µPC1876

13

Data Sheet S11666EJ4V0DS00

2.

FUNCTION OF EACH BLOCK

In the US, TV audio signals are broadcast in FM modulation. The stereo (L–R), Sub Audio Program (SAP) and

telemetry signals are multiplexed in a higher frequency band than the monaural (L+R) signal (50 Hz to 15 kHz).

The US MTS system base-band spectrum is described before:

Figure 2-1. US MTS System Base-Band Spectrum

(15.734 kHz)

Modulation frequency (Hz)

50

25

15

5

3

0

Stereo pilot

signal

Monaural

signal (L+R)

Stereo signal (L–R)

Sub Audio Program (SAP) signal

Telemetry

signal

Table 2-1. US MTS System Base-Band Spectrum

Signal frequency band

Signal processing system

Maximum audio

carrier deviation (kHz)

Monaural signal (L+R)

50 Hz to 15 kHz

25

Stereo pilot signal

15.734 kHz

Only stereo broadcasting

5

Stereo signal (L–R)

50 Hz to 15 kHz

50

dbx noise reduction processing

Sub Audio Program (SAP)

50 Hz to 10 kHz

signal

maximum frequency deviation 10 kHz)

dbx noise reduction processing

Telemetry

Audio

0 to 3.4 kHz

signal

Data

0 to 1.5 kHz

maximum frequency deviation 3 kHz)