Design and evaluation of universal modulators

Abstract

Communication systems are extensively used in a large number of applications such as radar, aerospace, naval/maritime communication, underwater communication, mobile communication and many more. The most important module in designing communication system includes design of modulators and different applications demand different types of modulators. Design of a universal modulator is an efficient solution for this. In this paper, design and FPGA implementation of an universal modulator using different approaches is proposed, which is capable of generating analog modulation schemes such as amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM) as well as digital modulation schemes such as amplitude shift keying (ASK), frequency shift keying (FSK) and phase shift keying (PSK). The proposed system is implemented with and without CORDIC (COordinate Rotation Digital Computer) algorithm using Xilinx System Generator blocksets. Also a universal modulator is proposed with and without reconfigurable architecture. The performance of all the universal modulators proposed in this work are compared with each other using Virtex-5 FPGA board. The results from proposed work is also compared with other approaches reported in literature. It is observed that each approach has its own advantages and disadvantages and an approach can be selected based on the design requirements and hardware availability.