| Abstract |
Software Defined Radios (SDR) are computer based systems that emulate the behavior of traditional radio systems by processing digitized radio signals. A SDR replaces the traditional fixed hardware radio with a system that may be reconfigured, both during operation to provide greater flexibility and by providing software upgrades to add new capabilities without requiring new hardware. These are powerful reasons for using SDR technology; however this flexibility comes at the cost of increased hardware cost and greater power consumption compared with traditional hardware radios.
In this thesis, we developed three complete Matlab/Simulink simulation models for Bluetooth wireless transceiver. These models have been implemented using three different modulation schemes namely, Gaussian Frequency Shift Keying (GFSK), pi/4 shifted Differential Quadrature Phase Shift Keying (pi/4 DQPSK) , and pi/8 shifted Differential Eight Phase Shift Keying (pi/8 D8PSK). The three models have been evaluated from the perspectives of Bit Error Rates (BER), spectral efficiency, and hardware complexity.
Moreover, we realized the pi/4 DQPSK model using the SDR implementation technology. We employed the Universal Software Radio Peripheral (USRP)-N210 as the hardware SDR architecture and the GNU-Radio as the software platform for implementing the Bluetooth transceiver. Bluetooth transceiver operates at 1600 hops per second. This means the frequency synthesizer has to hop from one frequency to the next, settle and communicate in less than 625uSec time. Unfortunately, tuning at such rates is not an easy task with the USRP SDR platform. Since, the RFX2400 daughterboard is able to tune typically within
250uSec , which is not fast enough to follow the moderate hopping rate of a Bluetooth system. Thus, we evaluated the influences of several tuning options, offered by the GNU-Radio "Universal Software Radio Peripheral" Hardware Driver (UHD), with respect to tuning time to figure out the tuning option that takes minimum tuning time. Finally, we had to design a new GNU-Radio block using the Python programming language to implement the frequency hopping block. |
