Beidou No.3 antenna automatic detection switching receiver

Abstract

The invention discloses an automatic detection switching receiver for a Beidou No.3 antenna. Comprising an antenna selection switching module which is used for receiving signals from multiple paths of antennas, filtering the signals, sending the filtered signals to a radio frequency module for processing, and transmitting emission signals output by the radio frequency module through the antennas; an instruction of the baseband module is received to perform antenna selection switching; the radio frequency module is used for performing down-conversion processing on the signal sent by the antenna selection switching module and sending the processed intermediate frequency signal to the baseband module; a BPSK signal sent by the baseband module is received, and the BPSK signal is up-converted into a radio frequency signal and then is transmitted to the antenna selection switching module; the baseband module is used for calculating the carrier-to-noise ratio of the intermediate frequency signal sent by the radio frequency module and determining the antenna with the highest carrier-to-noise ratio; and the antenna selection switching module is controlled to switch to the antenna with the highest carrier-to-noise ratio. According to the scheme, RNSS signal stable receiving and RDSS short message communication can be realized without human intervention.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and particularly to a Beidou-3 antenna automatic detection and switching receiver. Background Art

[0002] The Beidou-3 global satellite navigation system has been officially launched, and the applications of Beidou in various industries will be more and more extensive and in-depth. In particular, the application requirements for RN+RD dual-mode receivers are increasing. On the one hand, RNSS can be used for positioning, and on the other hand, the position can be sent out through RDSS short messages, so that the position of the user can be known even in places without mobile communication signals. However, due to the uneven distribution of the positions of the satellites in the sky, the antenna performance of some receivers is limited or the position is not fixed, resulting in the inability to receive satellite signals well. Especially for the RDSS short message application, the terminal antenna needs to be directly facing the satellite direction. A deviation in the direction will lead to a decrease in the communication success rate, and even the situation of unable to communicate. Therefore, how to ensure the effective reception of satellite signals is crucial: (1) By optimizing the antenna of the receiver to ensure that the azimuth angle of the antenna is large enough, so as to ensure that the receiver can stably receive satellite signals. However, such an antenna is large in volume and high in cost, and it cannot cover 360° azimuth. For some miniaturized or other special application scenarios, the antenna performance cannot meet the requirements, and it is impossible to ensure the stable satellite search of the receiver; (2) For some handheld or human-intervened application scenarios, the direction of the antenna can be adjusted manually to align with the satellites in the sky. Especially for the RDSS short message service, the communication success rate can be significantly improved. However, this method has poor operability and may require a long time to adjust for non-professionals. (3) In order to better align with the satellites in the sky, an IMU can be added to the antenna device to determine the direction of the antenna device. For the RDSS regional short message service, the azimuth of the satellites in the sky is determined. As long as the direction specified by the IMU is consistent with the satellite direction, the communication success rate of the short message service can be greatly improved. This method still requires manual adjustment of the antenna. (4) For some unmanned devices, they need to send their own position coordinates through short messages. At this time, if the antenna direction is incorrect, the communication success rate of the short message will be very low. Summary of the Invention

[0003] To solve the above technical problems, an embodiment of the present invention provides a Beidou-3 antenna automatic detection and switching receiver.

[0004] The technical solution of the embodiment of the present invention is realized as follows: An embodiment of the present invention provides a Beidou-3 antenna automatic detection and switching receiver. The receiver is externally connected to multiple transceiver antennas with different azimuths. The receiver includes an antenna selection and switching module, a radio frequency module, and a baseband module: The antenna selection and switching module is used to receive signals from multiple antennas, filter the signals and send them to the RF module for down-conversion processing, and at the same time transmit the transmitted signals output by the RF module through the antenna; and receive the antenna switching instruction sent by the baseband module and perform antenna selection and switching according to the antenna switching instruction. The RF module is used to perform down-conversion processing on the signals sent by the antenna selection and switching module, and send the processed intermediate-frequency signals to the baseband module; receive the BPSK signals sent by the baseband module, up-convert the BPSK signals into RF signals and transmit them to the antenna selection and switching module for external transmission. The baseband module is used to calculate the carrier-to-noise ratio of the intermediate-frequency signals sent by the RF module, determine the antenna with the highest carrier-to-noise ratio; and control the antenna selection and switching module to switch to the antenna with the highest carrier-to-noise ratio.

[0005] In one embodiment, the RF module includes multiple RF chips, and the number of the RF chips is the same as the number of antennas.

[0006] In one embodiment, one of the multiple RF chips has S RF channels, L RF channels, B3 RF channels and B2 RF channels, and the remaining RF chips have B3 RF channels and B2 RF channels.

[0007] In one embodiment, the baseband module includes 1 baseband chip.

[0008] In one embodiment, the antenna selection and switching module includes multiple combiners, a first RF switch, a second RF switch, and multiple filters: wherein, each combiner is connected to an antenna, and each combiner is also respectively connected to the first RF switch and the second RF switch. The first RF switch is connected to the S RF channel of the RF module through a filter, and the second RF switch is connected to the L RF channel of the RF module through a filter; each combiner is also connected to the B3 RF channel of an RF chip in the RF module through a filter, and each combiner is also connected to the B2 RF channel of an RF chip in the RF module through a filter; the first RF switch and the second RF switch are also connected to the output control port of the baseband chip. The combiner is used to perform combining processing on the S received signals of the S RF channel, the L transmitted signals of the L RF channel, the B3 signals of the B3 RF channel and the B2 signals of the B2 RF channel. The first RF switch is used to select one combiner to receive signals. The second RF switch is used to select one combiner to send signals. The filter is used to filter the received signals.

[0009] In one embodiment, the number of the antennas is 2.

[0010] The embodiments of the present invention have the following beneficial effects: In this embodiment, stable reception of RNSS signals and RDSS short message communication can be achieved without human intervention in some special application scenarios, ensuring the success rate of short message communication. Description of the Drawings

[0011] Figure 1 is a schematic structural diagram of a general receiver in the prior art; Figure 2 is a schematic structural diagram of a Beidou-3 antenna automatic detection and switching receiver according to an embodiment of the present invention; Figure 3 is a specific schematic structural diagram of a Beidou-3 antenna automatic detection and switching receiver according to an embodiment of the present invention; Figure 4 is a schematic execution flow diagram of a Beidou-3 antenna automatic detection and switching receiver according to an embodiment of the present invention. Detailed Embodiments

[0012] Before introducing the solution of this embodiment, the related content of a general receiver in the prior art will be introduced first.

[0013] The Beidou-3 global satellite navigation system has been officially launched, and the application of Beidou in all walks of life will be more and more extensive and in-depth. Especially the application demand for RN+RD dual-mode receivers is increasing. On the one hand, RNSS can be used for positioning, and on the other hand, the position can be sent out through RDSS short messages, so that the position of the user can be known even in places without mobile communication signals. However, due to the uneven distribution of the positions of the satellites in the sky, the antenna performance of some receivers is limited or the position is not fixed, resulting in poor reception of satellite signals. Especially for RDSS short message applications, the terminal antenna needs to be directly facing the satellite direction. Deviation in the direction will lead to a decrease in the communication success rate, and even the situation of unable to communicate. Generally, a relatively large antenna is configured for the receiver. The antenna facing the satellites in the sky can ensure stable reception of satellite signals. However, for some miniaturized or other special application scenarios, the antenna performance cannot meet the requirements, and it is impossible to ensure stable satellite search by the receiver. At this time, it is usually necessary to add a gyroscope to determine the orientation and adjust the antenna direction through human intervention to ensure stable signal transmission and reception. The circuit block diagram of a traditional general receiver is as Figure 1 shown: Generally, a general receiver usually only externally connects one antenna, and ensures the stability of signal transmission and reception by improving the performance and installation direction of the antenna. Once the antenna performance is poor, the stability of the system will be greatly reduced, especially the success rate of RDSS transmission and reception will be greatly reduced. It mainly includes the following parts: 1. The B3 and B2 received signals of RNSS and the S received and L transmitted signals of RDSS are combined by a combiner 101 and then connected to an active antenna, and signal transmission and reception are performed through this one antenna. In some miniaturized terminal applications, the antenna performance may be poor, the antenna coverage range is not large enough, or in some special application scenarios, the antenna orientation cannot be directly facing the satellite. A single antenna cannot ensure the stable satellite signal transmission and reception in these applications; 2. The satellite signals received by the antenna are divided into four paths, sent to the radio frequency chip 201 through the filter 103 for up and down conversion processing. After the received satellite signals become intermediate frequency, they are sent to the baseband chip 301 for acquisition, tracking, and resolution processing, and then the carrier-to-noise ratio and azimuth angle of multiple satellites can be obtained, and RNSS positioning can be performed normally. However, the direction of the antenna cannot be determined, so the success rate of RDSS communication cannot be guaranteed; 3. In order to determine the antenna direction, an IMU sensor 401 needs to be added to the antenna or the receiving device. The IMU sensor 401 can calculate the orientation of the device. Although the orientation is known, if the device is not directly facing the satellite in the sky, the antenna direction still needs to be adjusted manually to improve the success rate of RDSS communication.

[0014] It can be clearly seen that ordinary receivers are limited by the antenna and can only meet conventional applications. If the antenna performance is to be improved, the size of the antenna needs to be increased, and the cost will also increase significantly, which cannot meet the requirements of some miniaturized application scenarios. In addition, sometimes manual intervention is required to ensure stable signal transmission and reception, which cannot meet the requirements of some unmanned special application scenarios. Therefore, ordinary receivers cannot meet the application requirements of some special scenarios.

[0015] Based on this, this embodiment provides a Beidou-3 antenna automatic detection and switching receiver. The receiver is externally connected to two antennas with different orientations. By calculating the carrier-to-noise ratio of the satellite signals received by the two antennas, it automatically switches to the antenna with a higher carrier-to-noise ratio for satellite signal transmission and reception.

[0016] The present invention will be further described in detail below in conjunction with the drawings and embodiments.

[0017] The embodiment of the present invention provides a Beidou-3 antenna automatic detection and switching receiver, as Figure 2 shown. The receiver is externally connected to multiple transceiver antennas with different orientations. The receiver includes an antenna selection and switching module 100, a radio frequency module 200, and a baseband module 300: The antenna selection and switching module 100 is used to receive signals from multiple antennas, filter the signals and send them to the radio frequency module 200 for down conversion processing, and at the same time transmit the transmitted signals output by the radio frequency module 200 through the antenna; and receive the antenna switching instruction sent by the baseband module 300 and perform antenna selection and switching according to the antenna switching instruction; The radio frequency module 200 is configured to perform down-conversion processing on the signal sent by the antenna selection and switching module 100, and send the processed intermediate frequency signal to the baseband module 300; receive the BPSK signal sent by the baseband module 300, and up-convert the BPSK signal into a radio frequency signal and then transmit it to the antenna selection and switching module 100 for external transmission; The baseband module 300 is configured to calculate the carrier-to-noise ratio of the intermediate frequency signal sent by the radio frequency module 200, determine the antenna with the highest carrier-to-noise ratio; and control the antenna selection and switching module 100 to switch to the antenna with the highest carrier-to-noise ratio.

[0018] In this embodiment, the radio frequency module 200 includes multiple radio frequency chips, and the number of radio frequency chips is the same as the number of antennas. One of the multiple radio frequency chips has S radio frequency channels, L radio frequency channels, B3 radio frequency channels, and B2 radio frequency channels, and the remaining radio frequency chips have B3 radio frequency channels and B2 radio frequency channels.

[0019] Meanwhile, the baseband module 300 includes 1 baseband chip.

[0020] Specifically, the antenna selection and switching module 100 includes multiple combiners, a first radio frequency switch, a second radio frequency switch, and multiple filters: among them, each combiner is connected to an antenna, and each combiner is also respectively connected to the first radio frequency switch and the second radio frequency switch. The first radio frequency switch is connected to the S radio frequency channel of the radio frequency module through a filter, and the second radio frequency switch is connected to the L radio frequency channel of the radio frequency module through a filter; each combiner is also connected to the B3 radio frequency channel of a radio frequency chip in the radio frequency module through a filter, and each combiner is also connected to the B2 radio frequency channel of a radio frequency chip in the radio frequency module through a filter; the first radio frequency switch and the second radio frequency switch are also connected to the output control port of the baseband chip; The combiner is configured to perform combining processing on the S received signal of the S radio frequency channel, the L transmitted signal of the L radio frequency channel, the B3 signal of the B3 radio frequency channel, and the B2 signal of the B2 radio frequency channel; The first radio frequency switch is configured to select one combiner to receive the signal; The second radio frequency switch is configured to select one combiner to send the signal; The filter is configured to filter the received signal.

[0021] In this embodiment, the number of transceiver antennas externally connected to the receiver can be multiple. Next, the present solution will be introduced by taking the number of 2 transceiver antennas as an example.

[0022] This embodiment provides a receiver that can achieve automatic detection and switching of BeiDou-3 antennas. The receiver is externally connected to two antennas with different orientations. By calculating the carrier-to-noise ratio (CNR) of the satellite signals received by the two antennas and the satellite azimuth angle, it automatically switches to a more suitable antenna for satellite signal transmission and reception without human intervention. The detailed functional block diagram is as shown in Figure 3 shown below: 1. To meet the requirements of some special application scenarios, the receiver can automatically select an antenna for signal transmission and reception without human intervention, ensuring the success rate of RDSS short message communication. The receiver is externally connected to two transceiver antennas, including an antenna selection and switching module 100, a radio frequency (RF) module 200, and a baseband module 300. Among them, the two externally connected antennas can be placed in different orientations to receive signals from two different directions for the receiver to process. The antenna selection and switching module 100 is responsible for receiving signals from the two antennas, performing antenna selection and switching, and filtering, and then sending them to the RF module 200 for down-conversion processing. The RF module 200 includes multiple RF chips 201, which are responsible for receiving RF signals for down-conversion processing, and at the same time receiving the BPSK signals from the baseband and up-converting them into RF signals for external transmission. The baseband module 300 includes a baseband chip 301, which is responsible for receiving intermediate frequency signals from different antennas and calculating the CNR, and at the same time controlling the antenna selection and switching module 100 to switch to the antenna with a better CNR for signal transmission and reception.

[0023] 2. The antenna selection and switching module 100 is externally connected to two antennas, and each antenna is respectively input into a combiner 101. The combiner 101 is responsible for combining the B3 and B2 signals of RNSS, the S received signal and the L transmitted signal of RDSS, and then connecting them to the antenna. Among them, the two combiners 101 share the same S and L RF channels, and one of the combiners 101 is selected through the RF switch 102. Only one antenna can be used at the same time. In addition, the two combiners 101 are respectively connected to different B3 and B2 RF channels, and can realize the simultaneous reception of RNSS signals by the two antennas. Filters 103 need to be added on the B3, B2, S, and L RF channels to suppress out-of-band interference signals and ensure stable signal transmission and reception; 3. The RF module 200 includes two RF chips 201, and the baseband module 300 includes 1 baseband chip 301. The antenna selection and switching module 100 is connected by two RF chips 201 and the baseband chip 301. The antenna selection and switching module 100 is also connected to the baseband chip 301 through the RF switch 102. The two RF chips 201 are used to implement signal up-conversion and down-conversion processing, down-converting the received RF signal into an intermediate frequency and then sending it to the baseband chip 301 for processing. The BPSK signal output by the baseband chip 301 is up-converted into an RF signal for transmission. One of the RF chips 201 realizes the down-conversion reception of B3, B2, and S signals and the up-conversion transmission of the L signal, and the other RF chip 201 realizes the down-conversion reception of B3 and B2 signals; 4. The intermediate frequency signal processed by the RF chip 201 is input into the baseband chip 301 for capture, tracking, and resolution processing, and then the carrier-to-noise ratio and azimuth angle of multiple satellites can be obtained. By comparing the carrier-to-noise ratio and azimuth angle of the satellite signals received by the two antennas, the approximate direction of the antenna can be determined, so as to judge which antenna is more suitable for RDSS transceiver. The baseband chip 301 controls the RF switch 102 in the antenna selection and switching module 100 to switch the RDSS transceiver channel to the corresponding antenna for short message communication and send the position information, which can greatly improve the communication success rate.

[0024] That is, referring to Figure 4 , the execution process of the receiver in this embodiment is as follows: Step S1: The baseband chip simultaneously receives the B2 and B3 satellite signals from the two antennas, and respectively calculates the carrier-to-noise ratio and azimuth angle of the satellites; Step S2: The baseband chip controls the RF switch to switch and select the S transceiver antenna, and respectively calculates the carrier-to-noise ratio of the RDSS received satellites; Step S3: Roughly judge the direction of the antenna by comparing the azimuth angles of the RNSS satellites received by different antennas, and at the same time compare the carrier-to-noise ratios of the RNSS and RDSS satellites of different antennas to determine the transmitting antenna of the RDSS; Step S4: The baseband chip controls the RF switch to select the corresponding antenna to perform the transceiver of the RDSS short message signal, and transmits the position information of the receiver.

[0025] This embodiment is for the Beidou-3 RNSS+RDSS application. In some cases, due to poor antenna performance or position, it is impossible to ensure the stable transceiver of satellite signals and other special requirements. A receiver that can realize the automatic detection and switching of Beidou-3 antennas is provided. It realizes the automatic detection and switching of the receiver antenna, ensuring the stable reception of RNSS signals and the success rate of RDSS short message communication. It is mainly reflected in the following aspects: 1. By connecting two external antennas, it makes up for the problem of poor performance of a single antenna under limited size; 2. Automatically identify the azimuth of the antenna by detecting the carrier-to-noise ratio and azimuth angle of the satellite signal through the baseband, without the need to additionally add devices such as IMU to determine the direction; 3. Automatically switch the antenna for signal transceiver by controlling the RF switch, without manual intervention, which is especially suitable for some unmanned application scenarios; 4. Automatically select the antenna with better signal for RDSS short message transceiver, greatly improving the communication success rate.

[0026] This embodiment can realize the stable reception of RNSS signals and the RDSS short message communication without manual intervention in some special application scenarios, ensuring the success rate of short message communication.

[0027] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements not only includes those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0028] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A BeiDou-3 antenna automatic detection and switching receiver, characterized in that: The receiver is externally connected to multiple transceiver antennas in different directions, and the receiver includes an antenna selection switching module, a radio frequency module and a baseband module: The antenna selection switching module is used to receive signals from multiple antennas, filter the signals and send them to the RF module for down-conversion processing, and transmit the transmission signals output by the RF module through the antenna; and receiving an antenna switching instruction sent by the baseband module, and performing antenna selection switching according to the antenna switching instruction; The radio frequency module is used to perform down-conversion processing on the signal sent by the antenna selection switching module, and send the processed intermediate frequency signal to the baseband module; Receive the BPSK signal sent by the baseband module, up-convert the BPSK signal into a radio frequency signal, and transmit it to the antenna selection switching module for external transmission; The baseband module is used to calculate the carrier-to-noise ratio of the intermediate frequency signal sent by the radio frequency module, determine the antenna with the highest carrier-to-noise ratio; and control the antenna selection switching module to switch to the antenna with the highest carrier-to-noise ratio.

2. The BeiDou-3 antenna automatic detection and switching receiver according to claim 1, characterized in that: The radio frequency module includes a plurality of radio frequency chips, and the number of the radio frequency chips is the same as the number of antennas.

3. The BeiDou-3 antenna automatic detection and switching receiver according to claim 2, characterized in that: One of the multiple RF chips has an S RF channel, an L RF channel, a B3 RF channel, and a B2 RF channel, and the remaining RF chips have a B3 RF channel and a B2 RF channel.

4. The BeiDou-3 antenna automatic detection and switching receiver according to claim 3, characterized in that: The baseband module includes a baseband chip.

5. The BeiDou-3 antenna automatic detection and switching receiver according to claim 4, characterized in that: The antenna selection switching module includes multiple combiners, a first RF switch, a second RF switch, and multiple filters: wherein each combiner is connected to an antenna, each combiner is also connected to the first RF switch and the second RF switch respectively, the first RF switch is connected to the S RF channel of the RF module through a filter, and the second RF switch is connected to the L RF channel of the RF module through a filter; each combiner is also connected to the B3 RF channel of an RF chip in the RF module through a filter, and each combiner is also connected to the B2 RF channel of an RF chip in the RF module through a filter; the first RF switch and the second RF switch are also connected to the output control port of the baseband chip; The combiner is used to combine the S receiving signal of the S radio frequency channel, the L transmitting signal of the L radio frequency channel, the B3 signal of the B3 radio frequency channel and the B2 signal of the B2 radio frequency channel; The first radio frequency switch is used to select a combiner to receive a signal; The second radio frequency switch is used to select a combiner to send a signal; The filter is used to filter the received signal.

6. The BeiDou-3 antenna automatic detection and switching receiver according to claim 1, characterized in that: The number of the antennas is 2.

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