USER TERMINAL, RADIO BASE STATION, DOWNLINK CONTROL CHANNEL RECEIVING METHOD AND MOBILE COMMUNICATION SYSTEM

• US 20140086201A1
• Filed: 04/24/2012
• Published: 03/27/2014
• Est. Priority Date: 05/02/2011
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Nagata, Satoshi, Abe, Tetsushi, Kishiyama, Yoshihisa, Takeda, Kazuaki
• Granted Patent: US 9,806,834 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04J 1/02 Details
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

The present invention is designed such that it is possible to optimize the effect of improving the efficiency of use of radio resources even when the number of user terminals to be multiplexed over the same radio resources is further increased. A user terminal performs downlink communication with a radio base station using a PDCCH resource region and a PDSCH resource region. The user terminal detects the starting position of the radio resources where the PDSCH and the PDCCH are frequency-division-multiplexed in the PDSCH resource region in the time direction, and receives the PDCCH that is frequency-division-multiplexed over the radio resources starting from the detected starting position.

Claims

1. A user terminal that performs downlink communication with a radio base station using a resource region for a downlink control channel and a resource region for a downlink shared channel, the user terminal comprising:

a detection section configured to detect a starting position of a radio resource where the downlink shared channel and the downlink control channel are frequency-division-multiplexed, in a time direction, in the resource region for the downlink shared channel; and

a receiving section configured to detect the downlink control channel that is frequency-division-multiplexed in the radio resource starting from the starting position detected in the detection section.

2. The user terminal according to claim 1, wherein:

the receiving section is configured to receive the number of OFDM symbols to constitute the resource region for the downlink control channel, from the radio base station; and

the detection section is configured to detect the starting position based on the number of OFDM symbols received in the receiving section.

3. The user terminal according to claim 1, wherein:

the receiving section is configured to receive identification information which identifies whether or not the number of OFDM symbols to be allocated to a delivery acknowledgement channel in the resource region for the downlink control channel is extended, from the radio base station; and

the detection section detects the starting position based on the identification information received in the receiving section.

4. The user terminal according to claim 1, wherein:

the receiving section receive is configured to an allocation starting position of a downlink shared channel that is allocated to a different component carrier by cross-carrier scheduling; and

the detection section is configured to detect the starting position based on the allocation starting position received in the receiving section.

5. A radio base station that performs downlink communication with a user terminal using a resource region for a downlink control channel and a resource region for a downlink shared channel, the radio base station comprising:

a multiplexing section configured to frequency-division-multiplex the downlink shared channel and the downlink control channel over a radio resource starting from a predetermined starting position in a time direction, in the resource region for the downlink shared channel; and

a transmission section configured to transmit the downlink control channel and the downlink shared channel that are frequency-division-multiplexed.

6. The radio base station according to claim 5, wherein the multiplexing section is configured to regard a (the number of OFDM symbols constituting the resource region for the downlink control channel+1)-th OFDM symbol as the predetermined starting position and to frequency-division-multiplex the downlink shared channel and the downlink control channel.

7. The radio base station according to claim 5, wherein, when the number of OFDM symbols to be allocated to a delivery acknowledgement channel in the resource region for the downlink control channel is extended, the multiplexing section is configured to regard a fourth OFDM symbol as the predetermined starting position and to frequency-division-multiplex the downlink shared channel and the downlink control channel.

8. The radio base station according to claim 5, wherein, when a downlink shared channel is allocated to a different component carrier by cross-carrier scheduling, the multiplexing section is configured to regard an allocation starting position of the downlink shared channel in the different component carrier as the predetermined starting position and to frequency-division-multiplex the downlink shared channel and the downlink control channel.

9. A method of receiving a downlink control channel using a resource region for a downlink control channel and a resource region for a downlink shared channel, the method comprising the steps of:

in a radio base station, frequency-division-multiplexing the downlink shared channel and the downlink control channel over a radio resource in the resource region for the downlink shared channel;

in a user terminal, detecting a starting position of the radio resources where the downlink shared channel and the downlink control channel are frequency-division-multiplexed, in a time direction; and

in the user terminal, receiving the downlink control channel that is frequency-division-multiplexed over the radio resource starting from the detected starting position.

10. A mobile communication system for performing downlink communication using a subframe having a resource region for a downlink control channel and a resource region for a downlink shared channel, the mobile communication system comprising:

in a radio base station, frequency-division-multiplexing the downlink shared channel and the downlink control channel over a radio resource in the resource region for the downlink shared channel;

in a user terminal, detecting a starting position of the radio resources where the downlink shared channel and the downlink control channel are frequency-division-multiplexed, in a time direction; and

in the user terminal, receiving the downlink control channel that is frequency-division-multiplexed over the radio resource starting from the detected starting position.