Apparatus for estimating arrival-angle and apparatus for beam-forming
The present invention relates to an apparatus for estimating an arrival-angle of a reception signal and a beam-forming apparatus in a radio wave receiver, such as radar. More specifically, the present invention relates to an apparatus for accurately estimating an arrival-angle of a reception signal, or an apparatus for performing the beam-forming of a reception signal by using a multi-reception array antenna, by using a reference value that is obtained by calculating the degree of distortion of the magnitude and phase of a signal for each reception angle.
1. An apparatus for estimating an arrival-angle of a signal by using an array antenna, the apparatus comprising:
a transmitting antenna configured to transmit a transmission signal to a target;
a plurality of receiving antenna configured to receive a signal reflected by the target through a plurality of receiving channels; and
a digital signal processor configured to
amplify the received signal, and
measure changes between the transmission signal and the received signal by analysing the received signal with the transmission signal to thereby measure information for the target,
wherein the digital signal processor comprises:
a phase compensation value calculating circuit configured to obtain a phase compensation value for each measurement angle by using a reference value that is obtained by calculating the degree of distortion of the magnitude and phase of the received signal for each measurement angle;
a steering vector calculating circuit configured to calculate a compensation steering vector by using an array antenna compensation value that is calculated by reflecting the phase compensation value and by using a predetermined steering vector; and
an arrival-angle estimating circuit configured to estimate an arrival-angle through a spectrum that is created based on the calculated compensation steering vector and the received signal that is received from two or more receiving channels of the array antenna.
2. The apparatus according to claim 1 , wherein the arrival-angle estimating circuit creates a compensation spectrum that is obtained by compensating for the spectrum of the received signal by reflecting the compensation steering vector and the received signal to a predetermined arrival-angle estimating algorithm in order to thereby estimate the arrival-angle of the received signal by using the compensation spectrum.
3. The apparatus according to claim 2 , wherein the arrival-angle estimating algorithm is one of the Bartlett beam-forming algorithm, the Capon beam-forming algorithm, or the MUSIC beam-forming algorithm.
4. The apparatus according to claim 1 , wherein the phase compensation value for each measurement angle is calculated from the reference value, the number of channels of the array antenna, the distance from a reference channel to each channel, and the wavelength of the received signal.
5. The apparatus according to claim 1 , wherein the reference value is a value in the form of a two-dimensional matrix, which is determined according to the receiving channel and the measurement angle of the array antenna.
6. An apparatus for performing the beam-forming of a reception signal by using an array antenna, the apparatus comprising:
a transmitting antenna configured to transmit a transmission signal to a target; and
a plurality of receiving antenna configured to receive a signal reflected by the target through a plurality of receiving channels,
wherein the apparatus is configured to
amplify the received signal, and
measure changes between the transmission signal and the received signal by analysing the received signal with the transmission signal to thereby measure information for the target,
wherein the apparatus comprises:
a phase compensation value calculating circuit configured to obtain a phase compensation value for each measurement angle by using a reference value that is obtained by calculating the degree of distortion of the magnitude and phase of a reception signal for each measurement angle;
a steering vector calculating circuit configured to calculate a compensation steering vector by using an array antenna compensation value that is calculated by reflecting the phase compensation value and by using a predetermined steering vector; and
a beam-forming circuit configured to determine the beam direction (θ) of the reception signal by using the calculated compensation steering vector and configured to form a reception signal beam according to the same.
7. The apparatus according to claim 6 , wherein the phase compensation value for each measurement angle is calculated from the reference value, the number of channels of the array antenna, the distance from a reference channel to each channel, and the wavelength of the reception signal.
8. The apparatus according to claim 6 , wherein the reference value is a value in the form of a two-dimensional matrix, which is determined according to the receiving channel and the measurement angle of the array antenna.