A BeiDou-3 antenna automatic detection and switching receiver

Abstract

The present invention discloses a BeiDou-3 antenna automatic detection and switching receiver. It includes an antenna selection and switching module, which receives signals from multiple antennas, filters the signals, and sends them to a radio frequency module for processing. The module also transmits the transmit signal output by the radio frequency module through the antenna; it also receives instructions from a baseband module to perform antenna selection and switching; the radio frequency module down-converts the signal sent by the antenna selection and switching module and sends the processed intermediate frequency signal to the baseband module; it receives the BPSK signal sent by the baseband module, up-converts the BPSK signal to an radio frequency signal, and transmits it to the antenna selection and switching module; the baseband module calculates the carrier-to-noise ratio of the intermediate frequency signal sent by the radio frequency module, determines the antenna with the highest carrier-to-noise ratio, and controls the antenna selection and switching module to switch to the antenna with the highest carrier-to-noise ratio. This solution enables stable RNSS signal reception and RDSS short message communication without human intervention.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular 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 application of BeiDou in various industries will become more and more extensive and in-depth. In particular, 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 user's position can be known even in places without mobile communication signals. However, due to the uneven distribution of satellite positions in the sky, the antenna performance of some receivers is limited or the position is not fixed, resulting in poor reception of satellite signals. In particular, the application of RDSS short messages requires the terminal antenna to face the direction of the satellite. Deviation from the direction will reduce the communication success rate and even lead to communication failure. Therefore, how to ensure the effective reception of satellite signals is crucial: (1) Ensure that the antenna azimuth angle is large enough by optimizing the receiver's antenna, so as to ensure that the receiver can stably receive satellite signals. However, such antennas are large and expensive, and they cannot cover 360°. For some miniaturized or other special application scenarios, the antenna performance cannot meet the requirements, and there is no way to ensure the stability of the receiver's satellite search. (2) For some handheld or human-intervention application scenarios, the direction of the antenna can be manually adjusted to align with the satellite in the sky, especially for RDSS short message services, which can significantly improve the communication success rate. However, this method is not easy to operate, and it may take a long time for non-professionals to adjust it. (3) In order to better align with the satellite in the sky, an IMU can be added to the antenna device to determine the direction of the antenna device. For RDSS regional short message services, the direction of the satellite in the sky is fixed. As long as the direction specified by the IMU is consistent with the direction of the satellite, 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 equipment, it is necessary to send its own position coordinates through short messages. At this time, if the antenna direction is wrong, the short message communication success rate 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 achieved as follows:

[0005] 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 in different orientations. The receiver includes an antenna selection and switching module, a radio frequency module, and a baseband module.

[0006] 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, while transmitting the transmit signal output by the RF module through the antenna; and receive the antenna switching instruction sent by the baseband module, and select and switch the antenna according to the antenna switching instruction;

[0007] The RF module is used to down-convert 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, and up-convert the BPSK signal into a RF signal and transmit it to the antenna selection switching module for external transmission;

[0008] 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.

[0009] In one embodiment, 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.

[0010] In one embodiment, 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.

[0011] In one embodiment, the baseband module includes one baseband chip.

[0012] In one embodiment, the antenna selection switching module includes multiple combiners, a first RF switch, a second RF switch, and multiple filters: 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 a RF chip in the RF module through a filter, and each combiner is also connected to the B2 RF channel of a 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;

[0013] The combiner is used to combine the S receive signal of the S radio frequency channel, the L transmit 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;

[0014] The first radio frequency switch is used to select a combiner to receive a signal;

[0015] The second radio frequency switch is used to select a combiner to send a signal;

[0016] The filter is used to filter the received signal.

[0017] In one embodiment, the number of the antennas is 2.

[0018] The embodiments of the present invention have the following beneficial effects:

[0019] This embodiment can achieve stable RNSS signal reception and RDSS short message communication in some special application scenarios without human intervention, thereby ensuring the success rate of short message communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of a common receiver in the prior art;

[0021] Figure 2 This is a structural diagram of a BeiDou-3 antenna automatic detection and switching receiver according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the specific structure of the BeiDou-3 antenna automatic detection and switching receiver according to an embodiment of the present invention;

[0023] Figure 4 The figure is a schematic diagram of the execution flow of the BeiDou-3 antenna automatic detection and switching receiver according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] Before introducing the solution of this embodiment, the relevant contents of the common receiver in the prior art are first introduced.

[0025] The BeiDou-3 global satellite navigation system has been officially launched, and the application of BeiDou in all walks of life will become more and more extensive and in-depth. In particular, there are more and more application demands for RN+RD dual-mode receivers. 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 user's position can be known even in places where there is no mobile communication signal. However, due to the uneven distribution of the positions of 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. In particular, the application of RDSS short messages requires the terminal antenna to face the direction of the satellite. Deviation from the direction will lead to a decrease in the success rate of communication, or even a situation where communication cannot be achieved. The general solution is to configure a relatively large antenna for the receiver. The antenna facing the satellite 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 there is no way to ensure that the receiver can search for stars stably. At this time, it is usually necessary to add a gyroscope to determine the direction, and adjust the antenna direction through manual intervention to ensure stable signal transmission and reception. The circuit block diagram of a traditional ordinary receiver is as follows Figure 1 As shown:

[0026] Ordinary receivers usually only have one external antenna. The stability of the receiving and transmitting signals is ensured 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. It mainly includes the following parts:

[0027] 1. The RNSS B3 and B2 receive signals and the RDSS S receive and L transmit signals are combined by combiner 101 and connected to an active antenna for signal transmission and reception. In some miniaturized terminal applications, antenna performance may be poor, the antenna coverage may be insufficient, or in some special application scenarios, the antenna orientation may not be directly facing the satellite. In these applications, a single antenna cannot guarantee stable satellite signal transmission and reception.

[0028] 2. The satellite signals received by the antenna are divided into four paths and sent to the RF chip 201 for up and down conversion through the filter 103. The received satellite signals are converted to intermediate frequencies and sent to the baseband chip 301 for capture, tracking, and resolution. The carrier-to-noise ratio and azimuth of multiple satellites can be obtained after this process, enabling normal RNSS positioning. However, the direction of the antenna cannot be determined, so the success rate of RDSS communication cannot be guaranteed.

[0029] 3. To determine the antenna direction, an IMU sensor 401 is added to the antenna or receiving device. The IMU sensor 401 can calculate the device's orientation. Even if the orientation is known, if the device is not directly facing a satellite, manual adjustment of the antenna direction is still required to improve the RDSS communication success rate.

[0030] It's clear that conventional receivers are limited by their antennas and can only meet conventional applications. Improving antenna performance requires increasing the size of the antenna, significantly increasing costs. This makes it impossible to meet the needs of some miniaturized applications. Furthermore, human intervention is sometimes required to ensure stable signal transmission and reception, making it unsuitable for specialized, unmanned applications. Therefore, conventional receivers are unable to meet the application requirements of some specialized scenarios.

[0031] Based on this, this embodiment provides a BeiDou-3 antenna automatic detection and switching receiver. The receiver is externally connected to two antennas in different directions. 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 to transmit and receive satellite signals.

[0032] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0033] The embodiment of the present invention provides a BeiDou-3 antenna automatic detection switching receiver, such as Figure 2 As shown, the receiver is externally connected to multiple transmitting and receiving antennas in different directions. The receiver includes an antenna selection switching module 100, a radio frequency module 200 and a baseband module 300:

[0034] The antenna selection and switching module 100 is used to receive signals from multiple antennas, filter the signals, and send them to the RF module 200 for down-conversion processing. At the same time, it transmits the transmit signal output by the RF module 200 through the antenna; and receives the antenna switching instruction sent by the baseband module 300, and selects and switches the antenna according to the antenna switching instruction;

[0035] The RF module 200 is used to down-convert the signal sent by the antenna selection 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, up-convert the BPSK signal into an RF signal, and then transmit it to the antenna selection switching module 100 for external transmission;

[0036] The baseband module 300 is used 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 switching module 100 to switch to the antenna with the highest carrier-to-noise ratio.

[0037] In this embodiment, the RF module 200 includes multiple RF chips, and the number of RF chips is the same as the number of antennas. 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.

[0038] Meanwhile, the baseband module 300 includes one baseband chip.

[0039] Specifically, the antenna selection switching module 100 includes multiple combiners, a first RF switch, a second RF switch, and multiple filters: each combiner is connected to an antenna, and 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;

[0040] The combiner is used to combine the S receive signal of the S radio frequency channel, the L transmit 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;

[0041] The first radio frequency switch is used to select a combiner to receive a signal;

[0042] The second radio frequency switch is used to select a combiner to send a signal;

[0043] The filter is used to filter the received signal.

[0044] In this embodiment, the number of external transceiver antennas connected to the receiver can be multiple. Below, this solution will be introduced using two transceiver antennas as an example.

[0045] This embodiment provides a receiver that can realize automatic detection and switching of BeiDou-3 antennas. The receiver is connected to two antennas in different directions. By calculating the carrier-to-noise ratio and satellite azimuth of the satellite signals received by the two antennas, it automatically switches to the more appropriate antenna for satellite signal reception and transmission without human intervention. The detailed functional block diagram is shown in the figure. Figure 3 As shown:

[0046] 1. To meet the needs of specialized applications, the receiver automatically selects antennas for signal transmission and reception without human intervention, ensuring the success rate of RDSS short message communication. The receiver is connected to two external transmit and receive antennas and includes an antenna selection and switching module 100, a radio frequency module 200, and a baseband module 300. The two external antennas can be placed in different orientations to receive signals from two different directions and forward them to the receiver for processing. The antenna selection and switching module 100 receives signals from the two antennas, performs antenna selection switching, filters them, and then down-converts them to the radio frequency module 200. The radio frequency module 200 includes multiple radio frequency chips 201, which receive radio frequency signals for down-conversion and up-convert BPSK signals received from the baseband signal to radio frequency signals for transmission. The baseband module 300 includes a baseband chip 301, which receives intermediate frequency (IF) signals from different antennas, calculates the carrier-to-noise ratio (C / N), and controls the antenna selection and switching module 100 to switch to the antenna with the best C / N ratio for signal transmission and reception.

[0047] 2. The antenna selection switching module 100 is externally connected to two antennas, and each antenna inputs a combiner 101. The combiner 101 is responsible for combining the B3 and B2 signals of RNSS and the S receiving signal and L transmitting signal of RDSS and then connecting them to the antenna. The two combiners 101 share the same S and L radio frequency channels, and one of the combiners 101 is switched and selected through the radio frequency switch 102. Only one antenna can be used at the same time. The other two combiners 101 are respectively connected to different B3 and B2 radio frequency channels, which can enable two antennas to receive RNSS signals at the same time. Filters 103 need to be added to the B3, B2, S, and L radio frequency channels to suppress out-of-band interference signals and ensure stable signal transmission and reception;

[0048] 3. The RF module 200 includes two RF chips 201, and the baseband module 300 includes one baseband chip 301. The antenna selection switching module 100 is connected to the baseband chip 301 by two RF chips 201, and the antenna selection switching module 100 is also connected to the baseband chip 301 through the RF switch 102. The two RF chips 201 are used to realize up- and down-conversion processing of signals, and the received RF signal is down-converted to an intermediate frequency and then processed by the baseband chip 301. The BPSK signal output by the baseband chip 301 is converted into an RF signal through up-conversion and transmitted. One of the RF chips 201 realizes down-conversion reception of B3, B2, and S signals and up-conversion transmission of L signals, and the other RF chip 201 realizes down-conversion reception of B3 and B2 signals;

[0049] 4. The IF signal processed by RF chip 201 is input into baseband chip 301 for capture, tracking, and calculation. The carrier-to-noise ratio and azimuth angles of multiple satellites can be obtained. By comparing the carrier-to-noise ratio and azimuth angles of the satellite signals received by the two antennas, the approximate direction of the antennas can be determined, thereby determining which antenna is more suitable for RDSS transmission and reception. Baseband chip 301 controls RF switch 102 within antenna selection switching module 100, switching the RDSS transmission and reception channel to the corresponding antenna for short message communication and location information transmission, greatly improving communication success rates.

[0050] See Figure 4 , the execution process of the receiver in this embodiment is:

[0051] Step S1: The baseband chip simultaneously receives B2 and B3 satellite signals from two antennas and calculates the carrier-to-noise ratio and azimuth of the satellite respectively;

[0052] Step S2: The baseband chip controls the RF switch to select the S transceiver antennas and calculates the carrier-to-noise ratio of the RDSS receiving satellites respectively;

[0053] Step S3: roughly determine 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 RDSS transmitting antenna;

[0054] Step S4: The baseband chip controls the RF switch to select the corresponding antenna to transmit and receive the RDSS short message signal, thereby transmitting the location information of the receiver.

[0055] This embodiment addresses special requirements for BeiDou-3 RNSS+RDSS applications, which in some cases cannot guarantee stable reception and transmission of satellite signals due to poor antenna performance or location. A receiver is provided that can automatically detect and switch the BeiDou-3 antenna. Automatic detection and switching of the receiver antenna is achieved, ensuring stable reception of RNSS signals and the success rate of RDSS short message communications. This is primarily reflected in the following aspects: 1. By connecting two external antennas, the poor performance of a single antenna is compensated for under limited size conditions; 2. The antenna's position is automatically identified by baseband detection of the satellite signal's carrier-to-noise ratio and azimuth angle, eliminating the need for additional equipment such as an IMU to determine direction; 3. By controlling the RF switch, the antenna is automatically switched for signal transmission and reception, eliminating the need for manual intervention, making it particularly suitable for unmanned applications; 4. The antenna with the best signal is automatically selected for RDSS short message transmission and reception, greatly improving the communication success rate.

[0056] This embodiment can achieve stable RNSS signal reception and RDSS short message communication in some special application scenarios without human intervention, thereby ensuring the success rate of short message communication.

[0057] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0058] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all 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 connected to multiple transmitting and receiving antennas in different directions. The receiver includes an antenna selection 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 radio frequency module for down-conversion processing, and transmit the transmission signals output by the radio frequency 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 down-convert 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 then 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; Among them, the antenna selection switching module includes multiple combiners, a first RF switch, a second RF switch, and multiple filters: each combiner is connected to an antenna, and 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 receive signal of the S radio frequency channel, the L transmit 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.

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 1, characterized in that: The number of the antennas is 2.

Images