MC92314 Datasheet, PDF (31/100 Pages) Motorola, Inc – DVB-T Single Chip Demodulator Application Note

Freescale Semiconductor, Inc.
Device Description
BER
2
1e-01
5
2
1e-02
5
2
1e-03
5
QEF ₂
1e-04
5
2
•_r=1/2
+_r=2/3
×_r=3/4
♥
+
×
♦
♦
♥
♦_r=5/6
♥_r=7/8
•
+
×
•
+
♥
♦
×
•
♥
0.00
♦
tion ^•
+
×
♦
♥
a •
+
×
m^♦
♥
for^•
+
×
In ^•
♦
•
+
y×
inar ^•
+
×
lim _1.00
2.00
3.00
4.00
5.00
Pre ^{Figure 3-8. BER versus SNR}
♥
♥♥
♥
♥
♦
Eb/N0 (dB)
6.00
3.2.3.2.2 Decoding Latency
A survivor depth of 96 is used to ensure reliable error correction for highrate punctured codes
such as the 7/8 code. The latency of the decoder (in symbols) is approximately 2.5 x the survivor
depth (the uncertainty in the latency is due to the input FIFO which gives a range of + or - 16
symbols).
NOTE
This latency applies for all coding rates not just the 7/8 rate.
The absolute worst case latency is thus: (2.5 x 96) + 16 = 256 symbols.
Single Chip DVB-T Demodulator - Rev. 1.3 (11/30/98)
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MOTOROLA
3-13