Safran CORTEX Series - Punctured Viterbi; Figure 17: Viterbi De-Puncturing Process

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 89
Punctured Viterbi 3.3.3.4
Punctured Viterbi is supported for most puncturing rates:
2
/
3
3
/
4
4
/
5
5
/
6
6
/
7
7
/
8
Puncturing codes (Code 0 and Code 1) and swap sequence must be programmed in the registry (see
section 0).
FIFO 1
FIFO 2
I1
I2
NULL
Code 1
Code 0
1
0
0
1
Swap sequence
0
0
1
Vector
Demodulator
Viterbi
Decoder
De-puncturing & swapping
Example: ¾ Punctured Dual Viterbi:
C0(1) C1(2) C0(4) C1(5)
C1(1) C0(3) C1(4) C0(6)
De-puncture
3/4
C0(1) NULL C0(3) C0(4) NULL C0(6)
C1(1) C1(2) NULL C1(4) C1(5) NULL
Registry keys : VitPunctCode0 : 1 1 0 1 1 0
VitPunctCode1 : 1 0 1 1 0 1
VitPunctSwap : 0 1 1 0 1 1
G1 Viterbi input = C0
G2 Viterbi input = C1
Viterbi decoder setting : “ G1-G2”
QPSK
demodulation
3/4
Punctured
3/4
Punctured
Viterbi (2,1,7)
decoder
Viterbi (2,1,7)
decoder
DNRZ
(option)
Figure 17: Viterbi De-puncturing Process.