Q

[evergloe]

Why do I use DVB-S2 B4 table, QPSK modulation, signal-to-noise ratio is 0, bit error rate is 0 when averaging more than 1000 blocks

[xdsopl]

Please elaborate. What are you trying to do?

[evergloe]

Please elaborate. What are you trying to do?

I'm reproducing the result graph of the first image, but my signal-to-noise ratio is set to 0 because the bit error rate is 0, not 0.15

[xdsopl]

This is what I am getting:

./testbench 0 S2 B4 QPSK 1000
testing LDPC(64800, 32400) code.
using noop interleaver.
0 Es/N0 => AWGN with standard deviation of 0.707107 and mean 0
5.17719e-07 Eb/N0, using spectral efficiency of 1 from 0.5 code rate and 2 bits per symbol.
1.79262 Es/N0, stddev 0.575246 of noise and 1 of signal estimated via hard decision.
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
decoder failed at converging to a code word!
33299 kilobit per second.
25 average iterations per block.
30.4062 average milliseconds per decode.
0.94774 Es/N0, stddev 0.634013 of noise and 1 of signal estimated from corrected symbols.
9033982 errors caused by AWGN.
2592989 erasures caused by quantization.
3081078 errors caused by decoder.
11100644 errors uncorrected.
0.171306 bit error rate.

Can you post your output?