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Post by levina on Aug 9, 2010 5:41:53 GMT -5
I'm using the demo in simulink-matlab to model a DVB-S2 system with particular focus on measuring out of band emissions. I would have to add square-root raised cosine filter and non-linear amplifiers to the model. However when I add the SRRC at the transmitter and receiver my BER becomes higher. I thought this subsystem is suppose to make it rather less.
Is there something I am not doing right.
I would be glad if I can get your advice.
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Post by charan langton on Aug 25, 2010 22:04:46 GMT -5
The addition of a RRC filter should have negligible effect on the BER. You are probably not slicing the signal at the optimum point or other demodulation error is happening.
The nonlinear amplification however will increase the BER for the same SNR.
Charan Langton
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Post by emiryuuu on Sept 20, 2010 2:49:56 GMT -5
Hello, I'm simulating DVB-S2 blocks' chain with SIMULINK Matlab. I'm using DVB-S2 demo already loaded in SIMULINK libraries, I want to add to it a Raised Cosine Filter in transmitting and in receiving, but I have high values of BER, around 0.49. What's Wrong?
I'm using those values about Raised Cosine Filter parameters:
Filter Type: Square Root
Group Delay: 2
Roll-off factor: 0.35
Upsampling factor: 8
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Post by emiryuuu on Sept 20, 2010 9:43:31 GMT -5
I Solved partially, Because in the LDPC Error Rate calculation block I setted a wrong delay, now 4 is the correct delay introduced by the Raised Cosine Filter. But Anyway, the BER remains too High. I.E. for Es/No = 40 dB I have 2.3e-05 BER.. too high!
If you want I can send you the model file.
what's wrong? I would have low BER values.
Please help me.
Thanks a lot,
Emilio.
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Post by charan langton on Oct 2, 2010 1:52:56 GMT -5
Do only have noise in the model? What about a non-linearity?
Charan
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