DVB-T2: New Signal Processing Algorithms for a Challenging Digital Video Broadcasting Standard

Digital Video Broadcasting-Terrestrial (DVB-T) is the most widely deployed digital terrestrial television system worldwide with services on air in over thirty countries. In order to increase its spectral efficiency and to enable new services the DVB consortium has developed a new standard named DVB-T2. A nearly definitive specification has already been published as a BlueBook as well as an implementation guideline, where the structure and main technical novelties of the standard have been defined. The imminent publication of the final DVB-T2 standard will give rise to the deployment of new networks and commercial products. The differences between the original DVB-T and the new DVB-T2 standards are many and important. The latest coding, interleaving and modulation techniques have been included in this large and flexible specification to provide capacity and robustness in the terrestrial transmission environment to fixed, portable and mobile terminals. Multiple-input multipleoutput (MIMO) techniques, low-density parity-check codes (LDPC), rotated constellations, new pilot patterns or large interleaving schemes are the most remarkable signal processing algorithms that have been included to overcome the limitations of the much simpler DVB-T broadcasting standard. This chapter focuses on the mentioned new algorithms and the opportunities that arise from a signal processing perspective. New transmission and reception techniques are proposed which can be used to enhance the performance of DVB-T2, such as iterative demapping and decoding, new antenna diversity schemes or more efficient channel estimation algorithms. Furthermore, the performance of the new standard is analyzed and evaluated through simulations focusing on the aforementioned algorithms. The behaviour of the standard is specially studied in single-frequency networks (SFN), where the vulnerability of the former standard is prohibitive when destructive interferences arise. The chapter first describes the main architecture and limitations of the original DVB-T specification. The physical layer of the new DVB-T2 standard is then defined, emphasizing the main differences in comparison to its predecessor. The next section of the chapter proposes and analyzes iterative demapping and decoding techniques at reception which can profit from the benefits of the new LDPC codes. Multi-antenna transmission and reception is