Signaling using phase rotation techniques in a digital communications system
DC CAFC
First Claim
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1. In a digital telecommunications system, a method for transmitting signaling information from a transmitter to a receiver comprising the steps of:
- identifying one of a plurality of information signals to be conveyed from the transmitter to the receiver in addition to data;
rotating each of one or more symbols by a common phase rotation factor, wherein the phase rotation factor uniquely identifies the one information signal to be conveyed from the transmitter to the receiver; and
transmitting each of the one or more phase-rotated symbols to the receiver.
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Abstract
In a telecommunications system, such as a cellular radio telecommunications system, transmission information, such as modulation scheme selection information, coding information or power level control commands, is efficiently conveyed from the transmitter to the receiver without increasing the bandwidth requirements and without introducing additional transmission delays. This can be accomplished by employing a data symbol phase rotation technique, wherein a sequence of data symbols, for example, a sequence of training symbols used for estimating the propagation characteristics of a given channel, are phase-rotated in accordance with a phase rotation factor that uniquely corresponds to the information being conveyed to the receiver. At the receiver, the symbols are de-rotated until the receiver recovers the training sequence. This allows the receiver to determine the phase rotation factor used to rotate the symbols at the transmitter. This, in turn, identifies the corresponding transmission information.
58 Citations
32 Claims
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1. In a digital telecommunications system, a method for transmitting signaling information from a transmitter to a receiver comprising the steps of:
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identifying one of a plurality of information signals to be conveyed from the transmitter to the receiver in addition to data;
rotating each of one or more symbols by a common phase rotation factor, wherein the phase rotation factor uniquely identifies the one information signal to be conveyed from the transmitter to the receiver; and
transmitting each of the one or more phase-rotated symbols to the receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7)
in the receiver, receiving a signal containing the one or more phase-rotated symbols;
generating samples of the received signal, wherein the samples correspond to the phase-rotated symbols;
de-rotating the samples, so as to recover a value associated with each of the one or more symbols; and
identifying the one information signal conveyed to the receiver from the transmitter as a function of the phase rotation factor required to recover the value associated with each of the one or more symbols.
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3. The method of claim 1, wherein the information signal represents one of a plurality of signal power control commands.
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4. The method of claim 1, wherein the information signal represents one of a plurality of modulation schemes.
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5. The method of claim 1, wherein the information signal represents coding information.
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6. The method of claim 1, wherein the one or more symbols are training symbols.
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7. The method of claim 1, wherein the one or more symbols include both training and data symbols.
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8. In a digital telecommunications system, a method for conveying modulation information from a transmitter to a receiver, said method comprising the steps of:
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selecting one of a plurality of modulation schemes;
modulating a sequence of training symbols in accordance with the selected one of the plurality of modulation schemes;
identifying a phase rotation factor which corresponds to the selected one of the plurality of modulation schemes, wherein at least one unique phase rotation factor is associated with each of the plurality of modulation schemes;
rotating the phase of each training symbol as a function of the identified phase rotation factor which corresponds to the selected one of the plurality of modulation schemes;
transmitting the sequence of phase-rotated training symbols to the receiver;
at the receiver, generating a sequence of de-rotated training symbols for each phase rotation factor by de-rotating the received sequence of phase-rotated training symbols as a function of each phase rotation factor;
comparing each sequence of de-rotated training symbols to an expected sequence of training symbols;
identifying the sequence of de-rotated training symbols that approximates the expected sequence of training symbols most accurately; and
identifying the selected one of the plurality of modulation schemes based on the phase rotation factor that produced the sequence of de-rotated training symbols that most closely approximated the expected sequence of training symbols. - View Dependent Claims (9, 10, 11, 12, 13, 14)
deriving a channel estimation for each sequence of de-rotated training symbols; and
prior to comparing each sequence of de-rotated training symbols to the expected sequence of training symbols, adjusting the sequence of expected training symbols as a function of the derived channel estimation corresponding to the sequence of de-rotated training symbols to which the sequence of expected training symbols is to be compared.
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10. The method of claim 8, wherein said step of selecting one of a plurality of modulation schemes is a function of a link quality adaptation assessment.
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11. The method of claim 8, wherein the sequence of training symbols to be transmitted to the receiver from the transmitter is the same for two or more of the modulation schemes.
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12. The method of claim 8, wherein the selected one of the plurality of modulation schemes involves Gaussian Minimum Shift Keying.
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13. The method of claim 8, wherein the selected one of the plurality of modulation schemes involves 4-Phase Shift Keying.
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14. The method of claim 8, wherein the selected one of the plurality of modulation schemes involves 8-Phase Shift Keying.
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15. In a digital telecommunications system, a method for identifying signaling information transmitted from a transmitter to a receiver along with data, said method comprising the steps of:
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receiving a signal containing a sequence of symbols transmitted from the transmitter, wherein the symbols include training symbols and data symbols, and wherein the phase associated with each symbol in the sequence of symbols has been rotated at the transmitter in accordance with a common phase rotation factor that corresponds to the signaling information;
generating samples from the received signal, wherein the samples correspond to the sequence of transmitted symbols;
recovering the sequence of transmitted symbols by de-rotating the samples in accordance with the common phase rotation factor; and
identifying the signaling information as a function of the common phase rotation n factor used to recover the sequence of transmitter symbols. - View Dependent Claims (16)
de-rotating each of the samples in accordance with a plurality of different phase rotation factors, wherein each of the plurality of different phase rotation factors corresponds to different signaling information, and wherein the de-rotation of the samples, in accordance with each of the different phase rotation factors, results in a sequence of de-rotated samples for each of the different phase rotation factors;
comparing each sequence of de-rotated samples to an expected sequence of symbols; and
identifying the phase rotation factor associated with the sequence of de-rotated samples that best matches the expected sequence of symbols.
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17. In a digital telecommunications system, an apparatus for transmitting signaling information from a transmitter to a receiver comprising:
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means for identifying one of a plurality of information signals to be conveyed from the transmitter to the receiver in addition to data;
means for rotating each of one or more symbols by a common phase rotation factor, wherein the phase rotation factor uniquely identifies the one information signal to be conveyed from the transmitter to the receiver; and
means for transmitting each of the one or more phase-rotated symbols to the receiver. - View Dependent Claims (18, 19, 20, 21, 22, 23)
in the receiver, means for receiving a signal containing the one or more phase-rotated symbols;
means for generating samples of the received signal, wherein the samples correspond to the phase-rotated symbols;
means for de-rotating the samples, so as to recover a value associated with each of the one or more symbols; and
means for identifying the one information signal conveyed to the receiver from the transmitter as a function of the phase rotation factor required to recover the value associated with each of the one or more symbols.
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19. The apparatus of claim 17, wherein the information signal represents one of a plurality of signal power control commands.
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20. The apparatus of claim 17, wherein the information signal represents one of a plurality of modulation schemes.
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21. The apparatus of claim 17, wherein the information signal represents coding information.
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22. The apparatus of claim 17, wherein the one or more symbols are training symbols.
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23. The apparatus of claim 17, wherein the one or more symbols include both training and data symbols.
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24. In a digital telecommunications system, an apparatus for conveying modulation information from a transmitter to a receiver, said apparatus comprising:
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means for selecting one of a plurality of modulation schemes;
means for modulating a sequence of training symbols in accordance with the selected one of the plurality of modulation schemes;
means for identifying a phase rotation factor which corresponds to the selected one of the plurality of modulation schemes, wherein at least one unique phase rotation factor is associated with each of the plurality of modulation schemes;
means for rotating the phase of each training symbol as a function of the identified phase rotation factor which corresponds to the selected one of the plurality of modulation schemes;
means for transmitting the sequence of phase-rotated training symbols to the receiver;
at the receiver, means for generating a sequence of de-rotated training symbols for each phase rotation factor by de-rotating the received sequence of phase-rotated training symbols as a function of each phase rotation factor;
means for comparing each sequence of de-rotated training symbols to an expected sequence of training symbols;
means for identifying the sequence of de-rotated training symbols that approximates the expected sequence of training symbols most accurately; and
means for identifying the selected one of the plurality of modulation schemes based on the phase rotation factor that produced the sequence of de-rotated training symbols that most closely approximated the expected sequence of training symbols. - View Dependent Claims (25, 26, 27, 28, 29, 30)
means for deriving a channel estimation for each sequence of de-rotated training symbols; and
prior to comparing each sequence of de-rotated training symbols to the expected sequence of training symbols, means for adjusting the sequence of expected training symbols as a function of the derived channel estimation corresponding to the sequence of de-rotated training symbols to which the sequence of expected training symbols is to be compared.
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26. The apparatus of claim 24, wherein said means for selecting one of a plurality of modulation schemes is a function of a link quality adaptation assessment.
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27. The apparatus of claim 24, wherein the sequence of training symbols to be transmitted to the receiver from the transmitter is the same for two or more of the modulation schemes.
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28. The apparatus of claim 24, wherein the selected one of the plurality of modulation schemes involves Gaussian Minimum Shift Keying.
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29. The apparatus of claim 24, wherein the selected one of the plurality of modulation schemes involves 4-Phase Shift Keying.
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30. The apparatus of claim 24, wherein the selected one of the plurality of modulation schemes involves 8-Phase Shift Keying.
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31. In a digital telecommunications system, a apparatus for identifying signaling information transmitted from a transmitter to a receiver along with data, said apparatus comprising:
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means for receiving a signal containing a sequence of symbols transmitted from the transmitter, wherein the symbols include training symbols and data symbols, and wherein the phase associated with each symbol in the sequence of symbols has been rotated at the transmitter in accordance with a common phase rotation factor that corresponds to the signaling information;
means for generating samples from the received signal, wherein the samples correspond to the sequence of transmitted symbols;
means for recovering the sequence of transmitted symbols by de-rotating the samples in accordance with the common phase rotation factor; and
means for identifying the signaling information as a function of the common phase rotation factor used to recover the sequence of transmitted symbols. - View Dependent Claims (32)
means for de-rotating each of the samples in accordance with a plurality of different phase rotation factors, wherein each of the plurality of different phase rotation factors corresponds to different signaling information, and wherein the de-rotation of the samples, in accordance with each of the different phase rotation factors, results in a sequence of de-rotated samples for each of the different phase rotation factors;
means for comparing each sequence of de-rotated samples to an expected sequence of symbols; and
means for identifying the phase rotation factor associated with the sequence of de-rotated samples that best matches the expected sequence of symbols.
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Specification
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Litigation Data
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Current AssigneeTelefonaktiebolaget LM Ericsson
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Original AssigneeTelefonaktiebolaget LM Ericsson
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InventorsJaverbring, Stefan, H{umlaut over (oo)}k, Mikael
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Primary Examiner(s)CORRIELUS, JEAN B
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Application NumberUS09/170,127Time in Patent Office1,477 DaysField of Search375/259, 375/260, 375/272, 375/261, 375/295, 375/316, 375/324, 375/340, 375/354, 375/371, 375/279, 375/269, 375/273, 375/308, 375/329US Class Current379/279CPC Class CodesH04L 27/0012 arrangements for identifyin...H04L 27/18 Phase-modulated carrier sys...H04L 5/12 the signals being represent...
