Communications device, infrastructure equipment and methods for receiving downlink control information
A communications device transmitting/receiving data to/from a mobile communications network includes a transmitter to transmit data to the mobile communications network via a wireless access interface, a receiver to receive data from the mobile communications network via the wireless access interface, and a controller. The wireless access interface includes plural time divided temporal units and in each temporal unit a down-link control channel and a down-link shared channel. The temporal units may be sub-frames of an LTE carrier. The controller can control the receiver to receive downlink control channel information transmitted by the mobile communications network in one or more control channel elements of the downlink control channel, and to receive the downlink control channel information by searching the downlink control channel in a predetermined sub-set of plural possible sets of control channel elements in one or more of the temporal units according to a fixed aggregation level.
1. A communications device for transmitting data to or receiving data from a mobile communications network, the communications device comprising:
circuitry configured to
transmit data to the mobile communications network via a wireless access interface provided by the mobile communications network;
receive data from the mobile communications network via the wireless access interface, the data provided in a radio frame that is divided into a plurality of time divided temporal units with a downlink control channel and a downlink shared channel included in each temporal unit; and
receive downlink control channel information transmitted by the mobile communications network in one or more control channel elements of the downlink control channel included in the radio frame, wherein the one or more control channel elements in which the downlink control channel information is transmitted is one of a plurality of sets of possible control channel elements in which the mobile communications network can transmit the downlink control information in one of the temporal units of the radio frame for the communications device to search for the downlink control information in each of the plurality of possible sets of control channel elements, wherein
the circuitry is configured to receive the downlink control channel information by searching the downlink control channel in a search space that includes at least one of (i) a predetermined sub-set of the plurality of possible sets of control channel elements in one or more of the temporal units of the radio frame according to a fixed aggregation level, and (ii) a second sub-set of possible control channel elements which is selected from the plurality of possible sets of the control channel elements in one or more temporal units according to a configurable aggregation level.
2. The communications device of claim 1 , wherein
the circuitry is configured to receive an indication, from the mobile communications network, of the second sub-set of possible sets of control channel elements for the one or more temporal units of the radio frame providing the configurable aggregation level.
3. The communications device of claim 1 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of the control channel elements is common for one or more other communications devices.
4. The communications device of claim 1 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of the control channel elements is specific to the communications device.
5. The communications device of claim 1 , wherein
each of the control channel elements of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of the control channel elements each comprise enhanced control channel elements of an enhanced downlink control channel.
6. The communications device of claim 1 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of the control channel elements changes from one of the plurality of possible sets of control channel elements to another of the plurality of possible sets of control channel elements from one of the temporal-units to another.
7. The communications device of claim 1 , wherein
the searching for the downlink control channel information in the predetermined sub-set of the plurality of possible sets of control channel elements according to the fixed aggregation level comprises searching a set of one or more control channel elements from the sub-set of possible sets of control channel elements in a temporal unit of the wireless access interface.
8. A method of receiving down link control information at a communications device from a mobile communications network, the method comprising:
receiving, via a wireless access interface, downlink control channel information transmitted by the mobile communications network in one or more control channel elements of a downlink control channel of a radio frame a plurality of temporal units, the wireless access interface being provided by the mobile communications network for transmitting data to or receiving data from the communications device, the radio frame being divided into a plurality of time divided temporal units with the downlink control channel and a downlink shared channel included in each temporal unit, wherein the one or more control channel elements in which the downlink control channel information is transmitted is one of a plurality of sets of possible control channel elements in which the mobile communications network can transmit the downlink control information in one of the temporal units of the radio frame for the communications devices to search for the downlink control information in each of the plurality of possible sets of control channel elements, wherein
the receiving comprises searching for the downlink control channel information by searching in a search space that includes at least one of (i) a predetermined sub-set of the plurality of possible sets of control channel elements in the downlink control channel for one or more of the temporal units of the radio frame according to a fixed aggregation level, and (ii) a second sub-set of possible control channel elements which is selected from the plurality of possible sets of the control channel elements in one or more temporal units according to a configurable aggregation level.
9. The method of claim 8 , further comprising:
receiving an indication, from the mobile communications network, of the second sub-set of possible sets of control channel elements for the one or more temporal units of the radio frame providing the configurable aggregation level.
10. The method of claim 9 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of control channel elements is common for one or more other communications devices.
11. The method of claim 8 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible set of control channel elements is specific to the communications device.
12. The method of claim 8 , wherein
each of the control channel elements of the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of control channel elements is an enhanced control channel element of an enhanced downlink control channel.
13. The method of claim 8 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of control channel elements changes from one set of the plurality of control channel elements to another set of the plurality of control channel elements from one of the time-units to another.
14. The method of claim 8 , wherein
the searching for the downlink control channel information in the predetermined sub-set of the plurality of possible sets of control channel elements according to the fixed aggregation level comprises searching a set of one or more control channel elements from the sub-set of possible sets of control channel elements in a temporal unit.
15. Circuitry for a communications device for transmitting data to or receiving data from a mobile communications network, the circuitry configured to:
receive, via a wireless access interface, downlink control channel information transmitted by the mobile communications network in one or more control channel elements of a downlink control channel of a radio frame a plurality of temporal units, the wireless access interface being provided by the mobile communications network for transmitting data to or receiving data from the communications device, the radio frame being divided into a plurality of time divided temporal units with the downlink control channel and a downlink shared channel included in each temporal unit, wherein the one or more control channel elements in which the downlink control channel information is transmitted is one of a plurality of sets of possible control channel elements in which the mobile communications network can transmit the downlink control information in one of the temporal units of the radio frame for the communications devices to search for the downlink control information in each of the plurality of possible sets of control channel elements, wherein
the receiving comprises searching for the downlink control channel information by searching in a search space that includes at least one of (i) a predetermined sub-set of the plurality of possible sets of control channel elements in the downlink control channel for one or more of the temporal units of the radio frame according to a fixed aggregation level, and (ii) a second sub-set of possible control channel elements which is selected from the plurality of possible sets of the control channel elements in one or more temporal units according to a configurable aggregation level.
16. The circuitry of claim 15 , wherein
the circuitry is further configured to receive an indication, from the mobile communications network, of the second sub-set of possible sets of control channel elements for the one or more temporal units of the radio frame providing the configurable aggregation level.
17. The circuitry of claim 15 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of control channel elements is common for one or more other communications devices.
18. The circuitry of claim 15 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible set of control channel elements is specific to the communications device.
19. The circuitry of claim 15 , wherein
each of the control channel elements of the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of control channel elements is an enhanced control channel element of an enhanced downlink control channel.
20. The circuitry of claim 15 , wherein
the one or both of the predetermined sub-set of the plurality of possible sets of control channel elements or the second sub-set of the possible sets of control channel elements changes from one set of the plurality of control channel elements to another set of the plurality of control channel elements from one of the time-units to another.