METHOD FOR ALLOCATING A SPREAD CODE IN CONSIDERATION OF CHARACTERISTICS OF SYMBOLS IN A CHANNEL USING A PLURALITY OF SPREAD CODES, PARTICULARLY FOR ALLOCATING WALSH CODES IN CONSIDERATION OF CHARACTERISTICS OF EACH SYMBOL IN ORDER TO TRANSMIT DATA HAVING A RELATIVELY HIGH IMPORTANCE IN A BETTER CHANNEL ENVIRONMENT

摘要

PURPOSE: A method for allocating a spread code in consideration of characteristics of symbols in a channel using a plurality of spread codes is provided to enhance transmission efficiency and allow a receiving end to receive information more effectively. CONSTITUTION: A plurality of symbols are classified according to their characteristics. A different spread code is allocated to each symbol, which is then spread. The symbols are turbo-encoded symbols each having systematic information or parity information. A spread code with a smaller channel utilization factor is allocated to the symbols having the systematic information. If a symbol having the systematic information exceeds a capacity limitation of the first transmission signal, the second Walsh code is allocated to a portion of the systematic symbol. If the number of systematic symbols exceeds an acceptance limitation of the first transmission signal, puncturing is performed regularly. If the number of systematic symbols is smaller than the acceptance limitation of the first transmission signal, the first spread code is allocated to the parity symbol.