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US 11,693,085 B2Granted
FMCW radar with interference signal suppression
AssigneeInfineon Technologies AG
InventorsPaul Meissner, Alexander Melzer, Mate Andras Toth
Life of this patent
Estimating the term…
Abstract
A method is described that can be used in a radar system. In accordance with one exemplary embodiment, the method includes calculating a first spectrum, which represents a spectrum of a segment of a complex baseband signal. The segment is assignable to a specific chirp of a chirp sequence contained in a first RF radar signal. The method further includes estimating a second spectrum, which represents a spectrum of an interference signal contained in the complex baseband signal, based on a portion of the first spectrum that is assigned to negative frequencies.
Claims21
A method, comprising:
- emitting a first radio frequency (RF) radar signal containing a chirp sequence;
- receiving a second RF radar signal;
- down-converting the second RF radar signal from an RF band into a baseband by an IQ mixer in order to obtain a complex baseband signal comprising an in-phase component and a quadrature component that is phase shifted by the IQ mixer from the in-phase component by 90°;
- converting the complex baseband signal into a complex digital baseband signal;
- applying a first fast Fourier transform (FFT) to the complex digital baseband signal to calculate a first spectrum that represents a spectrum of a segment of the complex baseband signal, wherein the segment is assigned to a specific chirp of the chirp sequence contained in the first RF radar signal;
- estimating a second spectrum, which represents a spectrum of an interference signal contained in the complex baseband signal, based on a portion of the first spectrum that is located at negative frequencies;
- and
- subtracting the second spectrum from the first spectrum to suppress the interference signal in the first spectrum to generate a compensated spectrum,
- wherein the first spectrum includes first spectral lines corresponding to radar echoes and second spectral lines corresponding to the interference signal, wherein the first spectral lines are located only at positive frequencies and the second spectral lines are located at negative frequencies and positive frequencies, wherein each second spectral line located at a negative frequency corresponds to a different second spectral line located at a positive frequency, and
- wherein estimating the second spectrum includes generating the second spectrum based on the second spectral lines that are located at the negative frequencies, including extracting the second spectral lines that are located at the negative frequencies, and mirroring the extracted second spectral lines to generate corresponding spectral lines that are located at positive frequencies, wherein the second spectrum includes the extracted second spectral lines that are located at the negative frequencies and the generated corresponding spectral lines that are located at positive frequencies.
7 more elements
A radar device, comprising:
- a radar transceiver having an oscillator configured to generate a first radio frequency (RF) radar signal containing a chirp sequence, and having a receiving channel comprising an IQ mixer configured down-convert a second RF radar signal from an RF band into a baseband in order to generate a complex baseband signal comprising an in-phase component and a quadrature component that is phase shifted by the IQ mixer from the in-phase component by 90°, wherein the complex baseband signal comprises a plurality of segments and each segment is assigned to a specific chirp of the chirp sequence;
- an analog-to-digital converter (ADC) configured to convert the complex baseband signal into a complex digital baseband signal;
- and
- at least one processor configured to:
- apply a first fast Fourier transform (FFT) to the complex digital baseband signal to calculate a first spectrum that represents a spectrum of a segment of the complex baseband signal;
- estimate a second spectrum, that represents a spectrum of an interference signal contained in the complex baseband signal, based on a portion of the first spectrum that is located at negative frequencies;
- and
- subtract the second spectrum from the first spectrum to suppress the interference signal in the first spectrum to generate a compensated spectrum,
- wherein the first spectrum includes first spectral lines corresponding to radar echoes and second spectral lines corresponding to the interference signal, wherein the first spectral lines are located only at positive frequencies and the second spectral lines are located at negative frequencies and positive frequencies, wherein each second spectral line located at a negative frequency corresponds to a different second spectral line located at a positive frequency, and
- wherein the at least one processor is configured to estimate the second spectrum by generating the second spectrum based on the second spectral lines that are located at the negative frequencies, including extracting the second spectral lines that are located at the negative frequencies, and mirroring the extracted second spectral lines to generate corresponding spectral lines that are located at positive frequencies, wherein the second spectrum includes the extracted second spectral lines that are located at the negative frequencies and the generated corresponding spectral lines that are located at positive frequencies.
7 more elements
A method, comprising:
- emitting a first radio frequency (RF) radar signal containing a chirp sequence;
- receiving a second RF radar signal;
- down-converting the second RF radar signal from an RF band into a baseband by an IQ mixer in order to obtain a complex baseband signal comprising an in-phase component and a quadrature component that is phase shifted by the IQ mixer from the in-phase component by 90°;
- converting the complex baseband signal into a complex digital baseband signal;
- applying a first fast Fourier transform (FFT) to the complex digital baseband signal to calculate a first spectrum that represents a spectrum of a segment of the complex baseband signal, wherein the segment is assigned to a specific chirp of the chirp sequence contained in the first RF radar signal;
- identifying spectral lines in the first spectrum that are assigned to a radar echo as those spectral lines in the first spectrum having an absolute value that exceeds a threshold value;
- and
- determining a second spectrum, that represents an estimated value for a spectrum of an interference signal contained in the complex baseband signal, based on the first spectrum, wherein the spectral lines that are assigned to the radar echo are disregarded when determining the second spectrum.
5 more elements
A radar device, comprising:
- a radar transceiver having an oscillator configured to generate a first radio frequency (RF) radar signal containing a chirp sequence, and having a receiving channel comprising an IQ mixer configured down-convert a second RF radar signal from an RF band into a baseband in order to generate a complex baseband signal comprising an in-phase component and a quadrature component that is phase shifted by the IQ mixer from the in-phase component by 90°, wherein the complex baseband signal comprises a plurality of segments and each segment is assigned to a specific chirp of the chirp sequence;
- an analog-to-digital converter (ADC) configured to convert the complex baseband signal into a complex digital baseband signal;
- and
- at least one processor configured to:
- apply a first fast Fourier transform (FFT) to the complex digital baseband signal to calculate a first spectrum that represents a spectrum of a segment of the complex baseband signal;
- identify spectral lines in the first spectrum that are assigned to a radar echo as those spectral lines in the first spectrum having an absolute value that exceeds a threshold value;
- determine a second spectrum, which represents an estimated value for the spectrum of an interference signal contained in the baseband signal, based on the first spectrum, wherein the spectral lines that are assigned to the radar echo are disregarded when determining the second spectrum.
4 more elements
Dependencies are inferred from the claim text.