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

A method of transmitting downlink control channels at a base station of an orthogonal frequency division multiplexing (OFDM) system, the method comprising:ntransmitting first information indicating related to 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 control channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;transmitting second information indicating related to 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 control channels that carry downlink control information; andtransmitting the HARQ ACK/NACKs and the downlink control information through the first control channels and second control channels, respectively,wherein first resources for the first control channels are identified from the first information, and second resources for the second control channels are identified from remaining resources excluding other than the first resources within the second region, andwherein the second control channels are physical downlink control channels (PDCCHs).

A method of receiving downlink control channels at a mobile terminal of an orthogonal frequency division multiplexing (OFDM) system, the method comprising:nreceiving first information indicating related to 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 control channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;receiving second information indicating related to 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 control channels that carry downlink control information; andreceiving the HARQ ACK/NACKs and the downlink control information through the first control channels and second control channels, respectively,wherein first resources for the first control channels are identified from the first information, and second resources for the second control channels are identified from remaining resources excluding other than the first resources within the second region, andwherein the second control channels are physical downlink control channels (PDCCHs).

A base station used in an orthogonal frequency division multiplexing (OFDM) system, the base station comprising:na radio frequency unit; anda processor,wherein the processor is configured to:transmit first information indicating related to 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 control channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;transmit second information indicating related to 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 control channels that carry downlink control information; andtransmit the HARQ ACK/NACKs and the downlink control information through the first control channels and second control channels, respectively,wherein first resources for the first control channels are identified from the first information, and second resources for the second control channels are identified from remaining resources excluding other than the first resources within the second region, andwherein the second control channels are physical downlink control channels (PDCCHs).

A mobile terminal used in an orthogonal frequency division multiplexing (OFDM) system, the mobile terminal comprising:na radio frequency unit; anda processor,wherein the processor is configured to: receive first information indicating related to 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 control channels that carry hybrid automatic repeat request (HARQ) ACK/NACKs;receive second information indicating related to 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 control channels that carry downlink control information; andreceive the HARQ ACK/NACKs and the downlink control information through the first control channels and second control channels, respectively,wherein first resources for the first control channels are identified from the first information, and second resources for the second control channels are identified from remaining resources excluding other than the first resources within the second region, andwherein the second control channels are physical downlink control channels (PDCCHs).