1. In a digital data transmission system including a transmitter for transmitting signals, a terrestrial repeater comprising:
a receiving unit for detecting at least one of 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, wherein said receiving unit comprises 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, 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 OPSK, D-OPSK, and pi4 D-OPSK modulated data, and 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;
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 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.
3. 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 including the modulated primary data, wherein the primary data is encoded with a first number of information bits per symbol.
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 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.
5. 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 the modulated primary data encoded with 2 bits per symbol.
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 secondary data encoded with the 1 bit per symbol.
7. 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.
8. 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.
9. 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.
10. The repeater of claim 3 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.
11. The repeater of claim 10 wherein said receiving unit is adapted to receive the third transmit signal encoded with 3 bits per symbol.
12. 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.
13. 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 including secondary data spread over multiple symbols.
14. The repeater of claim 12 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.
15. The repeater of claim 12 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.
16. 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.
17. The repeater of claim 14 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.
18. 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.
19. The method of claim 17 further comprising the steps of interpreting the combined data signal and providing the information to an output unit.
20. 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, wherein said receiving unit comprises 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, 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 pi4 D-QPSK modulated data, and 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;
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.
21. The repeater of claim 20 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.
22. The repeater of claim 20 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.
23. The repeater of claim 20 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.
24. The repeater of claim 20 wherein said receiving unit is adapted to receive the third transmit signal, the third transmit signal comprising OFDM modulated data.
25. The repeater of claim 20 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.
26. The repeater of claim 20 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.
27. The repeater of claim 20 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.
28. The repeater of claim 20 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.
29. In a digital data transmission system including a transmitter for transmitting signals, a terrestrial repeater comprising:
a receiving unit for detecting at least one of 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 comprising OFDM modulated data;
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 wherein said receiving unit is adapted to receive the third transmit signal, the third transmit signal comprising OFDM modulated signal is inserted.
30. The repeater of claim 29 wherein said receiving unit comprises 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.
31. The repeater of claim 29 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 pi4 D-QPSK modulated data.
32. The repeater of claim 29 wherein said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals each comprising 8PSK modulated data.
33. The repeater of claim 29 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.
34. The repeater of claim 29 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.
35. The repeater of claim 29 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.
36. The repeater of claim 29 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.
37. The repeater of claim 29 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.
38. The repeater of claim 29 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.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Device for determining the dispersive influence of a measurement, in particular a measurement of distance, along a path according to the principles of phase or pulse modulation,
with means for the emission (1, 2, 3, 4) of electromagnetic radiation with at least two carrier wavelengths,
with means for the reception (7, 8, 9) of the at least two carrier wavelengths,
with means for travel time measurements (10) of the at least two different carrier wavelengths along the path,
with means for calculating (11) the dispersive influence on the measurement from the at least two measured travel times,
characterized in that
the means for emission (1, 2, 3, 4) are so designed that they will at least
in the form of at least a first semiconductor laser (2) emit a first carrier wavelength in the infrared or red wavelength region,
in the form of at least a second semiconductor laser (3) emit a second carrier wave-length in the violet wavelength region.
2. Device according to claim 1,
characterized in that
means to calculate a correction of the dispersive effects, for instance in distance measurements, are present.
3. Device according to one of the preceding claims,
characterized in that
the second carrier wavelength is in the range from 390 nm to 420 nm or from 425 nm to 455 nm.
4. Device according to one of the preceding claims,
characterized in that
the first semiconductor laser (2) and the second semi-conductor laser (3) have an identical or common electronic controller (1).
5. Device according to one of the preceding claims,
characterized in that
the electromagnetic radiation of the second carrier wavelength is intensity-modulated with rise times at most in the nanosecond range, and preferably in the picosecond range.
6. Device according to one of the preceding claims,
characterized in that
the means for reception (7, 8, 9) of electromagnetic radiation have a common optics for the at least two carrier wavelengths.
7. Device according to one of the preceding claims,
characterized in that
the means for reception (7, 8, 9) of electromagnetic radiation have optics with reflective elements.
8. Device according to one of the preceding claims,
characterized in that
at least one carrier wavelength, particularly the second carrier wavelength, is stabilized, for instance by
distributed feedback (DFB),
distributed Bragg reflector (DBR),
fibre Bragg grating (FBG), or
Fabry-Perot etalon locking.
9. Device according to one of the preceding claims,
characterized in that
means are present to compensate, preferably by calculation, an influence of thermal drift of at least one carrier wavelength, particularly the second carrier wavelength, on the dispersive effect, or to avoid this drift, preferably by temperature regulation of the means for emission.
10. Device according to one of the preceding claims,
characterized in that
the device or at least one of its means is modularly conceived.
11. Use of a device according to one of the preceding claims for correcting the influences on distance measurements resulting from dispersion.
12. Geodetic instrument, particularly a theodolite,
characterized in that
this is instrument has a device for determining the dispersive influence according to one of the claims 1 to 10.