Channel characterization and training within multiple user, multiple access, and/or MIMO wireless communications

An apparatus, comprising:

• a baseband processing module for generating a multi-cast sounding frame;
• and
• a plurality of antennae for transmitting the multi-cast sounding frame to a plurality of wireless communication devices;
• and wherein:
• the multi-cast sounding frame including a plurality of sounding feedback instructions corresponding respectively to each of the plurality of wireless communication devices;
• in response to the multi-cast sounding frame, the plurality of antennae receiving a plurality of sounding feedback signals from the plurality of wireless communication devices or from a first subset of the plurality of wireless communication devices based upon an order according to the plurality of sounding feedback instructions by which the plurality of sound feedback signals are provided, the order configured to accommodate a feedback exchange interruption;
• based on the plurality of sounding feedback signals, the baseband processing module generating a multi-user packet;
• the plurality of antennae transmitting the multi-user packet to the plurality of wireless communication devices or to a second subset of the plurality of wireless communication devices;
• and
• the multi-user packet including a plurality of acknowledgement instructions corresponding respectively to each of the plurality of wireless communication devices or each of the second subset of the plurality of wireless communication devices.

A method for operating a wireless communication device, the method comprising:

• generating a multi-cast sounding frame, which includes a sounding feedback instruction;
• operating a plurality of antennae for transmitting the multi-cast sounding frame to a plurality of wireless communication devices;
• in response to the multi-cast sounding frame, receiving a plurality of sounding feedback signals from the plurality of wireless communication devices or from a first subset of the plurality of wireless communication devices based upon an order according to the sounding feedback instruction by which the plurality of sounding feedback signals are provided, the order configured to accommodate feedback exchange interruption;
• based on the plurality of sounding feedback signals, generating a multi-user packet;
• and
• operating the plurality of antennae for transmitting the multi-user packet to the plurality of wireless communication devices or to a second subset of the plurality of wireless communication devices.