Search area based control channel monitoring
According to an embodiment of the invention, a method of operating a control node for communication with at least one receiving node is provided. The communication is structured in frames comprising several subframes ( 1 ) which may be divided into subbands in the frequency domain. The method comprises transmitting a control channel in a search area ( 8 ) of one of the subframes ( 1 ). The search area ( 8 ) comprises a configurable time span and may span one or more of the subbands.
1. A method of operating a control node for communication with at least one user equipment, the communication being structured in frames comprising several subframes, the method comprising:
transmitting, in a search area in only a subset of the subframes, a control channel between the control node and the at least one user equipment so as to allow the at least one user equipment to refrain from monitoring a control channel in a subframe other than in the subset of the subframes so that the at least one user equipment has a reduction in power consumption, the search area comprising a configurable time span and the subset of the subframes in which the control channel is transmitted being indicated by a bit map.
2. The method according to claim 1 , wherein the position of the search area depends on an index of the user equipment.
3. The method according to claim 1 , wherein the position of the search area is alternating between one of the subframes having the search area and the following subframe having the search area.
4. The method according to claim 3 ,
wherein the subframes are divided into a first slot and a second slot in the time domain, and
wherein the position of the search area alternates between the first slot and the second slot.
5. The method according to claim 1 , wherein the control channel comprises uplink grants and downlink assignments.
6. The method according to claim 1 , wherein the time span is shorter than the time duration of the subframe.
7. The method according to claim 1 , wherein the control node is a base station.
8. The method according to claim 1 , wherein the control node is a relay node.
9. The method of claim 1 , wherein the search area is in a data region of the subset of the subframes.
10. The method of claim 1 , wherein the control channel is based on UE-specific reference signals.
11. The method of claim 1 , wherein the control channel is an enhanced physical downlink control channel (E-PDCCH).
12. A method of operating a user equipment for communication with at least one control node, the communication being structured in frames comprising several subframes, the method comprising:
searching for a control channel in a search area in only a subset of the subframes, the search area comprising a configurable time span and the subset of the subframes in which the control channel is transmitted being indicated by a bit map; and
refraining from monitoring a control channel in a subframe other than in the subset of the subframes so as to reduce a power consumption of the user equipment.
13. The method according to claim 12 , wherein the position of the search area depends on an index of the user equipment.
14. The method according to claim 12 , wherein the position of the search area is alternating between one of the subframes having the search area and the following subframe having the search area.
15. The method according to claim 14 ,
wherein the subframes are divided into a first slot and a second slot in the time domain, and
wherein the position of the search area alternates between the first slot and the second slot.
16. The method according to claim 12 , wherein the control channel comprises uplink grants and downlink assignments.
17. The method according to claim 12 , wherein the time span is shorter than the time duration of the subframe.
18. The method according to claim 12 , wherein the control node is a base station.
19. The method according to claim 12 , wherein the control node is a relay node.
20. A control node configured to communicate with at least one user equipment with the communication being structured in frames comprising several subframes, the control node comprising a transmitter, wherein the transmitter is configured to:
transmit, in a search area in only a subset of the subframes, a control channel between the control node and the at least one user equipment so as to allow the at least one user equipment to refrain from monitoring a control channel in a subframe other than in the subset of the subframes so that the at least one user equipment has a reduction in power consumption, the search area comprising a configurable time span and the subset of the subframes in which the control channel is transmitted being indicated by a bit map.
21. A user equipment configured to communicate with at least one control node, the communication being structured in frames comprising several subframes, the user equipment comprising a controller, wherein the controller is configured to:
search for a control channel in a search area in only a subset of the subframes, the search area comprising a configurable time span and the subset of the subframes in which the control channel is transmitted being indicated by a bit map; and
refraining from monitoring a control channel in a subframe other than in the subset of the subframes so as to reduce a power consumption of the user equipment.
22. A control node, comprising:
a transmitter for communication with at least one user equipment, the communication being structured in frames comprising several subframes; and
a controller configured to control the transmitter to transmit a control channel in a search area in only a subset of one of the subframes so as to allow the at least one user equipment to refrain from monitoring a control channel in a subframe other than in the subset of the subframes so that the at least one user equipment has a reduction in power consumption, the search area comprising a configurable time span and the subset of the subframes in which the control channel is transmitted being indicated by a bit map.
23. A user equipment, comprising:
a receiver for communication with a control node, the communication being structured in frames comprising several subframes; and
a controller configured to:
search for a control channel in a search area in only a subset of the subframes, the search area comprising a configurable time span and the subset of the subframes in which the control channel is transmitted being indicated by a bit map; and
refrain from monitoring a control channel in a subframe other than in the subset of the subframes so as to reduce a power consumption of the user equipment.