Independent sub-band size for precoding matrix indicator and channel quality indicator

A host configured to operate in a communication system to provide an over-the-top, OTT, service, the host comprising:

• processing circuitry configured to provide user data;
• and
• a network interface configured to initiate transmission of the user data to a network node in a cellular network for transmission to a user equipment, UE,
• the network node having a communication interface and processing circuitry configured to perform a method for receiving channel state information, CSI, feedback using a multi-beam precoder codebook, the method comprising:
• receiving the CSI feedback from the UE according to a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size, wherein the first sub-band size is smaller than the second sub-band size, wherein the CSI feedback indicates a linear combination of precoder vectors for each of a plurality of frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combinations of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors.

The host computer of claim 1, the method further comprising:

• determining the sub-band CQI granularity;
• determining the sub-band PMI granularity;
• and
• configuring the wireless device with the sub-band CQI granularity and the sub-band PMI granularity.

A method implemented in a communication system including a host computer, one or more base stations and a user equipment, UE, comprising:

• at the host computer, providing user data;
• and
• at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the one or more base stations wherein at least one of the one or more base stations is configured to:
• receive, channel state information, CSI, feedback from the UE according to a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size, wherein the first sub-band size is smaller than the second sub-band size, wherein the CSI feedback indicates a linear combination of precoder vectors for each of a plurality of frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combinations of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors, and wherein the CSI feedback is received using a multi-beam precoder codebook.

The method of claim 4, the at least one of the one or more base stations further configured to:

• determine the sub-band CQI granularity;
• determine the sub-band PMI granularity;
• and
• configure the UE with the sub-band CQI granularity and the sub-band PMI granularity.

A communication system including a host computer comprising:

• processing circuitry configured to provide user data;
• and
• a communication interface configured to initiate transmission of the user data to
• a communication network for transmission to a user equipment, UE, wherein the communication network comprises at least one base station having a radio interface and base station processing circuitry, the base station processing circuitry configured to:
• receive, channel state information, CSI, feedback from a wireless device according to a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size, wherein the first sub-band size is smaller than the second sub-band size, wherein the CSI feedback indicates a linear combination of precoder vectors for each of a plurality of frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combinations of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors, and wherein the CSI feedback is received using a multi-beam precoder codebook.

The system of claim 7, the at least one base station further configured to:

• determine the sub-band CQI granularity;
• determine the sub-band PMI granularity;
• and
• configure the UE with the sub-band CQI granularity and the sub-band PMI granularity.

A host computer comprising:

• processing circuitry configured to provide user data;
• and
• a communication interface configured to forward user data to a cellular network for transmission to a user equipment, UE,
• the UE configured to transmit channel state information, CSI, feedback using a multi-beam precoder codebook, and the UE comprising a radio interface, memory operable to store instructions and processing circuitry operable to execute the instructions, whereby the UE is operable to:
• receive a configuration for a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity for the UE, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size, wherein the first sub-band size is smaller than the second sub-band size;
• and
• transmit the CSI feedback to a base station, wherein the CSI feedback is in accordance with the sub-band CQI granularity and the sub-band PMI granularity, wherein the CSI feedback indicates a linear combination of precoder vectors for each of a plurality of frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combinations of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors.