Re: [802.3_10SPE] Scrambler proposal Hongming An
Thanks Conrad!
1) - the first four 4b5b symbols need to be robustly detected to start the scrambler in the receiver
Yes this is valid argument. First for DME theoretically if you see a "0" to"1" transition you will determine the clock edge and data edge therefore recover the data and clock, JJJK has 32bits which should be sufficient for the scrambler after last "K". In fact the PLCA is based on this assumption otherwise it will not work;
2) short control frames with the first four 4b5b symbols should also be free of spikes in the emissions PSD
Yes these JJJK is a repeated pattern but just 4bytes which is a very small portion of the rest of preamble and payload. In our sim, the effect of these K codes are take into account.
Best regards,
Hongming
-----Original Message-----
From: Zerna, Conrad [mailto:conrad.zerna@xxxxxxxxxxxxxxxxx]
Sent: Wednesday, February 28, 2018 8:30 AM
To: STDS-802-3-10SPE@xxxxxxxxxxxxxxxxx
Subject: [802.3_10SPE] Scrambler proposal Hongming An
Hi Hongming,
your proposal to apply the scrambler earlier in the frame than payload data, is interesting. And I agree, that any preamble should have a good DC balance.
However, you have to take care of two things:
- the first four 4b5b symbols need to be robustly detected to start the scrambler in the receiver
- short control frames with the first four 4b5b symbols should also be free of spikes in the emissions PSD
Regards, Conrad
________________________________________________________________________
To unsubscribe from the STDS-802-3-10SPE list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-10SPE&A=1
________________________________________________________________________
To unsubscribe from the STDS-802-3-10SPE list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-10SPE&A=1