CHANNEL STATE INFORMATION FOR ADAPTIVELY CONFIGURED TDD COMMUNICATION SYSTEMS

• US 20140269460A1
• Filed: 03/07/2014
• Published: 09/18/2014
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Papasakellariou, Aris, Zhang, Jianzhong
• Granted Patent: US 9,306,725 B2
• Time in Patent Office: Days
• US Class Current: 370/294
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/1469 using time-sharing

Abstract

Methods and apparatus of a base station or a User Equipment (UE) in communication with each other are provided. The UE is configured by the base station for operation with an adapted Time Division Duplex (TDD) UpLink-DownLink (UL-DL) configuration. A process enabling the base station to configure a UE with resources for obtaining channel and interference measurements in two sets of Transmission Time Intervals (TTIs) and a process for the UE to obtain a Channel State Information (CSI) from the channel and interference measurements in the two sets of TTIs are provided.

Claims

1. A method comprising:

transmitting, by a base station to a User Equipment (UE) for communication using Time Division Duplexing (TDD)

a System Information Block (SIB) indicating a first TDD UpLink-DownLink (UL-DL) configuration, wherein a TDD UL-DL configuration is defined over a time period of ten SubFrames (SFs) that comprise DL SFs where a communication direction is from the base station to the UE, UL SFs where a communication direction is from the UE to the base station, and special SFs where a communication direction can be both from the base station to the UE and from the UE to the base station, and wherein each SF of the ten SFs has a unique time domain index;

a Physical DL Control CHannel (PDCCH) conveying a DL Control Information (DCI) format indicating an adaptation of the first TDD UL-DL configuration to a second TDD UL-DL configuration;

configuration information for resources of a non-zero power Channel State Information Reference Signal (CSI-RS), for resources of a first Channel State Information Interference Measurement (CSI-IM), and for resources of a second CSI-IM wherein the non-zero power CSI-RS resources, the first CSI-IM resources, and the second CSI-IM resources are respectively in a subframe that is a DL subframe, a DL subframe, and an UL subframe in the first TDD UL-DL configuration;

receiving, by the UE

the SIB indicating the first TDD UL-DL configuration;

the DCI format indicating the second TDD UL-DL configuration;

the configuration information; and

measuring, by the UE, a first quantity based on signaling received in the non-zero power CSI-RS resources and on the first CSI-IM resources and a second quantity based on signaling received in the non-zero power CSI-RS resources and on the second CSI-IM resources when the UL subframe is a DL subframe in the second TDD UL-DL configuration.

2. The method of claim 1, further comprising:

computing, by the UE, from the first quantity a first Channel Quality Indicator (CQI) and from the second quantity a second CQI.

3. The method of claim 2, wherein the first quantity and the second quantity are respectively a first Signal-to-Noise and Interference Ratio (SINR) and a second SINR.

4. The method of claim 2, further comprising:

configuring, by the base station to the UE, a periodic transmission for the first CQI and a periodic transmission for the second CQI wherein when the first CQI and the second CQI are to be transmitted in a same UL subframe, the UE transmits the second CQI and suspends transmission of the first CQI.

5. The method of claim 1, wherein the second CSI-IM resources are in every subframe that is an UL subframe in the first TDD UL-DL configuration and a DL subframe in the second TDD UL-DL configuration.

6. The method of claim 1, wherein the second CSI-IM resources are in a set of configured subframes that include at least one UL subframe in the first TDD UL-DL configuration that is a DL subframe in the second TDD UL-DL configuration.

7. The method of claim 1, further comprising:

receiving, by the UE from the base station, in a DL subframe of the second TDD UL-DL configuration that is an UL subframe in the first TDD UL-DL configuration, a DCI format scheduling a transmission by the UE of a Physical Uplink Shared CHannel (PUSCH) that includes multiplexing in the PUSCH of a Channel State Information (CSI) report, and transmitting by the UE the CSI report in the PUSCH wherein the UE computes the CSI based on signaling received in the non-zero power CSI-RS resources and in second CSI-IM resources only in the DL subframe.

8. A method comprising:

transmitting, by a base station to a first User Equipment (UE) for communication using Time Division Duplexing (TDD)

a System Information Block (SIB) indicating a first TDD UpLink-DownLink (UL-DL) configuration, wherein a TDD UL-DL configuration is defined over a time period of ten SubFrames (SFs) that comprise DL SFs where a communication direction is from the base station to the UE, UL SFs where a communication direction is from the UE to the base station, and special SFs where a communication direction can be both from the base station to the UE and from the UE to the base station, and wherein each SF of the ten SFs has a unique time domain index;

a Physical DL Control CHannel (PDCCH) conveying a DL Control Information (DCI) format indicating an adaptation of the first TDD UL-DL configuration to a second TDD UL-DL configuration;

receiving, by the UE

the SI indicating the first TDD UL-DL configuration;

the DCI format indicating the second TDD UL-DL configuration; and

measuring, by the UE, a first quantity in a first set of DL subframes of the second TDD UL-DL configuration to determine a first Channel State Information (CSI) and a second quantity in a second set of DL subframes of the second TDD UL-DL configuration to determine a second CSI, wherein the UE discards a measurement of the second quantity in a DL subframe from the second set of DL subframes from the determination of the second CSI if the measurement value is smaller than a second threshold value.

9. The method of claim 8, wherein the first set of DL subframes includes all DL subframes of the first TDD UL-DL configuration and the second set of DL subframes includes at least one DL subframe of the second TDD UL-DL configuration that is an UL subframe in the first TDD UL-DL configuration.

10. The method of claim 8, wherein the base station configures to the UE using higher layer signaling, the first set of DL subframes and the second set of DL subframes.

11. The method of claim 8, wherein the UE discards a measurement of the first quantity in a DL subframe in the first set of DL subframes from the determination of the first CSI if the measurement has a value that is larger than or equal to a first threshold value.

12. The method of claim 8, wherein the UE includes the discarded measurement of the second quantity in the determination of the first CSI.

13. The method of claim 8, wherein a measurement is based on a Common Reference Signal (CRS) transmitted by the base station, and the first quantity and the second quantity are a Signal to Noise and Interference Ratio (SINR) the UE computes respectively based on a CRS reception by the UE in the first set of DL subframes and in the second set of DL subframes.

14. A base station comprising:

a transmitter configured to transmit to a User Equipment (UE)

a System Information Block (SIB) indicating a first Time Division Duplexing (TDD) UpLink-DownLink (UL-DL) configuration, wherein a TDD UL-DL configuration is defined over a time period of ten SubFrames (SFs) that comprise DL SFs where a communication direction is from the base station to the UE, UL SFs where a communication direction is from the UE to the base station, and special SFs where a communication direction can be both from the base station to the UE and from the UE to the base station, and wherein each SF of the ten SFs has a unique time domain index;

a Physical DL Control CHannel (PDCCH) conveying a DL Control Information (DCI) format indicating an adaptation of the first TDD UL-DL configuration to a second TDD UL-DL configuration; and

configuration information for resources of a non-zero power Channel State Information Reference Signal (CSI-RS), for resources of a first Channel State Information Interference Measurement (CSI-IM), and for resources of a second CSI-IM wherein the non-zero power CSI-RS resources, the first CSI-IM resources, and the second CSI-IM resources are respectively in a subframe that is a DL subframe, a DL subframe, and an UL subframe in the first TDD UL-DL configuration.

15. The apparatus of claim 14, wherein the second CSI-IM resources are in every subframe that is an UL subframe in the first TDD UL-DL configuration and a DL subframe in the second TDD UL-DL configuration.

16. The apparatus of claim 14, wherein the second CSI-IM resources are in a set of configured subframes that include at least one UL subframe in the first TDD UL-DL configuration that is a DL subframe in the second TDD UL-DL configuration.

17. A User Equipment (UE) comprising:

a receiver configured to receive

a System Information Block (SIB) transmitted from a base station and indicating a first Time Division Duplexing (TDD) UpLink-DownLink (UL-DL) configuration, wherein a TDD UL-DL configuration is defined over a time period of ten SubFrames (SFs) that comprise DL SFs where a communication direction is from a base station to the UE, UL SFs where a communication direction is from the UE to the base station, and special SFs where a communication direction can be both from the base station to the UE and from the UE to the base station, and wherein each SF of the ten SFs has a unique time domain index;

a Physical DL Control CHannel (PDCCH) transmitted from the base station and conveying a DL Control Information (DCI) format indicating an adaptation of the first TDD UL-DL configuration to a second TDD UL-DL configuration; and

a measurement unit configured to measure a first quantity in a first set of DL subframes of the second TDD UL-DL configuration to determine a first Channel State Information (CSI) and a second quantity in a second set of DL subframes of the second TDD UL-DL configuration to determine a second CSI, wherein the apparatus discards a measurement of the second quantity in a DL subframe from the second set of DL subframes from the determination of the second CSI if the measurement value is smaller than a second threshold value.

18. The apparatus of claim 17, wherein the first set of DL subframes includes all DL subframes of the first TDD UL-DL configuration and the second set of DL subframes includes at least one DL subframe of the second TDD UL-DL configuration that is an UL subframe in the first TDD UL-DL configuration.

19. The apparatus of claim 17, wherein the apparatus discards a measurement of the first quantity in a DL subframe in the first set of DL subframes from the determination of the first CSI if the measurement has a value that is larger than or equal to a first threshold value.

20. The apparatus of claim 17, wherein a measurement is based on a Common Reference Signal (CRS) transmitted by the base station, and the first quantity and the second quantity are a Signal to Noise and Interference Ratio (SINR) the apparatus computes, respectively, based on a CRS reception in the first set of DL subframes and in the second set of DL subframes.