New robust sensing methods for DVB-T signals

The regulations for operation in the TV white space (TVWS) have been developed and released in USA and UK It is believed that the ongoing TVWS related standardization projects, such as IEEE P802.19.1, IEEE P802.11af and IEEE P802.22, will encourage the regulation development in more countries and regions. Current regulations commonly require the TV band device (TVBD) or the sensing only TVBD to be capable of detecting incumbent TV signals of very low power level within a short time. To fulfill the strict requirements on both of sensitivity and sensing time while keeping the hardware implementation cost below a desired level, we propose two new sensing methods for DTV signals of DVB-T standard: the optimal one requires time synchronization and is therefore called The Proposed_Syn while the sub-optimal one requires no time synchronization and is called The Proposed_Asyn. Both computer simulation results and hardware testing results are shown in this paper. Simulation results show that for achieving a goal of high detection probability (≥90%) and low false alarm probability (≤1%) at a very low SNR (=-20dB) in AWGN channel, in comparison with conventional sensing methods, The Proposed_Syn reduces sensing time by 50% and both proposed methods can significantly reduce hardware implementation cost by potentially reducing multiplexer number more than 99%. Hardware sensing prototype testing results have further verified the improved performance by using the proposed sensing methods.