TV EXPLORER HD+ manual - Promax

USER’S MANUAL. TV EXPLORER HD +Figure 42.- DVB-S2 (QPSK/8PSK) signals LBER measurement screen.The BER measurement is provided in scientific notation (i.e. 2.7 E-7 means2.7x10 -7 , that is to say two incorrect bits of every 1,000) and through an analogue bar (asits length is smaller the signal quality will be better). The analogue representation is doneon a logarithmic scale (not linear).With the aim to have a reference about the signal quality, it is considered that asystem has a good quality when it decodes less than one non-correctable error for everytransmission hour. This border is known as QEF (Quasi-Error-Free) and it correspondsapproximately to a BER after Viterbi of 2.0E-4 BER (2.0x10 -4 ). This value is marked onthe measurement bar of the BER after Viterbi and therefore, BER for acceptable signalsmust be at the left side of this mark.Next it is shown the tuning frequency and the frequency deviation in MHz betweenthe tuned frequency and the one, which optimises the BER.Finally it is shown a status line with information about the detected signal. Thepossible messages that can appear and its meaning are shown in the following list. Themessages are exposed from less to more fulfilment of the MPEG-2 standard:No signal receivedAny signal has been detected.Signal receivedA signal is detected but it can not be decoded.Carrier recoveredA digital carrier has been detected but it can not be decoded.Viterbi synchronizedA digital carrier has been detected and the Viterbi algorithm is synchronized, buttoo many frames arrive with non correctable errors. It is not possible to quantify theBER.MPEG-2 TS DVB-SCorrect detection of a MPEG-2 signal.Page 62 01/2011