Array antenna system of wireless base station

Claim 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: 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.

Claim 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: 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.

Claim 4

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: 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.

Claim 5

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: 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.

Claim 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: 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.

Claim 7

The system according to claim 3, wherein said adaptive weight calculating means adopts an antenna element corresponding to a correlation signal having the highest power level as said mth antenna element.

Claim 8

The system according to claim 3, wherein said adaptive weight calculating means obtains an average value, per prescribed time, of the correlation signal of said in-phase and quadrature-phase components and calculates adaptive weights using this average value.

Claim 9

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: 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.

Claim 10

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: 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.

Claim 11

The system according to claim 6, wherein said adaptive weight calculating means adopts an antenna element corresponding to a correlation signal having the highest power level as said mth antenna element.

Claim 12

The system according to claim 6, wherein said adaptive weight calculating means obtains an average value, per prescribed time, of the correlation signal of said in-phase and quadrature-phase components and calculates adaptive weights using this average value.

Claim 13

The system according to claim 2, wherein said adaptive weight calculating means forms, from among the correlation signals obtained from the output signals of respective antenna elements, sets of two correlation signals each in order of descending reception level, and averages a phase difference between the correlation signals in each set upon applying weighting conforming to the reception level, thereby calculating the phase difference between correlation signals of neighboring antenna elements, and calculates adaptive weights using the phase differences.

Claim 14

The system according to claim 2, further comprising: a beam former, which is provided between the array antenna and said correlation signal calculating means, for performing beam forming; and a reverse beam former, which is provided between said correlation signal calculating means and said adaptive weight calculating means, for performing an operation that is the reverse of beam forming.

Claim 15

The system according to claim 10, further comprising a selector for selecting, in dependence upon traffic, a path along which beam forming is performed and a path along which no beam forming is performed.