Aperiodic and periodic CSI feedback modes for coordinated multi-point transmission

A user equipment, comprising:

• a control system configured to report channel state information (CSI) to each of two or more transmission points from which the user equipment is receiving signals using at least two channel state information (CSI) processes,
• wherein a first of the at least two CSI processes corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
• wherein the first of the at least two CSI processes is used for generating a CSI report,
• wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes,
• wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process,
• wherein, in response to a collision between at least two CSI reports to different ones of the two or more transmission points each with reporting type of a same priority and employing different CSI processes, the control system is configured to drop one of the at least two CSI reports based upon configuration indices associated with the CSI processes for the two CSI reports, and
• wherein, in response to a collision between at least two CSI reports to different ones of the two or more transmission points each with reporting type of a same priority and employing a same CSI measurement process, the control system is configured to drop one of the at least two CSI reports based upon indices associated the two or more transmission points.

A base station, comprising:

• a transceiver configured to transmit a signal containing information regarding configuration of at least two channel state information (CSI) processes,
• wherein a first of the at least two CSI processes corresponds a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
• wherein the first of the at least two CSI processes is used for generating a first CSI report,
• wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes, and
• wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process;
• and
• a controller configured to determine, from a received CSI report, CSI for a first of the at least two CSI processes.

A base station, comprising:

• a control system configured to receive channel state information (CSI) reports from a user equipment reporting CSI to each of two or more transmission points from which the user equipment is receiving signals using at least two CSI processes,
• wherein a first of the at least two CSI process corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
• wherein the first of the at least two CSI processes is used for generating a CSI report,
• wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank-indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes,
• wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process,
• wherein in response to a collision between at least two CSI reports from the user equipment to different ones of the two or more transmission points each with reporting type of a same priority and employing different CSI processes, a received one of the at least two CSI reports is based upon configuration indices associated with the CSI processes for the two CSI reports and,
• wherein in response to a collision between at least two CSI reports from the user equipment to different ones of the two or more transmission points each with reporting type of a same priority and employing a same CSI process, a received one of the at least two CSI reports is based upon indices associated with the two or more transmission points.

A method, comprising:

• receiving, in a user equipment, a signal containing information regarding configuration of at least two channel state information (CSI) processes,
• wherein a first of the at least two CSI processes corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
• wherein the first of the at least two CSI processes is used for generating a first CSI report, and
• wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes, and
• wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process;
• determining, in the user equipment, the configurations of the at least two CSI processes from the received signal;
• and
• using the first CSI reporting configuration to generate the first CSI report including the RI determined by the second CSI process.

A method, comprising:

• reporting, from a user equipment, channel state information (CSI) to each of two or more transmission points from which the user equipment is receiving signals using at least two CSI processes,
• wherein a first of the at least two CSI processes corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
• wherein the first of the at least two CSI processes is used for generating a first CSI report,
• wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes,
• wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process;
• in response to a collision between at least two CSI reports from the user equipment to different ones of the two or more transmission points each with reporting type of a same priority and employing different CSI processes, dropping, at the user equipment, one of the at least two CSI reports based upon configuration indices associated with the two CSI reports;
• and
• in response to a collision between at least two CSI reports to different ones of the two or more transmission points each with reporting type of a same priority and employing a same CSI process, dropping, at the user equipment, one of the at least two CSI reports based upon indices associated the two or more transmission points.