Specifications
5/9/13 888-2857-001 3-67
WARNING: Disconnect primary power prior to servicing.
Section 3 Operation
Platinum VAX-C Series
L1 Mode Choices are BPSK, QPSK, 16QAM, or 64QAM. The L1 Mod referred to
above gives a choice of the modulation constellation for the P2 symbol(s).
L1 refers to the Layer 1 signalling within the T2 frame. L1 is split into three
main sections: The P1 signalling, the L1-pre signalling and L1-post
signalling. The the L1-pre and post signalling is carried by the P2 symbol(s),
which may also carry data.
PAPR Choices are None, ACE, TR, or ACE & TR.PAPR = peak to average power
ratio. This choice allows two methods of peak to average power ratio
reduction.
TR = Tone Reservation
ACE = Active constellation extension, The active constellation extension
technique should not be applied when rotated constellations are used or
when MISO is used.
Data Symbols per T2
frame
Programming range varies with the FFT size and the guard interval. The
maximum number of data symbols per T2 frame is given in the table below.
An odd number must be entered. If an even number or a number which is
over the limit is entered, the exciter will mute. A larger number is more data
efficient, but it also increases receiver lockup time.
T2 Frames per
Superframe
A super-frame is composed of a set of T2-frames consisting of a particular
number of consecutive T2-frames. A super-frame may include FEF (future
extension frames) parts, two FEF parts can not be adjacent (must be
separated by one or more T2 frames), and if FEFs are used, the super-frame
ends with a FEF part. The maximum time for the super-frame length (TSF) is
64 seconds if FEFs are not used (equivalent to 255 T2 frames of 250 ms) and
128 seconds if FEFs are used. The maximum number of T2 frames are
independent of the number of FEF parts used.
Softkeys
Setup Displays Setup screen.
Exciter Home Displays Exciter Home screen.
Table 3-40 Number of Carriers and Carrier Spacing
FFT Mode (No. Carriers) 1K 2K 4K 8K 16K 32K
Theoretical Max. Carriers 1024 2048 4096 8192 16384 32768
No. Carriers Normal Mode 853 1705 3409 6817 13633 27265
No. Carriers Extended Mode N/A N/A N/A 6912 13920 27840
Spacing Between Carriers Hz. 8929 4464 2232 1116 558 279
Table 3-39 Xmtr Home>Exciter Home>Setup>DVB-T2 Modulator>Next x3
(screen 4)
Field Explanation