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RE: PAM-5, what are your BERs ?


At 02:17 PM 29-02-2000 -0500, Edward Chang wrote:
>We are discussing the product developments, which are based on proved
>theorems and equations to mathematically calculate all designs.  After that,
>setting up tests to confirm that the test data, and the analyses are
>correlated.  Otherwise, repeat the procedures to achieve the goals.
>Finally, it will go through extensive system tests and BER tests to certify
>a product.
>Engineers do not just "looking at a scope", then make the comment.  They
>theorize it, quantify it, then make comments.

right.  that may have been a bad choice of analogy, on my part.  i apologize 
if i have offended anyone.  in my read of this thread things seem fairly clear --
i gather, from all of this, that Vivek has a lot of experience in this, perhaps 
you do too.  it's my experience that Vivek's assessment is accurate, as posted.

>Unless, some one has extensive communication product development experience
>in the past, it is hard for a one to grasp, and appreciate the contents of
>the comments put forward on reflectors by those serious contributors.

agreed.  in any event a more rigorous proof is best delivered in an HSSG
meeting.  here, we can best highlight one or more concerns.

>The cascading of the frequency response of each component to predict the
>over-all system frequency response is a well known basic tool implemented by
>all circuit  designers.  It is as predictable as, 1+1 = 2.

well, i suppose so, though i'm not certain i follow your analogy.  here, i want
to suggest that observation of "a closed eye diagram" may be 'necessary'
but isn't always -sufficient- indication of intolerably high BER.  i believe there 
must be additional work.

J M Wincn, Staff Engineer
Cielo Communications, Inc.
325 Interlocken Pkwy, Bldg A
Broomfield, CO 80021-3497
Voice: 303-464-2264
Cell: 408-394-5283
Fax: 303-460-6348