Radar device

Patent metadata

Field	Value
Publication number	US-9448303-B2
Application number	US-201214122175-A
Country	US
Kind code	B2
Filing date	May 25, 2012
Priority date	Jun 1, 2011
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

A first radar transmitter and a second radar transmitter transmit a first modulation signal and a second modulation signal which are generated by repeating a predetermined time of code sequences, each of which has a predetermined code length, using a first code width and a second code width, respectively. An A/D converter converts the modulation signal into a discrete signal in a sampling cycle shorter than a difference between the first code width and the second code width. A positioning section separates a plurality of reception signals using a first correlation value based on outputs from the A/D converter and a first delay section corresponding to the first code width and a second correlation value based on outputs from the A/D converter and a second delay section corresponding to the second code width.

First claim

The invention claimed is:

1. A radar device comprising:
a first radar transmitter including:
first transmission signal generating circuitry which, in operation, generates a first modulation signal in which a predetermined number of code sequences are repeated using a first code width, each code sequence having a predetermined code length; and
first transmission radio frequency (RF) circuitry which, in operation, converts the first modulation signal into a first RF radar transmission signal and transmits the first radar transmission signal from a first transmission antenna; and

a second radar transmitter including:
second transmission signal generating circuitry which, in operation, generates a second modulation signal in which a predetermined number of code sequences are repeated using a second code width, each code sequence having the predetermined code length;
second transmission RF circuitry which, in operation, converts the second modulation signal into a second RF radar transmission signal and transmits the second radar transmission signal from a second transmission antenna; and

one or more radar receivers including:
reception RF circuitry which, in operation, converts a RF reflected wave signal received by a reception antenna into a baseband signal and performs quadrature detection for the converted baseband signal;
analog to digital (A/D) converting circuitry which, in operation, samples the quadrature-detected baseband signal in a sampling cycle;
first delay circuitry which, in operation, delays an output signal from the A/D converting circuitry by a predetermined number of samples corresponding to the first code width;
first correlation value calculating circuitry which, in operation, calculates a first correlation value based on the output signal from the A/D converting circuitry and an output signal from the first delay circuitry;
second delay circuitry which, in operation, delays the output signal from the A/D converting circuitry by a predetermined number of samples corresponding to the second code width; and
second correlation value calculating circuitry which, in operation, calculates a second correlation value based on the output signal from the A/D converting circuitry and an output signal from the second delay circuitry.

2. The radar device according to claim 1 , wherein
the A/D converting circuitry in the one or more radar receivers converts the received first or second radar transmission signal into a discrete signal in a predetermined sampling cycle, and
a difference between the first code width and the second code width is equal to or more than the sampling cycle.

3. The radar device according to claim 1 , wherein
the first radar transmitter further includes first transmission controlling circuitry which, in operation, outputs a first transmission trigger signal indicating a generation time of the first modulation signal, and
the second radar transmitter further includes second transmission controlling circuitry which, in operation, outputs a second transmission trigger signal indicating a generation time of the second modulation signal.

4. The radar device according to claim 1 , wherein
each of the one or more radar receivers includes:
first adding circuitry which, in operation, adds a predetermined number of outputs from the first correlation value calculating circuitry; and
second adding circuitry which, in operation, adds a predetermined number of outputs from the second correlation value calculating circuitry.

5. A radar device comprising:
a first radar transmitter including:
first transmission signal generating circuitry which, in operation, generates a first modulation signal in which a predetermined number of code sequences are repeated, each code sequence having a first code length; and
first transmission radio frequency (RF) circuitry which, in operation, converts the first modulation signal into a first RF radar transmission signal and transmits the first radar transmission signal from a first transmission antenna;

a second radar transmitter including:
second transmission signal generating circuitry which, in operation, generates a second modulation signal in which a predetermined number of code sequences are repeated, each code sequence having a second code length; and
second transmission RF circuitry which, in operation, converts the second modulation signal into a second RF radar transmission signal and transmits the second radar transmission signal from a second transmission antenna, wherein,
codes in the first modulation signal and the second modulation signal have a common duration and one of the first code length and the second code length is not an integer multiple of the other code length; and

one or more radar receivers including:
reception RF circuitry which, in operation, converts a RF reflected wave signal received by a reception antenna into a baseband signal and performs quadrature detection for the converted baseband signal;
analog to digital (A/D) converting circuitry which, in operation, samples the quadrature-detected baseband signal in a sampling cycle;
first delay circuitry which, in operation, delays an output signal from the A/D converting circuitry by a predetermined number of samples corresponding to the duration of the first modulation signal which corresponds to the first code length;
first correlation value calculating circuitry which, in operation, calculates a first correlation value based on the output signal from the A/D converting circuitry and an output signal from the first delay circuitry;
second delay circuitry which, in operation, delays the output signal from the A/D converting circuitry by a predetermined number of samples corresponding to the duration of the second modulation signal which corresponds to the second code length; and
second correlation value calculating circuitry which, in operation, calculates a second correlation value based on the output signal from the A/D converting circuitry and an output signal from the second delay circuitry.

6. The radar device according to claim 5 , wherein
the first radar transmitter further includes first transmission controlling circuitry which, in operation, outputs a first transmission trigger signal indicating a generation time of the first modulation signal, and
the second radar transmitter further includes second transmission controlling circuitry which, in operation, outputs a second transmission trigger signal indicating a generation time of the second modulation signal.

7. The radar device according to claim 1 , further comprising:
positioning circuitry which, in operation, estimates a distance to a target based on outputs from the first correlation value calculating circuitry and the second correlation value calculating circuitry, or outputs from the first adding circuitry and the second adding circuitry, wherein,
for each of the one or more radar receivers, the positioning circuitry includes:
transmission time detecting circuitry which, in operation, detects a transmission time of each of the first radar transmission signal and the second radar transmission signal based on the first transmission trigger signal and the second transmission trigger signal;
correlation value peak detecting circuitry which, in operation, detects a peak time of each of the outputs more than a predetermined reference level, based on the outputs from the first correlation value calculating circuitry and the second correlation value calculating circuitry, or the outputs from the first adding circuitry and the second adding circuitry;
arrival delay time calculating circuitry which, in operation, calculates an arrival delay time until the reflected wave signal arrives, based on each of the transmission times detected by th

Assignees

• Kishigami Takaaki
• Nakagawa Yoichi
• Mukai Hirohito
• Panasonic Ip Man Co Ltd

Inventors

• Kishigami Takaaki
• Nakagawa Yoichi
• Mukai Hirohito

Classifications

• G01S13/003

  Bistatic radar systems; Multistatic radar systems · CPC title

• G01S13/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S13/46) · CPC title

• G01S13/284

  using coded pulses · CPC title

• G01S13/878

  Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector (G01S13/874 takes precedence) · CPC title

• G01S7/28

  Details of pulse systems · CPC title