Safran CORTEX Series - Page 6

HIGH DATA RATE RECEIVER
HDR-4G+ USER’S MANUAL
Ref. DTU 100782
Is.Rev 3.5
Date: June 1, 2021
© Safran Data Systems – IMP000074 e14r1
This document is the property of Safran Data Systems.
It cannot be duplicated or distributed without expressed written consent.
Page 6
PRN-BER Computation ............................................................................................................................ 108 3.3.8
BER on Separate I & Q Channels ......................................................................................................... 108 3.3.8.1
BER on Merged I & Q Channels .......................................................................................................... 108 3.3.8.2
Digital Outputs ......................................................................................................................................... 109 3.3.9
Doppler and Integrated Phase Measurement ........................................................................................ 110 3.3.10
Introduction ......................................................................................................................................... 110 3.3.10.1
Required setup for optimal performance............................................................................................. 110 3.3.10.2
Sampling rate ...................................................................................................................................... 111 3.3.10.3
Accumulated Phase Format ................................................................................................................ 112 3.3.10.4
Displaying the carrier offset of the Doppler port in the DMU window .............................................. 115 3.3.10.5
Interpolation Process ........................................................................................................................... 116 3.3.10.6
Doppler Computing ............................................................................................................................ 116 3.3.10.7
Impact of Phase Errors on Doppler Computing .................................................................................. 117 3.3.10.8
Sampling Period Resolution................................................................................................................ 117 3.3.10.9
Error Due to Computing .................................................................................................................. 117 3.3.10.9.1
Error Due to Floating Representation .............................................................................................. 118 3.3.10.9.2
Es/N0 estimators in DVB-S2 and SCCC environment ........................................................................... 118 3.3.11
Warning............................................................................................................................................... 118 3.3.11.1
Standard Es/N0 estimation .................................................................................................................. 118 3.3.11.2
Data-aided Es/N0 estimation in SCCC and DVB-S2 ......................................................................... 120 3.3.11.3
DATA PROCESSING ...................................................................................................................................... 123 3.4
Functional Breakdown of the Data Processing Unit ............................................................................... 123 3.4.1
Frame Synchronization & Ambiguity Resolution ..................................................................................... 124 3.4.2
Frame Synchronization Strategy ........................................................................................................... 124 3.4.2.1
Frame Synchronizer Input ..................................................................................................................... 125
3.4.2.2
Automatic PSK Ambiguity Resolution ................................................................................................. 125 3.4.2.3
CCSDS Data De-randomizer ................................................................................................................... 126 3.4.3
Customized Data De-randomization ........................................................................................................ 127 3.4.4
CRC Frame Checking .............................................................................................................................. 128 3.4.5
(255,223) Reed-Solomon Decoding ......................................................................................................... 128 3.4.6
(255,239) Reed-Solomon Decoding ......................................................................................................... 129 3.4.7
(10,6) Reed-Solomon Frame Header Decoding ....................................................................................... 129 3.4.8
Specific Decoding ..................................................................................................................................... 129 3.4.9
LDPC Decoding ..................................................................................................................................... 130 3.4.10
Introduction ......................................................................................................................................... 130 3.4.10.1
LDPC 7/8 for near-earth applications ................................................................................................. 130 3.4.10.2
AR4JA LDPC ½, 2/3, 4/5 codes for deep space applications ........................................................... 130 3.4.10.3
Implementation ................................................................................................................................... 130 3.4.10.4
Performances ....................................................................................................................................... 131 3.4.10.5
Recording and Data Transmission over Ethernet .................................................................................. 131 3.4.11
General consideration ......................................................................................................................... 131 3.4.11.1
Data Storage ........................................................................................................................................ 131 3.4.11.2
TCP-IP Data Recovery........................................................................................................................ 132 3.4.11.3
Archiving and FTP Recovery ............................................................................................................. 133 3.4.11.4
Generality ......................................................................................................................................... 133 3.4.11.4.1
Overview ....................................................................................................................................... 133 3.4.11.4.1.1
Data files structure ........................................................................................................................ 134 3.4.11.4.1.2
Report files structure ..................................................................................................................... 134 3.4.11.4.1.3
Standard FTP CCSDS mode ............................................................................................................ 135 3.4.11.4.2
FTP user defined mode .................................................................................................................... 137 3.4.11.4.3
Playback function ................................................................................................................................... 138 3.4.12