Radar device

Abstract

A radar device employs a configuration provided with: a receiver which, in operation, receives one or more radar transmission signals transmitted from another radar device, in an interference measurement segment in which transmission of a radar transmission signal from the radar device is stopped; A/D conversion circuitry which, in operation, converts the one or more radar transmission signals from the other radar device received by the receiver from one or more analog signals into one or more digital signals; and an interference detection circuitry which, in operation, performs a correlation calculation between each of one or more discrete samples that is the one or more digital signals and a prescribed coefficient sequence to detect one or more prescribed frequency components included in the one or more digital signals, as one or more interference signal components.

What is claimed is: 
     
         1 . A radar device, comprising:
 a receiver which, in operation, receives one or more radar transmission signals transmitted from another radar device, in an interference measurement segment in which transmission of one or more radar transmission signals from the radar device is stopped;   A/D conversion circuitry which, in operation, converts the one or more radar transmission signals from the other radar device received by the receiver from one or more analog signals into one or more digital signals; and   interference detection circuitry which, in operation, performs a correlation calculation between each of the one or more discrete samples that is the one or more digital signals and a prescribed coefficient sequence to detect one or more prescribed frequency components included in the one or more digital signals, as one or more interference signal components.   
     
     
         2 . The radar device according to  claim 1 , wherein
 the interference detection circuitry performs the correlation calculation using a coefficient sequence in which the prescribed coefficient sequence is repeated.   
     
     
         3 . The radar device according to  claim 1 , further comprising:
 a transmitter which, in operation, stops the transmission of the one or more radar transmission signals in the interference measurement segment, and transmits the one or more radar transmission signals in a distance measurement segment in which a distance from the radar device to a target is measured.   
     
     
         4 . The radar device according to  claim 3 , further comprising:
 transmission control circuitry which, in operation, periodically switches between the interference measurement segment and the distance measurement segment.   
     
     
         5 . The radar device according to  claim 1 , further comprising:
 interference determination circuitry which, in operation, compares each of the detected one or more interference signal components with a prescribed determination level in the interference measurement segment, determines that one or more interference components are not present when each of the one or more interference signal components is equal to or less than the determination level, and determines that the one or more interference components are present when any of the one or more interference signal components exceeds the determination level.   
     
     
         6 . The radar device according to  claim 5 , further comprising:
 interference countermeasure control circuitry which, in operation, based on the interference determination result detected in the interference measurement segment, performs interference countermeasure control in the subsequent distance measurement segment.   
     
     
         7 . The radar device according to  claim 6 , wherein
 the interference countermeasure control circuitry changes a carrier frequency of the radar device.   
     
     
         8 . The radar device according to  claim 6 , wherein
 the interference countermeasure control circuitry changes directivity of an antenna of the radar device for a prescribed time interval.   
     
     
         9 . The radar device according to  claim 6 , wherein
 the interference countermeasure control circuitry increases a code length of the one or more radar transmission signals in the distance measurement segment for a prescribed time interval.   
     
     
         10 . The radar device according to  claim 1 , wherein
 the prescribed coefficient sequence includes a coefficient sequence {1, −j, −1, j} (in which j is an imaginary unit).