Method for receiving control information in orthogonal frequency division multiplexing system of mobile communication system

Abstract

The present invention relates to receiving control information in an orthogonal frequency division multiplexing (OFDM) system of a mobile communication system. The present invention includes receiving information related to a number of OFDM symbols in a subframe for receiving first control information, receiving information related to a number of OFDM symbols in the subframe for receiving second control information, decoding the first control information according to the received information related to the number of OFDM symbols in the subframe for receiving the first control information, and decoding the second control information according to the received information related to the number of OFDM symbols in the subframe for receiving the second control information, wherein the number of OFDM symbols for receiving the first control information is less than or equal to the number of OFDM symbols for receiving the second control information.

What is claimed is: 
     
       1. A method of transmitting downlink channels at a base station of an orthogonal frequency division multiplexing (OFDM) system, the method comprising:
 transmitting first information indicating a size m of a first region through a broadcast channel, wherein the first region is defined by m OFDM symbol(s) starting from a beginning of a subframe and the first region is used for first channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;   transmitting second information indicating a size n of a second region through a physical control format indicator channel (PCFICH), wherein the second region is defined by n OFDM symbol(s) starting from the beginning of the subframe and the second region is used for second channels that carry downlink control information; and   transmitting the HARQ ACK/NACKs and the downlink control information through the first channels and second channels, respectively,   wherein first resources for the first channels are identified from the first information, and second resources for the second channels are identified from remaining resources excluding the first resources within the second region, and   wherein the second channels are physical downlink control channels (PDCCHs).   
     
     
       2. The method of  claim 1 , wherein the size n is configured to be equal to or greater than the size m such that n≧m. 
     
     
       3. A method of receiving downlink channels at a mobile terminal of an orthogonal frequency division multiplexing (OFDM) system, the method comprising:
 receiving first information indicating a size m of a first region through a broadcast channel, wherein the first region is defined by m OFDM symbol(s) starting from a beginning of a subframe and the first region is used for first channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;   receiving second information indicating a size n of a second region through a physical control format indicator channel (PCFICH), wherein the second region is defined by n OFDM symbol(s) starting from the beginning of the subframe and the second region is used for second channels that carry downlink control information; and   receiving the HARQ ACK/NACKs and the downlink control information through the first channels and second channels, respectively,   wherein first resources for the first channels are identified from the first information, and second resources for the second channels are identified from remaining resources excluding the first resources within the second region, and   wherein the second channels are physical downlink control channels (PDCCHs).   
     
     
       4. The method of  claim 3 , wherein the size n is configured to be equal to or greater than the size m such that n≧m. 
     
     
       5. The method of  claim 3 , further comprising:
 performing operations in accordance with one of the second channels received through the second region that is designated to the mobile terminal.   
     
     
       6. A base station used in an orthogonal frequency division multiplexing (OFDM) system, the base station comprising:
 a radio frequency unit; and   a processor,   wherein the processor is configured to:   transmit first information indicating a size m of a first region through a broadcast channel, wherein the first region is defined by m OFDM symbol(s) starting from beginning of a subframe and the first region is used for first channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;   transmit second information indicating a size n of a second region through a physical control format indicator channel (PCFICH), wherein the second region is defined by n OFDM symbol(s) starting from the beginning of the subframe and the second region is used for second channels that carry downlink control information; and   transmit the HARQ ACK/NACKs and the downlink control information through the first channels and second channels, respectively,   wherein first resources for the first channels are identified from the first information, and second resources for the second channels are identified from remaining resources excluding the first resources within the second region, and   wherein the second channels are physical downlink control channels (PDCCHs).   
     
     
       7. The base station of  claim 6 , wherein the size n is configured to be equal to or greater than the size m such that n≧m. 
     
     
       8. A mobile terminal used in an orthogonal frequency division multiplexing (OFDM) system, the mobile terminal comprising:
 a radio frequency unit; and   a processor,   wherein the processor is configured to: receive first information indicating a size m of a first region through a broadcast channel, wherein the first region is defined by m OFDM symbol(s) starting from a beginning of a subframe and the first region is used for first channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;   receive second information indicating a size n of a second region through a physical control format indicator channel (PCFICH), wherein the second region is defined by n OFDM symbol(s) starting from the beginning of the subframe and the second region is used for second channels that carry downlink control information; and   receive the HARQ ACK/NACKs and the downlink control information through the first channels and second channels, respectively,   wherein first resources for the first channels are identified from the first information, and second resources for the second channels are identified from remaining resources excluding the first resources within the second region, and   wherein the second channels are physical downlink control channels (PDCCHs).   
     
     
       9. The mobile terminal of  claim 8 , wherein the size n is configured to be equal to or greater than the size m such as n≧m. 
     
     
       10. The mobile terminal of  claim 8 , wherein the processor is further configured to:
 perform operations in accordance with one of the second channels received through the second region that is designated to the mobile terminal.   
     
     
       11. A method of transmitting control information in a wireless communication system by a broadcasting manner, the method comprising:
 transmitting first information related to control information by the broadcasting manner in a first number of Orthogonal Frequency Division Multiplexing (OFDM) symbols,   wherein the first number of OFDM symbols carrying the first information has a predetermined value; and   transmitting second information related to control information in a second number of OFDM symbols,   wherein a frame comprises a plurality of OFDM symbols including the second information following the first information,   wherein the second number of OFDM symbols carrying the second information is variable per the frame,   wherein the second number of OFDM symbols carrying the second information is transmitted in the frame,   wherein interval in which the first number of OFDM symbols carrying the first information changes is greater than an interval in which the second number of OFDM symbols carrying the second information changes.   
     
     
       12. The method of claim 11, wherein the first number of OFDM symbol for the first information is 1. 
     
     
       13. A method of receiving control information in a wireless communication system by a broadcasting manner, the method comprising:
 receiving first information related to control information by the broadcasting manner in a first number of Orthogonal Frequency Division Multiplexing (OFDM) symbol,   wherein the first number of OFDM symbols carrying the first information has a predetermined value; and   receiving second information related to control information in a second number of OFDM symbols,   decoding the second number of OFDM symbols using the second information,   wherein a frame comprises a plurality of OFDM symbols including the second information following the first information,   wherein the second number of OFDM symbols carrying the second information is variable per the frame,   wherein the second number of OFDM symbols carrying the second information is transmitted in the frame,   wherein interval in which the first number of OFDM symbols carrying the first information changes is greater than an interval in which the second number of OFDM symbols carrying the second information changes.   
     
     
       14. The method of claim 13, wherein the first number of OFDM symbol for the first information is 1. 
     
     
       15. The method of claim 13, the method includes:
 decoding the received first information and second information.