Method and apparatus for communicating by using different types of carriers in radio communication system supporting carrier aggregation

• US 9,326,281 B2
• Filed: 02/28/2013
• Issued: 04/26/2016
• Est. Priority Date: 02/28/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Bonghoe, Seo, Dongyoun, Yang, Suckchel, Ahn, Joonkui
• Primary Examiner(s): Lai, Andrew
• Assistant Examiner(s): LEE, ANDREW CHUNG CHEUNG
• Application Number:
  US14/380,664
• Publication Number:
  US 20150049687A1
• Time in Patent Office: 1,153 Days
• Field of Search: 370204-215, 370/252, 370310-337
• US Class Current: 1/1
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/16 Involving different core network technologies, e.g. a packet-switched [PS] bearer in combination with a circuit-switched [CS] bearer
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states

Abstract

Provided through the present application are a method and an apparatus for use in a radio communication system, which supports carrier aggregation and carries out communication in subframe units. More specifically, user equipment operating in a first type carrier for receiving from a base station, a first piece of control information, which is related to the first type carrier and a second type carrier that support the carrier aggregation, can measure a radio signal to carry out radio resource management with respect to the first type carrier by using a first reference signal, which is included in the first type carrier, and/or a second reference signal, which is included in the second type carrier.

Claims

1. A method of performing communication between a user equipment (UE) and a base station in a radio communication system which supports carrier aggregation and performs communication in subframe units, the method comprising:

receiving, from a base station, first control information which supports the carrier aggregation and is related to a first type carrier and a second type carrier;

measuring a radio signal by using at least one of a first reference signal included in the first type carrier and a second reference signal included in the second type carrier in order for the UE which operates in the first type carrier to perform radio resource management for the first type carrier; and

transmitting a result of measuring the radio signal to the base station, wherein the first type carrier does not contain a synchronization signal,

wherein the UE, which operates in the first type carrier, maintains synchronization for the first type carrier by using a synchronization signal included in the second type carrier,

wherein the first reference signal is at least one of a channel state information reference signal (CSI-RS) and a cell specific reference signal (CRS) which are related to the first type carrier,

wherein the second reference signal is at least one of a channel state information reference signal (CSI-RS) and a cell specific reference signal (CRS) which are related to the second type carrier, and

wherein a cell specific reference signal (CRS) is included in only some of all subframes in the first type carrier.

2. The method of claim 1, wherein the first type carrier is a synchronized carrier, and the second type carrier is a synchronization reference carrier,

wherein the synchronization signal includes a primary synchronization signal (PSS) and a secondary synchronization signal (SSS),

wherein a physical downlink control channel (PDCCH) is not included in the first type carrier, and

wherein a PDCCH or an enhanced PDCCH is included in all subframes in the second type carrier.

3. The method of claim 1, wherein the first type carrier is a synchronized carrier, and the second type carrier is a synchronization reference carrier,

wherein the synchronization signal includes a primary synchronization signal (PSS) and a secondary synchronization signal (SSS),

wherein the first type carrier does not include a physical downlink control channel (PDCCH), and

wherein the second type carrier includes the PDCCH and a cell specific reference signal (CRS) in all subframes.

4. The method of claim 1, wherein the UE, which operates in the first type carrier, calculates at least one of a reference signal received power (RSRP), a reference signal received quality (RSRQ), and a path loss by using at least one of the first reference signal and the second reference signal.

5. The method of claim 1, wherein the UE, which operates in the first type carrier, calculates the RSRP by using only the second reference signal, and interference measurement for measuring the RSRQ is calculated by using only the first reference signal.

6. The method of claim 1, further comprising:

receiving, from the base station, second control information which indicates configuring or activating at least one of the first type carrier and the second type carrier as a secondary cell, wherein the configuration or activation is performed based on the result of measurement.

7. The method of claim 6, wherein, when one of the first type carrier and the second type carrier is configured or activated as a secondary cell, the first type carrier and the second type carrier are simultaneously configured or activated as the secondary cell.

8. The method of claim 5, wherein a length of a cyclic shift (cyclic prefix) which is applied to the first type carrier is set to be the same or longer than the length of the cyclic shift which is applied to the second type carrier.

9. The method of claim 6, further comprising:

receiving a signal, from the base station, which indicates a primary cell ID as a physical cell ID.

10. The method of claim 6, wherein, after the first type carrier and the second type carrier are activated, if the second type carrier is deactivated, the first type carrier is deactivated simultaneously with the second type carrier.

11. The method of claim 1, further comprising:

determining whether synchronization of the first type carrier is maintained,

wherein the first type carrier does not include a physical downlink control channel (PDCCH),

wherein a downlink radio link quality is measured by using a channel state information reference signal (CSI-RS) which is related to the first type carrier, and it is determined whether synchronization of the first type carrier is maintained according to the measured downlink radio link quality.