Analyzing Bit Error Rate using Universal Software Radio Peripheral (USRP) Software Defined Radio in Indoor and Outdoor Environments

Abstract

Wireless Communications had radical growth because of the necessity of people being connected. However, interference, noise, and multiple fading have adverse effects to a reliable system. Bit Error Rate has its own importance in Quality of Service (QOS). This thesis performed an analysis and measurement of bit error rates over long term scales in both indoor as well as outdoor environments with the help of Software Defined Radio’s (SDR). Software Defined Radio technology provides cost effective approach and flexibility whereas the hardware approach of traditional systems has significant limitations. We used SDR that implements radio functionalities in software. The transmissions have been achieved using the Universal Software Radio Peripheral (USRP), with the time synchronization and signal processing occurring in the GNU Radio environment on the Linux platform. The GNU radio allows us to modify several channel parameters to test the behavior of the wireless channel in the real time environment. In an indoor environment, radios were separated by 20 meters in the presence of an obstruction, which caused signal attenuation. And for outdoor environment, radios were separated by 50 meters, so noise played as major role. A series of packets have been transmitted between the two USRP radios with different channel properties in multiple scenario’s. Bit error rate was computed, visualized and compared across multiple scenarios using MATLAB for different modulation schemes like BPSK, QPSK and GMSK. Observed results show a series of time dynamics of BER which are not commonly studied in the literature.