Radar system for interference avoidance based on vehicle heading

1. A radar system for a vehicle, comprising a control unit and a radar transceiver arrangement with at least one ego radar transceiver, where, for the at least one ego radar transceiver, the control unit is adapted to:

determine a present direction of the ego radar transceiver in dependence of a vehicle heading,

determine a reserved frequency band corresponding to the present direction, and to

determine a first extended frequency band comprising and extending beyond the reserved frequency band,

wherein the control unit is further adapted to:

detect presence of an interfering radar transceiver, and to operate the ego radar transceiver in the first extended frequency band in a first case wherein the interfering radar transceiver is not detected during operation of the ego radar transceiver in the first extended frequency band, and to operate the ego radar transceiver in the reserved frequency band in a second case wherein the interfering radar transceiver is detected during operation of the ego radar transceiver.

2. The radar system according to claim 1 , wherein the control unit is further adapted to:

determine a second extended frequency band comprising and extending beyond the first extended frequency band, and to operate the ego radar transceiver in the second extended frequency band in a third case wherein an interfering radar transceiver is not detected while operating the ego radar transceiver in the second extended frequency band and to operate the ego radar transceiver in the first extended frequency band or in the reserved frequency band in a third case wherein an interfering radar transceiver is detected while operating the ego radar transceiver in the second extended frequency band.

3. The radar system according to claim 2 , wherein the first extended frequency band and the second extended frequency band excludes the reserved frequency band corresponding to a direction opposite to the present direction.

4. The radar system according to claim 1 , wherein the control unit is adapted to generate a random outcome, and to detect presence of the interfering radar transceiver during radar operation in the first extended frequency band or in the second extended frequency band in dependence of the random outcome.

5. The radar system according to claim 1 , wherein the ego radar transceiver is configured to avoid radar transmission at the same frequency and time instant as the interfering radar transceiver, wherein the control unit is adapted to detect presence of the interfering radar transceiver in the first extended frequency band or in the second extended frequency band in dependence of an interference level in a received radar signal of the ego radar transceiver.

6. The radar system according to claim 1 , wherein the reserved frequency band is determined based on a center frequency corresponding to the direction and on a pre-configured reserved bandwidth.

7. The radar system according to claim 6 , wherein the center frequency is given as a linear function of the direction.

8. The radar system according to claim 6 , wherein the center frequency is given as a piecewise constant function of the direction.

9. The radar system according to claim 1 , wherein the control unit is adapted to detect the presence of the interfering radar transceiver by monitoring a received radar signal of the ego radar transceiver.

10. The radar system according to claim 9 , wherein the control unit is adapted to detect the presence of the interfering radar transceiver by measuring a noise floor level associated with the received signal.

11. The radar system according to claim 9 , wherein the control unit is adapted to detect the presence of the interfering radar transceiver based on a difference between consecutive time domain samples of the received radar signal.

12. The radar system according to claim 1 , wherein the control unit is adapted to perform signal repair of the received radar signal or to have a slanted polarization direction of the radar transceiver.

13. The radar system according to claim 1 , wherein the control unit is adapted to determine the present direction by use of Global Navigation Satellite System, data, or by an electronic compass comprised in the radar system.

14. A method performed by a control unit in a radar system comprising a radar transceiver arrangement with at least one ego radar transceiver, the method comprising the steps of:

determining a present direction of the ego radar transceiver,

determining a reserved frequency band corresponding to the present direction,

determining a first extended frequency band comprising and extending beyond the reserved frequency band,

detecting the presence of an interfering radar transceiver in the first extended frequency band, and

operating the ego radar transceiver in the first extended frequency band in a first case wherein an interfering radar transceiver is not detected in the first extended frequency band and

operating the ego radar transceiver in the reserved frequency band in a second case wherein an interfering radar transceiver is detected in the first extended frequency band.

15. A vehicle comprising the radar system according to claim 1 .