KR20070110721A - Automotive radar dualmode system with wireless communication - Google Patents

Abstract

An automotive radar dual mode system with a wireless communication function is provided to improve sensitivity as using a low cost antenna by simplifying a frequency conversion system. An automotive radar dual mode system includes a signal processor(10). The signal processor has a radar mode(110) and a communication mode(120). In the radar mode, distance, speed and azimuth angle are measured by using DBF(Digital Beam Forming) to a converted radar signal among digital signals outputted from a radar receiver. In the communication mode, compensation of location of a vehicle or information exchange between vehicles is performed by analyzing a converted communication signal among the digital signals.

Description

Automotive radar dualmode system with wireless communication

1 is an overall block diagram of a vehicle radar dual mode system with a wireless communication function according to an embodiment of the present invention,

2 is a block diagram illustrating in detail a DBF receiver and a DBF transmitter connected to each transmit / receive antenna array;

3 is a diagram illustrating an exemplary embodiment of a vehicle radar dual mode system and a signal output from a transmitter of the system according to the present invention.

<Description of the reference numerals for the main parts of the drawings>

10: signal processing unit of the radar system

20: receiver of the radar system

30: transmitting unit of the radar system

220: DBF receiver of the receiver

330: DBF transmitter of the transmitter

2210: I / Q down converter in the DBF receiver

3300: I / Q upconverter in DBF transmitter

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle radar system and a communication system, and more particularly, to a vehicle dual band radar system having a wireless communication function in a millimeter / submillimeter band using digital beam forming (DBF) technology. will be.

Recently, as the demand for short-range high resolution radar in the millimeter / submillimeter band increases, research on this continues. High resolution radar systems that can determine or resolve distances between adjacent objects are widely used for industrial and military purposes, and are used mainly for vehicle radar systems in real life. The vehicle radar system is an essential technology for implementing an intelligent transportation system, and detects the movement of another vehicle or object that is moving or stationary in a radius of about 10 m or more, thereby preventing accidents caused by poor weather conditions or inattention of a driver. It is a safe driving system of vehicles developed for the purpose of prevention.

Conventional high resolution radar systems use a method of detecting an object in front of a limited range using a multi-beam antenna with high gain to obtain high resolution spatial resolution within a small detection angle. In particular, since a multi-beam antenna can detect only a single target for each antenna or each beam, a large number of high gain antennas must be used to detect a large number of targets, thereby increasing the number of antennas. As the system becomes bulky, it is not suitable for a vehicle radar system.

In addition, the conventional vehicle radar system uses a bulky multi-antenna having a high gain as a transmission / reception antenna, so that the overall volume of the system is large, and the intermediate frequency (IF) of several stages in the process of converting the RF signal to the IF signal RF system is relatively complex because it needs to be converted. Since the price of each RF component used in such an RF system is very high, the cost of the entire system increases, which makes it difficult to commercialize a high resolution radar system.

On the other hand, the conventional system has developed the vehicle radar system and the communication system separately, and each system has used a different frequency and RF system. Conventional vehicle communication system uses a satellite communication or a communication method through a base station of the main road surface, in this case a dedicated system for communication is required, the use frequency is usually 10GHz or less, so the entire communication system is limited space Compared to the size of the vehicle having a relatively large volume. That is, in a communication system applied to a conventional vehicle, since a new system is manufactured and installed for each service to accommodate a radar and various communication services, it is difficult to implement a system in a vehicle having a limited space in reality. There is a problem of using expensive equipment and waste of frequency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and simplifies the frequency conversion system so that the reception characteristics can be improved while using a low-cost antenna in accordance with the requirements of price-performance and popularization in a vehicle radar system, and DBF technology By using to reduce the complexity of the RF system while obtaining a very high resolution.

In addition, the use of DBF technology simplifies the RF system and uses a wide range of frequency bandwidths in the millimeter / submillimeter band, thereby attempting to use communication services in the radar system. In other words, by integrating the vehicle radar system and the communication system in dual mode, DBF technology is applied to the radar and communication system to obtain ultra-high resolution images, enabling various intelligent communication services and high-speed data communication in communication, and reducing frequency waste. It aims at being able.

In the vehicle radar dual mode system having a wireless communication function according to the present invention for achieving the above object, by applying the DBF technology to the converted radar signal of the digital signal output from the radar receiver to determine the distance, speed and azimuth And a signal processing unit having a radar mode to measure and a communication mode for analyzing the converted communication signal among the digital signals output from the radar receiver to compensate for the location of the vehicle or to exchange information between the vehicles. It features. In this case, the signal processing unit may switch to the radar mode at the radar signal input and to the communication mode at the communication signal input according to coding of the input digital signal.

Next, the signal processor is a radar transmitter for transmitting a mixed signal of the radar signal and the communication signal for the vehicle collision prevention and safe driving in the millimeter / sub-millimeter band and the other radar signal reflected back from the transmitted radar signal It is connected to the radar receiver which receives the communication signal transmitted from and outputs it as a digital signal.

Here, the radar receiver comprises an antenna array comprising at least three antenna elements arranged at equal intervals or boiling intervals for receiving the radar signal and the communication signal, and the signal received in the antenna array intermediate frequency (IF ) And a DBF receiver that converts the signal into an I / Q vector. And an image reject filter for removing noise of the intermediate frequency (IF) signal output from the DBF receiver, and an automatic gain control (AGC) for adjusting phase and gain of the noise-removed intermediate frequency (IF) signal. And an A / D converter for converting an intermediate frequency (IF) signal, which is an analog output signal of the AGC, into a digital signal. In this case, the DBF receiver includes a low noise amplifier (LNA) for amplifying the signal received in the antenna array, and an I / Q for converting the amplified signal into an I / Q vector and an intermediate frequency (IF) signal. A down converter and a local oscillator and a power divider connected to each of the I / Q down converters may be included. In detail, the I / Q down converter converts the amplified signal into an intermediate frequency (IF) signal and simultaneously outputs an I / Q vector to a demodulator for outputting the I / Q vector. A variable gain amplifier for amplifying an IF signal and a mixer for modulation and demodulation of signals of I and Q channels among the output signals of the variable amplifier are preferable.

The radar transmitter may include a D / A converter for converting the mixed signal into an analog signal, a bandpass filter for passing the signal converted by the D / A converter only in a specific band, and the bandpass filter. A DBF transmitter for converting a passing signal into an I / Q vector and a signal for transmitting an intermediate frequency (IF) signal, and two or more antennas arranged at regular intervals to transmit the signal converted by the DBF transmitter It may include an antenna array comprising a device. In this case, the DBF transmitter converts the signal passing through the band pass filter into an I / Q vector and converts it into a signal for transmitting an intermediate frequency (IF) signal and the respective I / Q converters. A local oscillator and a power divider connected to the up converter, and a high power amplifier connected to the I / Q up converter to amplify the converted signal. In detail, the I / Q up converter includes a variable gain amplifier for amplifying a signal obtained by converting a signal passing through the bandpass filter into an I / Q vector, and amplified I / Q vector. It is preferable to include a modulator for converting the converted signal into an intermediate frequency (IF) signal for transmission, and a mixer for modulation and demodulation of the signals of the I and Q channels output from the modulator. In this case, the transmitter antenna, characterized in that for radiating a signal mixed with a radar signal of a certain period and a communication signal corresponding to the interval time of the radar signal.

Here, the antenna of the antenna array is a small-cost, low-cost broadband flat panel antenna, the antenna elements are weighted and synthesized by the weight of each of the antenna elements by the weight (weight), and synthesized in a plurality of signal processors It is characterized in that the plurality of incoming and outgoing wave to be transmitted and received are arranged to obtain a desired signal.

In the vehicle radar dual mode system having the wireless communication function, the radar receiver and the radar transmitter except the antenna array are manufactured by a low-cost millimeter / submillimeter band CMOS RF process method.

Hereinafter, an embodiment of a vehicle radar dual mode system having a wireless communication function according to the present invention will be described in detail with reference to FIGS. 1 to 3.

1 is an overall block diagram of a vehicle radar dual mode system with a wireless communication function according to an embodiment of the present invention.

The present invention provides a signal processing unit 10 having a radar mode for measuring the location of a relative vehicle through a digital signal output from the radar receiver and a communication mode for communication between vehicles or other communication services, and reflected from the transmitted signals. Receiving unit 20 for receiving a radar signal and a communication signal transmitted from another vehicle and outputting it as a digital signal, and a signal mixed with a radar signal and a communication signal for preventing vehicle collision and safe driving in the millimeter / sub-millimeter band The transmitter 30 can be broadly divided.

In the radar system according to the present invention, the signal processor 10 measures a frequency of the signal by applying a DBF technique to the radar signal of the digital signal output from the radar receiver 20 and measures the distance and relative speed with the opponent vehicle Radar mode 110 to measure and the communication mode 120 for the detection of communication signals other than the radar signal. The radar mode 110 and the communication mode 120 may be used at the same time, in which case the corresponding reception mode is applied according to the coding of the received RF signal. Since the same frequency and the same RF system is used, the radar mode 110 and the communication mode 120 may be used simultaneously, or one of the modes may be selectively used.

The dual mode method of the signal processing unit divides a frequency of one transmission path into a radar signal and a communication signal by dividing a predetermined time width, and a user can repeatedly use the entire frequency bandwidth of the vehicle radar system and various communication systems. Can increase the frequency utilization accordingly.

The receiver 20 of the vehicle radar dual mode system includes three radar signals, which are arranged at half-wavelength intervals, for example, to receive various radar signals and radar signals that are reflected and returned from obstacles among the signals transmitted from the transmitter 30. An antenna array 210 including the above antenna elements and a DBF receiver 220 for converting the received signal into an intermediate frequency (IF) signal and an I / Q vector. In the DBF receiver 220, an image reject filter for removing additional noise from the I / Q modulation and demodulation signal and separating the reception signal stage and the intermediate frequency (IF) signal stage to improve the stability of the receiver. , 230), AGC 240 for adjusting the phase and gain of the intermediate frequency (IF) signal converted in the I / Q down converter 2210, and the intermediate frequency (IF) which is an analog output signal of the AGC 240 An A / D converter 250 for converting a signal into a digital signal is connected.

The transmitter 30 of the vehicle radar dual mode system includes a D / A converter 310 for converting a digital signal from the signal processor 10 into an analog signal, and a band pass for passing the converted signal only in a specific band. A filter 320, a DBF transmitter 330 for converting the intermediate frequency (IF) signal passing through it into an I / Q vector and a signal for transmission, and a half, for example, for transmitting the converted signal. And an antenna array 340 including two or more antenna elements arranged at wavelength intervals.

2 is a block diagram illustrating in detail a DBF receiver 220 and a DBF transmitter 330 connected to each of the transceiver antenna arrays of FIG. 1.

The DBF receiver 220 is a low noise amplifier (LNA) 2200 for amplifying the signal received by the antenna array 210, and I for converting the amplified signal into an intermediate frequency (IF) signal and outputting it as an I / Q vector. / Q down converter 2210, and a local oscillator 2220 and a power divider 2230 connected to each of the I / Q down converter 2210. The low noise amplifier (LNA) 2200 increases the strength of the received signal and serves to amplify the antenna signal while reducing the noise of the receiver. The local oscillator 2220 supplies a LO frequency for frequency synthesis, and when channel selection is required, the local oscillator 2220 may select a channel by changing the LO frequency.

More specifically, the I / Q down converter 2210 includes the same number of demodulators 2212 as the antenna elements for converting the amplified signal into an intermediate frequency (IF) signal and outputting the same as an I / Q vector. A variable gain amplifier (2214) for amplifying an intermediate frequency (IF) signal output as a / Q vector, and a mixer 2216 for modulation and demodulation of signals of the I-channel and Q-channel having the frequency-converted 90-degree phase difference Is done. At this time, as the LO frequency generated by the local oscillator 2220 is input to the demodulator with a 90-degree phase delay in either the I channel or the Q channel, the data carried in the received signal is converted into an I / Q vector. The VGA 2214 or AGC 240 in the DBF receiver 220 cannot sufficiently amplify the weak received signal with the receiver's low noise amplifier (LNA) 2200 alone. Used for random adjustment.

In general, the use of an intermediate frequency (IF) signal requires several additional frequency conversions, so that a plurality of demodulators are used, a filter is used for each demodulator, and an expensive IF element is used. Becomes large. In addition, in terms of performance, a lot of noise is generated by repeated frequency conversion. In order to solve this problem, the radar system according to the present invention has the advantage of reducing the overall production cost and further improving the reception performance by simplifying the process of converting the RF signal into the IF signal as much as possible.

In addition, as the RF system is simplified, the reception performance is improved, so that the same frequency and the same RF system can be used in a communication system, thereby repeatedly using the radar mode and the communication mode in one system.

Next, the DBF transmitter 330 converts a signal passing through the bandpass filter into an I / Q vector and an I / Q up converter 3300 for converting an intermediate frequency (IF) signal into a signal for transmitting. Local oscillator 2220 and power divider 2230 connected to I / Q up converter 3300 and high output amplifiers PA and 3310 respectively connected to I / Q up converter 3300 to amplify the converted signal. )

More specifically, the I / Q up converter 3300 includes a variable gain amplifier 3302 for amplifying an intermediate frequency (IF) signal having a 90 degree phase delay passed through the band pass filter 320, A modulator 3304 for converting the intermediate frequency (IF) signal converted into the amplified I / Q vector to a signal for transmission, and for demodulation and demodulation of the signal of the I-channel and Q-channel having the frequency-converted 90 degree phase difference. And a mixer 3306. The converted and transmitted signal is a signal such as the sum of the LO frequency generated by the local oscillator 2220 and the intermediate frequency (IF) signal of the I / Q vector.

3 is a diagram illustrating an exemplary embodiment of a vehicle radar dual mode system and a signal output from a transmitter of the system according to the present invention.

For example, as shown in FIG. 3, if the first pulse and the seventh pulse correspond to the radar signal in the signal using the same frequency, the second to sixth pulses corresponding to the interval time between the radar signals, etc. By dedicating to a communication signal, the full bandwidth of the signal can be used. Since the frequency corresponding to the idle time between the radar signals can be used, it is possible to solve the problem of frequency wastage that the conventional radar system has. In addition, it is possible to maximize the advantages of the conventional system used separately by suggesting a vehicle radar dual mode system that can form a communication network with the adjacent vehicle to exchange state information of various vehicles. Integrating both systems is possible by simplifying the RF system using DBF® technology.

The RF system using DBF technology in the vehicle radar dual mode system according to the present invention has been described above. Conventional radar systems receive noise in a wide range of frequencies in the process of transmitting and receiving signals, and there is a problem that the efficiency is reduced due to a complex RF system, the radar system according to the present invention uses a DBF technology By receiving only a signal in a desired frequency range and greatly reducing the noise signal level due to other multiple access interference, it is possible to solve the problems of the prior art. In addition, the present invention has the advantage that the hardware complexity of the system can be reduced by using a DBF receiver and DBF transmitter more simplified than the RF system used in the prior art.

Next, in a vehicle radar dual mode system according to the present invention, a low-cost, small-sized flat panel antenna having a relatively low gain and a 3dB beam width of more than a degree may be used as a transmission / reception antenna. In the case of the conventional vehicle radar system, there are problems of the space and the production cost increase of the radar system in the vehicle by using a large number of bulky antennas having high gain in order to widen the high resolution spatial resolution and the forward detection range. This problem can be solved by using a low cost, small antenna. The number of transmit / receive antennas may vary according to the signal processing type, and the physical distance between the antennas may also be optimized according to the algorithm used.

Next, the vehicle radar system according to the present invention manufactures the receiver and the transmitter except the antenna using a low-cost millimeter / submillimeter CMOS process technique. In recent years, by gradually applying technology using CMOS (Complementary Metal Oxide Semiconductor) in the RF field, it is possible to lower the high price of current GaAs and SiGe processes, and the RF unit can be manufactured with a single CMOS chip together with the signal processing unit. The price of the system can be significantly lowered. CMOS is a circuit in which various passive devices and components are taken together with a semiconductor device on a semiconductor substrate, and there are MMIC (Monolithic Microwave Integrated Circuit) and RFIC (Radio Frequency Integrated Circuit) technologies using the same. An MMIC is usually a unit made up of a combination of one amplifier, two to three amplifiers, and an RFIC is a mixture of these circuits. The use of CMOS in RF enables the RF processor to easily integrate not only the analog RF but also the digital part, so the added value is very high. In the vehicle radar system according to the present invention, a conventional complex radar system can be simplified by printing the receiver 20 and the transmitter 30 of the entire system on one circuit board using a CMOS process technique.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the above-described specific embodiments, and the present invention is not usually limited to the scope of the present invention as claimed in the claims. Anyone skilled in the art can make various modifications, as well as such changes fall within the scope of the claims.

Radar system according to the present invention is a vehicle dual-mode radar system using DBF technology, compared to the conventional high resolution radar system, the spatial resolution is very excellent and using a simple structure IF system, the complex structure of the conventional RF system By simplifying, the noise generated in the frequency conversion process can be reduced, thereby improving reception performance.

In addition, it is possible to use a small low-cost flat-panel antenna having a small gain of 3dB instead of the high gain bulky multiple antennas used in the conventional high resolution radar system, thereby lowering the production cost.

In addition, the simplified RF system and improved reception allow the incorporation of automotive radar systems with intelligent communication services or new communication technologies. By dedicating the idle time of the radar signal to various communication signals, cost and space constraints and frequency waste can be reduced. When using a communication system, the vehicle-to-vehicle communication allows more information on adjacent vehicles to be supplemented and supplemented by vehicle radar, and communication technology between vehicles in the millimeter / submillimeter band. Because of the relatively wide bandwidth, a wide range of communication services are possible without the installation of a separate communication system.

Next, the vehicle dual-mode radar system according to the present invention can reduce the production cost while reducing the complexity of the system by printing the radar transmitter and receiver except for the antenna unit on a single semiconductor substrate using a low-cost CMOS process technique.

Therefore, the present invention can be used as an important auxiliary device for the automatic operation system and the safe operation of a vehicle such as a vehicle, and can satisfy various communication services.

Claims (12)

A radar mode that measures distance, speed, and azimuth by applying DBF technology to the converted radar signal among the digital signals output from the radar receiver, and analyzes the converted communication signal among the digital signals output from the radar receiver to analyze A vehicle radar dual mode system having a wireless communication function, characterized in that it comprises a signal processing unit having a communication mode for complementing the location or information exchange between the vehicle. The method of claim 1, And the signal processing unit switches to the radar mode at the radar signal input and to the communication mode at the input of the communication signal according to the coding of the input digital signal. The method of claim 1 The signal processing unit, A radar transmitter for transmitting a signal in which a radar signal and a communication signal are mixed for vehicle collision prevention and safe driving in a millimeter / submillimeter band; And The radar dual mode system for a vehicle with a wireless communication function, characterized in that connected to the radar receiving unit for receiving a communication signal transmitted from another vehicle and the radar signal reflected back of the transmitted radar signal and output as a digital signal. The method of claim 3, wherein The radar receiver, An antenna array comprising three or more antenna elements arranged at equal or boiling intervals to receive the radar signal and the communication signal; A DBF receiver for converting a signal received in the antenna array into an intermediate frequency (IF) signal and an I / Q vector; An image reject filter for removing noise of an intermediate frequency (IF) signal output from the DBF receiver; AGC (Autometic Gain Control) for adjusting the phase and gain of the noise-controlled intermediate frequency (IF) signal; And And an A / D converter converting an intermediate frequency (IF) signal, which is an analog output signal of the AGC, into a digital signal. The method of claim 4, wherein The DBF receiver, A low noise amplifier (LNA) for amplifying a signal received at the antenna array; An I / Q down converter converting the amplified signal into an I / Q vector and an intermediate frequency (IF) signal; And And a local oscillator and a power divider connected to each of the I / Q down converters. The method of claim 5, The I / Q down converter, A demodulator for converting the amplified signal into an intermediate frequency (IF) signal and outputting the same as an I / Q vector; A variable gain amplifier for amplifying an intermediate frequency (IF) signal output as the I / Q vector; And And a mixer for modulating and demodulating the signals of the I and Q channels among the output signals of the variable amplifier. The method of claim 3, wherein The radar transmitter, A D / A converter for converting the mixed signal of the radar signal and the communication signal into an analog signal; A bandpass filter for passing the signal converted by the D / A converter only in a specific band; A DBF transmitter for converting a signal passing through the bandpass filter into an I / Q vector and a signal for transmitting an intermediate frequency (IF) signal; And And an antenna array comprising two or more antenna elements arranged at regular intervals to transmit the signal converted by the DBF transmitter. The method of claim 7, wherein The DBF transmitter, An I / Q up converter for converting the signal passing through the band pass filter into an I / Q vector and a signal for transmitting an intermediate frequency (IF) signal; A local oscillator and a power divider connected to the respective I / Q up converters; And And a high power amplifier connected to the I / Q up-converter to amplify the converted signal. The method of claim 8, The I / Q up converter, A variable gain amplifier for amplifying a signal obtained by converting the signal passing through the band pass filter into an I / Q vector; A modulator for converting the signal converted into the amplified I / Q vector into an intermediate frequency (IF) signal for transmission; And And a mixer for modulating and demodulating signals of I and Q channels output from the modulator. The method of claim 7, wherein The transmitter antenna of the vehicle radar dual mode system with a wireless communication function, characterized in that for radiating a mixed signal of a radar signal of a predetermined period and the communication signal corresponding to the interval time of the radar signal. The method according to claim 4 or 7, The transmit / receive antenna of the antenna array is a small low-cost broadband flat panel antenna, and the antenna elements are transmitted and received by a plurality of signal processors by weighting and combining signals transmitted and received by the antenna elements by their respective weights. A vehicle radar dual mode system having a wireless communication function, characterized in that the plurality of arrival waves are further synthesized and arranged to obtain a desired signal. The method of claim 3, wherein The radar receiver and the radar transmitter except for the antenna array in the vehicle radar dual mode system with a wireless communication function is manufactured by a low-cost millimeter / sub-millimeter band CMOS RF processing method for a vehicle radar dual with a wireless communication function Mod system.

Images