Method and system for transmitting satellite signals and receiver thereof

• US 10,237,630 B2
• Filed: 01/11/2018
• Issued: 03/19/2019
• Est. Priority Date: 09/09/2013
• Status: Active Grant

• Current Assignee: RAI Radiotelevisione Italiana SPA (Government of Italy)
• Original Assignee: RAI Radiotelevisione Italiana SPA (Government of Italy)
• Inventors: Morello, Alberto, Mignone, Vittoria, Sacco, Bruno
• Primary Examiner(s): Pendleton, Brian T
• Assistant Examiner(s): Luong, Alan H
• Application Number:
  US15/868,769
• Publication Number:
  US 20180132013A1
• Time in Patent Office: 432 Days
• Field of Search: 725 63, 725 68, 725 71, 725 74, 725 78, 725 83, 725 85, 725116, 380225, 370338
• CPC Class Codes: H04B 7/18523 Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 65/61 for supporting one-way streaming services, e.g. Internet radio
• CPC Class Codes: H04N 21/23655 Statistical multiplexing, e.g. by controlling the encoder to alter its bitrate to optimize the bandwidth utilization
• CPC Class Codes: H04N 21/6143 involving transmission via a satellite
• CPC Class Codes: H04N 21/8547 involving timestamps for synchronizing content

Abstract

A transmission system, a receiver and a method for satellite signal transmission, wherein the satellite signals includes respective data streams consisting of a sequence of data packets. The method incudes: subdividing the data packets of the data stream, through a splitter, into a first and at least one second data pseudo-streams; modulating the first and at least one second data pseudo-streams through a first and at least one second modulators, respectively; transmitting the modulated data pseudo-streams through respective transmission channels (Ch#1 . . . Ch#N), wherein, in order to generate the data pseudo-streams, the splitter will: select each data packet of the data stream; interrogate the modulators in a sequential manner in order to identify that modulator which, among the modulators, is available to accept the data packet, and send the latter to it; send a null data packet to the remaining modulators.

Claims

1. A transmitter comprising:

a splitter configured to receive a data stream comprising data packets and configured to subdivide the data stream into a plurality of data pseudo-streams, wherein subdividing the data stream into the plurality of data pseudo-streams comprises;

the splitter diverting a first data packet from the data stream so that the first data packet is added to a first data pseudo-stream, and

when the splitter diverts the first data packet to the first data pseudo-stream, the splitter also sends a null data packet to any remaining data pseudo-streams in the plurality of data pseudo-streams;

a plurality of modulators each configured to modulate one of the data pseudo-streams;

the transmitter being further configured to transmit the modulated data pseudo-streams through respective transmission channels.

2. A transmitter according to claim 1, wherein one of the plurality of modulators is a master modulator comprising a counter block operating at a frequency equal to a symbol rate of the master modulator, wherein the transmitter is configured to add a value of the counter block to each data packet of the data pseudo-streams that is sent to a modulator.

3. A transmitter according to claim 2, wherein the value is inserted in the ISSY field of each data packet.

4. A transmitter according to claim 1, wherein the splitter is configured to interrogate each of the modulators in order to identify which modulator is available to accept a data packet to be transmitted, and to send the data packet to be transmitted to the identified modulator.

5. A transmitter according to claim 1, wherein each modulator is configured to send a packet request to the splitter through a control signal.

6. A transmitter according to claim 1, wherein η

i is a spectral efficiency of an i-th modulator and mcd is a lowest common denominator of a set of spectral efficiencies η

1, . . . , η

N, and wherein the splitter is arranged to pack each data pseudo-stream according to a time periodicity equal to (η

1+ . . . +η

N)×

mcd packets of the data stream, so that, given a period of the data stream, the data pseudo-streams will have the same period, within which an i-th data pseudo-stream will contain η

i×

mcd data packets extracted from the data stream and any remaining packets will be null, and wherein time positions of the data packets of the data stream are kept unchanged in the data pseudo-streams.

7. A transmitter according to claim 1, wherein the data stream is a single-type MPEG-TS stream, wherein a Null Packet Deletion mode and/or a Dummy Frame Insertion mode are activated in the modulators.

8. A transmitter according to claim 1, wherein a transmission rate adapter system is disabled in the modulators.

9. A transmitter according to claim 1, wherein Service Information tables are transmitted on the data pseudo-streams, the tables containing information necessary for knowing frequency positions of channels that are bonded together for transmitting the data stream and for identifying a master channel.

10. A transmitter according to claim 9, wherein, when a data packet of the data stream contains a piece of information of a first Service Information table, a presence of the piece of information being indicated by a PID field in a header of the data packet, the data packet will be simultaneously sent to all of the data pseudo-streams so that no data pseudo-stream will contain a null packet.

11. A receiver for receiving a satellite signal sent through a plurality of transmission channels, comprising:

a plurality of demodulators each configured to demodulate a signal received from one of the plurality of transmission channels and to output a data pseudo-stream,

a merger arranged downstream the demodulators, configured to receive the data pseudo-streams and to merge the data pseudo-streams to obtain a reconstructed data stream that includes a sequence of data packets,

wherein, the merger is configured to;

re-align the data pseudo-streams on a basis of a value of a field of the data packet;

select, for each data packet of the re-aligned pseudo-streams, one that contains a non-null packet; and

insert the non-null packet into the reconstructed data stream.

12. The receiver according to claim 11, wherein, if at a certain time instant all the data packets of the data pseudo-streams are null packets, then the merger is configured to insert a null packet into the reconstructed data stream.

13. The receiver according to claim 11, wherein the field of the data packet is an ISSY field.

14. The receiver according to claim 11, wherein a Null Packet Reinsertion mode is activated in the demodulators.

15. The receiver according to claim 11, wherein the data pseudo-streams are re-aligned on a basis of an ISCR (“

Input Stream Clock Reference”

) subfield transmitted in an ISSY (“

Input Stream Synchronizer”

) field.

16. A method for managing an incoming data stream, the method comprising:

receiving a data stream that is comprised of data packets;

subdividing the data stream into a plurality of data pseudo-streams by performing the following;

diverting a first data packet from the data stream so that the first data packet is added to a first data pseudo-stream, and

sending a null data packet to any remaining data pseudo-streams in the plurality of data pseudo-streams when the first data packet is diverted to the first data pseudo-stream;

modulating each of the plurality of data pseudo-streams; and

transmitting each of the plurality of modulated data pseudo-streams through respective transmission channels.

17. The method of claim 16, wherein the data stream is an MPEG-TG transmission stream.