JP2002064331A - Multibeam antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multibeam antenna system for homing in on the GPS satellites or the like, in which system configuration is simplified. SOLUTION: Signal processing parts 301-30k are composed of software or firmware and a receiving module for converting the frequencies of the received signals of so-called DBF antennas 101-10n for constructing a phased array antenna is synchronized to a local signal. Besides, the relative position of the GPS satellites decoded by a message decoding means 43 is obtained, a directivity control means 46 operates the azimuth to the GPS satellites by using that output, and a virtual multibeams and directed toward the GPS satellites at all the time by DBF technology by using the signal processing parts 301-30k.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multi-beam antenna device, and more particularly to a multi-beam antenna device for Global Positioning System (GPS) signals using digital beamforming (DBF).

[0002]

2. Description of the Related Art DGPS that can improve the accuracy of GPS while utilizing private signals is well known. DGPS is a system that transmits the error of a GPS signal at a known point to a mobile station to improve the accuracy and reliability of the mobile station. However, the accuracy and reliability of this system are based on the performance of the reference station. Is clear.

In recent years, there has been a movement to use this DGPS system for transportation systems and the like. DG using geostationary satellite
Systems for transmitting PS signals to mobiles are being considered in the aviation field. In such a system, the number of GPS satellites is usually increased apparently, and a pseudo range is provided so that accurate positioning calculation can be performed even when the satellite arrangement is deteriorated. Therefore, the pseudo range providing device is not limited to the GPS satellite, but may be a geostationary satellite, a pseudo satellite installed on the ground, or the like, and the supply sources thereof are increasing.

[0004] A risk that has always been a top priority in such systems and is being discussed around the world is the presence of interference affecting the GPS frequency band. In particular, there is a concern that the user reception signal may be unlocked due to interference radio waves. In this case, the navigation signal cannot be received, and the continuity of the system is interrupted. In the aviation and transportation fields, it is required that the system can be used at all times due to its public nature.

[0005] The Federal Aviation Administration (FAA) has been studying a countermeasure plan for interfering radio waves since the beginning of system development, and reported a problem with interfering radio waves (The Johns Hopkins Un
iversity, Applied Physics Laboratory, GPS Risk Asses
sment Study Final Report, January, 1999). In addition, other reports (M. Geyer, DOT Volpe Center, R. Fra
zier, FAA, FAA GPS Mitigation Program, ION-99, Nashvil
le, TN, September, 1999) and is considered an international concern. In normal DGPS, when interference due to interference radio waves occurs, accuracy degradation occurs in all mobile stations using the correction value of the reference station system,
Or, it becomes unusable.

Conventionally, as a first countermeasure against such interference radio waves, a method of forming a null in the arrival direction of the interference wave using a phased array antenna using a phase shifter has been adopted. . If the direction of a transmission source such as GPS can be specified as a second countermeasure method for interference radio waves,
A method has been considered in which the beam of the phased array antenna is directed to the transmitter.

[0007]

SUMMARY OF THE INVENTION However, in the first method,
In the above countermeasure method, the first problem is that it is necessary to know the direction from which the interference radio wave arrives. Usually, the location where the interference wave is generated is unknown, and it is difficult to know the direction of arrival. Since the form of the interfering radio wave is also unknown, in the case of relatively easy CW or pulsed interfering wave, the direction can be identified by scanning NULL, but a signal similar to the GPS signal is intentionally interfered. In such a case, it is very difficult to know the direction of arrival accurately (MUSIC method). The second problem is that the satellite near the formed NULL has a low received radio wave intensity.

Further, the above-mentioned second countermeasure method has a problem that the apparatus becomes large-scale. This is because a phaser system is required for forming beams by the number of satellites. For example, as shown in FIG. 5, in a multi-beam antenna apparatus using a 5 × 5 element antenna array 110, a GPS signal received by a 5 × 5 element antenna array 110
Phaser array 112 to fourth phaser array 113-4
And distributed to the two phase shifter arrays.

Each of the first to fourth phase shifter arrays 112 to 113 is provided with 25 phase shifters, and signals from each element of the antenna array 110 input to each phase shifter are provided. Are phase-shifted, respectively, supplied to the corresponding combiners 114 to 115 and combined, and output first to fourth beams directed toward the transmitter.

As described above, the conventional multi-beam antenna shown in FIG. 5 requires 25 phase shifters to form one beam, whereas the GPS system uses GPS signals from at least four satellites or more. Need to receive. Therefore, to stably track these satellites, it is necessary to control four or more beams. Therefore, it is necessary to prepare four phase shifter arrays each composed of 25 phase shifters, and use a distributor 111 that couples the phase shifter array and the antenna array 110. Also, as shown in FIG. 5, a combiner 11 for combining the output signals of the phase shifter arrays 112 to 113.
4 to 115 are also required.

Further, as a conventional multi-beam antenna device, a phased array device for obtaining a wide band by using a DBF.
Antennas are also conventionally known (JP-A-10-303).
634). In this conventional apparatus, a virtual antenna is assumed in an area surrounded by a plurality of antenna elements, and an estimating unit obtains a coefficient corresponding to each of the plurality of antenna elements from a position vector of the virtual antenna and the plurality of antenna elements. The received I / Q data of the virtual antenna is estimated from the coefficients and the received I / Q data at the plurality of antenna elements. By estimating the virtual antenna, a combined output equivalent to that when the virtual antenna actually exists can be obtained. Since the size of the antenna can be increased accordingly, the band of the antenna element can be widened.

However, this conventional device has a problem that the interference prevention function cannot be realized because there is no cooperation with the GPS. That is, the sampling between the DBF and the GPS correlator is asynchronous, so that a temporal quantum error occurs in the correlation result. At the same time, since the directivity can be obtained in only one direction, the satellite required for the positioning calculation is required. This is a problem in that radio waves cannot always be received.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a multi-beam antenna device for homing a GPS satellite or the like whose device configuration is simplified.

Another object of the present invention is to provide a multi-beam antenna apparatus capable of improving the receiving sensitivity of each satellite and improving the reliability of GPS reception in an environment where an interfering wave exists. .

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an array antenna having digital beamforming, wherein n (n is an integer of 2 or more) antenna elements and n antennas are provided. The high frequency signal from the satellite received by each of the elements is converted into an I signal and a Q signal based on the local signal.
After being detected and separated into signals, the signal is converted into a digital signal synchronized with the local signal, n receiving modules provided for each of the n antenna elements, and a signal output from the receiving module is received as an input, respectively. K (k is an integer of 2 or more) signal processing units that perform phase delay and weighting on each of the input signals and then perform vector synthesis to output signals having virtual directivity, respectively, and A pseudo-random code generator for generating a pseudo-random code corresponding to a satellite, and a pseudo-random code generator are provided corresponding to the k signal processing units. The correlation between the output signal of the signal processing unit and the pseudo-random code is obtained. Decode information relating to k correlators that output the time as the arrival time of the high-frequency signal and the orbit data of the satellite included in the signals from the k correlators. A phase delay for each of the k signal processing units based on the information about the orbit data from the reading unit and the decoding unit such that the directivity of the signal output from the signal processing unit tracks the corresponding satellite. It has a directivity control means for controlling the amount and the weighting value, respectively, and a local signal generating means for receiving a pseudo random code from a pseudo random code generator as a synchronization signal and generating a local signal. .

According to the present invention, the relative position of the satellite is known based on the information on the orbit data of the satellite to be received from the decoding means, and the directivity control means calculates the direction of the satellite using the output of the relative position. , K signal processing units, the phase delay amount and the weighting value are controlled so that the directivity of the signal output from the signal processing unit tracks the corresponding satellite. Array antenna with digital beamforming (DBF) interfacing with receiver (DBF antenna)
To track a large number of satellites
can do. According to the present invention, a virtual beam having directivity can be formed for each satellite.

Here, each of the k signal processing units receives as input the signals output from the n receiving modules, and based on the control signals from the directivity control means, respectively, for a plurality of input signals. A phase delay and weighting means for varying the amount of phase delay and weighting given to the input signal, and a vector synthesis operation of the signal from the phase delay and weighting means to obtain a signal having virtual directivity. It is characterized by being composed of software or firmware. According to the present invention, since the signal processing unit is configured by software or firmware, the configuration of the signal processing unit can be simplified as compared with the case where the signal processing unit is configured by hardware.

Further, the receiving module converts a high-frequency signal from a satellite received by the antenna element using a local signal, and detects and separates the signal into an I signal and a Q signal. And A / D conversion means for converting the Q signal into a digital signal with a sampling clock synchronized with the local signal.

Further, in order to achieve the above object, the present invention is provided in correspondence with k correlators and measures the variance of the correlation result output from the correlators, and the measured value is a predetermined value. If the measured value is larger than a predetermined value, a flag signal indicating that interference is being received is output to the positioning calculation processing, and the corresponding signal is excluded from the positioning calculation. It is characterized by having quality judgment means. According to the present invention, when the direction of the pseudo-range providing device of the satellite coincides with the direction of the interference source by accident, a flag signal is output from the signal quality determination means to the positioning calculation processing,
Since the corresponding signal was excluded from the positioning calculation,
Satellites that match the direction of the interferer can be avoided.

[0020]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a multi-beam antenna device according to the present invention. As shown in the figure, the multi-beam antenna device according to the present embodiment has n antenna elements 10 ₁ to 10 _n and _n antenna elements 10 ₁ to 10 _{n provided} in one-to-one correspondence. number of receiving module 20 ₁ to 20 _n and, k-number of the signal processing section 3
0 ₁ and to 30 _k, a correlator 41 ₁ to 41 _k provided in one-to-one correspondence with the output side of the signal processing unit 30 ₁ to 30 _k,
Signal quality determining means 42 _{1 to} 42 _k provided on the output side of these correlators in a one-to-one correspondence;
3, a pseudo-random code generating means 44 receives the pseudo-random code from the pseudo-random code generator 44 as an input, a local signal generator 45 for supplying a local signal to the receiving module 20 ₁ to 20 _n, the message decoding means 4
Receiving a third decoding result as an input, the signal processor 30 _1-3
And a directivity control means 46 for supplying a control signal to 0 _k .

The receiving module 20 _1, and one vector generating means 21 _1, two A / D converters 22 ₁ and 23 ₁
It is composed of Similarly, the other receiving module 2
0 _{2 to} 20 _n each correspond to one vector generation unit 21.
_{2 to} 21 _n and two A / D converters 22 _{2 to} 22 _n and 23
It is composed of a ₂ ~ 23 _n. Also, the signal processing unit 30
1 has m inputs and m phase delay units 31 ₁ to 31 ₁ .
31 _m , m weighting means 32 _{1 to} 32 _m, and vector combining means 33 for adding and combining the output signals of the _m weighting means 32 _{1 to} 32 _m . Other signal processing unit 30 ₂ to 30 _m even if the signal processing unit 30 ₁
Similarly to the above, it is composed of m phase delay means, m weighting means, and one vector combining means.

Next, the operation of this embodiment will be described.
You. Antenna element 10₁-10_nHigh frequency received by
The signal is transmitted to the corresponding receiving module 20₁~ 2
0_nRespectively. Receiving module 20₁~ 20
_nThen, the vector generation means 21 ₁~ 21_nInput height at
The local signal output from the local signal generator 45 as the frequency signal
Is converted to an intermediate frequency (IF) signal based on
You. Here, in frequency conversion performed using a mixer or the like,
Force phase information is saved. Because of this, the vector generated hand
Step 21₁~ 21_nThen, the output local signal of the local signal generator 45 is
Signal into signals orthogonal to each other, and
And I and Q signals by frequency conversion
It is possible to separate.

The I signal and the Q signal output from the vector generating means 21 _{1 to} 21 _n correspond to the real axis component and the imaginary axis component when the input RF signal is represented by a vector. These I and Q signals are supplied to the A / D converter 22 ₁ through 22 _n and 23 ₁ ~ 23 _n, wherein based on a sampling clock synchronized with a local signal from a local signal generator 45 digital converted to a signal, is distributed to the k is the signal processing unit 30 ₁ to 30 _k.

The signal processing unit 30 ₁ to 30 _k is a processing unit that is built in software, is performed by the software of k distribution. Since all the signal processing unit 30 ₁ to 30 _k performs the same processing with the same configuration, it will be representatively described signal processing unit 30 _1, the signal processing unit 30 ₁ is input from the reception module 20 ₁ to 20 _n The output of the directivity control unit 46 is controlled by the amount of phase shift given to the digital signal by the m (= 2n) phase delay units 31 _{1 to} 31 _m and the value of the weight multiplied by the weighting units 32 _{1 to} 32 _m. The signals are controlled independently so that the maximum gains are directed in the directions of the n satellites according to the instruction of the signal, and the combining means 33 performs a vector combining operation to obtain virtual directivity. In this process, the interference wave components included in each of the antenna elements 10 ₁ to 10 _n are canceled and attenuated.

The signal output from the signal processing unit 30 ₁ to 30 _k, the pseudo-random code is supplied to the correlator 41 ₁ to 41 _k, where corresponds to the GPS satellite to be received from the pseudo-random code generating means 44 Is correlated. The time of the output having the largest correlation from the correlators 41 _{1 to} 41 _k is _represented by G
The PS signal is output to the positioning calculation process as the arrival time. The output signals of the correlators 41 _{1 to} 41 _k include information on the orbit data of the GPS satellite called a navigation message. This information is input to the message decoding means 43.

The message decoding means 43 determines the arrangement of the GPS satellites from the input orbit data and the current time, outputs the arrangement to the directivity control means 46, and generates a pseudo-random signal corresponding to the visible satellite. , The satellite constellation is transmitted to the pseudo-random code generation means 44. DGP
In the case of S, the phase center coordinates of the antenna are known. Therefore, the relative direction of the pseudo distance supply device such as a satellite can be calculated geometrically. Based on the calculated value, the value required to form a directional beam toward each GPS satellite is inputted from the directional control means 46 to the signal processing unit 30 ₁ to 30 _k.

On the other hand, a synchronization signal is supplied from the pseudo random code generation means 44 to the local generator 45. Thus, I in the receiving module 20 ₁ to 20 _n, a signal that is detected in the Q baseband, the output digital signal of the A / D converter 22 ₁ through 22 _n and 23 ₁ ~ 23 _n is the GPS code and coherent , The quantization error in the correlation processing of the correlators 41 _{1 to} 41 _k can be minimized.

The signal quality judging means 42 _{1 to} 42 _k measure the variance of the detection results of the correlators 41 _{1 to} 41 _k. If the measured value is larger than a predetermined measured value, it is determined that interference has occurred. The flag signal is output to the positioning calculation process. here,
The positioning calculation process is a process of calculating the coordinates of the phase center of the GPS antenna based on the pseudo distance from each GPS satellite.
When the flag signal is output from the a-th (a = 1 to k) signal quality determination unit 42a to the positioning calculation processing, it is determined that the signal quality from the GPS satellite located in the a-th beam direction is degraded. Exclude the pseudorange from that GPS satellite.

Incidentally, the sun is also known to be a kind of interference source. Even when the direction of the GPS satellite coincides with the direction of the sun, the signal quality from the GPS satellite deteriorates.
Exclude the pseudorange from that GPS satellite. Where G
When excluding the pseudorange from the PS satellite, the GPS
The directivity of the virtual beam to the satellite is maintained. Thereafter, interference may be eliminated.

As described above, according to the present embodiment,
A so-called DBF antenna, which constructs a phased array antenna by software, and a GPS receiving circuit are linked to direct virtual n multi-beams to n GPS satellites, thereby securing a required signal-to-jamming ratio.

Next, the effect of this embodiment will be described with reference to FIGS. FIG. 2 is a system diagram showing an example of the relationship between the multi-beam antenna device of the present invention, a GPS satellite, and an interference source. In the figure, in a multi-beam antenna device 51 of the present invention, n directional virtual beams 53 _{1 to} 53 having virtually directivity are provided by antenna elements (10 ₁ to 10 _{n in} FIG. 1) arranged on a hemisphere 53. _n is formed. Each of the virtual beams 53 _{1 to} 53 _n is a GPS satellite SV # 1.
Since the SVs #n have different directivities, an interfering radio wave 57 from an interference source 56, which can be considered to have been emitted from an unknown direction, and a radio wave from a GPS satellite SV # 1 are reflected by a reflecting object 54. The level of the interference wave caused by the reflected multipath 55 can be relatively reduced. Also, GP
Separate virtual beams 53 _{1 for} each of the S satellites SV # 1 to SV # n
Due to the use of to 53 _n, the interference of the satellite each other can be reduced so-called internal interference.

Also, since a GPS satellite orbits around the earth in one day, its angular velocity changes as slowly as the sun. According to the present invention, the reception sensitivity to each GPS satellite is improved because the virtual beam always tracks the satellite direction instead of time division while the GPS satellite is visible.

FIG. 3 shows a pattern calculation result of an antenna array having an opening surface of 2500 mm to 300 mm. As shown in the figure, the beam width is about 5 degrees, which is an angle at which a GPS satellite passes in about 20 minutes. In this directionality,
It is possible to attenuate the signal outside the beam by about 30 degrees. In other words, it is possible to improve the interference resistance performance by 30 dB.

Further, in the multi-beam antenna of the present embodiment, the signal processing section 30 ₁ required for multi-beam formation.
Due to the realized to 30 _n in software or firmware, it is possible to realize the whole multi-beam antenna device with a relatively simple hardware. In addition, since the reception sensitivity is improved and the S / N from each GPS satellite is improved, the fluctuation component included in the pseudorange is reduced, and the beam tracks the satellite direction while the satellite is visible. available pseudoranges same time satellite positioning calculation, it is possible to exclude the pseudoranges from more signal quality judging means 42 ₁ through 42 _k satellite signal quality is deteriorated by, accuracy can be improved.

Further, in the present embodiment, when the direction of the sun coincides with the direction of the GPS satellite, the GPS satellite can be not used, so that it is possible to cope with solar interference. In addition,
In the above embodiment, n virtual beams are converted into n GPs.
Although it has been described that the satellite is directed to the S satellite, one or a plurality of the satellites may be directed to a pseudolite installed on the ground. In this case, the level change of the signal from the pseudo satellite installed on the ground is much larger than the level change of the GPS signal from the GPS satellite, but in the present embodiment, the directivity for the pseudo satellite installed on the ground is changed. Since the gain can be made smaller than that for the GPS satellites by the message decoding means 43 and the directivity control means 46, the near-far problem of the pseudolite can be solved.

Next, embodiments of the antenna system according to the present invention will be described. FIG. 4A shows an example in which elements are arranged on a hemispherical surface. By arranging a plurality of antenna elements on this hemispherical surface as indicated by 52 in FIG. It has the ideal property that the gain change is small.

The antenna system shown in FIG. 4B is a simple configuration example in which planes are connected to each other, and a multi-element antenna element is arranged on planes 61, 62 and the like. This antenna array does not require a curved surface correction operation. FIG.
(C) is a simpler antenna array. In FIG. 6C, a vertical array 63 has a plurality of antenna arrays, and constitutes an antenna system having directivity only in the vertical direction, and receives an electric wave from a vertex. This is a configuration in which one antenna element 64 is combined. In this antenna array, the interference removal capability is reduced, but the antenna can be easily constructed.

The arrangement of the antenna elements may be other than that shown in FIG. 4. Even if an optimal system such as an environment is selected, the antenna elements can be used in the means of the present invention. The signal processing unit 30 ₁ to 30 _k has been described as being configured by software can also be implemented in firmware, such as a digital signal processor (DSP).

[0039]

As described above, according to the present invention,
It has the following features. (1) Since directivity can be given to each satellite direction, the level of an interference wave can be relatively reduced. (2) Since directivity is provided in the direction of each satellite and multi-beams can be tracked, the reception sensitivity to each satellite can be improved. (3) Since separate beams are used for each satellite,
Interference between satellites, so-called internal interference, can be reduced. (4) Since a distributor, a phase delay unit, a weighting unit, a combining unit, and the like necessary for multi-beam formation are realized by software or firmware, these multi-beam antennas should be realized by relatively simple hardware. Can be. (5) The reception sensitivity is improved for the reason of (4), and the S / N from each satellite is improved, so that the fluctuation component included in the pseudo range is reduced, and the time division is performed while the satellite is visible. Since the multi-beams are always tracked in the direction of the satellite, the pseudo-range of each satellite at the same time can be used for positioning calculation.In addition, the pseudo-range from the satellite whose signal quality has deteriorated can be excluded by the signal quality judgment means. Can be improved. (6) When the direction of the GPS satellite coincides with the direction of the sun, the G
Since the signal quality of the GPS signal received from the PS satellite is deteriorated, the GPS satellite can not be used by excluding the pseudorange, and the sun is also a kind of interference source and is located outside the directional beam. In this case, sufficient attenuation can be obtained, so that the problem of solar interference can be solved. (7) Since the directivity gain for the pseudo satellites installed on the ground can be set independently of the directivity gain for the other GPS satellites, the problem of near and far of the pseudo satellites can be solved.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a system diagram showing an example of the relationship between the multi-beam antenna device of the present invention, a GPS satellite, and an interference source.

FIG. 3 is a diagram showing an example of a pattern calculation result of an antenna array.

FIG. 4 is a diagram showing each example of an antenna array.

FIG. 5 is a block diagram of an example of the related art.

[Explanation of symbols]

10 ₁ to 10 _n antenna 20 ₁ to 20 _n receive module 21 ₁ through 21 _n vector generating means _{22 1 ~22 n, 23 1 ~23} n A / D converters 30 ₁ to 30 _k signal processing unit 31 ₁ to 31 _m Phase delay means 32 _{1 to} 32 _m weighting means 33 combining means 41 _{1 to} 41 _k correlator 42 _{1 to} 42 _k signal quality determining means 43 message decoding means 44 pseudo-random code generating means 45 local signal generator 46 directivity control means 51 Multibeam antenna device 52 Antenna array 531 to 53n arranged on hemisphere Virtual beam 54 Reflecting object 55 Multipath 56 Interference source 57 Interfering electric wave SV # 1 to SV # n GPS satellite

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toru Inoshita 5-7-1 Shiba, Minato-ku, Tokyo F-term in NEC Corporation (reference) 5J021 AA05 AA06 AB02 AB06 DB01 EA02 FA06 FA13 FA14 FA18 FA29 GA02 GA05 GA08 HA02 HA03 HA07 JA10 5J062 CC07 EE04 GG02

Claims (7)

[Claims] 1. An antenna having n (n is an integer of 2 or more) antenna elements constituting an array antenna having digital beamforming, and a high-frequency signal from a satellite received by each of the n antenna elements, The I signal and Q based on the local signal
After being detected and separated into signals, the signal is converted into a digital signal synchronized with the local signal, n receiving modules provided for each of the n antenna elements, and a signal output from the receiving module as an input. K (k is an integer of 2 or more) signal processing units for receiving and performing phase delay and weighting on each of a plurality of input signals, and then performing vector synthesis to output virtual directivity signals; A pseudo-random code generator for generating a pseudo-random code corresponding to a satellite to be received, provided in correspondence with the k signal processing units, and correlating an output signal of the signal processing unit with the pseudo-random code. K correlators that output the time of highest correlation as the arrival time of the high-frequency signal; and the satellite trajectory included in the signals from the k correlators. Decoding means for decoding the information on the road data, and based on the information on the orbit data from the decoding means, for each of the k signal processing units, the directivity of the signal output from the signal processing unit is Direction control means for controlling each of the amount of phase delay and weighting so as to track the corresponding satellite, The pseudo-random code from the pseudo-random code generator is input as a synchronization signal, and the local signal is And a local signal generating means for generating the signal. 2. The method according to claim 1, wherein each of the k signal processing units includes the n signal processing units.
Receiving the signals output from the plurality of receiving modules as inputs, and based on the control signals from the directivity control means for each of the plurality of input signals, a phase delay amount and a weighting value to be given to the input signals. Variable phase delay and weighting means, and a synthesis means for outputting a signal having a virtual directivity by performing a vector synthesis operation on the signal from the phase delay and weighting means, and is configured by software or firmware. 2. The multi-beam antenna device according to claim 1, wherein 3. The receiving module, wherein the high frequency signal from the satellite received by the antenna element is frequency-converted using the local signal, and a vector generating means for detecting and separating into an I signal and a Q signal; 2. The multi-beam antenna according to claim 1, further comprising A / D conversion means for converting each of the I signal and the Q signal into a digital signal with a sampling clock synchronized with the local signal. 4. Corresponding to the k correlators are provided,
Measure the variance of the correlation result output from the correlator, compare whether the measured value is greater than a predetermined value,
When the measured value is larger than a predetermined value, a signal quality determination unit that outputs a flag signal indicating that interference has been received to the positioning calculation process and excludes the corresponding signal from the positioning calculation. The multi-beam antenna device according to claim 1 or 2, wherein: 5. The multi-beam antenna device according to claim 1, wherein said n antenna elements are arranged on a hemispherical surface. 6. The apparatus according to claim 1, wherein the n antenna elements are arranged on a connected plane.
A multi-beam antenna device as described. 7. The multi-beam antenna device according to claim 1, wherein the satellite includes at least a GPS satellite.