BER and EVM significance

[Jayeshkumar Prajapati]

Please can you suggest me some preferable values of BER and EVM for WDM OFDM based ROF system up to 1000 to 2500 Km channel span?
suggest me good reference if you can please…

[Jayeshkumar Prajapati]

please i need your valuable comments on my question…

[Priti Garg]

BER should be within10^-9 to 10^-12

[Dr. Dhiman Kakati]

Hi Preeti,
BER should be less than 10^-9 in electrical domain.

Regards,
Dhiman

[Abhilash Achanta]

Hi Jayeshkumar,

I am also working on RoF link. However, I am not considering WDM in my work and my range is upto 70 Km

Acceptable BER for RoF links is upto 10e-3. This value is known as ‘FEC limit BER’. This means that the we can tolerate any BER less than 10e-3 and the Forward Error Correction Codes (FEC) help in bringing down the BER to less than 10e-9.

I suggest that you run your simulation for different fiber lengths and check at what length BER is attaining 10e-3. This is the maximum distance your link can have.

I had attended an IEEE conference recently and one of them presented their work – BER comparison in ROF links.

[Priti Garg]

Thanks for sharing useful information
can you suggest what BER i should expect for an OFDM based QAM 16 link of 20 km length
Thanks

[Abhilash Achanta]

There is no standard values for BER as such. It depends on the components on the link such as Laser, fiber’s attenuation, amplifiers and photodetectors. For whatever length you simulate, you MUST ensure that BER is below 10e-3.
When I ran my simulation for OFDM based 16-QAM link at 20 Km length, the BER value was zero.

[Priti Garg]

Hi Abilash

i am attaching one sample file on OFDM if irun this i getBER =0.06 on BER test set, is it acceptable?

Regards

[Priti Garg]

I am attaching screen shot as I could not attach file

Attachments:

1. 

   coh-ofdm.png
   

[Abhilash Achanta]

No. Not at all acceptable. BER of 0.06 means there are 6 errors for every 100 bits of data. This cannot be corrected using FEC.
So, try reducing the fiber length until you get BER of 10e-3 which is acceptable

[Priti Garg]

Hi Abhilash

thanks or your reply.
As far as i read from previous posts we can not use BER analyser to measure BER for an OFDM system and we should use BER test set instead.

Is there any other way to measure BER in an OFDM system ?

Regards

[SAHOUI ELARABI]

hi abhilash_achanta

please, could you upload the paper where you got the BER less than 10-3?

regards

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