Pulse or digital communications – Receivers – Automatic frequency control
Reexamination Certificate
2000-11-03
2004-10-26
Burd, Kevin M (Department: 2631)
Pulse or digital communications
Receivers
Automatic frequency control
C375S376000
Reexamination Certificate
active
06810097
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a carrier reproduction circuit used in a receiver for receiving a signal transmitted via for example a satellite, such a receiver, and a loop filter circuit and an oscillator circuit used in the receiver etc.
2. Description of the Related Art
In May 1997, Japan's Radio Regulatory Council gave its stamp of approval to a draft basic plan regarding promotion of broadcasting by satellites following the existing four systems (hereinafter, referred to as “post-BS-4 satellites”) so as to take over for example the standard television broadcasting of the stage of the third broadcasting satellite using the satellite use frequency. The plan called for (1) starting digital broadcasting by post-BS-4 satellites by the year 2000, (2) securing in the post-BS-4 satellites transitional channels for broadcasting of the same content as the existing four systems of broadcasting so as to take over the standard television broadcasting of the stage of the third broadcasting satellite, and (3) focusing on high definition television (HDTV) broadcasting other than (2).
Upon receipt of this report, the Japan Digital Broadcasting System Committee discussed technical conditions such as a transmission line encoding systems, multiplexing systems, a limited reception systems, and information source encoding systems assuming the requested conditions for satellite digital broadcasting based on proving tests. It issued a report concerning the technical conditions of the satellite digital broadcasting system in February 1998.
In this report, the Committee called for the adoption of trellis coded 8-phase shift keying (TC8PSK) with its high efficiency of frequency utilization among the phase shift keying (PSK) modulation systems suited for satellite transmission in the application of the specific transmission line encoding. Further, it decided on a system enabling switching to another PSK modulation system such as a quadrature PSK (QPSK) system since there is a tradeoff between efficiency of frequency utilization and tolerance to attenuation by rain and enabling achievement of a further higher service time rate. On the other hand, it also envisioned that a plurality of HDTV signals of different carriers would be multiplexed and transmitted by a single satellite repeater and considered as well transmission by a plurality of transport streams (TS) in order to improve the independence of Individual programs. Further, it called for multiplexing of transmission and multiplexing configuration control (TMCC) signals for control for transmission systems in areas other than MPEG control items, for example, the switching of the modulation systems and flexible configuration of a plurality of transport streams.
A TMCC signal contains TMCC information indicating a transport stream and modulation system for every slot data in a frame.
Below, an explanation will be made of the transmission line encoding system described in the report.
FIG. 1
is a view of the configuration of a broadcast satellite transmitter
1
employing the related transmission line encoding system.
As shown in
FIG. 1
, the broadcast satellite transmitter
1
has a Reed-Solomon encoder
2
, a frame builder
3
, an energy disperser
4
, an interleaver
5
, a convolution/trellis encoder
6
, a TMCC signal generator
7
, a Reed-Solomon encoder
8
, an energy disperser
9
, a modulator
10
, and a burst signal generator
11
.
The Reed-Solomon encoder
2
sequentially receives as its input, as shown in
FIG. 2A
, 188 bytes of Moving Picture Experts Group transport stream (MPEG-TS) packets S
0
having one byte of an MPEG use synchronization word (
47
h
) in a header, performs Reed-Solomon (
204
,
188
) encoding on the MPEG-TS packets S
0
, and generates
204
bytes of slot data S
2
shown in
FIG. 2B
comprised of the MPEG-TS packets S
0
plus 16 bytes of parity data.
The frame builder
3
, as shown in
FIG. 2C
, builds a frame FL
1
by 48 slots SL
1-1
to SL
1-48
input from the Reed-Solomon encoder
2
and similarly builds frames FL
2
to FL
8
. As shown In
FIG. 3
, it builds one super frame SFL by the eight frames FL
1
to FL
8
.
Note that, in
FIG. 3
, a case where the header bytes of the slot data are replaced by a frame synchronization signal portion TAB
2
, a super frame synchronization signal TAB
2
, and a TMCC signal portion is shown, but the header bytes of the slot data in the super frame SFL built by the frame builder
3
become MPEG use synchronization words.
The energy disperser
4
performs energy dispersal processing for adding a pseudo random signal generated by for example “X
15
+X
14
+1” in order to avoid a succession of the same logic values except at the header bytes of the slot data (MPEG use synchronization words) in units of the super frames SFL input from the frame builder
3
.
The interleaver
5
writes the super frame SFL subjected to the energy dispersal processing at the energy disperser
4
into a buffer memory and performs a read operation in a predetermined read direction except at the header byte of the slot data to thereby interleave the data.
The TMCC signal generator
7
uses the input TMCC information SI to generate, as shown in
FIG. 4
, 8 bytes of TMCC signals per frame and the 2 bytes of frame synchronization signal TAB
1
and the super frame synchronization signal TAB
2
added before and after them. As shown in
FIG. 4
, synchronization words W
1
for frame synchronization are set in the frame synchronization signals TAB
1
of the frames FL
1
to FL
8
. The TMCC information is set in the TMCC signals of the frames FL
1
to FL
6
. The parity data of the TMCC information to be added at the Reed-Solomon encoder
8
are set in the TMCC signals of the frames FL
7
and FL
8
. A synchronization word W
2
for super frame synchronization is set in the super frame synchronization signal TAB
2
of the frame FL
1
. Synchronization words W
3
for frame synchronization are set in the super frame synchronization signals TAB
2
of the frames FL
2
to FL
8
. Here, the synchronization word W
3
is obtained by inverting all the bits of the synchronization word W
2
.
The Reed-Solomon encoder
8
performs Reed-Solomon (
64
,
48
) encoding in units of the TMCC signals (TMCC information) of the frames FL
1
to FL
6
of the super frame SFL shown in FIG.
4
and sets the resultant parity data in the TMCC signals of the frames FL
7
and FL
8
shown in FIG.
4
. The Reed-Solomon encoder
8
does not encode the frame synchronization signal TAB
1
and the super frame synchronization signal TAB
2
.
The energy disperser
9
performs energy dispersal processing of the TMCC signals input from an external code error correctert
8
. The energy dispersal processor
9
does not perform the energy dispersal processing for the frame synchronization signal TAB
1
and the super frame synchronization signal TAB
2
but outputs them as they are.
The convolution/trellis encoder
6
generates transmission signals by replacing the header bytes of the slot data of the super frame SFL input from the interleaver
5
by the frame synchronization signal TAB
1
, the TMCC signal, and the super frame synchronization signal TAB
2
from the energy disperser
9
, performs convolution encoding on the signals, among the related transmission signals, to be subjected to binary PSK (BPSK) or QPSK modulation at the modulator
10
, and performs trellis encoding on the signals to be subjected to the
8
PSK modulation at the modulator
10
, and outputs the results thereof to the modulator
10
.
The modulator
10
performs BPSK modulation on the convolution encoded frame synchronization signal TAB
1
, TMCC signal, and super frame synchronization signal TAB
2
and sequentially transmits them, then transmits the main signals of the slot data modulated by the individual modulation systems and building the super frame SFL. Note that the modulation system of each slot data is designated by the TMCC information of the TMCC signal in the super frame two super frames before.
Further, the modulat
Burd Kevin M
Frommer William S.
Frommer & Lawrence & Haug LLP
Simon Darren M.
Sony Corporation
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