[Sls-ngu] FW: NGU direction

[Kazz, Greg J (313B)]

All,

I welcome the discussion within NGU on Ed's ideas below.

Ed is pointing out that a lot of the functionality that NGU would require to advance the state of the art of the current TC standard is within the scope of functionality of the on-board radio. Another aspect he did not touch upon is link layer security - this function could also be done within the radio.

Thanks,

Greg

From: Greenberg, Edward (313B)
Sent: Monday, September 27, 2010 4:06 PM
To: Lee Pitts; Victor Sank; Shames, Peter M (313B); SDLS WG; Howie Weiss; Johnson, Charles E (4400-Affiliate); Kazz, Greg J (313B); David Israel; Moe Kluksdahl; Lindolfo Martinez; Gain Paolo Calzolari; Takahiro Yamada; Edwards, Charles D (6000); Pollara, Fabrizio (3320); Hamkins, Jon (332B); Andrews, Kenneth S (332B); Hooke, Adrian J (9000); Lee, Dennis K (332C); Gilles Moury; Guy Lesthievent
Subject: NGU direction


I have been searching for a way to achieve a new a effective uplink and keep running into stone walls.  The following is what I understand:

A. If we want to get better uplink coding gain the onboard transponder needs to be upgraded to accomplish the following:

 1.  The receiver must provide soft symbols to the code decoder
 2.  The receiver design should require less power in the carrier to allow more power in the data.
 3.  The receiver should provide a mechanism to perform time correlation in the ranging syatem
 4.  The transceiver should be capable of providing ranging in the TLM channel when the ranging rate is lower than the data rate
    *   This will effect the TLM rate because of interference but we should determine its accepability
B.  The requirement for short command with low receiver latency for emergency commanding in tumbling events has significantly decreased or vanished.

 *   Near earth missions have lots of power to support high rates even to omni antennas
 *   deep space missions require safe modes for responding to anomalies with reduced but constant communication connections
C.  Better codes like the 1024 rate 1/2 LDPC code can provide 8db performance improvement.

 *   This can be accomplished using a TC lite protocol eliminating the BCH code or using AOS with frames locked to codeblocks.


So maybe the NGU WG should be expanded to include Radio personnel (including the Software defined radio), R.F. Modulation and link and coding protocol personnel.
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