ANSI SCTE 56 pdf free download
ANSI SCTE 56 pdf free download.Digital Multiprogram Distribution by Satellite.
3.1.2 Matched filter
This universal element of a satellite IRD performs the complementary pulse shaping filtering type according to the roll-off. The use of a Finite Impulse Response (FIR) digital filter could provide equalization of the channel linear distortions in the IRD.
This universal element of a satellite IRD shall be capable of processing signal with the following shaping and roll-off factors:
Square Root Raised Cosine: a=0.35 and 0.20
Band-limited 4th order Butterworth Standard and Truncated-spectrum modes
Information about the template for the signal spectrum at the modulator output is given in § 5.1.
3.1.3 Convolutional decoding
This universal element of a satellite IRD performs first level error protection decoding. It will operate at an input equivalent “hard decision” BER in the order of between 101 and 102 (depending on the adopted code rate), and will produce an output BER about 2x l0 or lower. This output BER corresponds to QEF service after outer code correction. It is possible that this unit makes use of “soft decision” information. This unit is in a position to try each of the code rates and puncturing configurations until lock is acquired. Furthermore, it is in a position to resolve m/2 demodulation phase ambiguity.
The inner code has the following characteristics:
• Viterbi and puncturing
• Code constraint length K = 7
3.1.4 Sync byte decoder
This universal element shall decode the sync bytes. This decoder provides synchronization information for the deinterleaving. It is also in a position to recover it ambiguity of QPSK demodulator (not detectable by the Viterbi decoder).
Specific characteristics are provided in § 5.3.
3.1.5 Convolutional deinterleaver
This universal element allows the error bursts at the output of the inner decoder to be randomized on a byte basis in order to improve the burst error correction capability of the outer decoder. This universal element of a satellite IRD shall be capable of receiving Ramsey Type III (Forney approach) (1= 12, M=l7 and J=l9) convolutional interleaver systems, as specifically defined in §5.4.
3.1.6 Reed Solomon decoder
This universal element of a satellite IRD provides second level error protection. It is in a position
to provide QEF output (i.e. BER of about 10b0 and l0’ 1) in the presence of input error bursts at a
BER of about 7x lO or better with infinite byte interleaving. In the case of interleaving depth I =
12, BER = 2x 1 O is assumed for QEF.
3.2 Transport and demultiplexing The block diagram of the Transport and Demultiplexing functions for the satellite IRD is presented in Fig. 5. The system shall be capable of receiving and demultiplexing packets following MPEG-2 transport multiplexer (see ISO/IEC 13818-1 [1]) as well as transport stream specific characteristics defined in 8 5.7. Conditional Access is out of the scope of this standard.
3.3.1 Video
This universal element of a satellite IRD shall require, as a minimum, the decoding of video formats lollowing the main profile main level MPEG-2 signals which have been coded as specified in ISO/IEC 13818-2 [2].
3.3.2 Audio
This universal element of a satellite IRD shall require the decoding of audio signals following the
MPEG-2 Layers! and!! (ISO/IEC 11172-3 [31) and Recommendation ITU -R BS.I 196, Annex 2
161 with constraints specified in ATSC-A/53 Annex B 141.
3.3.3 Data
This block addresses the functions to process the data associated to the transport multiplex. This
item is out of the scope of this standard.
4 Summary characteristics of digital multiprogram TV systems by satellite
Table 1 provides information on relevant parameters which characterize the systems in use in the world. It includes core functions as well as additional essential functions.ANSI SCTE 56 pdf download.
