Method and apparatus for estimating direction of arrival of radar reception signal using antenna array extrapolation

An apparatus for estimating a DOA of a radar reception signal using antenna array extrapolation, comprising:

• a ULA antenna unit including N antennas for receiving a radar signal reflected ad returned after transmitting the radar signal forward, wherein the N antennas are arranged in a row and spaced apart by a distance d;
• a passband unit configured to extract an intermediate frequency signal of the radar reception signal received through the ULA antenna unit and converts the extracted intermediate frequency signal of the reception signal into a digital signal;
• and
• a data processing unit that is configured to generate a plurality of virtual reception signals, each of the virtual reception signals being generated by:
• (i) obtaining a transformation matrix which represents a relationship between phases of reception signals received through ith to (N−2+i)th antennas and a phase of reception signal received through (N−1+i)th antenna, by using the reception signal in digital form provided from the passband unit, where i is a natural number having an initial value greater than 1 and N has a value that is greater than the initial value of i:
• (ii) generating a phase of a virtual reception signal received through a new (N+i)th virtual antenna by multiplying values corresponding to phases of the reception signals received through (i+1)th to (N−1+i)th antennas by the obtained transformation matrix;
• and
• (iii) obtaining a magnitude component of the virtual reception signal received through the (N+i)th virtual antenna by averaging magnitudes of the reception signals received through ith to (N−1+i)th antennas,
• wherein the ‘obtaining of the transformation matrix’, the ‘generating of the phase of the virtual reception signal’, and the ‘obtaining of the magnitude component of the virtual reception signal’ are performed iteratively for each of the plurality of virtual reception signals, while increasing the number i, until the number i becomes equal to a predetermined threshold value M, the threshold value M being greater than the initial value of i.