Method to increase performance of secondary data in a heirarchial modulation scheme

• US 20070195868A1
• Filed: 04/25/2007
• Published: 08/23/2007
• Est. Priority Date: 11/26/2003
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Walker, Glenn, Hiatt, Michael, Dibiaso, Eric
• Granted Patent: US 7,656,966 B2
• Time in Patent Office: Days
• US Class Current: 375/211
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04L 27/3466 by providing an alternative to one signal point
• CPC Class Codes: H04L 27/3488 Multiresolution systems

Abstract

This invention provides a receiver for use in a SDAR system which includes a receiving unit having satellite signal detection means for detecting a first transmit signal transmitted from a first communication satellite and a second transmit signal transmitted from a second communication satellite, the first transmit signal produced when the transmitter modulates a primary data stream with a secondary data stream on a first carrier wave associated with the first communication satellite and the second transmit signal produced when the transmitter modulates the primary and secondary data streams on a second carrier wave associated with the second communication satellite, and an encoder re-encodes the primary and the secondary data on a third carrier wave, forming a third transmit signal which is re-transmitted to a receiver using a terrestrial repeater. This invention also provides a method of receiving transmitted data.

Claims

1. In a digital data transmission system including a transmitter for transmitting signals, a terrestrial repeater comprising:

a receiving unit for detecting a first transmit signal and a second transmit signal, the first transmit signal transmitted from a first communication satellite and produced when the transmitter modulates a primary and a secondary data on a first carrier wave associated with the first communication satellite, and the second transmit signal transmitted from a second communication satellite and produced when the transmitter modulates the primary and the secondary data on a second carrier wave associated with the second communication satellite;

an encoder for re-encoding the primary and the secondary data on a third carrier wave to form a third transmit signal; and

a re-transmitter for transmitting the third transmit signal to a receiver.

2. The repeater of claim 1 wherein said receiving unit includes an antenna in communication with a tuner unit for receiving the first and the second transmit signals, wherein the primary and the secondary data are modulated on the first and the second carrier waves using a M-PSK modulating scheme.

3. The repeater of claim 2 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including primary data comprising one of QPSK, D-QPSK and pi/4 D-QPSK modulated data.

4. The repeater of claim 3 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including secondary data comprising modulated data in the form of a phase offset relative to the modulated primary data.

5. The repeater of claim 4 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including secondary data comprising BPSK modulated data.

6. The repeater of claim 4 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including the modulated primary data, wherein the primary data is encoded with a first number of information bits per symbol.

7. The repeater of claim 6 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including the modulated secondary data, wherein the secondary data is encoded with a second number of information bits per symbol that is lower than the first number of information bits.

8. The repeater of claim 6 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including the modulated primary data encoded with 2 bits per symbol.

9. The repeater of claim 7 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including the modulated secondary data encoded with the 1 bit per symbol.

10. The repeater of claim 1 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals each comprising 8-PSK modulated data.

11. The repeater of claim 1 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals each comprising non-uniform 8-PSK modulated data.

12. The repeater of claim 1 wherein said receiving unit is adapted to receive first and the second transmit signals, the first and the second transmit signals each comprising Gray coded 8-PSK modulated data.

13. The repeater of claim 6 wherein said receiving unit is adapted to receive the third transmit signal encoded with a third number of information bits per symbol, the third number of information bits per symbol greater than the first and the second numbers of information bits per symbol.

14. The repeater of claim 13 wherein said receiving unit is adapted to receive the third transmit signal encoded with 3 bits per symbol.

15. The repeater of claim 1 wherein said receiving unit is adapted to receive the third transmit signal, the third transmit signal comprising OFDM modulated data.

16. The repeater of claim 3 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals each including secondary data spread over multiple symbols.

17. The repeater of claim 15 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals each including secondary data spread over a multiple of 2 symbols.

18. The repeater of claim 15 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals each including secondary data encoded to ensure a zero mean offset over the multiple symbols such that for each positive phase offset, there is a corresponding negative phase offset.

19. The repeater of claim 1 wherein said receiving unit is adapted to receive the first and the second transmit signals including primary data and secondary data, wherein the primary data is encoded with a different forward error correction algorithm than the secondary data.

20. The repeater of claim 17 wherein said receiving unit is adapted to receive the first and the second transmit signals, said signals including primary data encoded with one of a block forward error correction algorithm and a convolutional forward error correction algorithm and secondary data encoded with one of a turbo coding forward error correction algorithm and a low density parity check coding forward error correction algorithm.

22. The method of claim 20 further comprising the steps of interpreting the combined data signal and providing the information to an output unit.

21. In a satellite audio radio service system, a method for receiving transmitted data, the method comprising the steps of:

receiving a primary data stream and a secondary data stream from both a first communication satellite and a second communication satellite, the primary data stream having a first data rate and the secondary data stream having a second data rate;

determining the validity of said first and said second data streams; and

hierarchically modulating the primary and the secondary data streams to form a combined data stream when the secondary data stream is determined to be an enhancement to the primary data stream, wherein the combined data stream has a third data rate greater than the first data rate.