Re: [BP] Informative Channel
sugawara,
1. The channel itself will essentially kill the 3rd and higher
harmonics of Nyquist. The full 2dB should apply.
2. Just how much good a DFE Rx will do, recognizing signals which
look like 5.156GHz sine waves and passing them while rejecting
interference which looks like a 5.156GHz sine wave, i do not
know. I hope to learn more.
4. Maybe i am too optimistic about riding over dips in the
transfer characteristic.
I plan to present some stuff in this general area at the Minneapolis
meeting, trying to come up with the correct values to use in the
interference tolerance test (72A, changing i think to 69A). Thank
you for helping me to clarify my thinking.
charles
--
|--------------------------------------------------------------------|
| Charles Moore
| Agilent Technologies
| ASIC Products Division
| charles_moore@agilent.com
| (970) 288-4561
|--------------------------------------------------------------------|
> Hello, Charles,
>
> I agree your "nits" points.
>
> 1. You are right for 4/pi (2dB) factor in a case of square wave at
> TX output.
> In actual case, for example there is 0.5pF stray capacitance
> including TX output transistors, ESD protectors, etc.,
> 3rd harmonic will be -13dB referring to 5GHz sine wave, and the
> factor between composite p-p vs sine wave is almost 1dB.
> This is the reason why I ignored the factor previously. But I
> agree that still 1dB difference exits.
>
> 2. I agree that RX equalization need to boost at least 5GHz.
>
> 4. Length of ..0101.. can be 31~32bit at PRBS31. In the case,
> its spectra distributes approximate 250MHz width. I'm not sure
> that it is wide enough to cover dip and peak of frequency ripple.
> I understand 5dB is too match. please teach me how many dB is
> reasonable.
> I guess 0101010 (8bit length) spreads approximate 1GHz, and ok to
> cover dip and peak.
>
>
> I am still wondering BER at lower S/N case.
>
>
> M. Sugawara
>