TW200541158A - Vehicle smart antenna apparatus - Google Patents

Abstract

A vehicle smart antenna apparatus has a plurality of the antenna devices line becoming a uniform linear array with one dimension. The distance of each antenna devices is a half of a predetermined wavelength. After each antenna devices confirm all satellites in the air, the antenna devices use a plurality of EM field with the different direction to cover all satellites. The present invention receives a plurality of wireless carried wave signals respectively with a mechanism, which saves the most power and suppresses the most electrical wave interference. In addition, the present invention further has a sample counting module coupled to the antenna devices. The sample counting module is used to take out and count a satellite information of the antenna devices for adjusting the radiation used to receive the satellite information of the antenna devices.

Description

200541158 13167twf.doc 发明. Description of the invention: [Technical field to which the invention belongs] The present invention relates to a smart antenna device, and more particularly to a smart antenna device for a vehicle. [Previous Technology] The Global Positioning System (hereinafter referred to as GPS) is a set of precise satellite navigation positioning plans that the US Department of Defense took 20 years and spent more than 12 billion US dollars to develop in 1973. Launched since 1978, and officially launched three-dimensional spatial positioning in October 1993. The development of GPS was developed to support the needs of aviation and aircraft in the military. The entire system was developed. A total of 26 artificial positioning satellites were distributed in 6 orbits, and each orbit was at an angle of 55 degrees, making GPS At any time and place on the earth, if the user is not covered by the terrain or building facilities, it will not be affected by the weather, and can receive signals from 4 to 8 positioning satellites for positioning. The satellite is about 20,000 kilometers above the ground, and it belongs to an orbiting satellite, which has a trajectory of about 12 hours, and its lifespan is about 75 years. GPS includes space unit, control unit and user unit. The space unit refers to 26 positioning satellites, and the control unit includes a master control station, three ground antennas, and five monitoring stations. In addition, the user unit refers to a device capable of receiving GPS satellite information, such as a PDA with a GPS function, a GPS device for a vehicle, etc. Because GPS is widely used, users can use receivers with different functions and accuracy according to different purposes. Smart antenna system is a kind of radio wave radiation technology that has emerged in recent years. It is mainly used in antennas of mobile phone base stations. Using a very complex "blind" algorithm, I estimate the user's position to form different electromagnetic waves. 200541158 13167twf .doc field type to save power and suppress interference signals in the same frequency band. FIG. 1 is a schematic diagram showing a conventional vehicle GPS antenna field type. Please refer to FIG. 1 ′ The conventional vehicle GPS antenna uses an omnidirectional or forward vehicle antenna to receive a positioning signal from a positioning satellite. For an omnidirectional antenna, it will receive positioning signals in the same field type for the entire sky, so it will often interfere with other signals. Figure 1 shows a forward-looking antenna. When viewed in a clockwise direction, although the forward-looking antenna has a high signal isolation for noise in the range of -90 degrees to 90 degrees, it is at 90 degrees. The range to _90 degrees is still susceptible to interference from other noise. [Summary of the Invention] Therefore, the object of the present invention is to provide a simpler smart antenna calculation method that utilizes the characteristics of satellites that are not highly mobile like ordinary mobile phone users. In the beginning, they will search the entire sky to learn about satellites. After the position, it can be divided into field patterns in all directions to cover all the satellites in the sky. This method can greatly reduce the general smart antenna because of the blindness, algorithm calculation time and wasted system resources. Another object of the present invention is to provide a smart antenna device for a vehicle, which can eliminate interference problems outside the field type. An object of the present invention is to provide a smart antenna device for a vehicle, which is connected to an electronic device. The smart antenna device for a vehicle of the present invention includes several antenna elements arranged in a one-dimensional equidistant antenna array (Uniform Linear Airay, ULA for short). The distance between these antenna elements is 1/2 of a preset wavelength. And these antenna elements and each antenna element will search all-sky satellites omnidirectionally at the beginning to determine the positions of all received satellites in the sky, and then use the antenna unit in several directions 200541158 13167twf.doc The electromagnetic field pattern covers all satellites. With the most power-saving and the largest radio interference suppression mechanism, a plurality of wireless carrier signals with satellite information are received separately. In addition, the present invention also includes a sampling calculation module, which is coupled to these antenna elements. The sampling calculation module is used for taking out and calculating the satellite information received by the antenna element to adjust the radiation pattern of the antenna element receiving the satellite information. In GPS, because the satellite information of at least 4 positioning satellites is needed, the three-dimensional coordinates of the current location can be determined. Therefore, the above-mentioned antenna elements include a first antenna element, a second antenna element, a third antenna element, and a fourth antenna element. The antenna elements are used in four directions to receive signals from four positioning satellites with different directions. Satellite information to find four positioning satellites in the most power-saving way to achieve positioning. The content of the above satellite information further includes parameters of at least one of longitude, latitude, speed, direction, and altitude to provide the electronic device coupled to the present invention for navigation and positioning. Generally speaking, satellite information is modulated on a wireless carrier signal of 1575.42 MHz, so the above-mentioned preset wavelength is 19 cm. From another perspective, the present invention provides a smart antenna device for a vehicle, which is also coupled to an electronic device. The smart antenna device for a vehicle of the present invention includes an antenna array and a radio frequency / intermediate frequency unit coupled to the antenna array. The antenna array has several antenna elements. Each antenna element determines all the received signals in the sky at the beginning. After reaching the position of the satellite, all the satellites are covered by the electromagnetic wave field pattern in several directions respectively. With the most power-saving and the largest radio wave interference suppression mechanism, most wireless carrier signals with satellite information are received separately, and the RF / The IF unit converts these wireless carrier signals into baseband signals. In addition, the present invention further includes the 200541158 13167twf.doc algorithm unit. The single-fiber frequency-rejection unit is designed to calculate the weight of each antenna element. The beam-synthesizing unit is a field type that receives light and receives signals from the airborne parts according to the enzymes of the boat. In addition, the smart antenna device of the present invention further includes a baseband signal processing unit, which is coupled to the beamforming unit and is used to filter out noise of the baseband signal. The baseband signal is sent to the electronic device coupled to the present invention, so that the electronic device performs navigation and positioning according to the baseband signal. @ As mentioned above, after the antenna elements included in the present invention determine the positions of all received satellites in the sky for each antenna, all the satellites are covered by electromagnetic wave fields of several directions to save the most. The power and maximum radio wave interference suppression mechanism respectively receive most of the wireless carrier signals with satellite information, and because the satellite's seat does not move too much in a short time, and it starts with the whole sky first Searching the satellite position reported by the satellite can determine the electromagnetic wave field type to be transmitted faster, eliminating the need for traditional smart antennas to use complex algorithms to estimate the target to determine the electromagnetic wave field type. It is also divided into multiple fields. The type covers satellite signals, so noise in other directions will be suppressed, so that the present invention will have better signal isolation for noise. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the preferred embodiments are described in detail below with reference to the accompanying drawings, as follows. [Embodiment] The following is a detailed description of the principles and implementation of the present invention, and in order to avoid 200541158 13167twf.doc to confuse the skilled person with the focus of the present invention, the GPS technology involved in the present invention will Spirit will not do special narration. FIG. 2 is a block diagram of a smart antenna device for a vehicle according to a preferred embodiment of the present invention. Please refer to FIG. 2. The so-called smart antenna is a group of antenna elements in a specific geometric arrangement. Therefore, in the present invention, the antenna array 210 has several antenna elements such as 212, and these antenna elements are arranged in a one-dimensional equidistant antenna array, and each antenna element is spaced a predetermined distance d. In this embodiment, the antenna array 210 is coupled to the sampling calculation module 220, and the satellite information of the positioning satellites received by the antenna array 210 is sent to the electronics such as the vehicle GPS device 230 through the sampling calculation module 220. Device for navigation and positioning. Please continue to refer to FIG. 2. In the present invention, after each antenna element is activated, it searches for the positions of all-sky satellites in an all-round manner, and each antenna determines the positions of all received satellites in the sky. Then, all the satellites are covered by the electromagnetic wave field pattern in several directions, which is the most power-saving and the largest radio interference suppression mechanism, and can determine the radio wave direction in the most simplified way to save computing resources, as shown in Figure 3. Show. In the present invention, all the satellite signals in the sky are divided into four receiving field types by using the preset four antenna units. It is expected that the minimum number of antenna units can be used to search for four satellites that can be located. , As shown in Figure 2. Among them, “the use of only four satellites can achieve satellite positioning characteristics” to use a minimum of four antenna units to emit four electromagnetic wave field patterns to cover all satellites in the sky. 3A and 3B are schematic diagrams of a shooting field type according to 200541158 13167twf.doc according to a preferred embodiment of the present invention. Please refer to FIG. 3A and FIG. B ′ for a skilled person to understand the features of the present invention, and only 212 examples are described below. In the present invention, after the antenna element searches for a direction, it will divide into several radio wave field patterns to cover all satellites in the sky. As shown in FIG. 3A. It is assumed that the receiving signal direction of the antenna element 212 is a range represented by a dotted line in FIG. 3B, that is, a radiation field type η. Therefore, a person skilled in the art can know from FIG. 3B that only satellite information included in the radiation field type 31 will be received, and the interference g number outside the radiation field type 31 will be suppressed. In addition, the sampling calculation module 22 in the present invention also adjusts the radiation field pattern of the antenna element based on satellite information. For example, in FIG. 3, 'when the original radiation field type 31 is blocked by, for example, a building and cannot receive satellite information, the sampling calculation module 220 may change the radiation field type of the antenna element 212 from 31 to 33 based on the satellite information ° Figure 4 is a schematic diagram of receiving satellite information by an antenna element according to a preferred embodiment of the present invention. Please refer to Figure 4. The radiation pattern 3 1 of the antenna 212 includes a positioning satellite 41 and a satellite M 4 4 When the satellite message is sent, the antenna 212 will cover the satellite message within the field range. In the preferred embodiment of the present invention, 'when the electronic device is in a moving state, the antenna element will first locate the electronic device in an all-round position i' and then locate the satellite with the highest power when communicating with it in the sky 'to Ensure that the maximum power satellite signal can be received, and 'because the electronic device is moving, the radiation field type shown in Figure 4 is not fixed', but the sampling calculation module 220 shown in Figure 2 will be uninterrupted. Calculate the satellites that have the highest power when communicating with them to control the radiation emitted by these antennas. 200541158 13167twf.doc field pattern. In the preferred embodiment of the present invention, it uses the slow movement of satellites and faster determination of the electromagnetic wave field type, in order to improve the shortcomings of conventional smart antennas that require complex "blind" algorithms to determine the electromagnetic wave field type. In a preferred embodiment of the present invention, the radiation field type emitted by the antenna element includes not only the satellite with the maximum communication power, but also other satellites that are not the maximum communication power. In a preferred embodiment of the present invention, the radiation field pattern emitted by the antenna element may, for example, cover all positioning satellites. Generally speaking, satellite information includes parameter data such as longitude, latitude, speed, direction and altitude. Therefore, the electronic device coupled to the sampling calculation module 220 can use the above parameter data for navigation and positioning. In GPS technology, satellite information is modulated on a wireless carrier signal with a preset frequency for transmission. This preset frequency is generally 1575.42MHz, and this frequency is also called the L1 frequency. Here, we use λ to represent the wavelength, y to represent the frequency, and C to represent the speed of light, we can use the following formula:

V and the wavelength λ of the wireless carrier signal obtained at L1 frequency is equal to 19 cm. Please continue to refer to FIG. 2. In the GPS technology, satellite signals from 4 different positioning satellites are needed to determine the three-dimensional coordinates of the location. Therefore, in this embodiment, the number of antenna elements is set to four, namely antenna elements 212, 214, 216, and 218, and each antenna element is spaced a predetermined distance d from each other. Because of the radiation field type of the antenna element, the distance between the two antenna elements is the most ideal when the received signal wavelength is W2. Because the wavelength λ of the wireless carrier signal of the L1 frequency is equal to 19 200541158 13167twf.doc cm ', the preset distance d is set to 9.5 cm in this embodiment. Although the number of antenna elements is set to four, the present invention is not designed in this way. Those skilled in the art can make corrections according to actual needs. In addition, the positioning satellite also has a wireless wave ## of the L2 frequency. When the present invention is designed to receive a wireless carrier signal of this frequency ', the above-mentioned preset distance d must be modified to 12 cm. Please refer to FIG. 2. In the sampling calculation module 220, the input of the RF / IF unit 222 is coupled to the antenna array 210, and its output string is connected to the algorithm unit 224 and the beam combining unit, respectively. 226. The beam synthesis unit = 226 sends the output of the algorithm unit 224 and the RF / IF unit 222 to an electronic device such as a GPS device 230 for navigation and positioning after processing. In more detail, the RF / IF unit 222 is used to convert a wireless carrier signal into a baseband signal to remove satellite information from the wireless carrier signal 'and send it to the algorithm unit 224 and the beam combining unit 226. Among them, for example, an algorithm unit 224 of a discrete signal processing (DSP) chip is used to calculate the weight of each antenna element, and the result is sent to a beam synthesis unit 226. The beam combining unit 226 adjusts the radiation field pattern of each antenna element receiving the wireless carrier signal according to the weight of each antenna element. The following provides a method for calculating the weight of an antenna element, but the present invention is not limited thereto. First, consider a κ far-field and narrow-band signal source, which is received by a one-dimensional isometric antenna array consisting of a group of M identical antenna elements, assuming all signal sources and all antennas 12 200541158 13167twf .doc components are coplanar incident. If the angle formed by the incident direction of the signal source Si⑴ and the vertical direction is h, the vector formed by the i-th received signal of the antenna array can be represented by the direction vector 2⑼ of the signal source as: where = ((9 ,. ) (Θ, ·)] 2 / τ 2ττ = 1 exp0— ^ sin ^ /) ··· exp〇 ~ (Ml) Jsin ^.) _ A λ '' T〃 represents the transposed matrix operator, d is The distance between the antenna elements, where d = A / 2, λ is the wavelength of the received signal. When there are K signals being received by the antenna array at the same time, and in the case of additive Gaussian white noise (AWGN), the received signal is re-expressed as (not considering the interference signal):

Kit) = ^ α (θι) s ((t) + N (t) = As S (t) + N (t) / = 1 where

As = \ ί (θχ \ ^ (θ2 \ ..., α {θ K)] s {t) = Let A⑴ be the noise signal of the i-th antenna element (〇 < i $ M), and both The signal sources are uncorrelated and have the same power σ 2. From the above formula, we can obtain the total set autocorrelation matrix of Z (〇:

R, x = E [mXl \ t) \ = AsRssA ^ a2IN where E □ is the expectation of the random signal process 値, 〃 represents the conjugate transpose operator, 1 = 4 " (〇j is the autocorrelation matrix of the signal source vector ; And when news 13 200541158 13167twf.doc

When the signal sources are Mutually Uncorrelated, Rss is a diagonal matrix of Kx K and the diagonal elements are the power of the signal source. IN represents the identity matrix of N × N. Considering the incidence of multiple target signal sources (that is, K > 1), the received signal of the antenna array includes K target signals with 0,40,... And white Gaussian noise existing in the antenna element, that is: / = 1 Then the output signal y⑴ of the beam combining unit 226 can be expressed as: · y (0 = = / = 1 where = = [〇2 (〇, ... ~ said represents the dimension weighting coefficient vector, \ '* 〃 represents the conjugate The output power of the beam combining unit 226 is:

Pout = E \ y (tf \ = JVHRxxJV where

Rxx-E [x (t) xH (t) \

Under the limitation of minimum output power, its mathematical formula can be expressed as: mmWHRxxW ly-χχ- and · CHW = f where C is the Mx K-dimensional limit matrix and Z is a Kx 1-dimensional vector, then we can get the best Solution: K〇pt = R ;: c (cHR ;: cylf Repeat the above calculation procedure to calculate the weight of each antenna. 14 200541158 13167twf.doc In addition, the sampling calculation module 220 includes the baseband signal The processing unit 228 is used for filtering out noise of the baseband signal (for example, inter-symbol interference (ISI)), and then sending it to the electronic device coupled to the sampling calculation module 220 for navigation and positioning. As mentioned above, because the present invention receives satellite information in a preset signal receiving direction, noise in other directions will be effectively suppressed ', so the present invention has better isolation for noise. The 'satellite message received by the present invention in the preset signal receiving direction' is the satellite signal with the highest power, so the present invention can also reduce the interference of other satellite signals with weaker power. Moreover, the radiation pattern of the present invention will follow the satellite message It changes dynamically, so the present invention can also have a good receiving ability in bad terrain such as buildings. Furthermore, the present invention can improve the conventional smart antennas that require complex "blind" algorithms to determine electromagnetic waves. Disadvantages of the field type. In addition, the present invention can use a minimum of four antenna units to emit four electromagnetic wave field types to cover all satellites in the sky. Although the present invention has been disclosed above in a preferred embodiment, it is not intended to limit The present invention, anyone skilled in the art, can make some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application. Brief description of the drawings] Figure 1 is a schematic diagram of a conventional GPS antenna field type for a vehicle. Figure 2 is a block diagram of a smart antenna device for a vehicle according to a preferred embodiment of the present invention. 15 200541158 13167twf.doc FIGS. 3A and 3B are schematic diagrams illustrating radiation patterns of an antenna element according to a preferred embodiment of the present invention. A preferred embodiment is a schematic diagram of an antenna element receiving satellite information. [Schematic description] 210: array antennas 212, 214, 216, 218 ·· antenna element 220: sampling calculation module 222: RF / IF unit 224: Algorithm unit 226: Beam synthesis unit 228: Baseband signal processing unit 230: Vehicle GPS device

Claims (1)

200541158 13167twf.doc The scope of patent application: 1. A smart antenna device for a vehicle, which is coupled to an electronic device. The smart antenna device for a vehicle includes: a plurality of antenna elements, which are arranged in a dimensional isometric antenna array (ULA), the antenna elements are separated from the next antenna element by 1/2 of a preset wavelength, and each of the antenna elements is determined from the position of the electronic device, and then is selected from a plurality of satellites. Receive four satellite messages with maximum power, and cover all satellite signals in the sky with four field types; and a sampling calculation module, coupled to the antenna elements, to retrieve and calculate the satellite messages to adjust The radiation pattern of the antenna elements receiving the satellite information. 2. The smart antenna device for a vehicle according to item 1 of the scope of patent application, wherein the antenna elements include a first antenna element, a second antenna element, a third antenna element, and a fourth antenna element . 3. The smart antenna device for a vehicle as described in item 1 of the patent application scope, wherein the preset wavelength is 19 cm. 4. The smart antenna device for a vehicle according to item 1 of the scope of the patent application, wherein the satellite information further includes parameters of at least one of longitude, latitude, speed, direction and altitude to provide the electronic device for navigation and positioning. 5. The smart antenna device for a vehicle as described in item 1 of the scope of patent application, wherein the satellite messages are modulated on a wireless carrier signal of a specific frequency. 6. The vehicle-mounted smart antenna device described in item 1 of the scope of patent application, wherein the frequency of the wireless carrier signal is 1575.42 MHz 7. The vehicle-mounted smart antenna device described in item 1 of the scope of patent application, 17 200541158 13167twf. doc The electronic device includes a vehicle GPS device. 8. —A smart antenna device for a vehicle, which is coupled to an electronic device. The smart antenna device for a vehicle includes: an antenna array having a plurality of antenna elements, and the antenna elements are used to determine the position of the satellite, Then search the satellites with higher communication receiving power from a plurality of satellites, and receive them in four radio wave field types; an RF / IF unit coupled to the antenna array for converting the wireless carrier signals into a base Frequency signal; an algorithm unit coupled to the RF / IF unit to calculate the weight of each of the antenna elements; and a beam combining unit coupled to the RF / IF unit and the algorithm unit, and The radiation pattern of the antenna elements receiving the wireless carrier signals is adjusted according to the weight of each of the antenna elements. 9. The smart antenna device for a vehicle as described in item 8 of the scope of the patent application, further comprising a baseband signal processing unit coupled to the beam synthesis unit to filter out noise of the baseband signal, and apply the baseband signal The frequency signal is sent to the electronic device, so that the electronic device performs navigation and positioning according to the base frequency signal. 10. The smart antenna device for a vehicle according to item 9 of the scope of patent application, wherein the noise of the baseband signal includes an inter-symbol interference (ISI). 11. The smart antenna device for a vehicle as described in item 8 of the scope of the patent application, wherein the satellite messages are sent by a plurality of positioning satellites. 12. The smart antenna device for a vehicle according to item 8 of the scope of patent application, wherein the algorithm unit is a discrete signal processing chip. 13. The smart antenna device for a vehicle according to item 8 of the scope of the patent application, wherein the electronic device includes a GPS device for a vehicle. 18