Communication method in relay nodes and destination nodes for aligned interference neutralization in interference channel

A communication method of a first relay node (R1) in a network comprising a first source node (S1), the first relay node (R1), a first destination node (D1), a second source node (S2), a second relay node (R2), and a second destination node (D2), the communication method comprising:

• receiving, at the first relay node (R1), streams X and Y from the first source node (S1);
• receiving, at the first relay node (R1), stream Z from the second source node (S2),
• wherein the streams Z and Y are aligned in a predetermined space;
• transmitting a signal comprising the stream X and an aligned signal (Y+Z) of the streams Z and Y to the first destination node (D1), so that the aligned signal (Y+Z) is to be received by the first destination node (D1) in an opposite direction with respect to an aligned signal (X+Z), which is generated and transmitted by the second relay node (R2);
• and
• transmitting the signal to the second destination node (D2), so that the stream X is to be received by the second destination node (D2) in an opposite direction with respect to the aligned signal (X+Z).

A communication method of a first destination node (D1) in a network comprising a first source node (S1), a first relay node (R1), the first destination node (D1), a second source node (S2), a second relay node (R2), and a second destination node (D2), the communication method comprising:

• receiving, at the first destination node (D1), an aligned signal (X+Z) from the second relay node (R2), wherein streams X and Z are aligned in the aligned signal (X+Z);
• receiving, at the first destination node (D1), the stream X and an aligned signal (Y+Z) from the first relay node (R1) in which the streams Y and Z are aligned;
• and
• removing the stream Z at the first destination node (D1) to neutralize an interference, wherein the aligned signal (X+Z) and the aligned signal (Y+Z) are received in opposite directions, and
• wherein the stream X and the stream Z are aligned, by the second relay node (R2), in a predetermined space based on a reception beamforming vector, the reception beamforming vector being orthogonal to a channel direction in which the second relay node (R2) receives the stream Y from the first source node (S1).

A communication method of a second destination node (D2) in a network comprising a first source node (S1), a first relay node (R1), a first destination node (D1), a second source node (S2), a second relay node (R2), and the second destination node (D2), the communication method comprising:

• receiving, at the second destination node (D2), an aligned signal (X+Z) from the second relay node (R2), wherein streams X and Z are aligned in the aligned signal (X+Z);
• receiving, at the second destination node (D2), the stream X and an aligned signal (Y+Z) from the first relay node (R1), wherein the streams Y and Z are aligned in the aligned signal (Y+Z);
• and
• removing the stream X at the second destination node (D2) to neutralize an interference,
• wherein the stream X and the aligned signal (X+Z) are received in opposite directions, and
• wherein the stream X and the stream Z are aligned, by the second relay node (R2), in a predetermined space based on a reception beamforming vector, the reception beamforming vector being orthogonal to a channel direction in which the second relay node (R2) receives the stream Y from the first source node (S1).