Cognitive Radio in TV White Space

In 2009, the Federal Communications Commission (FCC) opened up unused television frequency bands for free and unlicensed operation, subject to some constraints. This band is called the TV White Space (TVWS). Applications envisioned for operation in the TVWS include Internet access points, femto-cellular base stations, smart-utility networks and emergency communication. In this paper, we develop a comprehensive framework for communication over the TVWS band. We develop novel techniques for modulation and adaptive channel coding for communication in the TVWS band. Since unlicensed TVWS spectrum usage is free, emphasis will be on power-efficiency of the modem. We propose an orthogonal frequency division multiplexing (OFDM) based framework for adapting the transmission bandwidth to the available number of unused TV bands. Further, the OFDM model will also allow for adaptation of transmission parameters (power, modulation alphabet and code rate)observed interference temperature in each band.