Method and an apparatus for providing channel quality information in a wireless communication system

Patent metadata

Field	Value
Publication number	US-9722749-B2
Application number	US-201615048569-A
Country	US
Kind code	B2
Filing date	Feb 19, 2016
Priority date	Jan 18, 2010
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A method for transmitting channel quality information for a downlink channel; a user equipment (UE) therefore; a method for receiving channel quality information for a downlink channel; and a base station therefore are discussed. The method for transmitting channel quality information for a downlink channel includes according to one embodiment receiving, by a user equipment (UE), configuration information on periodic channel state information (CSI) reporting by higher layer signaling; determining, by the UE, a channel quality information index at least based on a number of a specific resource element; and transmitting the determined channel quality information index to a base station. The number of the specific resource element is determined based on a UE-specific reference signal overhead. A resource element allocated for a Channel Status Information-Reference Signal (CSI-RS) is regarded as the specific resource element regardless of transmitting the CSI-RS.

First claim

What is claimed is:

1. A method for transmitting channel quality information for a downlink channel, the method comprising:
receiving, by a user equipment (UE), configuration information on periodic channel state information (CSI) reporting by higher layer signaling;
determining, by the UE, a channel quality information index at least based on a number of a specific resource element; and
transmitting the determined channel quality information index to a base station,
wherein the number of the specific resource element is determined based on a UE-specific reference signal overhead, and
wherein a resource element allocated for a Channel Status Information-Reference Signal (CSI-RS) is regarded as the specific resource element regardless of transmitting the CSI-RS.

2. The method of claim 1 , wherein the UE-specific reference signal overhead is determined according to a rank value,
wherein the UE-specific reference signal overhead within one resource block for one subframe is 12 resource elements for the rank value of 1 or 2, and
wherein the UE-specific reference signal overhead within one resource block for one subframe is 24 resource elements for the rank value of 3, 4, 5, 6, 7 or 8.

3. The method of claim 1 , wherein the UE is configured for reporting at least one of a Precoding Matrix Indicator (PMI) or a Rank Indication (RI).

4. The method of claim 1 , wherein the configuration information on periodic CSI reporting includes a transmission period of channel information and an offset for the transmission period in subframe units.

5. The method of claim 1 , wherein the determined channel quality information index is transmitted to the base station on a Physical Uplink Control Channel (PUCCH).

6. A user equipment (UE) for transmitting channel quality information for a downlink channel, the UE comprising:
a receiver configured to receive a downlink signal from a base station;
a transmitter configured to transmit an uplink signal to the base station; and
a processor connected to the receiver and the transmitter and configured to control operations of the UE,
wherein the processor is further configured to:
control the receiver to receive configuration information on periodic channel state information (CSI) reporting by higher layer signaling,
determine a channel quality information index at least based on a number of a specific resource element, and
control the transmitter to transmit the determined channel quality information index,

wherein the number of the specific resource element is determined based on a UE-specific reference signal overhead, and
wherein a resource element allocated for a Channel Status Information-Reference Signal (CSI-RS) is regarded as the specific resource element regardless of transmitting the CSI-RS.

7. The UE of claim 6 , wherein the UE-specific reference signal overhead is determined according to a rank value,
wherein the UE-specific reference signal overhead within one resource block for one subframe is 12 resource elements for the rank value of 1 or 2, and
wherein the UE-specific reference signal overhead within one resource block for one subframe is 24 resource elements for the rank value of 3, 4, 5, 6, 7 or 8.

8. The UE of claim 6 , wherein the UE is configured for reporting at least one of a Precoding Matrix Indicator (PMI) or a Rank Indication (RI).

9. The UE of claim 6 , wherein the configuration information on periodic CSI reporting includes a transmission period of channel information and an offset for the transmission period in subframe units.

10. The UE of claim 6 , wherein the determined channel quality information index is transmitted to the base station on a Physical Uplink Control Channel (PUCCH).

11. A method for receiving channel quality information for a downlink channel, the method comprising:
transmitting, by a base station to a user equipment (UE), configuration information on periodic channel state information (CSI) reporting by higher layer signaling; and
receiving, by the base station, a channel quality information index,
wherein the channel quality information index is determined by the UE at least based on a number of a specific resource element,
wherein the number of the specific resource element is determined based on a UE-specific reference signal overhead, and
wherein a resource element allocated for a Channel Status Information-Reference Signal (CSI-RS) is regarded as the specific resource element regardless of transmitting the CSI-RS.

12. A base station for receiving channel quality information for a downlink channel, the base station comprising:
a receiver configured to receive an uplink signal from a user equipment (UE);
a transmitter configured to transmit a downlink signal to the UE; and
a processor connected to the receiver and the transmitter so as to control operations of the base station,
wherein the processor is further configured to:
control the transmitter to transmit, to the UE, configuration information on periodic channel state information (CSI) reporting by higher layer signaling, and
control the receiver to receive a channel quality information index, wherein the channel quality information index is determined by the UE at least based on a number of a specific resource element,

wherein the number of the specific resource element is determined based on a UE-specific reference signal overhead, and
wherein a resource element allocated for a Channel Status Information-Reference Signal (CSI-RS) is regarded as the specific resource element regardless of transmitting the CSI-RS.

Assignees

• Lg Electronics Inc

Inventors

• Seo In Kwon
• Lee Dae Won
• Kim Ki Jun

Classifications

• H04W72/21

  in the uplink direction of a wireless link, i.e. towards the network · CPC title

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04L5/0051

  of dedicated pilots, i.e. pilots destined for a single user or terminal · CPC title

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04W88/08

  Access point devices · CPC title