METHOD AND DEVICE FOR TRANSMITTING AND RECEIVING DOWNLINK CONTROL CHANNEL FOR CONTROLLING INTER-CELL INTERFERENCE IN WIRELESS COMMUNICATION SYSTEM

• US 20130223400A1
• Filed: 11/10/2011
• Published: 08/29/2013
• Est. Priority Date: 11/12/2010
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Seo, Inkwon, Seo, Hanbyul, Kim, Kijun
• Granted Patent: US 9,144,069 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• 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 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

The present invention relates to a wireless communication system, and more particularly, to a method and device for transmitting and receiving a downlink control channel for controlling inter-cell interference in a wireless communication system. An embodiment of the present invention provides a method for transmitting a downlink control channel from a base station to a terminal, and the method may comprise: a step of determining whether a downlink subframe is of a first type or a second type; and a step in which if the downlink subframe is of the first type, the number of OFDM symbols for transmitting the downlink control channel is set to a preset value (N), and the downlink control channel is transmitted using N OFDM symbols.

Claims

1. A method of transmitting a downlink control channel, which is transmitted to a user equipment by a base station, comprising the steps of:

determining whether a downlink subframe corresponds to a first type subframe or a second type subframe;

setting a number of OFDM (orthogonal frequency division multiplexing) symbols used for a transmission of the downlink control channel to a predefined number (N) if the downlink subframe corresponds to the first type subframe, and transmitting the downlink control channel on the OFDM symbols amounting to a number equal to the N.

2. The method of claim 1, wherein information on the number of the OFDM symbols used for the transmission of the downlink control channel is not transmitted in the downlink subframe corresponding to the first type subframe.

3. The method of claim 1, further comprising the steps of:

if the downlink subframe corresponds to the second type subframe, transmitting information on the number of the OFDM symbols used for the transmission of the downlink control channel via PCFICH (physical control format indicator channel), and transmitting the downlink control channel on the OFDM symbols amounting the a number equal to the information transmitted via the PCFICH.

4. The method of claim 1, wherein the first type subframe comprises a subframe having an inter-cell interference coordination performed thereon by a neighboring cell and wherein the second type subframe comprises a subframe having the inter-cell interference coordination not performed thereon by the neighboring cell.

5. The method of claim 4, wherein the inter-cell interference coordination performed subframe comprises the subframe configured by the neighboring cell as one of ABS (almost blank subframe), MBSFN (multicast broadcast single frequency network) subframe, or ABS-with-MBSFN subframe.

6. The method of claim 1, wherein the downlink control channel comprises a PDCCH (physical downlink control channel).

7. A method of receiving a downlink control signal, which is received by a user equipment from a base station, comprising the steps of:

measuring a power of a signal received from each of a serving cell and a neighboring cell, and calculating a difference value resulting from subtracting the power of the signal received from the neighboring cell from the power of the signal received from the serving cell;

comparing the difference value to a prescribed reference value;

if the difference value is equal to or smaller than the prescribed reference value, assuming that a number of OFDM (orthogonal frequency division multiplexing) symbols used for a transmission of the downlink control channel from the serving cell as a predefined value (N), and decoding the downlink control channel on the OFDM symbols amounting to a number equal to the N.

8. The method of claim 7, further comprising the steps of:

if the difference value is greater than the prescribed reference value, obtaining information on the number of the OFDM symbols used for the transmission of the downlink control channel by decoding PCFICH (physical control format indicator channel) from the serving cell; and

decoding the downlink control channel on the OFDM symbols amounting to a number equal to the information obtained via the PCFICH.

9. The method of claim 7, wherein the prescribed reference value is determined based on an SINR (signal-to-interference plus noise ratio) meeting a decoding condition of the PCFICH from the serving cell.

10. The method of claim 7, wherein the prescribed reference value is determined based on a reception power difference value for determining whether to operate a handover.

11. The method of claim 10, wherein the prescribed reference value is set to either a value higher than a reception power difference value for determining whether to operate a handover into the neighboring cell from the serving cell in a range expansion area of the serving cell or a value lower than a reception power difference value for determining whether to operate the handover into the neighboring cell from the serving cell in a range expansion area of the neighboring cell

12. The method of claim 7, wherein a result of measuring the power of the signal received from each of the serving cell and the neighboring cell is reported to the base station.

13. The method of claim 7, wherein the downlink control channel comprises a PDCCH (physical downlink control channel).

14. A base station, which transmits a downlink control channel, comprising:

a receiving module configured to receive an uplink signal from a user equipment;

a transmitting module configured to transmit a downlink signal to the user equipment; and

a processor configured to control the base station including the receiving module and the transmitting module, the processor configured to determine whether a downlink subframe corresponds to a first type subframe or a second type subframe, the processor configured to set a number of OFDM (orthogonal frequency division multiplexing) symbols used for a transmission of the downlink control channel to a predefined number (N) if the downlink subframe corresponds to the first type subframe, the processor configured to transmit the downlink control channel on the OFDM symbols amounting to a number equal to the N.

15. A user equipment, which receives a downlink control channel, comprising:

a receiving module configured to receive a downlink signal from a base station;

a transmitting module configured to transmit an uplink signal to the base station; and

a processor configured to control the user equipment including the receiving module and the transmitting module, the processor configured to measure a power of a signal received from each of a serving cell and a neighboring cell, the processor configured to calculate a difference value resulting from subtracting the power of the signal received from the neighboring cell from the power of the signal received from the serving cell, the processor configured to compare the difference value to a prescribed reference value, the processor configured to assume that a number of OFDM (orthogonal frequency division multiplexing) symbols used for a transmission of the downlink control channel from the serving cell as a predefined value (N) if the difference value is equal to or smaller than the prescribed reference value, the processor configured to decode the downlink control channel on the OFDM symbols amounting to a number equal to the N.