Radial modes for oam mimo communication

A method of orbital angular momentum “OAM” multiple-input multiple-output “MIMO” communication at a receiver, comprising:

• selecting, from a plurality of azimuth modes, an azimuth mode for receiving an OAM MIMO transmission from a transmitter to the receiver, wherein the receiver includes a first number of antenna circles that each include a second number of antenna elements, wherein the azimuth mode defines a discrete Fourier transform “DFT” vector of a first size less than or equal to the second number;
• selecting, from a plurality of radial modes associated with the azimuth mode, a radial mode for receiving the OAM MIMO transmission, wherein the plurality of radial modes includes at least a first radial mode defining a first beamforming vector and a second radial mode defining a second beamforming vector, wherein each one of the first beamforming vector and the second beamforming vector includes the DFT vector weighted and repeated for a number of times less than or equal to the first number, wherein the first beamforming vector and the second beamforming vector are orthogonal to each other;
• and
• receiving a signal by the receiver from the transmitter using an OAM MIMO beam that is configured according to the radial mode.

A transmitter apparatus for orbital angular momentum “OAM” multiple-input multiple-output “MIMO” communication, comprising:

• a memory;
• and
• a processor coupled with the memory and configured to:
• select, from a plurality of azimuth modes, an azimuth mode for an OAM MIMO transmission from the transmitter apparatus to a receiver apparatus, wherein the transmitter apparatus includes a first number of antenna circles that each include a second number of antenna elements, wherein the azimuth mode defines a discrete Fourier transform “DFT” vector of a first size less than or equal to the second number;
• select, from a plurality of radial modes associated with the azimuth mode, a radial mode for the OAM MIMO transmission, wherein the plurality of radial modes includes at least a first radial mode defining a first beamforming vector and a second radial mode defining a second beamforming vector, wherein each one of the first beamforming vector and the second beamforming vector includes the DFT vector weighted and repeated for a number of times less than or equal to the first number, wherein the first beamforming vector and the second beamforming vector are orthogonal to each other;
• and
• transmit a signal by the transmitter apparatus to the receiver apparatus using an OAM MIMO beam that is configured according to the radial mode.

A receiver apparatus for orbital angular momentum “OAM” multiple-input multiple-output “MIMO” communication, comprising:

• a memory;
• and
• a processor coupled with the memory and configured to:
• select, from a plurality of azimuth modes, an azimuth mode for receiving an OAM MIMO transmission from a transmitter apparatus to the receiver apparatus, wherein the receiver apparatus includes a first number of antenna circles that each include a second number of antenna elements, wherein the azimuth mode defines a discrete Fourier transform “DFT” vector of a first size less than or equal to the second number;
• select, from a plurality of radial modes associated with the azimuth mode, a radial mode for receiving the OAM MIMO transmission, wherein the plurality of radial modes includes at least a first radial mode defining a first beamforming vector and a second radial mode defining a second beamforming vector, wherein each one of the first beamforming vector and the second beamforming vector includes the DFT vector weighted and repeated for a number of times less than or equal to the first number, wherein the first beamforming vector and the second beamforming vector are orthogonal to each other;
• and
• receive a signal by the receiver apparatus from the transmitter apparatus using an OAM MIMO beam that is configured according to the radial mode.