Co-Channel Secondary Deployment Over DTV Bands Using Reconfigurable Radios

This paper investigates the possibility of co-channel secondary transmission over the operational digital terrestrial video (DTV) broadcast bands within the interference limits of the DTV receivers. Aided by emulated DTV transmission experiments, secondary transmission-caused interference to the DTV receiver is analyzed. Using this understanding of interference behavior, a new transmission scheme for the secondary network nodes is proposed. The scheme selects the best communication parameters in terms of transmit power, spectral overlap, temporal occupancy, symbol duration, and modulation scheme to achieve a desired quality of service target within the interference limits of the DTV receivers. This is achieved without having information about the presence of DTV receivers. The feasibility as well as limits of the proposed secondary deployment scheme are then analyzed. This study is expected to serve as a valuable planning tool in deploying cognitive secondary networks over DTV transmission bands.