Enhanced srs transmission for mimo operation in lte-a

A method of wireless communication, comprising:

• determining, by a base station, a precoded sounding reference signal (SRS) vector for one or more user equipments (UEs), wherein the determined precoded SRS vector includes one of:
• determining the precoded SRS vector on a per UE basis;
• enabling the precoded SRS vector for at least one of:
• a frequency division duplex (FDD) system or a time division duplex (TDD) system;
• and
• enabling the precoded SRS vector for aperiodic SRS only;
• and
• transmitting the determined precoded SRS vector from the base station to at least one of the one or more UEs.

A method of wireless communication, comprising:

• determining, at a base station, a density of sounding reference signal (SRS) transmissions for a user equipment (UE);
• indicating the density of SRS transmissions to the UE;
• and
• receiving, at the base station, the SRS transmissions from the UE.

An apparatus configured for wireless communication, comprising:

• means for detecting, at a mobile device, an observed interference level for each one of a plurality of receiver chains of the mobile device;
• means, executable in response to detecting an imbalance in the observed interference level for the plurality of receiver chains, for precoding a sounding reference signal (SRS) to indicate the imbalance;
• and
• means for transmitting the precoded SRS.

An apparatus configured for wireless communication, comprising:

• means for determining, by a base station, a precoded sounding reference signal (SRS) vector for one or more user equipments (UEs), wherein the determined precoded SRS vector includes one of:
• means for determining the precoded SRS vector on a per UE basis;
• means for enabling the precoded SRS vector for at least one of:
• a frequency division duplex (FDD) system or a time division duplex (TDD) system;
• and
• means for enabling the precoded SRS vector for aperiodic SRS only;
• and
• means for transmitting the determined precoded SRS vector from the base station to at least one of the one or more UEs.

An apparatus configured for wireless communication, comprising:

• means for determining, at a base station, a density of sounding reference signal (SRS) transmissions for a user equipment (UE);
• means for indicating the density of SRS transmissions to the UE;
• and
• means for receiving, at the base station, the SRS transmissions from the UE.

A computer program product for wireless communications in a wireless network, comprising:

• a non-transitory computer-readable medium having program code recorded thereon, the program code including:
• program code for causing at least one computer to detect, at a mobile device, an observed interference level for each one of a plurality of receiver chains of the mobile device;
• program code, executable in response to detecting an imbalance in the observed interference level for the plurality of receiver chains, for causing at least one computer to precode a sounding reference signal (SRS) to indicate the imbalance;
• and
• program code for causing at least one computer to transmit the precoded SRS.

A computer program product for wireless communications in a wireless network, comprising:

• a non-transitory computer-readable medium having program code recorded thereon, the program code including:
• program code for causing at least one computer to determine, by a base station, a precoded sounding reference signal (SRS) vector for one or more user equipments (UEs), wherein the determined precoded SRS vector includes one of:
• program code for causing at least one computer to determine the precoded SRS vector on a per UE basis;
• program code for causing at least one computer to enable the precoded SRS vector for at least one of:
• a frequency division duplex (FDD) system or a time division duplex (TDD) system;
• and
• program code for causing at least one computer to enable the precoded SRS vector for aperiodic SRS only;
• and
• program code for causing at least one computer to transmit the determined precoded SRS vector from the base station to at least one of the one or more UEs.

A computer program product for wireless communications in a wireless network, comprising:

• a non-transitory computer-readable medium having program code recorded thereon, the program code including:
• program code for causing at least one computer to determine, at a mobile device, a density of sounding reference signal (SRS) transmissions;
• and
• program code for causing at least one computer to transmit SRS by the mobile device based at least in part on the determined density.

A computer program product for wireless communications in a wireless network, comprising:

• a non-transitory computer-readable medium having program code recorded thereon, the program code including:
• program code for causing at least one computer to determine, at a base station, a density of sounding reference signal (SRS) transmissions for a user equipment (UE) served by the base station;
• program code for causing at least one computer to indicate the density of SRS to the UE;
• and
• program code for causing at least one computer to receive, at the base station, the SRS transmissions from the UE.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to detect, at a mobile device, an observed interference level for each one of a plurality of receiver chains of the mobile device;
• to precode a sounding reference signal (SRS) to indicate the imbalance in response to detecting an imbalance in the observed interference level for the plurality of receiver chains;
• and
• to transmit the precoded SRS.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to determine, by a base station, a precoded sounding reference signal (SRS) vector for one or more user equipments (UEs), wherein the determined precoded SRS vector includes one of:
• to determine the precoded SRS vector on a per UE basis;
• to enable the precoded SRS vector for at least one of:
• a frequency division duplex (FDD) system or a time division duplex (TDD) system;
• and
• to enable the precoded SRS vector for aperiodic SRS only;
• and
• to transmit the determined precoded SRS vector from the base station to at least one of the one or more served UEs.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to determine, at a mobile device, a density of sounding reference signal (SRS) transmissions;
• and
• to transmit SRS by the mobile device based at least in part on the determined density.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to determine, at a base station, a density of sounding reference signal (SRS) transmissions for a user equipment (UE);
• to indicate the density of SRS transmissions to the UE;
• and
• to receive, at the base station, the SRS transmissions from the UE.