Method for digital wireless communications
First Claim
Patent Images
1. A receiving apparatus comprising:
- a receiving section that receives a reception signal and outputs a reception quadrature baseband signal based on the reception signal;
an amplitude distortion estimator that outputs an amplitude estimation signal estimating an amplitude distortion of the reception quadrature baseband signal, using a pilot symbol included in the reception quadrature baseband signal; and
a frequency distortion estimator that outputs a frequency estimation signal estimating a frequency distortion of the reception quadrature baseband signal, using the pilot symbol included in the reception quadrature baseband signal,whereinthe reception quadrature baseband signal includes the pilot symbol, first symbols placed both immediately before and after the pilot symbol, and data symbols;
the pilot symbol is placed on an I axis or a Q axis on an IQ plane; and
each of the first symbols is placed on the same axis as the pilot symbol and is placed at any one of a plurality of signal point candidates on the IQ plane.
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Abstract
In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established.
35 Citations
20 Claims
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1. A receiving apparatus comprising:
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a receiving section that receives a reception signal and outputs a reception quadrature baseband signal based on the reception signal; an amplitude distortion estimator that outputs an amplitude estimation signal estimating an amplitude distortion of the reception quadrature baseband signal, using a pilot symbol included in the reception quadrature baseband signal; and a frequency distortion estimator that outputs a frequency estimation signal estimating a frequency distortion of the reception quadrature baseband signal, using the pilot symbol included in the reception quadrature baseband signal, wherein the reception quadrature baseband signal includes the pilot symbol, first symbols placed both immediately before and after the pilot symbol, and data symbols; the pilot symbol is placed on an I axis or a Q axis on an IQ plane; and each of the first symbols is placed on the same axis as the pilot symbol and is placed at any one of a plurality of signal point candidates on the IQ plane. - View Dependent Claims (2, 3, 4, 5)
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6. A reception signal processing apparatus comprising:
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an amplitude distortion estimator that outputs an amplitude estimation signal estimating an amplitude distortion of a reception quadrature baseband signal, using a pilot symbol included in the reception quadrature baseband signal; and a frequency distortion estimator that outputs a frequency estimation signal estimating a frequency distortion of the reception quadrature baseband signal, using the pilot symbol included in the reception quadrature baseband signal, wherein the reception quadrature baseband signal includes the pilot symbol, first symbols placed both immediately before and after the pilot symbol, and data symbols; the pilot symbol is placed on an I axis or a Q axis on an IQ plane; and each of the first symbols is placed on the same axis as the pilot symbol and is placed at any one of a plurality of signal point candidates on the IQ plane. - View Dependent Claims (7, 8, 9, 10)
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11. A receiving method comprising:
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a receiving step of receiving a reception signal and outputting a reception quadrature baseband signal based on the reception signal; an amplitude distortion estimating step of outputting an amplitude estimation signal estimating an amplitude distortion of the reception quadrature baseband signal, using a pilot symbol included in the reception quadrature baseband signal; and a frequency distortion estimating step of outputting a frequency estimation signal estimating a frequency distortion of the reception quadrature baseband signal, using the pilot symbol included in the reception quadrature baseband signal, wherein the reception quadrature baseband signal includes the pilot symbol, first symbols placed both immediately before and after the pilot symbol, and data symbols; the pilot symbol is placed on an I axis or a Q axis on an IQ plane; and each of the first symbols is placed on the same axis as the pilot symbol and is placed at any one of a plurality of signal point candidates on the IQ plane. - View Dependent Claims (12, 13, 14, 15)
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16. A reception signal processing method comprising:
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an amplitude distortion estimating step of outputting an amplitude estimation signal estimating an amplitude distortion of a reception quadrature baseband signal, using a pilot symbol included in the reception quadrature baseband signal; and a frequency distortion estimating step of outputting a frequency estimation signal estimating a frequency distortion of the reception quadrature baseband signal, using the pilot symbol included in the reception quadrature baseband signal, wherein the reception quadrature baseband signal includes the pilot symbol, first symbols placed immediately before and after the pilot symbol, and data symbols; the pilot symbol is placed on an I axis or a Q axis on an IQ plane; and each of the first symbols is placed on the same axis as the pilot symbol and is placed at any one of a plurality of signal point candidates on the IQ plane. - View Dependent Claims (17, 18, 19, 20)
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Specification