Communication apparatus and communication method

• US 9,775,167 B2
• Filed: 12/06/2016
• Issued: 09/26/2017
• Est. Priority Date: 08/12/2011
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Sun Patent Trust
• Inventors: Horiuchi, Ayako, Nishio, Akihiko
• Primary Examiner(s): Nguyen, Brian D
• Assistant Examiner(s): NGUYEN, TOAN D
• Application Number:
  US15/370,814
• Publication Number:
  US 20170086218A1
• Time in Patent Office: 294 Days
• CPC Class Codes: H04L 1/0006 by adapting the transmission format
• CPC Class Codes: H04L 1/0046 Code rate detection or code type detection H04L1/0038 takes precedence; detection of the data rate H04L25/0262; for packet format H04L1/0091
• 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 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/1273 of downlink data flows
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

In a base station (100), a division number calculating unit (103) calculates the division number of a PRB pair on the basis of a first number of REs capable of mapping an allocation control signal, a second number of REs capable of mapping signals other than the allocation control signal, and a reference value, which is the number of REs satisfying the reception quality request in a terminal (200) for the allocation control signal, in each PRB pair. Then, a control signal mapping control unit (104) determines a search space by determining a control channel element group constituting a plurality of mapping unit resource region candidates within a CCE group obtained by separating each PRB pair contained in a first group into the same number as the division number.

Claims

1. A communication apparatus comprising:

a receiver which, in operation, receives a signal including downlink control information;

a controller which, in operation, sets a division number based on a number of OFDM symbols used for an Enhanced Physical Downlink Control CHannel (EPDCCH), the division number being a number of Control Channel Elements (CCEs) per resource block pair, and, in operation, specifies a plurality of resource region candidates by using the division number, each resource region candidate including at least one CCE, wherein the controller, in operation, sets the division number such that the division number for a subframe having a Normal cyclic prefix length is larger than the division number for a subframe having an Extended cyclic prefix length; and

a decoder which, in operation, decodes the plurality of resource region candidates to obtain the downlink control information.

2. The communication apparatus according to claim 1, wherein the EPDCCH is a resource region that is defined in a data region of a subframe and that is configured to transmit either of the downlink control information and downlink data.

3. The communication apparatus according to claim 1, wherein

the controller, in operation, sets the division number such that the division number for a downlink normal subframe is larger than the division number for a special subframe having a gap period for switching between a downlink and an uplink.

4. The communication apparatus according to claim 1, wherein

the resource block pair comprises two slots.

5. The communication apparatus according to claim 1, wherein

each CCE includes a plurality of resource elements.

6. The communication apparatus according to claim 1, wherein

the division number is acquired by dividing a specified number by a number of resource elements included in one CCE.

7. A communication method comprising:

receiving a signal including downlink control information;

setting a division number based on a number of OFDM symbols used for an Enhanced Physical Downlink Control CHannel (EPDCCH), the division number being a number of Control Channel Elements (CCEs) per resource block pair, and specifying a plurality of resource region candidates by using the division number, each resource region candidate including at least one CCE, wherein the division number is set such that the division number for a subframe having a Normal cyclic prefix length is larger than the division number for a subframe having an Extended cyclic prefix length; and

decoding the plurality of resource region candidates to obtain the downlink control information.

8. The communication method according to claim 7, wherein the EPDCCH is a resource region that is defined in a data region of a subframe and that is configured to transmit either of the downlink control information and downlink data.

9. The communication method according to claim 7, wherein

the division number is set such that the division number for a downlink normal subframe is larger than the division number for a special subframe having a gap period for switching between a downlink and an uplink.

10. The communication method according to claim 7, wherein

the resource block pair comprises two slots.

11. The communication method according to claim 7, wherein

each CCE includes a plurality of resource elements.

12. The communication method according to claim 7, wherein

the division number is acquired by dividing a specified number by a number of resource elements included in one CCE.