Re: PAM-5, what are your BERs ?

[Ed Grivna <elg@xxxxxxxxxxx>]

Hi Sean,

unfortuantely, FEC has additional drawbacks beyond just latency.  the
primary concern here would be that you need to ratchet-up the signaling 
rate even faster to include the overhead of sending the FEC bits.  
Depending on the amount of redundancy in the FEC information,
you may need to increase the signalling rate as much as 5-to-10%.

Regards,

Ed Grivna
Cypress Semiconductor

> 
> Hello,
> 
> With regards to the BER problem, are we open to the possible use of forward 
error
> correction to correct for bit errors in the transmission stream. Currently in
> T1X1.5, there is a submission for inband FEC based on a BCH-3 code that turns 
a
> 1x10**-7 BER into a corrected BER of 1x10**-17. Prehaps a BCH-1 code could be 
used?
> Using FEC would introduce the need for some additional bits within the frame 
format
> and it would probably introduce some latency, but it would introduce some 
coding
> gain.
> 
> Cheers,
> Sean
> 
>