Patent ID: 7599440

Claim:
A downlink control channel allocation method performed in a mobile communication system, comprising: forming one or more orthogonal code channels, wherein said forming comprises dividing one transmission time interval (TTI) to form one or more basic allocation units of a control channel by using a first orthogonal code, and extending the one or more basic allocation units to the one or more orthogonal code channels by using a second orthogonal code; allocating the one or more orthogonal code channels to each classified group or each terminal, wherein the one or more allocated orthogonal code channels are allocated thereto with a time division multiplexing and a code division multiplexing; determining a transmission power of each orthogonal code channel to transmit an information symbol, wherein the transmission power is differently applied to each orthogonal code channel based on transmission information or transmission power margin information reported from a user for scheduling, wherein a short Hadamard code channel is allocated to a group requesting low power or a high transmission rate and a long Hadamard code channel is allocated to a group requesting high power or a low transmission rate; and transmitting an information symbol through one of the orthogonal code channels, wherein a length of the first orthogonal code determines a number of available orthogonal codes and characteristics of a transport channel for the one or more orthogonal code channels.