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Narrowband Data Transmission in TV White Space: An Experimental Performance Analysis

Abstract:

TV White Spaces (TVWS) are UHF or VHF TV channels that are not under use by TV broadcasters at a particular time. As a means of achieving the global objective of efficient utilization of expensive spectrum bandwidth, TVWS can be exploited by Cognitive Radio (CR) enabled Software Defined Radio (SDR) systems for alternative services like communications for disaster-time rescue teams, Internet service for hard-to-reach communities etc. In this contribution, we report the design and prototype development of a testbed for real-time testing of secondary user transmission in TVWS. Once an unused TV channel has been identified, our system uses that idle channel for transmitting and receiving a narrowband signal. The testbed is built on Universal Software Radio Peripheral (USRP) 2901 device powered by GNU Radio software, RTL SDR 2832U and Spectrum Analyzer Tektronix MDO4054-3. Using 25kHz narrow bands within the TV channel#23 in Windsor, ON, Canada, and considering text, voice, and image data, we show channel and transmission characteristics through measured Bit Error Rate (BER) and constellation diagrams. Based on the experimental results, we affirm that it is possible to use this approach to successfully implement narrowband dynamic spectrum access (DSA) by secondary users over an idle TV channel.