FRFT based Method of Modulation Techniques for SDR

Abstract

Software Defined Radio (SDR) works on a programmable hardware platform. Except for the antenna section, the conventional radio can be defined in a programmable hardware such as general purpose PC, special purpose digital signal processor or dedicated software defined radio kit. It represents a very flexible and generic radio platform which is capable of operating with various modulation types, waveform formats, and different bandwidths over a wide range of frequencies. SDR is evolving to be a promising solution for these challenges such as interoperability, global seamless connectivity encountered in wireless communication. In the case of digital modulation, sending bit stream with least bit error is the aim of every technique. Amplitude modulation, frequency modulation, phase modulation and also combination of these have been employed to distinguish ones and zeros or even combinations of ones and zeros. Factional Fourier Transform (FRFT) having its basis function as chirp signal, exhibits different orthogonal basis function with change in chirp rate. In this paper, possibility of employing basis functions of FRFT to distinguish various bit combination in digital signal transmission, is exploited. Results are presented for M=2b-ary QAM signaling and is found to be a promising method of digital modulation.