically shifted legacy preamble portion is time-shifted with respect to the legacy preamble portion;
• and
• a second current protocol preamble portion in accordance with the second current standard wireless communication protocol of the MIMO wireless communication.

A method for generating a multiple input multiple output (MIMO) wireless communication, the method comprises:

• generating a first frame for transmission from a first antenna over a wireless channel for the MIMO wireless communication, wherein the first frame includes:
• a legacy preamble portion in accordance with a legacy standard wireless communication protocol, wherein the legacy preamble portion includes at least a first training sequence and a second training sequence and a signal field,
• wherein the signal field is formatted in accordance with the legacy wireless communication protocol and includes information that is interpretable by a legacy device to determine a specific period of time that the wireless channel is in use for avoiding a collision with the MIMO communication;
• and
• a current protocol preamble portion in accordance with a second current standard wireless communication protocol of the MIMO wireless communication;
• and
• generating a second frame for transmission from a second antenna over a wireless channel for the MIMO wireless communication, wherein the second frame includes:
• a cyclically shifted legacy preamble portion in accordance with the legacy standard wireless communication protocol, wherein the cyclically shifted legacy preamble portion includes a cyclically shifted first training sequence, a cyclically shifted second training sequence and a cyclically shifted signal field, wherein the cyclically shifted legacy preamble portion is time-shifted with respect to the legacy preamble portion;
• and
• a second current protocol preamble portion in accordance with the second current standard wireless communication protocol of the MIMO wireless communication.