Radar System Having Arrangements and Methods for the Decoupling of Transmitting and Receiving Signals and for the Suppression of Interference Radiation

• US 20120001791A1
• Filed: 04/01/2010
• Published: 01/05/2012
• Est. Priority Date: 04/06/2009
• Status: Active Grant

• Current Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Original Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Inventors: Wintermantel, Markus
• Granted Patent: US 9,182,476 B2
• Time in Patent Office: Days
• US Class Current: 342/109
• CPC Class Codes: G01S 13/26 wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
• CPC Class Codes: G01S 13/343 using sawtooth modulation
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/023 Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: G01S 7/0233 Avoidance by phase multiplex
• CPC Class Codes: G01S 7/038 Feedthrough nulling circuits
• CPC Class Codes: G01S 7/2926 by integration
• CPC Class Codes: G01S 7/2928 Random or non-synchronous interference pulse cancellers
• CPC Class Codes: G01S 7/356 involving particularities of FFT processing

Abstract

Radar system for covering the surroundings, designed such that one or several sequences of identical or similar individual signals are radiated per transmitting antenna in a measuring cycle, which sequences are interlaced where appropriate, wherein the average time interval of said individual signals is greater than the propagation time of received signals that corresponds to the maximally interesting distance, particularly for determining the relative velocity of objects and for increasing the detection sensitivity.

Receiving means are provided in which the signals that are received by reflection from objects are mixed with high-frequency signals, whereby low-frequency receiving signals are generated that represent sequences of individual signals, and the phase position thereof is varied over successive low-frequency individual receiving signals by varying the phase position of the individual transmitting signals and/or of the high-frequency signals used for mixing and/or of the low-frequency individual receiving signals themselves.

Claims

1. Method for the suppression of interference radiation for a radar system for a motor vehicle, wherein

one or several sequences of essentially identical high-frequency individual signals are radiated in a measuring cycle and the average time interval of said individual signals is greater than the propagation time of received signals that corresponds to a maximally interesting distance, particularly for determining the relative velocity of objects and for increasing the detection sensitivity;

received signals are mixed with high-frequency signals, whereby low-frequency receiving signals are generated that represent sequences of individual signals; and

the phase position thereof is varied over successive low-frequency individual receiving signals by varying the phase position of the individual transmitting signals and/or of the high-frequency signals used for mixing and/or of the low-frequency individual receiving signals themselves.

2. Method according to claim 1, wherein the amplitude curve of the radiated signals includes one or several sequences of short pulses and the phase position is varied from pulse to pulse in each case.

3. Method according to claim 1, wherein the frequency curve of the radiated signals includes one or several sequences of linear frequency ramps of identical slope each and the phase position is varied from ramp to ramp in each case.

16. Method according to claim 1, in which the variation of the phase position of the individual transmitting signals and/or of the high-frequency signals used for mixing and/or of the low-frequency individual receiving signals is a determinate, pseudo-random or random variation or is made up of a determinate component and a random or pseudo-random component.

17. Method according to claim 1, in which the phase position is varied by enabling a signal to be optionally inverted, i.e., by enabling the phase of the signal to be rotated by 180°

or to be left unchanged.

18. Method according to claim 1, in which the variation of the phase position is used for making interference coupling or interference radiation caused by the radar system itself or by other systems behave in an uncorrelated manner relative to received signals of objects during signal processing so that a significant part of said coupling or radiation can be suppressed, said interference coupling or interference radiation occurring in the radar frequency range or in the range in which the low-frequency part of an electronic evaluation unit operates or is sensitive.

19. Method according to claim 1, wherein, when different antennas transmit and receive simultaneously, at least a large part of components of the high-frequency signals used for mixing that are unintentionally radiated by the receiving antennas on account of, e.g., non-ideal decoupling or incomplete reverse isolation of the receiving path are separated, by the variation of the phase positions, from the signals radiated by the transmitting antennas after their reflection from objects and reception in the signal processing means.

20. Method according to claim 19, in which there are several antennas for transmitting and/or receiving that are used in different combinations in a parallel or serial manner, the angle of objects relative to the radar system is determined from the signals that are received by reflection from these objects in different antenna combinations, and angle determination errors are at least largely avoided by the variation of the phase position.

21. Method according to claim 19, in which the variation of the phase position is designed such that the superposition of the power radiated by the transmitting antennas and by the receiving antennas does not result in any angle regions of significantly reduced detection sensitivity.

22. Method according to claim 1, in which an integration over the low-frequency individual receiving signals is performed in the signal processing means that is correlated to the useful components and uncorrelated to the spurious components so that the spurious components only result in noise and thus cannot result in incorrect object detection and/or in a significantly incorrect determination of object quantities.

23. Method according to claim 1, in which several antennas transmit simultaneously, wherein the phase position of the individual transmitting signals of different antennas relative to each other is varied, thereby allowing an at least approximate separation of the transmitting signals of different antennas when received by the same antenna.

24. Method according to claim 23, wherein two antennas transmit simultaneously and the phase position of the individual transmitting signals of the two antennas relative to each other is varied in a random or pseudo-random manner or alternately from individual transmitting signal to individual transmitting signal by 0°

and 180°

.

25. Method according to claim 1, in which several antennas receive simultaneously, wherein a summation of their receiving signals in the high-frequency or low-frequency range is performed and the phase position of the individual receiving signals of different antennas relative to each other is varied during said summation, thereby allowing an at least approximate subsequent separation of the receiving signals of different antennas in the signal processing means so that a part of the processing of the receiving signals can be performed in a shared path.

26. Method according to claim 1, in which prior to, during or after the evaluation of respectively one individual receiving signal, the phase position variation used therefor is corrected.

27. Radar system for covering the surroundings of a motor vehicle and for suppressing effects of interference radiation by the method according to claim 1, comprising

transmitting means for the radiation of transmitting signals, wherein said transmitting means may include several antennas;

receiving means for the reception of transmitting signals reflected from objects, wherein said receiving means may include several antennas; and

signal processing means for processing the received signals,

wherein one or several sequences of essentially identical high-frequency individual signals are radiated in a measuring cycle and the average time interval of said individual signals is greater than the propagation time of received signals that corresponds to a maximally interesting distance, particularly for determining the relative velocity of objects and for increasing the detection sensitivity

and received signals are mixed with high-frequency signals, whereby low-frequency receiving signals are generated that represent sequences of individual signals, characterized in that

means for phase angle rotation of individual signals are also provided and the phase position thereof is varied over successive low-frequency individual receiving signals by varying the phase position of the individual transmitting signals and/or of the high-frequency signals used for mixing and/or of the low-frequency individual receiving signals themselves by said means for phase angle rotation.

4-15. -15. (canceled)