Beamforming using an antenna array

A network node for transmitting a signal using a beamforming antenna array, the antenna array comprising physical antenna elements of a first polarization and physical antenna elements of a second polarization, and the signal requiring use of a partial antenna array of the antenna array, the partial antenna array requiring less than all of the physical antenna elements of the antenna array for transmission of the signal, the network node comprising:

• processing circuitry;
• memory containing instructions executable by the processing circuitry whereby the network node is operative to:
• form at least one virtual antenna element for the partial antenna array to create a virtual aperture smaller than the full antenna aperture of the antenna array;
• connect each of the at least one virtual antenna element to at least one physical antenna element of the first polarization and at least one physical antenna element of the second polarization such that the at least one virtual antenna element at least partly utilize the full antenna aperture;
• and
• transmit the signal using the physical antenna elements connected to the at least one virtual antenna element.

A method for transmitting a signal using a beamforming antenna array, the antenna array comprising physical antenna elements of a first polarization and physical antenna elements of a second polarization, and the signal requiring use of a partial antenna array of the antenna array, the partial antenna array requiring less than all of the physical antenna elements of the antenna array for transmission of the signal, the method being performed by a network node and comprising:

• forming at least one virtual antenna element for the partial antenna array to create a virtual aperture smaller than the full antenna aperture of the antenna array;
• connecting each of the at least one virtual antenna element to at least one physical antenna element of the first polarization and at least one physical antenna element of the second polarization such that the at least one virtual antenna element at least partly utilize the full antenna aperture;
• and
• transmitting the signal using the physical antenna elements connected to the at least one virtual antenna element.

A method for transmitting a signal using a beamforming antenna array, the method being performed by a wireless device and comprising:

• obtaining an indication for transmission of the signal requiring use of less than all of the physical antenna elements of the antenna array for transmission of the signal;
• reducing the full antenna aperture of the antenna array by forming virtual antenna elements for the less than all of the physical antenna elements of the antenna array;
• connecting each of the virtual antenna elements to at least part of all physical antenna elements of the antenna array such that the virtual antenna elements at least partly utilize the full antenna aperture;
• and
• initiating transmission of the signal using the array of the virtual antenna elements.

A non-transitory computer readable recording medium storing a computer program product for transmitting a signal using a beamforming antenna array, the antenna array comprising physical antenna elements of a first polarization and physical antenna elements of a second polarization, and the signal requiring use of a partial antenna array of the antenna array, the partial antenna array requiring less than all of the physical antenna elements of the antenna array for transmission of the signal, the computer program product comprising software instructions which, when run on processing circuitry of a network node, causes the network node to:

• form at least one virtual antenna element for the partial antenna array to create a virtual aperture smaller than the full antenna aperture of the antenna array;
• connect each of the at least one virtual antenna element to at least one physical antenna element of the first polarization and at least one physical antenna element of the second polarization such that the at least one virtual antenna element at least partly utilize the full antenna aperture;
• and
• transmit the signal using the physical antenna elements connected to the at least one virtual antenna element.