Wireless receiving apparatus and method thereof

A method performed by a wireless receiving apparatus, the method comprising:

• generating an N′×B′ weight matrix W whose columns are orthogonal to each other by decomposing an estimated N′×M′ channel matrix, defined between M′ transmitting antennas of one or more wireless transmitting apparatuses and N′ receiving antennas coupled to the wireless receiving apparatus, into the N′×B′ weight matrix W and a B′×M′ matrix containing two or more non-zero matrix elements in each column, wherein B′ is an integer less than or equal to N′−1 and greater than or equal to M′, or generating a combination of an N′×B′ sub-weight matrix W1 and at least one second sub-weight matrix, wherein a product of the sub-weight matrix W1 with the at least one second sub-weight matrix is equal to the weight matrix W;
• performing first receive beamforming on received signals of the N′ receiving antennas using the weight matrix W or the sub-weight matrix W1;
• and
• performing a belief propagation (BP) algorithm using signals which the first receive beamforming has been performed for and transmitted via a fronthaul.

A non-transitory computer readable medium storing a program for causing a computer to perform a method for a wireless receiving apparatus, wherein the method comprises:

• generating an N′×B′ weight matrix W whose columns are orthogonal to each other by decomposing an estimated N′×M′ channel matrix, defined between M′ transmitting antennas of one or more wireless transmitting apparatuses and N′ receiving antennas coupled to the wireless receiving apparatus, into the N′×B′ weight matrix W and a B′×M′ matrix containing two or more non-zero matrix elements in each column, wherein B′ is an integer less than or equal to N′−1 and greater than or equal to M′, or generating a combination of an N′×B′ sub-weight matrix W1 and at least one second sub-weight matrix, wherein a product of the sub-weight matrix W1 with the at least one second sub-weight matrix is equal to the weight matrix W;
• performing first receive beamforming on received signals of the N′ receiving antennas using the weight matrix W or the sub-weight matrix W1;
• and
• performing a belief propagation (BP) algorithm using signals which the first receive beamforming has been performed for and transmitted via a fronthaul.

A Radio Unit (RU) included in a wireless receiving apparatus and configured to be coupled via a fronthaul to a Distributed Unit (DU) of the wireless receiving apparatus, the RU comprising:

• at least one beamforming weight generator configured to:
• generate an N′×B′ weight matrix W whose columns are orthogonal to each other by decomposing an estimated N′×M′ channel matrix, defined between M′ transmitting antennas of one or more wireless transmitting apparatuses and N′ receiving antennas coupled to the wireless receiving apparatus, into the N′×B′ weight matrix W and a B′×M′ matrix containing two or more non-zero matrix elements in each column, wherein B′ is an integer less than or equal to N′−1 and greater than or equal to M′;
• or
• generate a combination of an N′×B′ sub-weight matrix W1 and at least one second sub-weight matrix, wherein a product of the sub-weight matrix W1 with the at least one second sub-weight matrix is equal to the weight matrix W;
• and
• a first beamformer configured to perform receive beamforming on received signals of the N′ receiving antennas using the weight matrix W or the sub-weight matrix W1 and provide beamformed signals to the DU via the fronthaul.

A Distributed Unit (DU) included in a wireless receiving apparatus and configured to be coupled via a fronthaul to a Radio Unit (RU) of the wireless receiving apparatus, the DU comprising:

• at least one beamforming weight generator configured to:
• generate an N′×B′ weight matrix W whose columns are orthogonal to each other by decomposing an estimated N′×M′ channel matrix, defined between M′ transmitting antennas of one or more wireless transmitting apparatuses and N′ receiving antennas coupled to the wireless receiving apparatus, into the N′×B′ weight matrix W and a B′×M′ matrix containing two or more non-zero matrix elements in each column, wherein B′ is an integer less than or equal to N′−1 and greater than or equal to M′;
• or
• generate a combination of an N′×B′ sub-weight matrix W1 and at least one second sub-weight matrix, wherein a product of the sub-weight matrix W1 with the at least one second sub-weight matrix is equal to the weight matrix W;
• and
• a belief propagation (BP) detector configured to perform a BP algorithm using signals, the signals being generated and transmitted via the fronthaul by the RU by performing receive beamforming on received signals of the N′ receiving antennas using the weight matrix W or the sub-weight matrix W1.