MVDS

From Wikipedia, the free encyclopedia

MVDS is an acronym for terrestrial Multipoint Video Distribution System.

        MVDS currently is a part of broader MWS (Multimedia Wireless System) standards.

In European Union MWS works in 10.7 - 13.5 and 40.5 - 43.5 GHz frequency bands.

The System is defined as the functional block of equipment performing the adaptation of the baseband TV signals from the output of the MPEG-2 transport multiplexer, to the MVDS channel characteristics. The following processes shall be applied to the data stream (see figure 1): - transport multiplex adaptation and randomization for energy dispersal; - outer coding (i.e. Reed-Solomon); - convolutional interleaving; - inner coding (i.e. punctured convolutional code); - baseband shaping for modulation; - modulation. MVDS services at millimetric frequency bands are particularly affected by power limitations, therefore ruggedness againstnoise and interference shall be the main design objective, rather than spectrum efficiency. To achieve a very high power efficiency without excessively penalizing the spectrum efficiency, the System shall use QPSK modulation and the concatenation of convolutional and RS codes. The convolutional code is able to be configured flexibly, allowing the optimization of the system performance for a given MVDS transmitter bandwidth. The System is suitable for single carrier per MVDS transmitter Time Division Multiplex (TDM) type applications. The System can also be used for multi-carrier Frequency Division Multiplex (FDM) type applications. The System is directly compatible with MPEG-2 coded TV signals. The modem transmission frame is synchronous with the MPEG-2 multiplex transport packets. If the received signal is above C/N and C/I threshold, the Forward Error Correction (FEC) technique adopted in the System is designed to provide a Quasi Error Free (QEF) quality target. The QEF means less than one uncorrected error-event per transmission hour, corresponding to Bit Error Ratio (BER) = 10-10 to 10-11 at the input of the MPEG-2 demultiplexer.

       Research for 42 GHz frequency has been done under the European Commition EMBRACE (Efficient Millimetre Broadband Radio Access for Convergence and Evolution) initiative.