METHOD AND APPARATUS FOR TRANSMITTING UPLINK SOUNDING REFERENCE SIGNAL

• US 20170048039A1
• Filed: 04/23/2015
• Published: 02/16/2017
• Est. Priority Date: 04/23/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: ZHAO, Zheng, LI, Yingyang, FU, Jingxing
• Granted Patent: US 10,764,007 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

Various embodiments of the present disclosure describe a terminal and a base station. Various embodiments of the present disclosure describe how to transmit the SRS on an FDD downlink carrier and effectively configure and transmit the FDD downlink carrier SRS, so that the FDD system has the channel reciprocity and is more suitable for a large-scale multi-antenna system. Various embodiments of the present disclosure describe an SRS transmission method and device when an uplink carrier of the FDD system can transmit an uplink signal and a downlink signal.

Claims

1. A method for transmitting an uplink sounding reference signal (SRS) at a terminal, comprising:

obtaining configuration and triggering information of the SRS;

determining a carrier and a subframe to transmit the SRS based on the configuration and triggering information, wherein the carrier is a frequency division duplex (FDD) downlink carrier or a flexible duplex uplink carrier;

obtaining power control information and determining a power value based on the obtained power control information; and

transmitting, to a base station, the SRS through the determined carrier and the subframe with the determined power value.

2. The method of claim 1, wherein when different serving cells are configured based on an FDD uplink carrier and the FDD downlink carrier, configuration and triggering information corresponding to each of the different serving cells is obtained.

3. The method of claim 1, wherein determining the carrier comprises:

obtaining a carrier direction indicator included in the configuration and triggering information;

wherein the carrier direction indicator indicates the carrier is an uplink carrier or a downlink carrier;

or

when an FDD uplink carrier is the flexible duplex uplink carrier, determining a carrier carrying the configuration and triggering information as the carrier.

4. The method of claim 1, wherein when a SRS transmission is triggered through a triggering type 1, determining the carrier comprises:

determining a carrier to transmit data scheduling by physical layer signaling to trigger the SRS transmission as the carrier;

or

determining a carrier to transmit physical layer signaling to trigger the SRS transmission as the carrier where the SRS transmission is located;

or

wherein when an FDD uplink carrier and an FDD downlink carrier within serving cell of the terminal share a same configuration and triggering information, the determining the carrier and the subframe comprises;

when the FDD uplink carrier supports an uplink transmission, determining the carrier and the subframe in accordance with an FDD mode; and

when the FDD uplink carrier supports both the uplink transmission and a downlink transmission, determining the carrier and the subframe in accordance with a TDD mode;

or

determining the carrier and the subframe in accordance with the FDD mode;

or

determining the carrier and the subframe in accordance with the TDD mode;

or

wherein when an FDD uplink carrier and an FDD downlink carrier within a serving cell of the terminal share a same configuration and triggering information, the method further comprises;

when the terminal does not determine that the FDD uplink carrier supports a downlink transmission, ignoring the obtained configuration and triggering information without performing the SRS transmission;

or

wherein when an FDD uplink carrier and an FDD downlink carrier within a serving cell use different configuration and triggering information, the operation of determining the carrier and the subframe comprises;

receiving, from the base station, higher layer signaling corresponding to the flexible duplex uplink carrier or the FDD downlink carrier and indicating a configuration and triggering mode; and

determining the carrier and the subframe where the SRS transmission is located in accordance with the configuration and triggering mode;

wherein the configuration and triggering information indicates a TDD mode or an FDD mode.

8. The method of claim 1, wherein when an FDD uplink carrier of a serving cell of the terminal supports a downlink transmission and the terminal does not determine a subframe for uplink/downlink distribution of the FDD uplink carrier, the method further comprises:

ignoring, by the terminal, a SRS configuration of which a triggering type is 0 without performing the SRS transmission;

or

according to downlink hybrid automatic retransmission request (HARQ) reference configuration, when a physical uplink shared channel (PUSCH) is not scheduled on a subframe which is not used as an uplink subframe and uplink pilot time slot (UpPTS), ignoring the SRS configuration of which the triggering type is 0 on the subframe without performing the SRS transmission.

9. The method of claim 1, wherein obtaining the SRS power control information comprises:

determining a power control adjustment value of the SRS on the FDD downlink carrier based on a received transmit power control (TPC) indication corresponding to the downlink carrier in a downlink control information (DCI) format;

wherein the operation of receiving the TPC indication comprises;

determining a TPC serial number of each of an uplink carrier and a downlink carrier according to higher layer signaling, and reading the TPC corresponding to the determined TPC serial number of the downlink carrier from the DCI format;

or

pre-designating a subframe carrying the DCI format corresponding to the downlink carrier and a subframe carrying the DCI format corresponding to the uplink carrier, and determining whether the TPC indication in the DCI format corresponds to the uplink carrier or the downlink carrier according to a subframe where the received DCI format is located.

10. The method of claim 1, wherein when the determined FDD downlink carrier supports a lower version terminal, the method further comprises:

obtaining the configuration and triggering information indicating that the SRS transmission was not performed on a subframe transmitting system information block (SIB), a paging signal, or a multimedia broadcast single frequency network (MBSFN) and/or on a subframe transmitting a SPS signal of the lower version terminal;

wherein the lower version terminal is a terminal which does not support the SRS transmission on the FDD downlink carrier.

11. The method of claim 4, further comprising:

receiving a higher layer signaling transmitted from the base station, wherein the higher layer signaling includes a subframe indication indicating that the SRS transmission is allowed within a configured periodicity.

13. The method of claim 9, further comprising:

receiving a channel quality indicator (CQI) measured by the terminal based on a downlink reference symbol, and combining the CQI with the channel information estimated based on the SRS to configure the downlink channel information;

or

receiving second downlink channel information between a part of antennas of the terminal and a transmitting antenna of the base station that is measured by the terminal based on a downlink reference symbol; and

combining the second downlink channel information with the channel information estimated based on the SRS to configure the downlink channel information,

wherein the part of the antennas of the terminal is a receiving antenna of the terminal that is not used as a transmitting antenna.

5-7. -7. (canceled)

12. A method for receiving an uplink sounding reference signal (SRS) and estimating a channel at a base station, comprising:

receiving the SRS from a terminal on a frequency division duplex (FDD) downlink carrier or a flexible duplex uplink carrier; and

estimating channel information based on the SRS, and configuring the channel information as first downlink channel information on the FDD downlink carrier or the flexible duplex uplink carrier.

14. (canceled)

15. A terminal device for transmitting an uplink sounding reference signal (SRS), the terminal comprising:

a controller configured to obtain configuration and triggering information of the SRS, determine a carrier and a subframe to transmit the SRS based on the configuration and triggering information, obtain power control information and determine a power value based on the obtained power control information;

wherein the carrier is a frequency division duplex (FDD) downlink carrier or a flexible duplex uplink carrier; and

a transceiver configured to transmit, to a base station, the SRS through the determined carrier and subframe with the determined power value.

18. The terminal device of claim 15, wherein when different serving cells are configured based on an FDD uplink carrier and the FDD downlink carrier, configuration and triggering information corresponding to each of the different serving cells is obtained.

19. The terminal device of claim 15, wherein the controller is configured to obtain a carrier direction indicator included in the configuration and triggering information, wherein the carrier direction indicator indicates the carrier is an uplink carrier or a downlink carrier;

or

when an FDD uplink carrier is the flexible duplex uplink carrier, determining a carrier carrying the configuration and triggering information as the carrier.

20. The terminal device of claim 15, wherein when an SRS transmission is triggered through a triggering type 1, the controller is configured to determine a carrier to transmit a data scheduling by physical layer signaling to trigger the SRS transmission as the carrier;

or

the controller is configured to determine a carrier to transmit a physical layer signaling to trigger the SRS transmission as the carrier where the SRS transmission is located;

or

wherein when an FDD uplink carrier and an FDD downlink carrier within serving cell of the terminal share a same configuration and triggering information, when the FDD uplink carrier supports an uplink transmission, the controller is configured to determine the carrier and the subframe in accordance with an FDD mode; and

when the FDD uplink carrier supports both the uplink transmission and a downlink transmission, the controller is configured to determine the carrier and the subframe in accordance with a TDD mode;

or

the controller is configured to determine the carrier and the subframe in accordance with the FDD mode;

or

the controller is configured to determine the carrier and the subframe in accordance with the TDD mode;

or

wherein when an FDD uplink carrier and an FDD downlink carrier within a serving cell of the terminal share a same configuration and triggering information, and when the terminal does not determine that the FDD uplink carrier supports a downlink transmission, the controller is configured to ignore the obtained configuration and triggering information without performing the SRS transmission;

or

wherein when an FDD uplink carrier and an FDD downlink carrier within a serving cell use different configuration and triggering information, the controller is further configured to control the transceiver to receive, from the base station, higher layer signaling corresponding to the flexible duplex uplink carrier or the FDD downlink carrier and indicating a configuration and triggering mode; and

determine the carrier and the subframe where the SRS transmission is located in accordance with the configuration and triggering mode;

wherein the configuration and triggering information indicates a TDD mode or an FDD mode.

21. The terminal device of claim 15, wherein when an FDD uplink carrier of a serving cell of the terminal supports a downlink transmission and the terminal does not determine a subframe for uplink/downlink distribution of the FDD uplink carrier, the controller is configured to ignore a SRS configuration of which a triggering type is 0 without performing the SRS transmission;

or

according to downlink hybrid automatic retransmission request (HARQ) reference configuration, when a physical uplink shared channel (PUSCH) is not scheduled on a subframe which is not used as an uplink subframe and uplink pilot time slot (UpPTS), the controller is configured to ignore the SRS configuration of which the triggering type is 0 on the subframe without performing the SRS transmission.

22. The terminal device of claim 15, wherein the controller is configured to determine a power control adjustment value of the SRS on the FDD downlink carrier based on a received transmit power control (TPC) indication corresponding to the downlink carrier in a downlink control information (DCI) format;

wherein the operation of receiving the TPC indication comprises;

the controller is configured to determine a TPC serial number of each of an uplink carrier and an downlink carrier according to higher layer signaling, and reading the TPC corresponding to the determined TPC serial number of the downlink carrier from the DCI format;

or

the controller is configured to pre-designate a subframe carrying the DCI format corresponding to the downlink carrier and a subframe carrying the DCI format corresponding to the uplink carrier, and determine whether the TPC indication in the DCI format corresponds to the uplink carrier or the downlink carrier according to a subframe where the received DCI format is located.

23. The terminal device of claim 15, wherein when the determined FDD downlink carrier supports a lower version terminal, the controller is further configured to obtain the configuration and triggering information indicating that the SRS transmission is not performed on a subframe transmitting system information block (SIB), a paging signal, or a multimedia broadcast single frequency network (MBSFN) and/or on a subframe transmitting a SPS signal of the lower version terminal;

wherein the lower version terminal is a terminal which does not support the SRS transmission on the FDD downlink carrier.

24. The terminal device of claim 23, wherein the transceiver is further configured to receive a higher layer signaling from the base station, the higher layer signaling includes a subframe indication indicating that the SRS transmission is allowed within a configured periodicity.

16. A base station device for receiving an uplink sounding reference signal (SRS) and estimating a channel, the base station comprising:

a transceiver configured to receive the SRS from a terminal on a frequency division duplex (FDD) downlink carrier or a flexible duplex uplink carrier; and

a processor configured to estimate channel information based on the SRS, to configure the channel information as first downlink channel information on the FDD downlink carrier or the flexible duplex uplink carrier.

17. The base station of claim 16, wherein the transceiver is further configured to receive a channel quality indicator (CQI) measured by the terminal based on a downlink reference symbol, and the controller is configured to combine the CQI with the channel information estimated based on the SRS to configure the downlink channel information;

or

wherein the transceiver is configured to receive second downlink channel information between a part of antennas of the terminal and a transmitting antenna of the base station that is measured by the terminal based on a downlink reference symbol, and the processor is configured to combine the second downlink channel information with the channel information estimated based on the SRS to configure the downlink channel information;

wherein the part of the antennas of the terminal is a receiving antenna of the terminal that is not used as a transmitting antenna.