Channel-sounding method using a plurality of antennas, and apparatus for same

Patent metadata

Field	Value
Publication number	US-9270356-B2
Application number	US-201013258428-A
Country	US
Kind code	B2
Filing date	Mar 22, 2010
Priority date	Mar 22, 2009
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

The present invention relates to a wireless communication system. More particularly, the present invention relates to a method and to an apparatus for transmitting an SRS in a multi-antenna system. The method comprises the steps of: acquiring specific information for discriminating a first antenna group and a second antenna group from among a plurality of antennas, wherein said first antenna group includes one or more antennas which are set to a turned-on state to perform communication with a base station, and said second antenna group includes one or more other antennas which are set to a turned-off state; transmitting an SRS to the base station if a predetermined condition is satisfied, under the condition that the second antenna group is set to the turned-off state; and setting the second antenna group to a turned-off state after the transmission of the SRS.

First claim

The invention claimed is:

1. A method of transmitting sounding reference signals in a wireless communication system, the method comprising:
generating, by a user equipment (UE), sounding reference sequences for multiple antenna ports of the UE,
wherein each sounding reference sequence is defined using a base sequence number and a cyclic shift value;
mapping, by the UE, each sounding reference sequence to resource elements of a corresponding antenna port of the multiple antenna ports on a single carrier frequency division multiple access (SC-FDMA) symbol of a subframe; and
transmitting, by the UE, the sounding reference sequences for the multiple antenna ports within the SC-FDMA symbol of the subframe,
wherein sounding reference sequences for a first group of antenna ports among the multiple antenna ports are mapped to a first set of every two resource elements in the SC-FDMA symbol of the subframe,
wherein sounding reference sequences for a second group of antenna ports among the multiple antenna ports are mapped to a second set of every two resource elements in the SC-FDMA symbol of the subframe, the second set being different from the first set,
wherein the cyclic shift value is defined for each antenna port within N cyclic shift values based on a signaled value and an offset corresponding to each antenna port of the multiple antenna ports, and
wherein N is a predetermined positive integer equal to or greater than 2.

2. The method of claim 1 , wherein the SC-FDMA symbol is a last SC-FDMA symbol of the subframe.

3. A method of processing sounding reference signals in a wireless communication system, the method comprising:
receiving, by a base station (BS), sounding reference sequences for multiple antenna ports of a user equipment (UE) on resource elements of a single carrier frequency division multiple access (SC-FDMA) symbol of a subframe,
wherein each sounding reference sequence is defined using a base sequence number and a cyclic shift value; and
de-mapping, by the BS, each sounding reference sequence from the resource elements of a corresponding antenna port of the multiple antenna ports on the SC-FDMA symbol of the subframe,
wherein sounding reference sequences for a first group of antenna ports among the multiple antenna ports are de-mapped from a first set of every two resource elements in the SCFDMA symbol of the subframe,
wherein sounding reference sequences for a second group of antenna ports among the multiple antenna ports are de-mapped from a second set of every two resource elements in the SC-FDMA symbol of the subframe, the second set being different from the first set,
wherein the cyclic shift value is defined for each antenna port within N cyclic shift values based on a signaled value and an offset corresponding to each antenna port of the multiple antenna ports, and
wherein N is a predetermined positive integer equal to or greater than 2.

4. The method of claim 3 , wherein the SC-FDMA symbol is a last SC-FDMA symbol of the subframe.

5. The method of claim 3 , further comprising:
estimating an uplink channel state using the de-mapped sounding reference sequences.

6. A user equipment (UE) for use in a wireless communication system, the UE comprising:
a radio frequency (RF) unit configured to transmit signals; and
a processor, configured to:
generate sounding reference sequences for multiple antenna ports of the UE,
wherein each sounding reference sequence is defined using a base sequence number and a cyclic shift value;
map each sounding reference sequence to resource elements of a corresponding antenna port of the multiple antenna ports on a single carrier frequency division multiple access (SC-FDMA) symbol of a subframe; and
transmit the sounding reference sequences for the multiple antenna ports within the SC-FDMA symbol of the subframe,
wherein sounding reference sequences for a first group of antenna ports among the multiple antenna ports are mapped to a first set of every two resource elements in the SC-FDMA symbol of the subframe,
wherein sounding reference sequences for a second group of antenna ports among the multiple antenna ports are mapped to a second set of every two resource elements in the SC-FDMA symbol of the subframe, the second set being different from the first set,
wherein the cyclic shift value is defined for each antenna port within N cyclic shift values based on a signaled value and an offset corresponding to each antenna port of the multiple antenna ports, and
wherein N is a predetermined positive integer equal to or greater than 2.

7. The UE of claim 6 , wherein the SC-FDMA symbol is a last SC-FDMA symbol of the subframe.

8. A base station (BS) for use in a wireless communication system, the BS comprising:
a radio frequency (RF) unit configured to transmit signals; and
a processor configured to:
receive sounding reference sequences for multiple antenna ports of a user equipment (UE) on resource elements of a single carrier frequency division multiple access (SC-FDMA) symbol of a subframe,
wherein each sounding reference sequence is defined using a base sequence number and a cyclic shift value; and
de-map each sounding reference sequence from the resource elements of a corresponding antenna port of the multiple antenna ports on the SC-FDMA symbol of the subframe,
wherein sounding reference sequences for a first group of antenna ports among the multiple antenna ports are de-mapped from a first set of every two resource elements in the SCFDMA symbol of the subframe,
wherein sounding reference sequences for a second group of antenna ports among the multiple antenna ports are de-mapped from a second set of every two resource elements in the SC-FDMA symbol of the subframe, the second set being different from the first set,
wherein the cyclic shift value is defined for each antenna port within N cyclic shift values based on a signaled value and an offset corresponding to each antenna port of the multiple antenna ports, and
wherein N is a predetermined positive integer equal to or greater than 2.

9. The BS of claim 8 , wherein the SC-FDMA symbol is a last SC-FDMA symbol of the subframe.

10. The BS of claim 8 , wherein the processor is further configured to estimate an uplink channel state using the de-mapped sounding-reference sequences.

Assignees

• Chung Jae Hoon
• Kwon Yeong Hyeon
• Han Seung Hee
• Noh Min Seok
• Lg Electronics Inc

Inventors

• Chung Jae Hoon
• Kwon Yeong Hyeon
• Han Seung Hee
• Noh Min Seok

Classifications

• H04W72/20

  Control channels or signalling for resource management · CPC title

• H04W76/27

  Transitions between radio resource control [RRC] states · CPC title

• H04L5/0053

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04B7/0693

  switching off a diversity branch, e.g. to save power · CPC title

• H04L1/0026

  Transmission of channel quality indication · CPC title