Planning Large Single Frequency Networks for DVB-T2

Abstract

[EN] The final coverage and associated performance of an SFN is a joint result of the properties of all transmitters in the SFN. Due to the large number of parameters involved in the process, finding the right configuration is quite complex. The purpose of the paper is to find optimal SFN network configurations for DVB-T2. Offering more options of system parameters than its predecessor DVB-T, DVB-T2 allows large SFN networks. However, self-interference in SFNs gives rise to restrictions on the maximum inter-transmitter distance and the network size. In order to make optimum use of the spectrum, the same frequency can be reused over different geographical areas - beyond the reuse distance to avoid co-channel interference. In this paper, a methodology based on theoretical network models is proposed. A number of network architectures and network reference models are considered here for different reception modes in order to study the effects of key planning factors on the maximum SFN size and minimum reuse distance. The results show that maximum bitrate, network size and reuse distance are closely related. In addition, it has been found that the guard interval is not the only limiting parameter and that its impact strongly depends on the rest of DVB-T2 mode parameters as well as on the network characteristics (Equivalent Radiated Power, effective height, inter-transmitter distance). Assuming that the C/N requirements are in the vicinity of 20 dB and bitrates over 30 Mbps, it has been found that the network can be as large as 360 x 360 km (delivering 39.2 Mbps) or even 720 x 720 km (delivering 37.5 Mbps). The reuse distance will also have a complex dependency on the DVB-T2 mode and especially the network parameters, ranging from below 100 to 300 km.