A secure spreader/Despreader for code division multiple access applications

This paper introduces the use of combined decimal sequences in a code division multiple access (CDMA) system. It presents the design and implementation of a DS-CDMA base-band module on an FPGA. The designed transceiver employs a combined D-sequence generator as a spreader/despreader unit. The transceiver have been designed using VHDL design entry method and simulated using Mentor Graphics FPGA Adv. Pro. The design is downloaded on Altera EPF10K10LC84 chip; it consumes 14% of the chip and operates at 128 MHz. The proposed transceiver design is implemented for eight users and can be extended for any number of users.