User apparatus, base station, control information detection method and control information transmission method

A base station that performs communication with a user apparatus in a mobile communication system, comprising:

• a mapping unit configured to map control information, addressed to the user apparatus, to a predetermined area in a time frequency resource of a downlink control channel;
• and
• a transmission unit configured to transmit the control information, as a radio signal, by a downlink control channel using a time frequency resource of the predetermined area,
• wherein the predetermined area is an area among a plurality of candidate areas where blind decoding is performed for detecting the control information in the user apparatus,
• the plurality of candidate areas are divided into a common candidate area where a plurality of user apparatuses commonly perform blind decoding and an individual candidate area for the user apparatus, and
• the mapping unit selects the predetermined area from the individual candidate area during a period when the user apparatus monitors a random access response.

A control information detection method executed by a user apparatus that communicates with a base station in a mobile communication system, comprising:

• a reception step of receiving a radio signal from the base station by a downlink control channel;
• and
• a control information detection step of detecting control information, addressed to the user apparatus, mapped to a predetermined area in a time frequency resource of the downlink control channel by performing blind decoding in a plurality of candidate areas which are candidates of the predetermined area,
• wherein, the plurality of candidate areas are divided into a common candidate area where a plurality of user apparatuses commonly perform blind decoding and an individual candidate area for the user apparatus, and
• in the control information detection step, the user apparatus performs blind decoding in the individual candidate area without performing blind decoding in the common candidate area during a period when the user apparatus monitors a random access response.

A control information transmission method executed by a base station that performs communication with a user apparatus in a mobile communication system, comprising:

• a mapping step of mapping control information, addressed to the user apparatus, to a predetermined area in a time frequency resource of a downlink control channel;
• and
• a transmission step of transmitting the control information, as a radio signal, by a downlink control channel using a time frequency resource of the predetermined area,
• wherein the predetermined area is an area among a plurality of candidate areas where blind decoding is performed for detecting the control information in the user apparatus,
• the plurality of candidate areas are divided into a common candidate area where a plurality of user apparatuses commonly perform blind decoding and an individual candidate area for the user apparatus, and
• in the mapping step, the base station selects the predetermined area from the individual candidate area during a period when the user apparatus monitors a random access response.