Method for determining start time of a physical downlink control channel

1. A method, comprising:

sending, by a base station, a configurable parameter set to a user equipment to be used in determining locations of a starting sub-frame of a downlink control channel that is repeatedly transmitted for the user equipment; and

sending to the user equipment, by the base station, the downlink control channel scheduled according to the configurable parameter set;

wherein the configurable parameter set sent to the user equipment comprises a repetition level and sub-frame offset information to determine the locations of the starting subframe of the downlink control channel.

2. The method according to claim 1 , wherein the configurable parameter set sent to the user equipment comprises a gap value, or a system frame offset value of the downlink control channel.

3. The method according to claim 1 , wherein the sub-frame offset information comprises a seed of a pseudo random number, a value related to cell radio network identity, or a sub-frame number within a system frame.

4. The method according to claim 1 , wherein the configurable parameter set is transmitted to the user equipment in physical layer, MAC layer or RRC layer signaling packet(s).

5. The method according to claim 1 , further comprising scheduling the downlink control channel with a single repetition level or multiple repetition levels in a single sub-frame.

6. The method according to claim 1 , further comprising:

receiving, by the base station, feedback from the user equipment confirming the correct reception of the downlink control channel; and

terminating, by the base station, said sending the downlink control channel to the user equipment.

7. A method, comprising:

receiving, by a user equipment, from a base station, a parameter set;

calculating, by the user equipment, locations of a starting sub-frame of a downlink control channel that is repeatedly transmitted for the user equipment according to the parameter set received; and

receiving the downlink control channel scheduled according to the parameter set;

wherein the parameter set comprises a repetition level and sub-frame offset information; and

wherein the locations of the starting sub-frame of the downlink control channel are calculated according to the repetition level and the sub-frame offset information.

8. The method according to claim 7 , wherein the parameter set is received in physical layer, MAC layer, or RRC layer signaling.

9. The method according to claim 7 , wherein the locations of the starting sub-frame of the downlink control channel are determined based on a gap value, and an offset value of the downlink control channel.

10. The method according to claim 9 , wherein the locations of the starting sub-frame are determined based on a seed of a pseudo random number, or a value related to a cell radio network temporary identity, or a pre-determined sub-frame number within a radio frame designated by the base station.

11. The method according to claim 7 , wherein the locations of the starting sub-frame of the downlink control channel are determined by a function

SF i =f ( r,m,n )

where SF i is the i-th sub-frame number derived from the j-th system frame number SFN j using

SF i =SFN j *10+ LS j

where LS j is a sub-frame number within SFN j , where LS j =0 to 9.

12. The method according to claim 7 , further comprising combining the downlink control channel received in repetition and decoding the combined downlink control channel.

13. The method according to claim 7 , further comprising sending feedback information to confirm or reject reception of the downlink control channel.

14. The method according to claim 13 , wherein when the feedback information indicates correct reception of the downlink control channel, the user equipment terminates said receiving the downlink control channel.

15. A base station 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, cause the base station to:

send a configurable parameter set to a user equipment to be used in determining locations of a starting sub-frame of a downlink control channel that is repeatedly transmitted for the user equipment; and

send, to the user equipment, the downlink control channel scheduled according to the configurable parameter set;

wherein the configurable parameter set sent to the user equipment comprises a repetition level and sub-frame offset information to determine the locations of the starting subframe of the downlink control channel.

16. A user equipment 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, cause the user equipment to:

receive, from a base station, a parameter set comprising a repetition level and sub-frame offset information to determine the locations of the starting subframe of the downlink control channel;

calculate locations of a starting sub-frame of a downlink control channel that is repeatedly transmitted for the user equipment according to the repetition level and the sub-frame offset information; and

receive the downlink control channel scheduled according to the parameter set.

17. The method according to claim 1 , wherein the repetition level comprises a number of repetitions to be used to transmit a same enhanced physical downlink control channel to the user equipment.

18. The method according to claim 13 , wherein in response to the feedback information indicating correct reception of the downlink control channel, the user equipment terminates said receiving the downlink control channel.