Enhanced SRS transmission for MIMO operation in LTE-A
First Claim
1. A method of wireless communication, comprising:
- receiving, from a base station, one or more precoded sounding reference signal (SRS) vectors indicating precoding to apply to a precoded SRS;
receiving a plurality of aperiodic SRS triggers, wherein the precoded SRS vectors are received with the plurality of aperiodic SRS triggers and the aperiodic SRS triggers are for triggering transmission of the precoded SRS;
detecting, at a mobile device, an observed interference level for each one of a plurality of receiver chains of the mobile device;
detecting, at the mobile device, an imbalance between the plurality of receiver chains based on the observed interference level for each one of the plurality of receiver chains;
in response to the detected imbalance between the plurality of receiver chains, precoding a SRS to indicate the imbalance; and
transmitting the precoded SRS.
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Accused Products
Abstract
Enhanced sounding reference signal (SRS) transmissions for multiple input, multiple output (MIMO) operation are disclosed in which a user equipment (UE) detects an observed interference level for each receiver chain of the UE. In response to an imbalance, the UE precodes a SRS targeting downlink operation to indicate the imbalance. The UE then transmits the precoded SRS. In alternative aspects, the precoded SRS vector may be determined by an evolved nodeB (eNB). In such aspects, the eNB determines the precoded SRS vector targeting downlink operations for the served UEs, wherein the determined precoded SRS vector includes determining the precoded SRS vector on a per UE basis, enabling the precoded SRS vector for either one or both of frequency division duplex (FDD) systems and time division duplex (TDD) systems, or enabling the precoded SRS vector for aperiodic SRS only. The eNB then transmits the determined precoded SRS vector to the UE.
23 Citations
29 Claims
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1. A method of wireless communication, comprising:
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receiving, from a base station, one or more precoded sounding reference signal (SRS) vectors indicating precoding to apply to a precoded SRS; receiving a plurality of aperiodic SRS triggers, wherein the precoded SRS vectors are received with the plurality of aperiodic SRS triggers and the aperiodic SRS triggers are for triggering transmission of the precoded SRS; detecting, at a mobile device, an observed interference level for each one of a plurality of receiver chains of the mobile device; detecting, at the mobile device, an imbalance between the plurality of receiver chains based on the observed interference level for each one of the plurality of receiver chains; in response to the detected imbalance between the plurality of receiver chains, precoding a SRS to indicate the imbalance; and transmitting the precoded SRS. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An apparatus configured for wireless communication, comprising:
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means for receiving, from a base station, one or more precoded sounding reference signal (SRS) vectors indicating precoding to apply to a precoded SRS; means for receiving a plurality of aperiodic SRS triggers, wherein the precoded SRS vectors are received with the plurality of aperiodic SRS triggers and the aperiodic SRS triggers are for triggering transmission of the precoded SRS; 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 for detecting, at the mobile device, an imbalance between the plurality of receiver chains based on the observed interference level for each one of the plurality of receiver chains; means, executable in response to the detected imbalance between the plurality of receiver chains, for precoding a SRS to indicate the imbalance; and means for transmitting the precoded SRS. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. 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 receive, from a base station, one or more precoded sounding reference signal (SRS) vectors indicating precoding to apply to a precoded SRS; program code for causing at least one computer to receive a plurality of aperiodic SRS triggers, wherein the precoded SRS vectors are received with the plurality of aperiodic SRS triggers and the aperiodic SRS triggers are for triggering transmission of the precoded SRS; 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 for causing at least one computer to detect, at the mobile device, an imbalance between the plurality of receiver chains based on the observed interference level for each one of the plurality of receiver chains; program code, executable in response to the detected imbalance between 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.
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29. An apparatus configured for wireless communication, the apparatus comprising:
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at least a transmitter; at least one processor; and a memory coupled to the at least one processor, wherein the at least one processor is configured; to receive, from a base station, one or more precoded sounding reference signal (SRS) vectors indicating precoding to apply to a precoded SRS; to receive a plurality of aperiodic SRS triggers, wherein the precoded SRS vectors are received with the plurality of aperiodic SRS triggers and the aperiodic SRS triggers are for triggering transmission of the precoded SRS; to detect, at a mobile device, an observed interference level for each one of a plurality of receiver chains of the mobile device; to detect, at the mobile device, an imbalance between the plurality of receiver chains based on the observed interference level for each one of the plurality of receiver chains; to precode a sounding reference signal (SRS) to indicate the detected imbalance in response to the detected imbalance between the plurality of receiver chains; and to transmit the precoded SRS by the transmitter.
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Specification