DL control channel structure enhancement

An apparatus, comprising:

• at least one processor;
• and
• at least one memory including computer program code,
• the at least one memory and the computer program code configured to, with the at least one processor and in response to execution of the computer program code, cause the apparatus to perform at least the following:
• signaling a user equipment to indicate whether the user equipment is to access one or both of a first downlink control region in a downlink subframe and an enhanced downlink control region in the downlink subframe, wherein the downlink subframe has a downlink transmission bandwidth and a time duration;
• placing in the first downlink control region a common downlink control channel message corresponding to at least the user equipment;
• in response to signaling indicating the user equipment is to access the first downlink control region, placing in the first downlink control region a downlink control channel message corresponding to the user equipment and comprising quadruplets of contiguous subcarriers spread over a plurality of physical resource blocks spread over the whole downlink transmission bandwidth for the first downlink control region, each quadruplet occupying a portion but not all of a physical resource block, and depending on the downlink control channel message placing or not placing a portion specific to the user equipment of a first physical downlink shared channel in the downlink subframe;
• in response to signaling indicating the user equipment is to access the enhanced downlink control region, placing in the enhanced downlink control region a downlink control channel message corresponding to the user equipment and comprising a plurality of subcarriers occupying one or more physical resource blocks contiguous in one or both of time and frequency, and depending on the determined downlink control channel message, placing or not placing a portion specific to the user equipment of a second physical downlink shared channel in the downlink subframe;
• and
• transmitting the subframe.