On the design of real multicellular DS-CDMA spreading sequences under total weighted squared correlation criterion

An algorithm for designing spreading sequences for an overloaded multicellular synchronous DS-CDMA system, on the uplink, is introduced. The criterion used to measure the optimality of the design is the total weighted square correlation (TWSC), assuming that the channel state information is known perfectly both at transmitter and receiver. By using this algorithm, it is possible to obtain orthogonal generalized WBE (Welch bound equality) sequence sets for any processing gain. The bandwidth of the initial generalized WBE signals of each cell is preserved in the extended signal space associated with the multicellular system. Mathematical formalism is illustrated by selected numerical examples.