By Philipp Hasse, Dirk Jaeger, Joerg Robert, Institut fuer Nachrichtentechnik at Technische Universitaet Braunschweig
Competition in the media and communication sector is increasing. MSOs have to align their business models with new emerging requirements on a permanent basis. Although requirements vary in different national markets in Europe and worldwide, the cost per transmitted bit is an important factor for staying competitive. Thus one of the key requirements for modern communication technologies defined by European MSOs is to increase the spectral efficiency of downstream transmissions by moving the efficiency as close as possible to the Shannon limit – the theoretical optimum. The second generation of the DVB system for cable – called DVB-C2 – is an innovative approach making use of state of the art communication technologies which have never been implemented in broadband cable networks before. An OFDM (Orthogonal Frequency Division Multiplex) based modulation scheme in combination with a two-dimensional interleaving (in both frequency and time) and an LDPC (Low Parity Density Code) error protection mechanism provide a spectral efficiency fractions of a dB below the Shannon limit. Will there ever be any reason to develop a new PHY for cable after DVB-C2 is widely implemented?