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Unformatted text preview: sing the following equation: L = (255-2E-q) I
such that L is a positive integer,
where E = error correction capability,
q = number of virtual fill symbols per R-S codeword, and
I = interleaving depth. 10.5.4 When 32-bit compatibility is required, the Transfer Frame length must be chosen so
that a) it is expressed by the equation in 10.5.3; and
b) the codeblock length (255-q)I (in octets) is a multiple of 4.
10.6 CASE 4: CONCATENATED The allowable lengths of Transfer Frames when the concatenated (Reed-Solomon and
convolutional) coding is used are the same as those for the Reed-Solomon–only case (Case
3) shown in 10.5.
10.7 CASE 5: TURBO
10.7.1 The Transfer Frame lengths shall be selected to match the information block lengths
for the selected Turbo code. NOTE – The Turbo Codes specified in section 5 of this Recommended Standard are block
10.7.2 Only the following information block lengths shall be used (values are in octets): a) 223;
d) 1115. CCSDS 131.0-B-2 Page 10-2 August 2011 CCSDS RECOMMENDED STANDARD FOR TM SYNCHRONIZATION AND CHANNEL CODING NOTE – Performance for only the above block lengths (i.e., Transfer Frame lengths) has
been validated by CCSDS and approved for use (values are in octets).
10.8 CASE 6: LDPC
10.8.1 The Transfer Frame lengths must match the information block lengths for the selected
LDPC code. NOTE – The LDPC Codes specified in section 7 of this Recommended Standard are block
10.8.2 When the rate-7/8 LDPC code is used, the only allowable Transfer Frame length is
10.8.3 When the 1/2-, 2/3-, and 4/5-rate LDPC codes are used, the allowable Transfer Frame
lengths are 128 octets, 512 octets, or 2048 octets. CCSDS 131.0-B-2 Page 10-3 August 2011 CCSDS RECOMMENDED STANDARD FOR TM SYNCHRONIZATION AND CHANNEL CODING 11 MANAGED PARAMETERS
11.1 OVERVIEW In order to conserve bandwidth on the space link, some parameters associated with
synchronization and channel coding are handled by management rather than by inline
communications protocol. The managed parameters are those whi...
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This document was uploaded on 03/06/2014.
- Spring '14