Methods and devices for spatial coding

A method in a controller node of a communication network, the method comprising:

• joint spatial coding, by the controller node, a symbol into a first spatial code text and into a second spatial code text different from the first spatial code text;
• grouping, by the controller node, transmit antennas of first and second base stations of the communication network into first and second transmit antenna groups based on a location of a coverage area of each of the transmit antennas;
• distributing the first spatial code text, by the controller node,
• to the first base station when one or more transmit antennas of the first base station are included in the first transmit antenna group, and
• to the second base station when one or more transmit antennas of the second base station are included in the first transmit antenna group;
• and
• distributing the second spatial code text, by the controller node,
• to the first base station when one or more transmit antennas of the first base station are included in the second transmit antenna group, and
• to the second base station when one or more transmit antennas of the second base station are included in the second transmit antenna group,
• wherein the first and second base stations comprise an unequal number of transmit antennas,
• wherein the first transmit antenna group comprises one or more transmit antennas of the first and/or the second base station, and the second transmit antenna group comprises one or more transmit antennas of the first and/or the second base station not included in the first transmit antenna group, and
• wherein the first spatial code text is for transmission to a user equipment via the first transmit antenna group and the second spatial code text is for transmission to the user equipment via the second transmit antenna group.

A controller node of a communication network, the controller node comprising:

• a control unit configured to
• joint spatial code a symbol into a first spatial code text and into a second spatial code text different from the first spatial code text, and
• group transmit antennas of first and second base stations of the communication network into first and second transmit antenna groups based on a location of a coverage area of each of the transmit antennas, and
• a network interface configured to
• distribute the first spatial code text to the first base station when one or more transmit antennas of the first base station are included in the first transmit antenna group,
• distribute the first spatial code text to the second base station when one or more transmit antennas of the second base station are included in the first transmit antenna group,
• distribute the second spatial code text to the first base station when one or more transmit antennas of the first base station are included in the second transmit antenna group, and
• distribute the second spatial code text to the second base station when one or more transmit antennas of the second base station are included in the second transmit antenna group,
• wherein the first and second base stations comprise an unequal number of transmit antennas,
• wherein the first transmit antenna group comprises one or more transmit antennas of the first and/or the second base station, and the second transmit antenna group comprises one or more transmit antennas of the first and/or the second base station not included in the first transmit antenna group, and
• wherein the first spatial code text is for transmission to a user equipment via the first transmit antenna group and the second spatial code text is for transmission to the user equipment via the second transmit antenna group.

A method in a base station of a communication network, the method comprising:

• receiving, at the base station, one or both of first and second spatial code texts of a joint spatial coding from a controller node of the communication network, the first and/or the second spatial code text being based a location of coverage area of each of one or more transmit antennas of the base station, the first and second code texts being different from each other;
• transmitting, by the base station, the first spatial code text to a user equipment via a first transmitting arrangement when the first spatial code text is received, the first transmitting arrangement comprising one or more transmitting antennas of the base station;
• and
• transmitting, by the base station, the second spatial code text to the user equipment via a second transmitting arrangement when the second spatial code text is received, the second transmitting arrangement comprising one or more transmitting antennas of the base station not included in the first transmitting arrangement;
• wherein in the communication network, there is another base station also transmitting the first and/or the second spatial code text to the user equipment, and
• wherein the base station and the another base station comprise an unequal number of transmit antennas.

A base station of a communication network, the base station comprising:

• a network interface configured to receive one or both of first and second spatial code texts of a joint spatial coding from a controller node of the communication network, the first and/or the second spatial code text being based a location of coverage area of each of one or more transmit antennas of the base station, the first and second code texts being different from each other;
• and
• a control unit configured to
• transmit the first spatial code text to a user equipment via a first transmitting arrangement when the first spatial code text is received, the first transmitting arrangement comprising one or more transmitting antennas of the base station, and
• transmit the second spatial code text to the user equipment via a second transmitting arrangement when the second spatial code text is received, the second transmitting arrangement comprising one or more transmitting antennas of the base station not included in the first transmitting arrangement,
• wherein in the communication network, there is another base station that also transmits the first and/or the second spatial code text to the user equipment, and
• wherein the base station and the another base station comprise an unequal number of transmit antennas.

A method in a user equipment of a communication network, the method comprising:

• receiving, at the user equipment, a first spatial code text from a first transmit antenna group and a second spatial code text from a second transmit antenna group;
• evaluating, by the user equipment, the first and second spatial code texts;
• selecting, by the user equipment, one of the first and second code texts based on the evaluating;
• and
• sending, by the user equipment, a feedback indicating the selection to a controller node of the communication network,
• wherein the communication network comprises first and second base stations with an unequal number of transmit antennas, and
• wherein the first transmit antenna group comprises one or more transmit antennas of the first and second base stations, and the second transmit antenna group comprises one or more transmit antennas of the first and second base stations not included in the first transmit antenna group such that the first spatial code text is received from at least one of the first and second base stations and the second spatial code text is received from at least the other of the first and second base stations.

A user equipment of a communication network, the user equipment comprising:

• a receiving arrangement configured to receive a first spatial code text from a first transmit antenna group and a second spatial code text from a second transmit antenna group, the receiving arrangement comprising at least one receiving antenna;
• a control unit configured to evaluate the first and second spatial code texts, and select one of the first and second code texts based on the evaluation;
• and
• a sending arrangement configured to send a feedback indicating the selection to a controller node of the communication network, the sending arrangement comprising at least one transmitting antenna,
• wherein the communication network comprises first and second base stations with an unequal number of transmit antennas, and
• wherein the first transmit antenna group comprises one or more transmit antennas of the first and second base stations, and the second transmit antenna group comprises one or more transmit antennas of the first and second base stations not included in the first transmit antenna group such that the receiving arrangement receives the first spatial code text from at least one of the first and second base stations and receives the second spatial code from at least the other of the first and second base stations.