Apparatus and method for modulating data message by employing orthogonal variable spreading factor (ovsf) codes in mobile communication system

A mobile station, capable of using a plurality of data channels and a control channel, that converts source data to a channel-modulated signal, comprising:

• a channel coding unit that encodes the source data to generate a plurality of data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;
• a code generator that generates spreading codes to be allocated to the channels, wherein each of the spreading codes is generated on the basis of a spreading factor related to a data rate for the respective channel and a code number for the respective channel;
• and
• a spreader that spreads the control channel and the data channels using the allocated spreading codes to thereby generate the channel-modulated signal, wherein:
• the spreading codes correspond to orthogonal variable spreading factor (OVSF) codes,
• the spreading code allocated to the control channel is represented by C256, 0, where 256 denotes the spreading factor and 0 the code number,
• the spreading codes allocated to first and second data channels are represented by C4, 1, and
• the code generator.

A spreading method for a mobile station, capable of using a plurality of data channels and a control channel, for converting source data to a channel-modulated signal, the spreading method comprising:

• encoding the source data to generate a plurality of data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;
• generating spreading codes to be allocated to the channels, wherein each of the spreading codes is generated on the basis of a spreading factor related to a data rate for the respective channel and a code number for the respective channel;
• and
• spreading the control channel and the data channels using the allocated spreading codes to thereby generate the channel-modulated signal, wherein:
• the spreading codes correspond to orthogonal variable spreading factor (OVSF) codes,
• the spreading code allocated to the control channel is represented by C256, 0, where 256 denotes the spreading factor and 0 the code number,
• the spreading codes allocated to first and second data channels are represented by C4, 1.