Baseband Processing of an SDR Frequency Hopping Transmitter

Abstract

Software defined radio (SDR) is a communication system which uses the software instead of the hardware to implement the radio components such as amplifiers, up/down mixer, filters, detectors, modulators, and demodulators on the personal computer (PC). SDR led to the development of the conventional radio to be a reconfigurable radio where various functions can be implemented on the same hardware platform in different times. Due to these powerful reasons, a smart applications and features could be added to the global system for mobile communications (GSM) standard to enhance its performance and achieve high quality of services over a wide range of radio applications.

In this thesis, the SDR frequency hopping (FH) transmitter using GSM standard has been designed, simulated and tested. First, speech encoding, channel encoding, interleaver, modulation and frequency hopping has been simulated on MATLAB/Simulink. Also, the Bit Error Rate (BER) has been calculated for several modulation techniques such as Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), Eight Phase Shift Keying (8PSK), and Binary Frequency Shift Keying (BFSK) in an additive white Gaussian noise channel (AWGN). Also, the performance of these modulations under different Signal-to-Noise ratio (SNR) values has compared.

Then, we realized the BFSK model using the SDR implementation technology. We employed the Universal Software Radio Peripheral (USRP)-N210 as the hardware SDR platform and the MATLAB/Simulink as the software for implementing the SDR transmitter. Finally, BFSK modulation with frequency hopping is used which produces protection against eavesdropping and jamming.