Patent ID: 7349460

Claim:
A multi-carrier (MC)/multi-carrier direct sequence (MC-DS) dual-mode adaptive code division multiple access (CDMA) apparatus, comprising: a user signal processing means for performing symbol modulation, repetition and spreading of bit stream for each of a plurality of users based on a transmission mode suitable for channel environment of each of the users, and generating modulated and spread chip streams for each of the users; a combining means for adding up all the modulated and spread chip streams for the users to generate a combined chip stream; a first interleaving means for interleaving the combined chip streams and generating a first interleaved stream; a second interleaving means for selectively performing a second interleaving on the first interleaved stream based on a spreading scheme selection signal which indicates a spreading scheme determined depending on system conditions and outputting a second interleaved stream; and a serial-to-parallel converting means coupled to output of the second interleaving means, the serial-to-parallel converting means to generate parallel signals based on the length of a sub-carrier, align chips belonging to a symbol in a same parallel signal if the spreading scheme is frequency-based, and align the chips in consecutive parallel signals if the spreading scheme is time-based.