Abstract
Digital TV (DTV) protection from the potential interference caused to a communication system using the cognitive radio (CR) technologies is so important for the frequency sharing between a DTV station and a communication system. In this letter, two results of the interference analysis at the co-channel bandwidth of 6MHz are provided. One is the requirement of the protection ratio (PR) to a DTV station, which means the received signal strength of a DTV station to the interfering signal strength of a communication system ratio. The other shows the interference effect to the service area of a DTV station, when the transmit power of a communication system is either 100W or 4W, and the PR of a DTV station is 15dB. Their results describe that an interferer's transmit power should be limited, because of protecting DTV station and sharing co-channel frequencies.