Array antenna system of wireless base station
First Claim
1. An array antenna system of a wireless base station in CDMA mobile communications for combining signals, which have been received by a plurality of antenna elements of an array antenna, upon subjecting the signals to prescribed amplitude weights and phase rotation, and despreading the combined signal, comprising:
- means for applying a correlation operation to an output signal from each antenna element to thereby calculate correlation signals corresponding to each antenna element that is correlated with a signal transmitted from a mobile station of interest;
means for calculating adaptive weights corresponding to each antenna element from the correlation signals;
means for multiplying, by the adaptive weights calculated for the respective antenna elements, output signals from the corresponding antenna elements and combining the resulting products to output a combined signal; and
demodulation means for despreading the combined signal.
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Accused Products
Abstract
An array antenna system of a wireless base station in CDMA mobile communications combines signals, which have been received by a plurality of antenna elements of an array antenna, upon subjecting the signals to amplitude and phase-rotation control, and despreads the combined signal. A searcher has matched filters which apply correlation operations to output signals from respective antenna elements to thereby calculate correlation signals that are correlated with a signal transmitted from a mobile station of interest. An adaptive weight calculating unit calculates adaptive weights for obtaining in-phase correlation signals from the respective antenna outputs. A beam former multiplies, by the adaptive weights, output signals from the corresponding antenna elements and combines the resulting products to output a combined signal. The combined signal is found for each path of multipaths and is input to a Rake receiver, which proceeds to identify data.
176 Citations
11 Claims
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1. An array antenna system of a wireless base station in CDMA mobile communications for combining signals, which have been received by a plurality of antenna elements of an array antenna, upon subjecting the signals to prescribed amplitude weights and phase rotation, and despreading the combined signal, comprising:
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means for applying a correlation operation to an output signal from each antenna element to thereby calculate correlation signals corresponding to each antenna element that is correlated with a signal transmitted from a mobile station of interest; means for calculating adaptive weights corresponding to each antenna element from the correlation signals; means for multiplying, by the adaptive weights calculated for the respective antenna elements, output signals from the corresponding antenna elements and combining the resulting products to output a combined signal; and demodulation means for despreading the combined signal.
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2. An array antenna system of a wireless base station in CDMA mobile communications for combining signals, which have been received by a plurality of antenna elements of an array antenna, upon subjecting the signals to prescribed amplitude weights and phase rotation, and despreading the combined signal, comprising:
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correlation signal calculating means for applying a correlation operation to an output signal from each antenna element to thereby calculate correlation signals corresponding to each antenna element that is correlated with a signal transmitted from a mobile station of interest, this being carried out for each path of multipaths from the mobile station of interest to the array antenna; adaptive weight calculating means for calculating adaptive weights corresponding to each antenna element from the correlation signals, this being carried out for each path of multipaths from the mobile station of interest to the array antenna; combining means provided for each path of multipaths from the mobile station to the antenna array for multiplying, by the adaptive weights calculated for every path and for the respective antenna elements, output signals from the corresponding antenna elements and combining the resulting products; and a Rake receiver having despreading means for despreading signal output by respective ones of the combining means and a combining unit for combining signals output by each of the despreading means upon applying a delay time adjustment thereto. - View Dependent Claims (9, 10, 11)
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3. An array antenna system of a wireless base station in CDMA mobile communications for combining signals, which have been received by a plurality of antenna elements of an array antenna, upon subjecting the signals to prescribed amplitude weights and phase rotation, and despreading the combined signal, comprising:
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correlation signal calculating means for applying a correlation operation to an output signal from each antenna element to thereby calculate correlation signals corresponding to each antenna element that is correlated with a signal transmitted from a mobile station of interest, this being carried out for each path of multipaths from the mobile station of interest to the array antenna; adaptive weight calculating means for calculating adaptive weights corresponding to each antenna element from the correlation signals, this being carried out for each path of multipaths from the mobile station of interest to the array antenna; combining means provided for each path of multipaths from the mobile station to the antenna array for multiplying, by the adaptive weights calculated for every path and for the respective antenna elements, output signals from the corresponding antenna elements and combining the resulting products; a Rake receiver having despreading means for despreading signal output by respective ones of the combining means and a combining unit for combining signals output by each of the despreading means upon applying a delay time adjustment thereto, a demodulator for quadrature-demodulating the output signal from the respective antenna element to thereby output in-phase and quadrature-phase component signals; wherein said correlation signal calculating means applies a correlation operation to each of the in-phase and quadrature-phase component signals and outputs said correlation signals, which have amplitude and phase characteristics, using in-phase and quadrature-phase component signals obtained by the correlation operation; and said adaptive weight calculating means multiplies a signal, which is obtained by inverting the phase of a correlation signal of an mth antenna element, by the correlation signals of all antenna elements, and outputs signals, which are obtained by inverting the phases of the resulting products, as adaptive weights for respective ones of the antenna elements, thereby making the phases of all correlation signals the same as the phase of the correlation signal of the mth antenna element. - View Dependent Claims (4, 5)
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6. An array antenna system of a wireless base station in CDMA mobile communications for combining signals, which have been received by a plurality of antenna elements of an array antenna, upon subjecting the signals to prescribed amplitude weights and phase rotation, and despreading the combined signal, comprising:
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correlation signal calculating means for applying a correlation operation to an output signal from each antenna element to thereby calculate correlation signals corresponding to each antenna element that is correlated with a signal transmitted from a mobile station of interest, this being carried out for each path of multipaths from the mobile station of interest to the array antenna; adaptive weight calculating means for calculating adaptive weights corresponding to each antenna element from the correlation signals, this being carried out for each path of multipaths from the mobile station of interest to the array antenna; combining means provided for each path of multipaths from the mobile station to the antenna array for multiplying, by the adaptive weights calculated for every path and for the respective antenna elements, output signals from the corresponding antenna elements and combining the resulting products; a Rake receiver having despreading means for despreading signal output by respective ones of the combining means and a combining unit for combining signals output by each of the despreading means upon applying a delay time adjustment thereto, a demodulator for quadrature-demodulating the output signal from the respective antenna element to thereby output in-phase and quadrature-phase component signals; wherein said correlation signal calculating means applies a correlation operation to each of the in-phase and quadrature-phase component signals and outputs said correlation signals, which have amplitude and phase characteristics, using in-phase and quadrature-phase components signals obtained by the correlation operation; said adaptive weight calculating means multiplies a signal, which is obtained by inverting the phase of a correlation signal of an mth antenna element, by the correlation signals of all antenna elements, decides a directional constraint vector C using the resulting products, generates a covariance matrix R using the correlation signals of the respective antenna elements, calculates an adaptive weight for each antenna element using the directional constraint vector C and the covariance matrix R and outputs the adaptive weights, thereby making the phases of all correlation signals the same as the phase of the correlation signal of the mth antenna element and reducing power of received interference waves. - View Dependent Claims (7, 8)
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Specification