Method for transmitting downlink control channel in a mobile communications system and a method for mapping the control channel to physical resource using block interleaver in a mobile communications system
A method for transmitting a downlink control channel in a mobile communication system and a method for mapping the control channel to physical resources using a block interleaver are provided. In order to transmit a downlink control channel in a mobile communication system, information bits are modulated to generate one or more modulation symbols according to a specific modulation scheme, the modulation symbols are interleaved using a block interleaver, and the interleaved modulated symbols are mapped to resource elements allocated for transmission of at least one control channel in a subframe, thereby transmitting the at least one control channel.
1. A method for transmitting a physical downlink control channel (PDCCH) in a mobile communication system, the method comprising:
inputting one or more symbol groups to a block interleaver;
outputting permuted symbol groups from the block interleaver;
mapping the outputted symbol groups to resource elements allocated for transmitting at least one PDCCH in a subframe; and
transmitting the at least one PDCCH,
wherein the outputted symbol groups are cyclically shifted using a cell identifier.
2. The method according to claim 1 , wherein the one or more symbol groups are written to the block interleaver in a row direction, and the one or more permuted symbol groups are read from the block interleaver in a column direction.
3. The method according to claim 1 , wherein the performed symbol groups is permuted by using a specific permutation pattern.
4. The method according to claim 1 , wherein a size of the block interleaver is determined according to a number of the cyclically shifted symbol groups transmitted in the subframe.
5. The method according to claim 4 , wherein a number of rows of the block interleaver is determined based on a predetermined number of columns of the block interleaver and the number of the cyclically shifted symbol groups transmitted in the subframe.
6. A apparatus for transmitting a physical downlink control channel (PDCCH) in a mobile communication system, the apparatus comprising:
a memory;
a block interleaver;
one or more transmission antennas; and
a processor functionally connected with the memory, the block interleaver and the one or more transmission antennas, that:
inputs one or more symbol groups to the block interleaver;
outputs permuted symbol groups from the block interleaver;
maps the outputted symbol groups to resource elements allocated for transmitting at least one PDCCH in a subframe; and
transmits the at least one PDCCH by using the one or more transmission antennas,
wherein the outputted symbol groups are cyclically shifted using a cell identifier.
7. The apparatus according to claim 6 , wherein the one or more symbol groups are written to the block interleaver in a row direction, and the one or more permuted symbol groups are read from the block interleaver in a column direction.
8. The apparatus according to claim 6 , wherein the performed symbol groups is permuted by using a specific permutation pattern.
9. The apparatus according to claim 6 , wherein a size of the block interleaver is determined according to a number of the cyclically shifted symbol groups transmitted in the subframe.
10. The apparatus according to claim 9 , wherein a number of rows of the block interleaver is determined based on a predetermined number of columns of the block interleaver and the number of the cyclically shifted symbol groups transmitted in the subframe.