PRELIMINARY DATA SHEET
MSP 34x7G
5. Appendix A: Overview of TV Sound Standards
5.1. NICAM 728
Table 5–1: Summary of NICAM 728 sound modulation parameters
Specification
I
B/G
L
D/K
5.85 MHz
Carrier frequency of
digital sound
6.552 MHz
5.85 MHz
5.85 MHz
Transmission rate
Type of modulation
728 kbit/s
Differentially encoded quadrature phase shift keying (DQPSK)
by means of Roll-off filters
Spectrum shaping
Roll-off factor
1.0
0.4
0.4
6.5 MHz AM mono
0.4
Carrier frequency of
analog sound component
6.0 MHz
5.5 MHz
6.5 MHz
FM mono
FM mono
FM mono
terrestrial
10 dB
cable
Power ratio between
vision carrier and
analog sound carrier
10 dB
10 dB
13 dB
7 dB
16 dB
13 dB
Power ratio between
analog and modulated
digital sound carrier
17 dB
11 dB
China/
Hungary
Poland
7 dB
12 dB
Table 5–2: Summary of NICAM 728 sound coding characteristics
Characteristics
Values
32 kHz
2
Audio sampling frequency
Number of channels
Initial resolution
14 bit/sample
Companding characteristics
Coding for compressed samples
Preemphasis
near instantaneous, with compression to 10 bits/sample in 32-samples (1 ms) blocks
2’s complement
CCITT Recommendation J.17 (6.5 dB attenuation at 800 Hz)
+12 dBm measured at the unity gain frequency of the preemphasis network (2 kHz)
Audio overload level
Micronas
57
MICRONAS [ MICRONAS ]
