Getting your BERs right
Getting your Bit Error Ratios right
A unique feature of the digital DVB-T modulator MO-170 is the insertion of bit errors in different stages of the DVB-T modulation chain. This can help to check the accuracy of the BER estimation algorithms implemented in high-end professional receivers.
A Channel BER (CBER or BER before the Viterbi decoder) ranging between 7.6x10-6 and 1.25x10-1 is generated by modifying the sequence of bits at the input to the constellation mapper. Analogously, the MO-170 is able to generate a Viterbi BER (VBER or BER after Viterbi) going from 3.7x10-9 to 6.2x10-2 by properly processing the bits at the output of the Reed-Solomon encoder. The main advantage of this technique when compared with varying the C/N to get the desired CBER or VBER, is its high resolution and unparalleled accuracy.
QEF VBER insertion in the MO-170 and BER measured
by the TV EXPLORER field strength meter
PROMAX is a leading manufacturer of test and measurement systems, broadcast and TV signal distribution equipment. Our product lines include measuring instruments for cable TV, satellite TV, broadcast, wireless and fibre optics networks, FTTH and GPON analyzers. DVB-T modulators, IP streamers or IP converters (ASI, DVB-T) are among the company’s latest developments.