DVB-C

Abstract: In this paper, we propose hierarchical modulation as a backward compatible solution for next generation digital video broadcasting over cables (DVB-C2). Without modifying the architecture of legacy receivers, supplementary data can be transmitted via an added layer superimposed onto the legacy layer, and the resultant increase of transmission power is only a small fraction of that used by the legacy system. To obtain the upper bounds for the achievable throughputs, the modulation constrained capacities are derived for this layered transmission scheme. We formulate the hierarchical constellation design as a nonlinear optimization problem and then solve it through a simplified numerical method, which searches for the appropriate power allocation ratio in one-dimension space. Finally, to examine the inter-operability of channel encoder/decoder between DVB-S2 and DVB-C2, we investigate the error performance of the proposed scheme employing the LDPC codes given by DVB-S2 standard.

Abstract: A brief summary of the key elements of the different baseline systems, as defined by the digital video broadcasting (DVB) project, is presented. As a major issue, in order to ensure economies of scale in the manufacturing phase and equipment connectivity, attention is paid to identify the common elements of DVB systems for each delivery media. The strategy followed by the DVB project has been to increase the number of common elements while keeping as peculiarities only those aspects strictly related to the physical properties of the transmission media. New ideas are flashed on the ways to implement interactive services by using existing infrastructure or by means of innovative concepts, as the SMATV grouping may be considered.

Abstract: It is well known that the performance of orthogonal frequency division multiplexing is highly sensitive to frequency offset. In this paper, we present theoretical results to assess the intercarrier interference reduction using general pulse shaping filters in digital video broadcasting over cable (DVB-C) systems. These pulses are characterized by only one design parameter, known as the roll-off factor. We found that for the DVB standard, which employs a raised cosine (RC) function, double-jump 1 (DJ1) filter outperforms the RC pulse as well as the rest of pulses in terms of both the bit error rate and the signal-to-interference ratio power. This is because the DJ1 pulse spectra presents the smallest lateral lobes and a broad main lobe.