Beamforming method and apparatus using a rate splitting scheme in a multi-cell multi-antenna interference channel

A target transmitter corresponding to a target receiver, the target transmitter comprising:

• a rate splitting encoder configured to encode a plurality of streams for transmission to the target receiver according to a rate splitting scheme;
• and
• a transmission beamforming unit configured to:
• use coordinated beamforming vectors as transmission beamforming vectors for N-M streams, the coordinated beamforming vectors enabling each individual stream of the N-M streams of the target transmitter to be decoded in different spatial dimension out of N-M spatial dimensions of the target receiver;
• and
• use transmission beamforming vectors for S-(N-M) streams to respectively align, in one of S-(N-M) spatial dimensions of the target receiver, one of remaining S-(N-M) streams of the target transmitter and one of streams of a neighbor transmitter, the streams of the neighbor transmitter corresponding to the remaining S-(N-M) streams of the target transmitter, when N is greater than M and less than N_req,
• wherein S is the number of streams, N is the number of antennas of the target transmitter, M is the number of antennas of the target receiver, and N_req is the multiplication of M and the total number of receivers.

A target receiver corresponding to a target transmitter, the target receiver comprising:

• a reception beamforming unit configured to use reception beamforming vectors to:
• remove, in a first reception spatial dimension, components associated with a second stream and a fourth stream included in a signal received by the target receiver;
• and
• remove, in a second reception spatial dimension, components associated with a first stream and a third stream included in the signal received by the target receiver, the first stream and the second stream being transmitted by the target transmitter, the third stream and the fourth stream being transmitted by a neighbor transmitter of the target transmitter;
• and
• a rate splitting decoder configured to:
• decode the first stream by removing a decodable common message of the third stream from the signal from which the components associated with the second stream and the fourth stream are removed;
• and
• decode the second stream by removing a decodable common message of the fourth stream from the signal from which the components associated with the first stream and the third stream are removed.

A method of allocating a frequency resource for a multi-cell communication system comprising a first cell, a second cell, and a third cell, the method comprising:

• allocating the same inner frequency resource to inner-cells of:
• the first cell;
• the second cell;
• and
• the third cell;
• and
• allocating:
• a first frequency resource to an outer-cell of the first cell;
• a second frequency resource to an outer-cell of the second cell;
• and
• a third frequency resource to an outer cell of the third cell,
• wherein the first frequency resource, the second frequency resource, and the third frequency resource partially overlap each other.