Method and apparatus with enhanced control messages and search space
A method of mapping control information in a wireless communication system is disclosed (FIG. 5 ). The method includes forming a subframe (FIG. 3 ) having a bandwidth and having plural regions ( 302 - 306 ). A base station (eNB) determines a communication mode with a remote user equipment. The base station maps control information specific to the user equipment into a first region of the subframe ( 508 ). The base station also maps control information common to plural user equipments into a second region of the subframe ( 512 ). The subframe is transmitted to the plural user equipments ( 412 , FIG. 4 ).
1. A method of mapping control information for wireless communication, comprising:
forming a subframe having a bandwidth;
mapping first control information specific to a user equipment (UE 1 ) into a first enhanced physical downlink control channel (EPDCCH) of the subframe, wherein the first control information is formatted according to downlink control information (DCI) format 1A with CRC scrambled by a cell radio network temporary identifier (C-RNTI), the first EPDCCH corresponding to a first set of resource blocks configured by a Radio Resource Control (RRC) message;
mapping second control information common to UE 1 and at least another user equipment (UE 2 ) into a second EPDCCH of the subframe, wherein the second control information has a DCI formed with CRC scrambled by a second type of RNTI different than the C-RNTI, the second EPDCCH corresponding to a second set of resource blocks configured by the RRC message;
mapping third control information into a physical downlink control channel (PDCCH) of the subframe, wherein the third control information is formatted according to DCI format 1A with CRC scrambled by a system information radio network temporary identifier (SI-RNTI); and
transmitting the subframe to UE 1 and UE 2 .
2. The method of claim 1 , wherein mapping the first control information includes determining a mapping of the first control information into the first EPDCCH in response to a type of common control information.
3. The method of claim 2 , wherein the second control information is transmit power control (TPC) information.
4. The method of claim 1 , wherein the subframe comprises a plurality of Physical Resource Block (PRB) pairs, and wherein a location of the first EPDCCH and a location of the second EPDCCH is indicated by a bitmap.
5. The method of claim 4 , wherein the bitmap has a length at least equal a total number of PRB pairs in the subframe.
6. A method of receiving control information by a user equipment (UE 1 ), comprising:
receiving a configuration of a subframe from a base station;
blind decoding a first enhanced physical downlink control channel (EPDCCH) of the subframe to receive first control information specific to the UE 1 , wherein the first control information is formatted according to downlink control information (DCI) format 1A with CRC scrambled by a cell radio network temporary identifier (C-RNTI), the first EPDCCH corresponding to a first set of resource blocks configured by a Radio Resource Control (RRC) message;
blind decoding a second enhanced physical downlink control channel (EPDCCH) of the subframe to receive second control information common to the UE 1 and at least another user equipment (UE 2 ), wherein the second control information has a DCI format with CRC scrambled by a second type of RNTI different than the C-RNTI, the second EPDCCH corresponding to a second set of resource blocks configured by the RRC message; and
blind decoding a physical downlink control channel (PDCCH) of the subframe to receive third control information, wherein the third control information is formatted according to DCI format 1A with CRC scrambled by a system information radio network temporary identifier (SI-RNTI).
7. The method of claim 6 , wherein the subframe comprises a plurality of Physical Resource Block (PRB) pairs, wherein of receiving the configuration comprises receiving a bitmap, and wherein a location of the first EPDCCH and a location of the second EPDCCH is indicated by the bitmap.
8. The method of claim 7 , wherein the bitmap indicates whether a PRB pair is for UE 1 .
9. The method of claim 7 , wherein the bitmap indicates whether a subframe is for UE 1 .
10. A method of communication between a base station and a plurality of user equipments (UE), comprising:
the base station forming a subframe;
generating first Downlink Control Information (DCI) comprising control information specific to a first UE (UE 1 ), wherein the first control information has a DCI format with CRC scrambled by a first type of radio network temporary identifier (RNTI);
generating second DCI comprising second control information common to UE 1 and at least a second user equipment (UE 2 ), wherein the second control information has a DCI format with CRC scrambled by a second type of RNTI different than the first type of RNTI;
generating third DCI comprising third control information wherein the third control information is formatted according to DCI format 1A with CRC scrambled by a system information radio network temporary identifier (SI-RNTI);
mapping the first DCI into a first Enhanced Physical Downlink Control Channel (EPDCCH) of the subframe, the first EPDCCH corresponding to a first set of resource blocks configured by a Radio Resource Control (RRC) message;
mapping the second DCI into a second EPDCCH of the subframe, the second EPDCCH corresponding to a second set of resource blocks configured by the RRC message;
mapping third control information into a physical downlink control channel (PDCCH) of the subframe; and
transmitting the subframe to UE 1 and UE 2 .
11. The method of claim 10 , wherein the subframe comprises a plurality of Physical Resource Block (PRB) pairs, and wherein a location of the first EPDCCH is indicated by a bitmap having a length at least equal to a total number of PRB pairs in the subframe.
12. The method of claim 11 , wherein the total number of PRB pairs is a function of a communication bandwidth between the base station and the plurality of user equipments.
13. The method of claim 10 , wherein the subframe comprises a plurality of Physical Resource Block (PRB) pairs, and wherein a location of the second EPDCCH is indicated by a bitmap having a length at least equal to a total number of PRB pairs in the subframe.
14. The method of claim 13 , wherein the total number of PRB pairs is a function of a communication bandwidth between the base station and the plurality of user equipments.
15. The method of claim 10 , further comprising mapping the second DCI into one of the second EPDCCH or the PDCCH of the subframe, wherein the mapping is determined by a format and a scrambling of the second DCI.
16. The method of claim 15 , wherein the subframe comprises a plurality of Physical Resource Block (PRB) pairs, and wherein a location of the PDCCH is indicated by a bitmap having a length at least equal to a total number of PRB pairs in the subframe.
17. The method of claim 15 , wherein the total number of PRB pairs is a function of a communication bandwidth between the base station and the plurality of user equipments.
18. The method of claim 10 , wherein the second DCI has a format 3 or 3A format with CRC scrambled by a Transmit Power Control Radio Network Temporary Identifier (TPC-RNTI).
19. The method of claim 10 , wherein the second DCI has a format 1A with CRC scrambled by one of a System Information Radio Network Temporary Identifier (SI-RNTI), a Paging Radio Network Temporary Identifier (P-RNTI), or a Random Access Radio Network Temporary Identifier (RA-RNTI).
20. The method of claim 10 , wherein the second DCI has a format 0 or 1A with CRC scrambled by a Temporary Cell Radio Network Temporary Identifier (C-RNTI).
21. The method of claim 1 ,
wherein the first EPDCCH has a UE-specific DCI format, and
wherein the second EPDCCH has a DCI format of 1A scrambled by one of a System Information Radio Network Temporary Identifier (SI-RNTI), a Paging Radio Network Temporary Identifier (P-RNTI), or a Random Access Radio Network Temporary Identifier (RA-RNTI) or a DCI format of format 3 or 3A with CRC scrambled by a Transmit Power Control Radio Network Temporary Identifier (TPC-RNTI).
22. The method of claim 1 , wherein the second control information is transmit power control (TPC) information.
23. The method of claim 6 , wherein the second control information is transmit power control (TPC) information.
24. The method of claim 6 , further comprising determining a mapping of the first control information into the first EPDCCH in response to a type of common control information.
25. A user equipment (UE 1 ), configured to:
receive a configuration of a subframe from a base station;
blind decode a first enhanced physical downlink control channel (EPDCCH) of the subframe to receive first control information specific to the UE 1 , wherein the first control information is formatted according to downlink control information (DCI) format 1A with CRC scrambled by a cell radio network temporary identifier (C-RNTI), the first EPDCCH corresponding to a first set of resource blocks configured by a Radio Resource Control (RRC) message;
blind decode a second enhanced physical downlink control channel (EPDCCH) of the subframe to receive second control information common to the UE 1 and at least another user equipment (UE 2 ), wherein the second control information has a DCI format with CRC scrambled by a second type of RNTI different than the C-RNTI, the second EPDCCH corresponding to a second set of resource blocks configured by the RRC message; and
blind decode a physical downlink control channel (PDCCH) of the subframe to receive third control information, wherein the third control information is formatted according to DCI format 1A with CRC scrambled by a system information radio network temporary identifier (SI-RNTI).
26. The UE 1 of claim 25 , wherein the subframe comprises a plurality of Physical Resource Block (PRB) pairs, wherein the UE 1 is further configured to receive a bitmap, and wherein a location of the first EPDCCH and a location of the second EPDCCH is indicated by the bitmap.
27. The UE 1 of claim 26 , wherein the bitmap indicates whether a PRB pair is for UE 1 .
28. The UE 1 of claim 26 , wherein the bitmap indicates whether a subframe is for UE 1 .
29. The UE 1 of claim 25 , wherein the second control information is transmit power control (TPC) information.
30. The UE 1 of claim 25 , wherein the UE 1 is further configured to determine a mapping of the first control information into the first EPDCCH in response to a type of common control information.