Radio frequency motion sensors may be configured for operation in a common vicinity so as to reduce interference. In some versions, interference may be reduced by timing and/or frequency synchronization. In some versions, a master radio frequency motion sensor may transmit a first radio frequency (RF) signal. A slave radio frequency motion sensor may determine a second radio frequency signal which minimizes interference with the first RF frequency. In some versions, interference may be reduced with additional transmission adjustments such as pulse width reduction or frequency and/or timing dithering differences. In some versions, apparatus may be configured with multiple sensors in a configuration to emit the radio frequency signals in different directions to mitigate interference between emitted pulses from the radio frequency motion sensors.

Radio frequency motion sensors may be configured for operation in a common vicinity so as to reduce interference. In some versions, interference may be reduced by timing and/or frequency synchronization. In some versions, a master radio frequency motion sensor may transmit a first radio frequency (RF) signal. A slave radio frequency motion sensor may determine a second radio frequency signal which minimizes interference with the first RF frequency. In some versions, interference may be reduced with additional transmission adjustments such as pulse width reduction or frequency and/or timing dithering differences. In some versions, apparatus may be configured with multiple sensors in a configuration to emit the radio frequency signals in different directions to mitigate interference between emitted pulses from the radio frequency motion sensors.

In order to enhance the performance with which a moving target is detected by a single sensor and with a degree of freedom in a transmission waveform, a moving-target detection system 1 has a transmission waveform setting means 101 for setting a transmission waveform St(t), a transmission means 102 for transmitting a wave having the set transmission waveform St(t), a reception means 103 for receiving a wave including a reflected wave from a target, a Doppler shift estimation means 104 for estimating a Doppler shift that occurs due to movement of the target from the transmission waveform St(t) and a reception waveform Sr(t) including the reflected wave, a transmission waveform deformation means 105 for generating a deformed transmission waveform in which the transmission waveform St(t) is deformed in accordance with the estimated Doppler shift, and a target sensing means 106 for sensing the target using the deformed transmission waveform.

In order to enhance the performance with which a moving target is detected by a single sensor and with a degree of freedom in a transmission waveform, a moving-target detection system 1 has a transmission waveform setting means 101 for setting a transmission waveform St(t), a transmission means 102 for transmitting a wave having the set transmission waveform St(t), a reception means 103 for receiving a wave including a reflected wave from a target, a Doppler shift estimation means 104 for estimating a Doppler shift that occurs due to movement of the target from the transmission waveform St(t) and a reception waveform Sr(t) including the reflected wave, a transmission waveform deformation means 105 for generating a deformed transmission waveform in which the transmission waveform St(t) is deformed in accordance with the estimated Doppler shift, and a target sensing means 106 for sensing the target using the deformed transmission waveform.

A secondary echo and a primary echo subjected to topographic echo processing are compared with each other. When there is a topographic echo in the primary echo or the secondary echo determined as a strong echo, an echo resulting from removal of the topographic echo is defined as a strong-topographic-echo-removed reception signal. Electric power of the topographic echo in the secondary echo or the primary echo determined as a weak echo and the strong-topographic-echo-removed reception signal are defined as weak echo parameters. Electric power of the weak echo estimated from a reception signal in a weak echo region resulting from phase correction of a reception signal resulting from removal of a frequency component of the strong echo from the strong-topographic-echo-removed reception signal representing the weak echo parameter, a spectral width of the weak echo representing the weak echo parameter, and a Doppler velocity of the weak echo are provided as spectral parameters.

A secondary echo and a primary echo subjected to topographic echo processing are compared with each other. When there is a topographic echo in the primary echo or the secondary echo determined as a strong echo, an echo resulting from removal of the topographic echo is defined as a strong-topographic-echo-removed reception signal. Electric power of the topographic echo in the secondary echo or the primary echo determined as a weak echo and the strong-topographic-echo-removed reception signal are defined as weak echo parameters. Electric power of the weak echo estimated from a reception signal in a weak echo region resulting from phase correction of a reception signal resulting from removal of a frequency component of the strong echo from the strong-topographic-echo-removed reception signal representing the weak echo parameter, a spectral width of the weak echo representing the weak echo parameter, and a Doppler velocity of the weak echo are provided as spectral parameters.

The present application discloses a new form of μ-STAP, referred to herein as post μ-STAP or Pμ-STAP, which overcomes the drawbacks associated with existing μ-STAP techniques. The Pμ-STAP techniques described herein facilitate the generation of additional training data and homogenization after pulse compression. For example, Pμ-STAP techniques may apply a plurality of homogenization filters to a pulse compressed datacube generated from an input radar waveform, which produces a plurality of new pulse compressed datacubes with improved characteristics. Unlike existing μ-STAP techniques described above, which require prepulse compressed data to operate, the Pμ-STAP techniques disclosed in the present application are designed to utilize pulse compressed data, and therefore may be readily applied to legacy radar systems.

A signal processing apparatus that performs signal processing on a Doppler spectrum derived from a reception signal of a reflected wave of pulsed undulation repeatedly transmitted into a space removes a topographic echo spectrum from the Doppler spectrum and extracts a plurality of candidate points of a target echo spectrum from the Doppler spectrum from which the topographic echo spectrum has been removed. Furthermore, the signal processing apparatus determines positional relation between the candidate points and a plurality of removed points of the topographic echo spectrum removed from the Doppler spectrum and extracts as an interpolation point, a point where the target echo spectrum is missing by removal of the topographic echo spectrum based on positional relation between the candidate points and the removed points in a direction of a frequency axis.

The Doppler signal processing device includes a frequency analyzer, an interference suppressor, an interference baseline estimator and a synthesizer. The frequency analyzer can generate a frequency domain signal according to a digital signal. The interference suppressor can perform a suppression operation to generate an interference suppressed frequency domain signal. The interference baseline estimator can generate or update the frequency domain interference estimation signal according to the frequency domain signal. The synthesizer can generate an interference suppressed digital signal according to the interference suppressed frequency domain signal, where the interference suppressed digital signal is related to the digital signal with the interference energy suppressed.

A method for determining direction information for at least one target object in a radar system for a vehicle. The first detection information is provided by at least two receive antennas of the radar system, wherein the first detection information is specific for a first radar signal transmitted by a first transmit antenna of the radar system. The second detection information is provided by the at least two receive antennas of the radar system, wherein the second detection information is specific for a second radar signal transmitted by a second transmit antenna of the radar system. A first angle determination and a second angle determination are performed. At least one comparison of the first angle information with the second angle information is performed in order to detect an ambiguity in the first angle determination for the determination of the direction information.