Signal separation in an orthogonal time frequency space communication system using MIMO antenna arrays

A communication device, comprising:

• an antenna arrangement;
• a receiver configured to:
• receive, from the antenna arrangement, a pilot signal associated with a location in a time-frequency plane wherein the pilot signal was transmitted from a transmit antenna element;
• receive signal energy transmitted by the transmit antenna element;
• measure, based upon the pilot signal, a two-dimensional time-frequency coupling channel between the transmit antenna element and the antenna arrangement,
• invert a representation of the two-dimensional time-frequency coupling channel to provide an inverted channel representation;
• and
• use the inverted channel representation to separate the signal energy into a time-frequency plane of information.

A method, comprising:

• providing, by a set of M antennas of a receiver, a set of M received signals wherein the set of M received signals are provided in response to N information signals transmitted by a set of N transmit antennas, where M and N are greater than one;
• measuring a plurality of two-dimensional coupling channels existing between the M antennas of the receiver and each of the N transmit antennas;
• inverting a representation of each of the plurality of two-dimensional coupling channels to provide a plurality of inverted channel representations;
• and
• separating, using the plurality of inverted channel representations, the M received signals into estimates of the N information signals.