RE: [amsat-bb] Fade remover

[Franklin Antonio <antonio@xxxxxxxxxxxx>]

At 05:50 PM 2/2/2001, Richard M. Hambly wrote:
>Unfortunately the CDP1802 CPU with 64k bytes ECC RAM running at 100K
>instructions/s in IHU-1 doesn't have the resources to handle the FEC
>and/or interleaving tasks.  It was a deliberate decision to stick with
>the tried and true technology for IHU-1.

If you begin with the notion that you can never change anything, then by 
definition, you can never improve.  No technology would exist if everyone 
followed this sort of logic, so its a darn good thing that they don't.

ENCODING an error-correcting code doesn't take much CPU.  It can be very 
simple.  The principles have been known about 30 years now.  Fear of 
error-correcting codes is irrational.

The following courtesy of Merriam Webster:

Ludd·ite
Function: noun
Etymology: perhaps from Ned Ludd, 18th century Leicestershire workman who 
destroyed machinery
Date: 1811
: one of a group of early 19th century English workmen destroying 
laborsaving machinery as a protest; broadly : one who is opposed to 
especially technological change
- Luddite adjective

Having said that, I do recognize the value of keeping the basic IHU very 
simple.  I think it is reasonable to argue that the situation we're in is a 
multiple failure at this point (omni antennas out of service, and 
difficulty controlling attitude), and such multiple failures were 
reasonably not considered during design.  To be clear, I'm not angry with 
the decisions that were made.

However arguing that a better link design couldn't be done is wrong.  Can 
be done with very simple 30-year-old coding technology.


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