摘要:
A method of calculating coefficients determining excitation amplitudes and phases for obtaining a desired antenna pattern of a circular array antenna comprising a plurality of antenna elements disposed circularly. Coefficients for a linear array antenna having the same number of antenna elements as the circular array antenna are determined by a Fourier series expansion in integral limits calculated from a beam direction and a beam width that are estimated from incoming radio waves and then are transformed into the coefficients for the circular array antenna. With this method, the beam direction and the beam width of the antenna pattern of the circular array antenna can be set at will. Consequently, this method enables adaptive control of sectored beams of sectored antennas at a base station or the like used for a mobile communication system, thus enhancing efficiency of the use of the antennas.
摘要:
A mobile station transmitted signal received at array antenna 11 is converted into an intermediate frequency signal in frequency conversion section 12, and converted into a digital signal in analog-digital conversion section 13. Arrival direction estimating section 15 estimates the number of mobile stations and directions thereof by processing the digital signal. Arrival direction tracking section 16 estimates a direction of a mobile station by sequential processing using an estimated result in arrival direction estimating section 15. Beam forming means 17 forms an antenna radiation beam to a direction of the estimated result in arrival direction tracking section 16.
摘要:
Array elements 111-1 to 111-n of array antenna 101 are arranged at respective different heights from a ground so as not to overlap to each other in a vertical direction. Received frequency conversion section 102 converts a radio frequency signal received at each of the array elements 111-1 to 111-n of array antenna 101 into an intermediate frequency signal or baseband signal. A/D conversion section 103 converts an analog signal output from received frequency conversion section 102 into a digital signal using a proper sampling frequency. Direction estimating section 105 estimates directions of an arrival radio signal in a horizontal plane and vertical plane using received digital signals obtained in A/D conversion section 103. It is thereby possible to suppress increases in the number of array elements and computation amount, and to improve estimation accuracy in the vertical direction and resolution at the time a plurality of signals arrive.
摘要翻译:阵列天线101的阵列元件111-1至111-n被布置在与地面不同的高度处,以便在垂直方向上彼此不重叠。 接收频率转换部分102将在阵列天线101的每个阵列元件111-1至111-n处接收的射频信号转换为中频信号或基带信号。 A / D转换部分103使用适当的采样频率将从接收频率转换部分102输出的模拟信号转换成数字信号。 方向估计部105使用在A / D转换部103中获得的接收数字信号来估计水平面和垂直面中的到达无线信号的方向。由此,可以抑制数组元素的数量的增加和计算量, 提高多个信号到达时的垂直方向的估计精度和分辨率。
摘要:
A direction of arrival (DOA) estimation apparatus of the present invention comprises a plurality of A/D converters that converts a plurality of complex base band signal obtained from the receiving signals of a plurality of antenna elements to respective complex digital signals, a plurality of low pass filters that outputs complex low pass signals with attenuated high frequency components of respective complex digital signals, a plurality of down samplers that outputs complex down sampled and multiplied signals by down sampling the complex low pass signals and multiplying by integral number of sampling intervals of respective A/D converters, and a data transfer section that stores respective complex down sampled signal thus obtained from respective antenna elements temporary and then transfers the data. A variable directional signal receiving and transmitting apparatus of the present invention performs an antenna directivity control based on the output data from the above data transfer section. With the composition of the present invention, an amount of data required for a DOA estimation process section is decreased and a composition of a data transfer section is simplified. With the composition of the present invention, a deterioration of an accuracy of direction estimation becomes minimum despite the simplification of the apparatus. Furthermore, a favorable receiving and transmitting quality is obtained by applying the DOA estimation apparatus for a transmitting and receiving apparatus.
摘要:
A device for estimating a direction-of-arrival of a radio wave, the device comprising an array antenna including a plurality of antenna elements for receiving a high frequency signal, a demultiplexer for demultiplexing the received high frequency signal for each of the plurality of antenna elements to generate a plurality of frequency component signals and a direction estimating unit for estimating the direction-of-arrival of the radio wave by using two or more of the plurality of frequency component signals which are contiguous in a frequency direction.
摘要:
A transmission weight computing section computes a transmission weight for directional transmission using an OFDM signal. A transmission correcting value memory section stores one correcting value for correcting the transmission weight for each sub-carrier of an OFDM signal or each band gathering a plurality of sub-carriers. A transmission weight correcting section corrects the transmission weight by the correcting value. A transmitting branch weights transmission data by a transmission weight outputted from the transmission weight correcting section on a sub-carrier-by-sub-carrier basis and delivers it to an antenna.
摘要:
An adaptive antenna radio communication device comprises a divided band direction estimating unit (4) for estimating the direction by calculating the cross correlations between a pilot signal and sub-carrier signals of the respective divided bands received by an array antenna (1) and calculating a spatial profile from correlation matrices determined by combining the correlation values between antenna elements of the different sub-carriers according to the output of the cross correlation calculation; a divided band array weight creating unit (5) for creating a weight of a receive array having a directional beam in the direction of estimation for each divided band; and a sub-carrier directivity creating unit (6) for creating a directivity by multiplication-combining the created receive array weight with the corresponding sub-carrier signal.
摘要:
A radio-wave arrival-direction apparatus calculates a correlation matrix of received signals by correlation calculation between antenna elements, and calculates a noise spatial eigenmatrix, of which each row or column is an eigenvector belonging to a noise eigen-space, by eigenvalue factorization of the correlation matrix. The apparatus also factorizes a matrix including a product of the noise spatial eigenmatrix and a conjugated and transposed matrix of it to an upper or lower triangular matrix, using cholesky factorization. The apparatus calculates an angle evaluation value in a predetermined angle range of an arrival-angle evaluation function using the derived upper or lower triangular matrix, and determines an arrival angle based on the calculation result. A calculation amount in a variable angle range can be thus reduced without causing accuracy degradation of arrival direction, in an algorism requiring an angle sweep for arrival angle estimation of MUSIC method or the like.
摘要:
Wireless communication apparatus adopting a time division duplex system for transmission and reception using plural antennas, deviation of amplitude and phase occurring between transmission and reception circuits is detected and corrected using a communication signal. Channel estimation means detects channel information based on reception output of N reception circuits having a one-to-one correspondence with N antennas. Correction value detection means finds a correction value for correcting deviation occurring between each of N transmission circuits and each of the N reception circuits based on the channel information. A wireless communication apparatus transmits an already known signal (training signal) to a base station with which the wireless communication apparatus conducts communications. The base station executes channel estimation based on the already known signal and generates and transmits a correction signal (probe signal). The correction value detection means of the wireless communication apparatus detects the correction value using the correction signal.
摘要:
In a wireless communication apparatus adopting a time division duplex system for executing transmission and reception using a plurality of antennas, deviation of amplitude and phase occurring between transmission and reception circuits is detected and corrected using a communication signal. Channel estimation means 105 detects channel information based on reception output of reception circuits 104-1 to 104-N provided in a one-to-one correspondence with a plurality of antennas 101-1 to 101-N. Correction value detection means 110 finds a correction value for correcting deviation occurring between each of transmission circuits 103-1 to 103-N and each of the reception circuits 104-1 to 104-N based on the channel information. A wireless communication apparatus 100 transmits an already known signal (training signal) to a base station with which the wireless communication apparatus conducts communications. The base station executes channel estimation based on the already known signal and generates and transmits a correction signal (probe signal). The correction value detection means 110 of the wireless communication apparatus 100 detects the correction value using the correction signal (probe signal).