Design and Implementation of Small Cell using Software Defined Radio

Abstract

In the last few years mobile data traffic has been increased exponentially. Due to in- creased mobile data traffic more connectivity issues has been emerged. To overcome these problems of increasing data traffic and connectivity problems more number of BTS (Base trans-receiver station) are to be installed but it is not a cost effective idea. The solution is to go for implementing small cells. Small cells are low powered radio access nodes which can operate in licensed and unlicensed spectrum and can cover a range of few kilometres. Implementation of small cell is a cost effective idea as they can handle heavy data traffic for a small area. There are many technologies for implementing small cell like FPGA based Zynq SoC (System on Chip), Real Time Desktop Software Defined Radio (RTL- SDR), GNU radio, Universal Software Radio Peripheral (USRP) etc. Today there are several service providers which offers different frequencies for telecom services like GSM, UMTS or CDMA. Implementing small cell using software defined radio (SDR) makes it more efficient because SDR is a radio communication system where hardware components are implemented by means of software. Hardwares like RTL-SDR provided by NooElec, FPGA based Zynq SoC and USRP B200 together with Xilinx platform studio, Matlab and Simulink act as a communication platform for implementing small cell. By using these hardwares, OSI model has been explained by showing ow of data in Physical layer whose role is to transmit and receive electromagnetic signals through a physical channel and Data link layer whose role is to generate the data frames and to perform frame synchro- nisation. Flow of data through different layers of OSI model are tested by transmitting and receiving the audio signals using different modulation schemes. Various components (e.g. Modulators, Symbol Generators, Demodulators, and Synchronisation Blocks etc.) which are the building blocks to design a small cell are implemented with the help of above listed hardwares and softwares.