1. A MIMO radar signal processing device comprising:
a plurality of transmission signal generating units to generate transmission
signals different from each other and output the generated transmission signals to
corresponding transmission antennas;
a plurality of matched filter banks, each receiving a reception signal from a
reception antenna corresponding to each of a plurality of reception antennas that capture
reflected waves obtained by transmission waves transmitted from the transmission
antennas, reaching an object and being reflected as arrival waves and transmission
signals from the plurality of transmission signal generating units, and outputting
matched filter outputs serving as vector elements of reception signal vectors using the
transmission signals from the plurality of transmission signal generating units as a
replica of a matched filter;
a tentative angle measuring unit to assume the matched filter outputs from the
plurality of matched filter banks as reception signals in a direct propagation mode by
arrival waves that are directly propagated after the transmission waves are reflected by
the object and obtain a tentative measured angle value for a reception signal vector of
interest corresponding to a range Doppler cell provided by target detection processing;
and
a bidirectional angle measuring unit to obtain a bidirectional measured angle
value constituted by a direction-of-departure and a direction-of-arrival for the reception
signal vector of interest from the matched filter outputs from the plurality of matched
filter banks and the tentative measured angle value calculated by the tentative angle
measuring unit.
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2. The MIMO radar signal processing device according to claim 1, wherein the
tentative measured angle value by the tentative angle measuring unit is obtained by
setting a direction-of-departure and a direction-of-arrival constituting a bidirectional
measured angle value in the reception signal vector of interest to be the same
propagation angle, and obtaining a propagation angle at which a directional spectrum
obtained using the propagation angle as a variable indicates a maximum value as a
tentative measured angle value.
3. The MIMO radar signal processing device according to claim 1 or 2, wherein
the bidirectional measured angle value in the bidirectional angle measuring unit is
obtained by setting the tentative measured angle value calculated by the tentative angle
measuring unit as a direction-of-departure constituting a bidirectional measured angle
value in the reception signal vector of interest and obtaining a direction-of-arrival
constituting a bidirectional measured angle value in the reception signal vector of
interest.
4. The MIMO radar signal processing device according to claim 1 or 2, wherein
the bidirectional measured angle value in the bidirectional angle measuring unit is
obtained by setting the tentative measured angle value calculated by the tentative angle
measuring unit as a direction-of-arrival constituting a bidirectional measured angle
value in the reception signal vector of interest and obtaining a direction-of-departure
constituting a bidirectional measured angle value in the reception signal vector of
interest.
5. The MIMO radar signal processing device according to claim 1 or 2, wherein
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the bidirectional measured angle value in the bidirectional angle measuring unit is one
of a first tentative bidirectional measured angle value obtained by setting the tentative
measured angle value calculated by the tentative angle measuring unit as a direction-ofdeparture constituting a bidirectional measured angle value in the reception signal
vector of interest to obtain a direction-of-arrival constituting a bidirectional measured
angle value in the reception signal vector of interest and a second tentative bidirectional
measured angle value obtained by setting the tentative measured angle value calculated
by the tentative angle measuring unit as a direction-of-arrival constituting a
bidirectional measured angle value in the reception signal vector of interest to obtain a
direction-of-departure constituting a bidirectional measured angle value in the reception
signal vector of interest.
6. The MIMO radar signal processing device according to claim 1, wherein
the tentative measured angle value by the tentative angle measuring unit is
obtained by setting a direction-of-departure and a direction-of-arrival constituting a
bidirectional measured angle value in the reception signal vector of interest to the same
propagation angle to obtain, as a tentative measured angle value, a propagation angle at
which a directional spectrum obtained using the propagation angle as a variable
indicates a local maximum value, and
when there are a plurality of tentative measured angle values obtained by the
tentative angle measuring unit, the bidirectional measured angle value in the
bidirectional angle measuring unit is obtained by calculating a difference between a
direction-of-departure and a direction-of-arrival using each of the plurality of tentative
side angle values as the other of the direction-of-departure and the direction-of-arrival
constituting the bidirectional measured angle value in the reception signal vector of
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interest to obtain the direction-of-departure and the direction-of-arrival at which the
calculated difference between the direction-of-departure and the direction-of-arrival is
minimum as the direction-of-departure and the direction-of-arrival constituting the
bidirectional measured angle value in the reception signal vector of interest.
7. The MIMO radar signal processing device according to any one of claims 1 to
6, further comprising a propagation mode distinguishing unit to distinguish whether a
propagation mode in a reception signal vector of interest for a bidirectional measured
angle value obtained by the bidirectional angle measuring unit is a direct propagation
mode or a multipath propagation mode on a basis of the bidirectional measured angle
value.
8. The MIMO radar signal processing device according to claim 7, wherein the
propagation mode distinguishing unit compares a value of a difference between a
direction-of-departure and a direction-of-arrival constituting a bidirectional measured
angle value obtained by the bidirectional angle measuring unit with a threshold,
distinguishes the propagation mode as a direct propagation mode when the value of the
difference is equal to or less than the threshold, and distinguishes the propagation mode
as a multipath propagation mode when the value of the difference exceeds the threshold.
9. A reception signal processing device of a MIMO radar signal processing
device, the reception signal processing device comprising:
a plurality of matched filter banks, each receiving a reception signal from a
reception antenna corresponding to each of a plurality of reception antennas that capture
reflected waves obtained by transmission waves transmitted from transmission
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antennas, reaching an object and being reflected as arrival waves and transmission
signals from a plurality of transmission signal generating units that output transmission
signals to the transmission antennas, and outputting matched filter outputs serving as a
vector element of a reception signal vector using the transmission signals from the
plurality of transmission signal generating units as a replica of a matched filter;
a tentative angle measuring unit to assume the matched filter outputs from the
plurality of matched filter banks as reception signals in a direct propagation mode by
arrival waves that are directly propagated after the transmission waves are reflected by
the object and obtain a tentative measured angle value for a reception signal vector of
interest corresponding to a range Doppler cell provided by target detection processing;
and
a bidirectional angle measuring unit to obtain a bidirectional measured angle
value constituted by a direction-of-departure and a direction-of-arrival for the reception
signal vector of interest from the matched filter outputs from the plurality of matched
filter banks and the tentative measured angle value calculated by the tentative angle
measuring unit.
10. The reception signal processing device of the MIMO radar signal processing
device according to claim 9, further comprising a propagation mode distinguishing unit
to distinguish whether a propagation mode in a reception signal vector of interest for a
bidirectional measured angle value obtained by the bidirectional angle measuring unit is
a direct propagation mode or a multipath propagation mode.