Operation Manual Part 2

Digital Liquid Cooled UHF
TV Equipment
Description / Test points / Location of units
9946 V1
45321648.01 104 A E
preliminary
44 / 131
Numéro / Number Doc. Rev. Lan
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16/06/2006
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Information contained is this document is confidential, is THOMSON property and cannot be disclosed in whatever form without prior written authorization of THOMSON.
3.2.3.4. Synthesizer
Topography ref.7
♦ A digital programmable synthesizer is provided to deliver a sinusoidal signal at the transmitting
frequency between 430 and 900 MHz with an output level of 10 dBm / 50 ohms.
3.2.3.5. GPS receiver
Topography ref.12
♦ This low power miniature board GPS enable to get the 1 pps signal 10 µs pulse, UTC, 10 MHz.
3.2.3.6. Miscellaneous
The frame of the exciter included one complementary device :
♦ An LED board for front panel indications. ( Rep. 3)
3.2.3.7. Input processing
3.2.3.7.1. SFN System
For the SFN network the input module plays another role. Stuffing locally is just not possible, as all
transmitters have to radiate the same information at the same time. A transport stream that supports
SFN differs from the MFN transport stream by including the pps and flo frames data signal. The Mega
frame structure corresponds to 8 COFDM frames in the 8k mode, 16 frames in 4k mode. The SFN
input module must be able to receive external synchronizaton signals, frequency reference and timing
signals from a common reference, e.g. a GPS signals.
3.2.3.8. Control of timing
In an SFN application, the control of timing from input to output of the COFDM exciter is extremely
important, like the ability of the COFDM exciter to synchronize in frequency and time to an external
reference.