Adaptation of control signaling transmissions to variations in respective resources

A method for a base station communicating with a user equipment (UE) to transmit control information on an enhanced physical downlink control channel (EPDCCH), the method comprising:

• transmitting configuration information indicating whether the UE monitors the one or more EPDCCH candidates in a specific subframe via higher layer signaling, wherein the configuration information comprises information on a bitmap and a bitmap size is associated with a number of subframes;
• determining a number of available resource elements (REs), the available REs being available to transmit the EPDCCH;
• generating the EPDCCH based on a first number or a second number of one or more EPDCCH candidates based on the determined number of the available REs, the first number and the second number being a number of the one or more EPDCCH candidates to monitor;
• transmitting the control information on the generated one or more EPDCCH candidates;
• and
• receiving or transmitting data scheduled by the transmitted control information from and to the UE,
• wherein the EPDCCH is generated based on the first number of the one or more EPDCCH candidates, if the number of the available REs is smaller than a predetermined number.

A user equipment (UE) apparatus for receiving control information on an enhanced physical downlink control channel (EPDCCH), the UE comprising:

• a receiver;
• a transmitter;
• and
• at least one processor configured to:
• receive configuration information indicating whether the UE monitors the one or more EPDCCH candidates in a specific subframe via higher layer signaling, wherein the configuration information comprises information on a bitmap and a bitmap size is associated with a number of subframes;
• determine a number of available resource elements (REs), the available REs being available to transmit the EPDCCH,
• select a first number or a second number of one or more EPDCCH candidates based on the determined number of the available REs, the first number and the second number being a number of the one or more EPDCCH candidates to monitor,
• monitor the one or more EPDCCH candidates based on the selected number to obtain the control information, and
• receive or transmit data scheduled by the obtained control information from and to the base station,
• wherein the first number of the one or more EPDCCH candidates is selected, if the number of the available REs is smaller than a predetermined number.

A base station apparatus for transmitting control information on an enhanced physical downlink control channel (EPDCCH), the base station comprising:

• a receiver;
• a transmitter;
• and
• at least one processor configured to:
• transmit configuration information indicating whether the UE monitors the one or more EPDCCH candidates in a specific subframe via higher layer signaling, wherein the configuration information comprises information on a bitmap and a bitmap size is associated with a number of subframes,
• determine a number of available resource elements (REs), the available REs being available to transmit the EPDCCH,
• generate the EPDCCH based on a first number or a second number of one or more EPDCCH candidates based on the determined number of the available REs, the first number and the second number being a number of the one or more EPDCCH candidates to monitor,
• transmit the control information on the generated one or more EPDCCH candidates, and
• receive or transmit data scheduled by the transmitted control information from and to the UE,
• wherein the EPDCCH is generated based on the first number of the one or more EPDCCH candidates, if the number of the available REs is smaller than a predetermined number.