EFFICIENT FRAMING SCHEMES FOR SUPPORTING VCM/ACM IN DIGITAL SATELLITE TRANSMISSION SYSTEMS
A digital communication system and method using a digital signal having a plurality of frames to transmit data, including a first frame and a second frame, wherein each of the plurality of frames has a frame structure; and wherein the first frame has, a plurality of codewords comprising user data, and a Next Frame Composition Table to set the structure for the second frame, and wherein the second frame has at least one codeword.
1 . A digital communication system using digital transmissions, the digital transmissions comprising:
a plurality of frames to transmit data, including a first frame and a second frame, wherein each of the plurality of frames has a frame structure;
wherein the first frame comprises,
a plurality of codewords comprising user data, and
a Next Frame Composition Table to set the structure for the second frame, and wherein the second frame comprises at least one codeword.
2 . The digital communication system of claim 1 , wherein the first frame further comprises a header, and the Next Frame Composition Table is in the header.
3 . The digital communication system of claim 1 , wherein the plurality of codewords in the first frame comprises a first codeword, and the Next Frame Composition Table is in the first codeword.
4 . The digital communication system of claim 1 , wherein the digital communication system uses an ACM mode.
5 . The digital communication system of claim 1 , wherein the digital communication system uses a VCM mode.
6 . The digital communication system of claim 1 , wherein the Next Frame Composition Table is to set the structure for every frame except the first frame.
7 . The digital communication system of claim 1 , wherein the Next Frame Composition Table defines the number of codewords per frame.
8 . The digital communication system of claim 1 , wherein each of the plurality of frames comprises at least one codeword.
9 . The digital communication system of claim 1 , wherein the Next Frame Composition Table is used to determine where the codewords start and stop.
10 . The digital communication system of claim 1 , wherein the Next Frame Composition Table defines a structure of the codewords.
11 . The digital communication system of claim 1 , wherein the Next Frame Composition Table defines a padding structure for at least one frame.
12 . The digital communication system of claim 1 , wherein the plurality of codewords in the first frame comprises a first codeword, and the Next Frame Composition Table is in a codeword other than the first codeword.
13 . The digital communication system of claim 1 , wherein the system uses at least one of the following modulation types: QPSK, 8PSK, 16APSK or 32APSK.
14 . The digital communication system of claim 1 , wherein the structure for the second frame comprises a modulation and/or a coding format.
15 . The digital communication system of claim 14 , wherein the modulation and/or coding format of the first codeword in a frame is overwritten by an auxiliary control code.
16 . The digital communication system of claim 1 , wherein codewords in at least one of the plurality of frames use different modulation.
17 . The digital communication system of claim 1 , wherein codewords in at least one of the plurality of frames use different FEC code rates.
18 . The digital communication system of claim 1 , wherein the Next Frame Composition Table reduces transmission overhead when the system uses the ACM mode
19 . The digital communication system of claim 1 , wherein delay-sensitive data is located in a first codeword of the first frame and non-delay-sensitive data is located in at least one other of the plurality of codewords in the first frame.
20 . The digital communication system of claim 1 , wherein data streams having different modulation and code rates are to be transmitted simultaneously in the ACM mode.
21 . The digital communication system of claim 1 , wherein a unique word position and a frame length in a VCM mode and an ACM mode are the same as those of a CCM mode.
22 . The digital communication system of claim 20 , wherein the VCM mode and the ACM mode are compatible with the CCM mode.
23 . The digital communication system of claim 1 , wherein for a VCM mode a modulation and a code rate are fixed for all the codewords in each frame.
24 . The digital communication system of claim 1 , wherein a VCM mode can accommodate different users with different link budget requirements.
25 . A method of digital communication, comprising:
transmitting a digital signal; and
receiving a digital signal;
wherein the digital signal comprises,
a plurality of frames to transmit data, including a first frame and a second frame, wherein each of the plurality of frames has a frame structure; and
wherein the first frame comprises,
a plurality of codewords comprising user data, and
a Next Frame Composition Table to set the structure for the second frame, and
wherein the second frame comprises at least one codeword.
26 . A digital communication system, comprising:
a transmitter to transmit a digital signal; and
a receiver to receive a digital signal;
wherein the digital signal comprises,
a plurality of frames to transmit data, including a first frame and a second frame, wherein each of the plurality of frames has a frame structure; and
wherein the first frame comprises,
a plurality of codewords comprising user data, and
a Next Frame Composition Table to set the structure for the second frame, and
wherein the second frame comprises at least one codeword.
27 . A digital communication system using digital transmissions, the digital transmissions comprising:
a plurality of frames to transmit data, wherein each of the plurality of frames has a frame structure comprising,
a frame header, and
a plurality of codewords, one of which comprises a Next Frame Composition Table to set the frame structure for the next frame.
28 . A method of digital communication, comprising:
transmitting a digital signal; and
receiving a digital signal;
wherein the digital signal comprises,
a plurality of frames to transmit data, wherein each of the plurality of frames has a frame structure; and
wherein each of the plurality of frames comprises,
a frame header, and
a plurality of codewords comprising user data, wherein at least one of the codewords comprises a Next Frame Composition Table to set the structure for the next frame.
29 . A digital communication system, comprising:
a transmitter to transmit a digital signal; and
a receiver to receive a digital signal;
wherein the digital signal comprises,
a plurality of frames to transmit data, wherein each of the plurality of frames has a frame structure; and
wherein each of the plurality of frames comprises,
a frame header, and
a plurality of codewords comprising user data, wherein at least one of the a Next Frame Composition Table to set the structure for the next frame.