In the field of wireless communications the idea of cognitive radio is of utmost interest. Due to its advantageous propagation properties, the TV white space can be considered to become the first commercial application of cognitive radio. It allows the usage of secondary communication systems at non-occupied frequency bands. Within this paper, spectrum sensing algorithms are introduced for the three predominant Chinese TV standards DTMB, CMMB, and PAL-D/K. A prototype platform is presented and its underlying architecture based on a combination of DSP and FPGA is illustrated including the setup of the cognitive radio application. Furthermore, the performance of the sensing algorithms implemented on the prototype platform is shown in comparison to simulation results. 1. Introduction The recent decade revealed increasing interests in the field of cognitive radio (CR) for wireless communication systems. It is considered as a key technology for significantly alleviating spectrum scarcity. The TV white space (TVWS), which refers to non-occupied frequency bands in the TV spectrum, that is below 900？MHz, is a desirable target for CR-based spectrum sharing due to its advantageous propagation properties compared to other frequency ranges on the one hand and due to its low utilization ratio on the other hand . Hence, deploying CR mechanisms in TVWS will probably become the first commercial application that brings CR from concept to reality. In the United States, the FCC has already made an official request to allow unlicensed users reusing TV bands without causing interference to incumbent users . In other countries, the corresponding regulatory authorities such as the CEPT in Europe are developing regulations on the unlicensed usage in TVWS as well. Besides the regulatory authorities, working groups such as IEEE 802.22  have started the standardization for cognitive radio applications. Spectrum sensing is a key element of CR and its application to TVWS has been widely studied. However, a variety of different TV standards exists which may differ from country to country, especially for digital TV standards. While in North America ATSC (Advanced Television Systems Committee) is deployed, in Europe, South Asia, and Africa, DVB-T/H (Digital Video Broadcasting-Terrestrial/Handheld) plays the predominant role. Further standards such as ISDB (Integrated Services Digital Broadcasting) developed in Japan or DMB (Digital Multimedia Broadcasting) developed in Korea are also used in various countries . As a result, it is hardly feasible to design a universal
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