Link monitoring signal generation method and circuit, link monitoring method and system

Abstract

The application discloses a link monitoring signal generation method and circuit, a link monitoring method and system. The application can discover signal link abnormal conditions in time through monitoring of an uplink target signal. Compared with the existing RFID detection label, the base station side of the present application does not need to be modified, and only needs to replace the existing RFID detection label on the indoor space side with a passive large frequency shift label, so that the base station side does not need to additionally install a monitoring signal source, a multi-band combiner and other equipment. Meanwhile, since the monitoring signal is an uplink and downlink guard band signal or an idle in-band signal, the normal work of the base station signal is not affected, and the terminal user experience is improved. The frequency shift label proposed in the present application can realize MHz large frequency shift under passive working conditions, and has the characteristics of low power consumption and long-term maintenance-free.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and more specifically, to a method and circuit for generating link monitoring signals, and a method and system for link monitoring. Background Technology

[0002] Indoor distributed antenna systems (DAS) utilize a network of antennas widely distributed throughout a building to extend mobile wireless signals. Depending on the type of DAS, antennas are typically connected using coaxial cables, high-speed balanced twisted-pair copper cables, and / or fiber optic cables, and can support 4G and 5G wireless signal transmission. The DAS relies on an antenna feeder system for signal transmission and distribution; any problems with the feeder system or connecting cables will directly affect signal coverage.

[0003] Currently, faults in indoor distributed antenna systems (DAS) active equipment (such as base stations and repeaters) can generally be monitored through a monitoring system. However, faults in indoor distributed antenna systems passive equipment or devices (feeders, passive devices, antennas, etc.) can only be checked manually by relying on spectrum analyzers or VSWR testers through on-site inspections. This is not only passive but also very inefficient and disturbs residents.

[0004] To address the aforementioned issues, the existing technology "A Mobile Communication Indoor Distribution Fault Location Instrument Based on RFID Technology" (Application No.: CN201821412670.4) employs an RFID monitoring indoor distribution system, such as... Figure 1 As shown, the principle is as follows: Host 2, acting as the main control unit, transmits the carrier signal source to the antenna through a splitter, providing energy to each RFID detection tag to activate it. The RFID detection tag detects the antenna's transmission power and feeds back the detected transmission power value to the host. When the antenna position is fixed, its transmission power and / or VSWR are relatively fixed and vary within a certain range. If the antenna's transmission power and / or VSWR exceed the corresponding range, it is determined that there is a problem with the link where the antenna is located. This allows for the determination of whether there are problems with passive components on the link, thereby detecting faults in the monitoring antenna link.

[0005] However, this solution has the following drawbacks: Firstly, the base station channel signal required for communication cannot be transmitted simultaneously with the RFID monitoring signal transmitted by the host. When the host transmits the monitoring signal, the base station channel signal must be turned off for a period of time, which will prevent users from communicating normally and reduce the user experience. Secondly, it requires modifications to the existing indoor distribution system, including the addition of a host and a multi-band combiner, resulting in high costs. Furthermore, RFID detection tags are susceptible to interference from base station channel signals, increasing the probability of errors; adding an RF bandpass filter to the RFID detection tags will further lower the detection threshold of the RFID signal. Summary of the Invention

[0006] This invention overcomes the shortcomings of the prior art by providing a method and circuit for generating link monitoring signals, a link monitoring method and system, in order to solve at least one technical problem existing in the prior art.

[0007] To address the aforementioned technical problems, one aspect of the present invention provides a method for generating link monitoring signals.

[0008] A link monitoring signal generation method, applied to a frequency-shift tag circuit, wherein the frequency-shift tag circuit is disposed inside or outside an indoor distributed antenna, includes the following steps:

[0009] Receive downlink target signals;

[0010] Generate uplink target signal state information that characterizes the features of downlink target signals;

[0011] Send uplink target signal.

[0012] In an indoor distributed antenna system (DAS) fault monitoring system, frequency shift tags are placed near the DAS antenna. Their working principle is as follows: when a fault occurs in the signal link from the base station to the DAS antenna, the quality of the uplink signal sent from the user terminal to the base station degrades or even ceases. Correspondingly, the quality of the uplink target signal received by the base station also degrades or even ceases. Therefore, by monitoring the uplink target signal, abnormal signal link conditions can be detected promptly.

[0013] A further technical solution involves generating uplink target signal state information that characterizes the features of downlink target signals, including the following steps:

[0014] It receives downlink target signals and generates broadband radio frequency signals with a frequency range covering DC to the downlink target signal frequency;

[0015] Frequency selection is performed on the broadband radio frequency signal to obtain the narrowband radio frequency signal, and the narrowband radio frequency signal is mixed with the downlink target signal to obtain the uplink target signal.

[0016] The present invention also provides a frequency-shift tag circuit, including a tag antenna module, a modulation module, and a frequency selection module II;

[0017] The tag antenna module is electrically connected to the first modulation port of the modulation module, and the second frequency selection module is electrically connected to the third modulation port of the modulation module.

[0018] The tag antenna module is configured to receive downlink target signals and transmit uplink target signals;

[0019] The modulation module is configured to receive downlink target signals from the tag antenna module and generate a broadband radio frequency signal with a frequency range covering DC to the downlink target signal frequency, and to transmit uplink target signals to the tag antenna module.

[0020] Frequency selection module 2 is configured to select the frequency of the broadband radio frequency signal to obtain a narrowband radio frequency signal, and then send the narrowband radio frequency to the modulation module to mix with the downlink target signal to obtain the uplink target signal.

[0021] Frequency shift tags are used to shift the downlink target signal frequency to the uplink target signal frequency and reflect it back to the monitoring unit.

[0022] A further technical solution is that the downlink target signal is a channel guard band signal or a signal within the channel band; the uplink target signal is a channel guard band signal or a signal within the channel band.

[0023] A further technical solution is that the modulation module includes a varactor diode, and the modulation module includes one of the following solutions:

[0024] Option 1:

[0025] The modulation module includes an inductor and a varactor diode. One end of the inductor is electrically connected to the first modulation port of the modulation module, the other end of the inductor is electrically connected to the positive terminal of the varactor diode, and the negative terminal of the varactor diode is electrically connected to the third modulation port.

[0026] Option 2:

[0027] The modulation module includes an inductor, a varactor diode, and a varactor diode. One end of the inductor is electrically connected to the first modulation port of the modulation module, the other end of the inductor is electrically connected to the positive terminal of the varactor diode, the negative terminal of the varactor diode is electrically connected to the negative terminal of the varactor diode, and the positive terminal of the varactor diode is electrically connected to the third modulation port.

[0028] Option 3:

[0029] The modulation module includes an inductor, a varactor diode, and a varactor diode. One end of the inductor is electrically connected to the first modulation port of the modulation module, and the other end of the inductor is electrically connected to the negative terminal of the varactor diode. The positive terminal of the varactor diode is electrically connected to the positive terminal of the varactor diode, and the negative terminal of the varactor diode is electrically connected to the third modulation port.

[0030] A further technical solution is that the modulation module includes a transistor, which is one of the following: unipolar transistor, field-effect transistor, junction field-effect transistor, metal-oxide-semiconductor field-effect transistor, two-dimensional electron gas transistor, and high electron mobility transistor.

[0031] A further technical solution is that the modulation module includes transistors, and the frequency shift tag circuit includes one of the following solutions:

[0032] Option 1:

[0033] The frequency shift tag circuit also includes a frequency selection module one, and the second modulation port of the modulation module is electrically connected to port one of the frequency selection module one;

[0034] Option 2:

[0035] The frequency shift tag circuit also includes a frequency selection module one, the second modulation port of the modulation module is electrically connected to port one of the frequency selection module one, and port two of the frequency selection module one is electrically connected to port two of the frequency selection module two.

[0036] Option 3:

[0037] The frequency shift tag circuit does not include frequency selection module one, and the second modulation port of the modulation module is electrically connected to port two of frequency selection module two;

[0038] In Schemes 1 to 3, the frequency selection module 1 is configured to filter the broadband radio frequency signal from the modulation module to obtain the broadband radio frequency signal 2.

[0039] A further technical solution is that, in Solution 1, the frequency selection module 1 includes a reflective band-stop filter, an LC series resonant circuit, and an LC parallel resonant circuit.

[0040] In Scheme 2, the frequency selection module 1 includes a through-pass bandpass filter, an LC series resonant circuit, and an LC parallel resonant circuit;

[0041] In schemes one to three, the frequency selection module two includes a passive piezoelectric resonator, an LC parallel resonant circuit, or an LC series resonant circuit.

[0042] A further technical solution is that passive piezoelectric resonators include passive crystal resonators, passive ceramic resonators, passive surface acoustic wave resonators, and passive MEMS piezoelectric resonators.

[0043] This invention also provides a link monitoring method applied to base station equipment, comprising the following steps:

[0044] The signal source generates a downlink target signal, which is then transmitted by the transceiver isolation unit to the indoor distributed signal feedback device, enabling the indoor distributed signal feedback device to generate uplink target signal status information that characterizes the downlink target signal.

[0045] The transceiver isolation unit receives uplink target signal status information and sends it to the monitoring unit;

[0046] The monitoring unit receives the uplink target signal from each antenna unit, and then determines whether the signal link of the corresponding antenna unit is faulty based on the status information of the uplink target signal received from the corresponding antenna unit.

[0047] This invention also provides a link monitoring method applied to indoor distributed antenna system (DAS) signal feedback equipment, comprising the following steps:

[0048] The downlink target signal is received, and the distribution unit distributes the downlink target signal to the indoor distributed antenna unit;

[0049] The indoor distributed antenna unit generates uplink target signal status information that characterizes the downlink target signal features and transmits the uplink target signal.

[0050] A further technical solution is that the downlink target signal is a channel guard band signal or a signal within the channel band; the uplink target signal is a channel guard band signal or a signal within the channel band.

[0051] A further technical solution is that the uplink target signal carries the identification information of the corresponding indoor distributed antenna.

[0052] A further technical solution is that the identity information includes the indoor distributed antenna number and the cell number where the indoor distributed antenna is located; or, it includes the channel frequency information corresponding to the indoor distributed antenna.

[0053] The present invention also provides a link monitoring system, comprising:

[0054] The signal source transmits downlink target signals;

[0055] Indoor distributed antenna units generate uplink target signal state information that characterizes the downlink target signal features;

[0056] The monitoring unit determines the operating status of the signal link between the signal source and each indoor distributed antenna based on the status information of the received uplink target signal.

[0057] A further technical solution is that the downlink target signal is a channel guard band signal or a signal within the channel band; the uplink target signal is a channel guard band signal or a signal within the channel band.

[0058] A further technical solution is that the indoor distributed antenna unit includes an indoor distributed antenna and a frequency shift tag;

[0059] Frequency shift tags are placed inside or outside the enclosure of the indoor distributed antenna;

[0060] The frequency shift tag stores the identification information of the corresponding antenna unit.

[0061] A further technical solution is that the identity information includes the indoor distributed antenna number and the cell number where the indoor distributed antenna is located; or, it includes the channel frequency information corresponding to the indoor distributed antenna.

[0062] Compared with the prior art, the present invention has at least the following beneficial effects: Compared with the existing RFID detection tags, the base station side of this solution does not need to be modified. It is only necessary to replace the existing RFID detection tags on the indoor space side with passive large frequency shift tags. The base station side does not need to install additional monitoring signal sources, multi-band combiners and other equipment. At the same time, since the monitoring signal is the uplink and downlink protection band signal or the uplink and downlink idle band signal, it does not affect the normal operation of the base station signal and improves the end user experience.

[0063] The frequency shift tag proposed in this solution can achieve a large frequency shift of MHz under passive operating conditions, and features low power consumption and long-term maintenance-free operation. Attached Figure Description

[0064] Figure 1 A schematic diagram of an existing mobile communication indoor distribution fault location device based on RFID technology;

[0065] Figure 2 This is a schematic diagram of the frequency shift tag circuit structure;

[0066] Figure 3 This is a schematic diagram of a modulation module circuit;

[0067] Figure 4 This is a schematic diagram of another modulation module circuit;

[0068] Figure 5 This is a schematic diagram of a link monitoring system. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0070] In one embodiment of the present invention, a method for generating a link monitoring signal is provided, the specific steps of which are as follows:

[0071] Receive downlink target signals;

[0072] Generate uplink target signal state information that characterizes the features of downlink target signals;

[0073] Send uplink target signal.

[0074] Generating uplink target signal state information that characterizes the features of downlink target signals includes the following steps:

[0075] It receives downlink target signals and generates broadband radio frequency signals with a frequency range covering DC to the downlink target signal frequency;

[0076] Frequency selection is performed on the broadband radio frequency signal to obtain a narrowband radio frequency signal, and the narrowband radio frequency signal is mixed with the downlink target signal to obtain the uplink target signal.

[0077] It should be noted that the downlink target signal can be the guard band signal of the channel, and the uplink target signal can be the in-band signal of the channel. The following explanation uses the guard band signal as the target signal to illustrate the implementation principle of this invention. It should be pointed out that although this invention uses the guard band signal as an example to illustrate the link monitoring implementation principle, this invention is not limited to the guard band signal and is equally applicable to in-band signals.

[0078] In one example, the idle uplink and downlink in-band signals are used as the uplink and downlink target signals, respectively.

[0079] In one example, taking power as a target signal characteristic, when the power of the downlink target signal (e.g., its frequency is 960MHz) received by the frequency shift tag is greater than the frequency shift tag driving power threshold, the frequency shift tag generates an uplink target signal (e.g., its frequency is 915MHz).

[0080] Under normal circumstances, when the signal link from the base station to the indoor distributed antenna is fault-free, the remote monitoring unit receives the uplink target signal at the first power level. However, when the signal link from the base station to the indoor distributed antenna fails, if the downlink target signal power received by the frequency shift tag is not greater than the frequency shift tag drive power threshold, the uplink target signal quality degrades or even becomes interrupted. Consequently, the remote monitoring unit receives the uplink target signal at the second power level, or may not receive the uplink target signal at all. Therefore, when the signal link from the base station to the indoor distributed antenna fails, monitoring the uplink target signal can promptly detect signal link anomalies.

[0081] It is understandable that the uplink target signal at the first power level is the superposition of the uplink target signal generated by the frequency shift tag and the uplink target signal generated during the communication service between the base station and the indoor user terminal; while the uplink target signal at the second power level is only the power level of the uplink target signal generated during the communication service between the base station and the indoor user terminal. Therefore, the first power level is greater than the second power level.

[0082] It should be noted that frequency shift tags need to be used in conjunction with indoor distributed antennas and link monitoring systems, but the frequency shift tags themselves also have independent functions. The role of the frequency shift tags is to generate uplink target signal status information that characterizes the downlink target signal features and send it to the base station.

[0083] Frequency shift tags can be passive tags or low-power tags that achieve the aforementioned large frequency shift. Large frequency shift refers to a frequency shift exceeding 1MHz, or exceeding 5MHz, or exceeding 20MHz. For example, shifting from the FDD downlink frequency to the FDD uplink frequency, and vice versa.

[0084] In some embodiments, the guard band signal is used as the monitoring signal, which can be shifted from the FDD downlink right guard band target signal frequency to the FDD uplink right guard band target signal frequency. For example, assuming 960MHz is the downlink right guard band target signal frequency and 915MHz is the uplink right guard band target signal frequency, then it can be shifted from 960MHz to 915MHz.

[0085] In some embodiments, the guard band signal is used as the monitoring signal, which can be shifted from the FDD downlink left guard band target signal frequency to the FDD uplink left guard band target signal frequency. For example, assuming 925MHz is the downlink left guard band target signal frequency and 880MHz is the uplink left guard band target signal frequency, then it can be shifted from 925MHz to 880MHz.

[0086] In some embodiments, the guard band signal is used as the monitoring signal, which can shift the target signal frequency of the FDD downlink left guard band to the target signal frequency of the FDD uplink right guard band. For example, assuming 925MHz is the target signal frequency of the downlink left guard band and 915MHz is the target signal frequency of the uplink right guard band, then it can be shifted from 925MHz to 915MHz.

[0087] In some embodiments, the guard band signal is used as the monitoring signal, which can shift the target signal frequency of the downlink right guard band to the target signal frequency of the uplink left guard band. For example, assuming 960MHz is the target signal frequency of the downlink right guard band and 880MHz is the target signal frequency of the uplink left guard band, then it can be shifted from 960MHz to 880MHz.

[0088] In one embodiment of the present invention, a frequency-shift tag circuit is provided, see [link to relevant documentation]. Figure 2 It includes a tag antenna module, a modulation module, and a frequency selection module 2;

[0089] The tag antenna module is electrically connected to the first modulation port of the modulation module, and the second frequency selection module is electrically connected to the third modulation port of the modulation module.

[0090] The tag antenna module is configured to receive downlink target signals and transmit uplink target signals;

[0091] The modulation module is configured to receive downlink target signals from the tag antenna module and generate a broadband radio frequency signal with a frequency range covering DC to the downlink target signal frequency, and to transmit uplink target signals to the tag antenna module.

[0092] Frequency selection module 2 is configured to select the frequency of the broadband radio frequency signal to obtain a narrowband radio frequency signal, and then send the narrowband radio frequency to the modulation module to mix with the downlink target signal to obtain the uplink target signal.

[0093] exist Figure 2 In the diagram, dashed lines are used to identify non-essential functional units or non-necessary connection paths to distinguish them from other essential functional units or defined connection paths.

[0094] In some embodiments, the present invention provides a frequency-shift tag that includes a housing and the aforementioned frequency-shift tag circuitry, wherein the frequency-shift tag circuitry is partially or wholly encapsulated within the housing.

[0095] Understandably, the frequency shift tag is placed inside or outside the indoor distributed antenna.

[0096] In one example, the indoor distributed antenna includes a housing. When the frequency shift tag is placed inside the indoor distributed antenna, the frequency shift tag can be attached to the inner surface of the housing of the indoor distributed antenna, for example. It is understood that the preferred attachment position is one that facilitates the frequency shift tag in receiving the downlink target signal while ensuring that the frequency shift tag causes minimal obstruction to the downlink target signal.

[0097] In one example, the indoor distributed antenna includes a housing. When the frequency shift tag is placed outside the indoor distributed antenna, the frequency shift tag can be attached to the outer surface of the housing of the indoor distributed antenna, for example. It is understood that the preferred attachment position is one that facilitates the frequency shift tag in receiving the downlink target signal while ensuring that the frequency shift tag causes minimal obstruction to the downlink target signal.

[0098] In one example, the indoor distributed antenna includes a housing. When the frequency shift tag is placed outside the indoor distributed antenna, for example, the frequency shift tag is placed within a certain distance range outside the housing of the indoor distributed antenna. It is understood that the preferred distance range is one that ensures that the frequency shift tag receives the downlink target signal while ensuring that the frequency shift tag causes minimal obstruction to the uplink and downlink target signals.

[0099] Understandably, in order to identify uplink target signals, the frequency shift tag of each antenna element stores the corresponding antenna element's identity (ID) information, and the uplink signal transmitted back by each antenna element contains the aforementioned ID information. Therefore, based on the ID information, the faulty antenna element and its signal link can be quickly located.

[0100] In some embodiments, the aforementioned ID information includes the cell number and the antenna number.

[0101] In some embodiments, the aforementioned ID information includes channel frequency information corresponding to each indoor distributed antenna.

[0102] It is understood that the aforementioned channel frequency information can be either channel guard band frequency information or channel band frequency information. For example, taking the channel guard band frequency as the mapping identifier for the corresponding antenna element, consider three indoor distributed antennas installed on different floors. Their uplink communication channel carrier frequencies are 910MHz, 911MHz, and 912MHz, and their uplink guard band target signal frequencies are 910.1MHz, 911.1MHz, and 912.1MHz, respectively. When excited by a downlink frequency of 960MHz, the frequency shift tag of the corresponding indoor distributed antenna will return the corresponding uplink frequency information, thereby distinguishing each indoor distributed antenna.

[0103] It is understandable that the frequency shift tag can be either a passive tag or a low-power tag that achieves the aforementioned large frequency shift. A passive tag is one that does not contain a battery or external power source. A low-power tag is one that has an internal energy storage unit, and its power consumption does not exceed a few hundred microwatts.

[0104] It is understandable that the frequency shift tag is excited by the downlink target signal. When the excitation power of the downlink target signal exceeds the driving power threshold of the frequency shift tag, the frequency shift tag starts to work and reflects the uplink target signal back to the monitoring unit.

[0105] The modulation module will be described in detail below.

[0106] The modulation module serves two purposes: firstly, to disperse the energy of the fed downlink target signal to obtain a broadband radio frequency signal with a frequency range covering DC to the downlink target signal frequency; secondly, to mix the narrowband radio frequency signal and the downlink target signal in the modulation module to obtain the uplink target signal, wherein the aforementioned narrowband radio frequency signal is obtained after the broadband radio frequency signal is frequency-selected by the frequency selection module two.

[0107] In some embodiments, the broadband radio frequency signal includes a signal with a frequency range from DC to the downlink target signal frequency. For example, the broadband radio frequency signal is configured to include radio frequency signals such as 5MHz, 10MHz, 15MHz, 20MHz, and 30MHz.

[0108] In some embodiments, the narrowband radio frequency signal obtained by the frequency selection module 2 after selecting the frequency of the broadband radio frequency signal includes radio frequency signals such as 5MHz, 10MHz, 15MHz, 20MHz, or 30MHz.

[0109] In some embodiments, the modulation module includes transistors.

[0110] In some embodiments, the transistor is a unipolar transistor. The unipolar transistor is preferably a field-effect transistor (FET). The FET is preferably a junction field-effect transistor, a metal-oxide-semiconductor field-effect transistor, a two-dimensional electron gas transistor, or a high electron mobility transistor.

[0111] In some embodiments, the modulation module includes a unipolar transistor, with the drain, source, and gate serving as a first modulation port, a second modulation port, and a third modulation port, respectively; or, the gate, drain, and source serving as a first modulation port, a second modulation port, and a third modulation port, respectively; or, the source, gate, and drain serving as a first modulation port, a second modulation port, and a third modulation port, respectively.

[0112] In some embodiments, the modulation module includes a bipolar transistor, with the collector, emitter, and base serving as a first modulation port, a second modulation port, and a third modulation port, respectively; or, the base, collector, and emitter serving as a first modulation port, a second modulation port, and a third modulation port, respectively; or, the emitter, base, and collector serving as a first modulation port, a second modulation port, and a third modulation port, respectively.

[0113] Since the frequency selection module is not mandatory, the transistor-based frequency shift tag circuit can be connected in the following ways.

[0114] See Figure 2 In the first connection method, the transistor-based frequency shift tag circuit also includes a frequency selection module one, and the second modulation port of the modulation module is electrically connected to port one of the frequency selection module one, i.e. Figure 2 The signal transmission path ① exists.

[0115] In the second connection method, the transistor-based frequency shift tag circuit also includes a frequency selection module one. The second modulation port of the modulation module is electrically connected to port one of the frequency selection module one, and port two of the frequency selection module one is electrically connected to port two of the frequency selection module two. Figure 2 Signal transmission paths ① and ② exist.

[0116] In the third connection method, the transistor-based frequency shift tag circuit does not include frequency selection module one, and the second modulation port of the modulation module is electrically connected to port two of the frequency selection module two, i.e. Figure 2 Signal transmission path ③ exists, while ① and ② do not.

[0117] Frequency selection module one is configured to filter the broadband RF signal from the modulation module to obtain broadband RF signal two. It is understood that the frequency range of broadband RF signal two is narrower than the frequency range of the broadband RF signal from the modulation module.

[0118] In some embodiments, in the aforementioned first connection method, the frequency selection module one includes a reflective band-stop filter, and the broadband radio frequency signal two arrives at port one of the frequency selection module two from port one of the frequency selection module one, sequentially through the second modulation port and the third modulation port of the modulation module. In this embodiment, as an example, the frequency selection module one includes a radio frequency open circuit, a radio frequency short circuit, and an LC parallel resonant circuit.

[0119] In some embodiments, in the aforementioned second connection method, the frequency selection module one includes a pass-through bandpass filter, and the first frequency selection signal reaches the second port of the frequency selection module two from the second port of the frequency selection module one. In this embodiment, as an example, the frequency selection module one includes an LC series resonant circuit and an LC parallel resonant circuit.

[0120] For the first three connection methods, in some embodiments, the frequency selection module 2 can be a passive piezoelectric resonator, an LC parallel resonant circuit, or an LC series resonant circuit. It is understood that passive piezoelectric resonators include passive crystal resonators, passive ceramic resonators, passive surface acoustic wave resonators, or passive MEMS piezoelectric resonators.

[0121] The process of generating a large frequency shift using a transistor-based modulation module is mainly as follows: The downlink target signal passes through the passive channel of the modulation module. During transmission through the passive channel, the energy of the downlink target signal is dispersed into a wideband RF signal 1, the frequency range of which extends from DC to the downlink target signal frequency. Either wideband RF signal 1 or wideband RF signal 2 (the specific choice depends on one of the three aforementioned connection methods) is frequency-selected by frequency selection module 2 to obtain a narrowband RF signal. This narrowband RF signal then enters the modulation module and is mixed with the fed downlink target signal to obtain the uplink target signal.

[0122] The frequency relationship before and after mixing is f. UL =f DL ±n×f r Where n is a positive integer, and its value represents the harmonic order; f DL f is the carrier frequency of the downlink target signal. r f is the narrowband radio frequency signal carrier frequency obtained after frequency selection by the frequency selection module. UL The carrier frequency of the uplink target signal.

[0123] It is understandable that uplink and downlink target signals can be input and output at the same port (e.g., the first modulation port) or at different ports. For example, the uplink target signal can be input from the first modulation port, and the downlink target signal can be input from the second modulation port (i.e., the first modulation port). Figure 2 (Signal transmission path ⑤) or the third modulation port (i.e. Figure 2 ④) Output of the signal transmission path in the middle.

[0124] The following is a detailed introduction to the modulation module based on varactor diodes.

[0125] Please refer to Figure 2 It should be noted that for modulation modules based on varactor diodes, frequency selection unit one and signal transmission paths ①, ②, ③ and ⑤ are not included.

[0126] In some embodiments, such as Figure 3 As shown, the modulation module based on a varactor diode includes an inductor L1 and a varactor diode D1. One end of the inductor L1 is electrically connected to the first modulation port of the modulation module, and the other end is electrically connected to the positive terminal of the varactor diode D1. The negative terminal of the varactor diode D1 is electrically connected to the third modulation port. The working principle of its frequency conversion is existing technology and will not be elaborated here.

[0127] In some embodiments, such as Figure 4 As shown, the modulation module based on varactor diodes includes inductor L1, varactor diode D1, and varactor diode D2. One end of inductor L1 is electrically connected to the first modulation port of the modulation module, and the other end is electrically connected to the positive terminal of varactor diode D1. The negative terminal of varactor diode D1 is electrically connected to the negative terminal of varactor diode D2, and the positive terminal of varactor diode D2 is electrically connected to the third modulation port. The working principle of its frequency conversion is existing technology and will not be elaborated here.

[0128] In some embodiments, the modulation module based on varactor diodes includes an inductor L1, a varactor diode D1, and a varactor diode D2. One end of the inductor L1 is electrically connected to the first modulation port of the modulation module, and the other end is electrically connected to the negative terminal of the varactor diode D1. The positive terminal of the varactor diode D1 is electrically connected to the positive terminal of the varactor diode D2, and the negative terminal of the varactor diode D2 is electrically connected to the third modulation port.

[0129] For a modulation module based on a varactor diode, the second frequency selection module can be a passive piezoelectric resonator or an LC parallel resonant circuit. It is understood that passive piezoelectric resonators include passive crystal resonators, passive ceramic resonators, passive surface acoustic wave resonators, or passive MEMS piezoelectric resonators.

[0130] In one embodiment of the present invention, a link monitoring method is provided, applied to base station equipment, comprising the following steps:

[0131] The signal source generates a downlink target signal, which is then transmitted by the transceiver isolation unit to the indoor distributed signal feedback device, enabling the indoor distributed signal feedback device to generate uplink target signal status information that characterizes the downlink target signal.

[0132] The transceiver isolation unit receives uplink target signal status information and sends it to the monitoring unit;

[0133] The monitoring unit receives the uplink target signal from each antenna unit, and then determines whether the signal link of the corresponding antenna unit is faulty based on the status information of the uplink target signal received from the corresponding antenna unit.

[0134] In one embodiment of the present invention, a link monitoring method is provided, applied to an indoor distributed antenna system (DAS) signal feedback device, comprising the following steps:

[0135] The downlink target signal is received, and the distribution unit distributes the downlink target signal to the indoor distributed antenna unit;

[0136] The indoor distributed antenna unit generates uplink target signal status information that characterizes the downlink target signal features and transmits the uplink target signal.

[0137] In one embodiment of the present invention, a link monitoring system is provided, comprising:

[0138] The signal source transmits downlink target signals;

[0139] Indoor distributed antenna units generate uplink target signal state information that characterizes the downlink target signal features;

[0140] The number of indoor distributed antenna units can be set according to the actual situation.

[0141] In some embodiments, the indoor distributed antenna unit includes an indoor distributed antenna and a frequency shift tag;

[0142] The aforementioned frequency shift tag includes a frequency shift tag circuit, and the frequency shift tag is disposed on or near the inner surface, outer surface, or surrounding area of ​​the indoor distributed antenna housing;

[0143] The frequency shift tag stores the ID information of the corresponding antenna element.

[0144] The monitoring unit determines the operating status of the signal link between the signal source and each indoor distributed antenna based on the status information of the received uplink target signal.

[0145] The following combination Figure 5 The link monitoring system is described below. Figure 5 This is a schematic diagram of the indoor distributed antenna system based on frequency shift tags provided in this application, including base station equipment. The base station equipment includes a signal source, a monitoring unit, and a transceiver isolation unit. The signal source is used to provide indoor communication signals, and the indoor communication signals are covered by indoor distributed antenna units installed in each indoor space.

[0146] The indoor distributed antenna unit includes an indoor distributed antenna and a frequency shift tag. The frequency shift tag can be set inside, outside or near the antenna radome. The frequency shift tag is used to shift the downlink target signal frequency to the uplink target signal frequency and reflect it back to the monitoring unit.

[0147] Understandably, when using guard band signals as monitoring signals, a guard band is set on both the left and right sides of the channel bandwidth, namely the left guard band and the right guard band. Based on this, the downlink target signal frequency can be either the downlink right guard band target signal frequency or the downlink left guard band target signal frequency; the uplink target signal frequency can be either the uplink right guard band target signal frequency or the uplink left guard band target signal frequency.

[0148] The monitoring unit receives the uplink target signal from each antenna unit, and then determines whether the signal link of the corresponding antenna unit is faulty based on the status information of the uplink target signal received from the corresponding antenna unit.

[0149] Using the uplink and downlink channel bandwidth signals of the base station as monitoring signals for the working status of the indoor distributed antenna signal path, specifically, it is only necessary to replace the existing RFID detection tags with passive high-frequency conversion tags, without the need to install additional monitoring signal sources, multi-band combiners, or other equipment. This has the advantages of low cost and no need for major system modifications. At the same time, since the monitoring signals are uplink and downlink protection band signals or uplink and downlink idle band signals, they do not affect the normal operation of the base station signals.

[0150] Although the invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of this disclosure. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A method for generating a link monitoring signal, applied to a frequency-shift tag circuit, wherein the frequency-shift tag circuit is disposed inside or outside an indoor distributed antenna, characterized in that, Includes the following steps: Receive downlink target signals; Generate uplink target signal state information that characterizes the features of downlink target signals; The process of generating uplink target signal state information that characterizes the features of downlink target signals includes the following steps: It receives downlink target signals and generates broadband radio frequency signals with a frequency range covering DC to the downlink target signal frequency; Frequency selection is performed on the broadband radio frequency signal to obtain a narrowband radio frequency signal, and the narrowband radio frequency signal is mixed with the downlink target signal to obtain the uplink target signal; Send uplink target signal.

2. A frequency-shift tag circuit, characterized in that, This includes a tag antenna module, a modulation module, and a frequency selection module 2; The tag antenna module is electrically connected to the first modulation port of the modulation module, and the second frequency selection module is electrically connected to the third modulation port of the modulation module. The tag antenna module is configured to receive downlink target signals and transmit uplink target signals; The modulation module is configured to receive downlink target signals from the tag antenna module and generate a broadband radio frequency signal with a frequency range covering DC to the downlink target signal frequency, and to send uplink target signals to the tag antenna module. The second frequency selection module is configured to select the frequency of the broadband radio frequency signal to obtain a narrowband radio frequency signal, and then send the narrowband radio frequency to the modulation module to mix it with the downlink target signal to obtain the uplink target signal.

3. The circuit as described in claim 2, characterized in that, The downlink target signal is a channel guard band signal or a signal within the channel band; the uplink target signal is a channel guard band signal or a signal within the channel band.

4. The circuit as described in claim 2, characterized in that, The modulation module includes a varactor diode, and the modulation module includes one of the following solutions: Option 1: The modulation module includes an inductor and a varactor diode. One end of the inductor is electrically connected to the first modulation port of the modulation module, the other end of the inductor is electrically connected to the positive terminal of the varactor diode, and the negative terminal of the varactor diode is electrically connected to the third modulation port. Option 2: The modulation module includes an inductor, a varactor diode, and a varactor diode. One end of the inductor is electrically connected to the first modulation port of the modulation module, the other end of the inductor is electrically connected to the positive terminal of the varactor diode, the negative terminal of the varactor diode is electrically connected to the negative terminal of the varactor diode, and the positive terminal of the varactor diode is electrically connected to the third modulation port. Option 3: The modulation module includes an inductor, a varactor diode, and a varactor diode. One end of the inductor is electrically connected to the first modulation port of the modulation module, and the other end of the inductor is electrically connected to the negative terminal of the varactor diode. The positive terminal of the varactor diode is electrically connected to the positive terminal of the varactor diode, and the negative terminal of the varactor diode is electrically connected to the third modulation port.

5. The circuit as described in claim 2, characterized in that, The modulation module includes a transistor, which is one of a unipolar transistor, a field-effect transistor, a junction field-effect transistor, a metal-oxide-semiconductor field-effect transistor, a two-dimensional electron gas transistor, or a high electron mobility transistor.

6. The circuit as described in claim 2, characterized in that, The modulation module includes a transistor, and the frequency shift tag circuit includes one of the following solutions: Option 1: The frequency shift tag circuit also includes a frequency selection module one, and the second modulation port of the modulation module is electrically connected to port one of the frequency selection module one; Option 2: The frequency shift tag circuit also includes a frequency selection module one, the second modulation port of the modulation module is electrically connected to port one of the frequency selection module one, and port two of the frequency selection module one is electrically connected to port two of the frequency selection module two. Option 3: The frequency shift tag circuit does not include frequency selection module one, and the second modulation port of the modulation module is electrically connected to port two of frequency selection module two; In Schemes 1 to 3, the frequency selection module 1 is configured to filter the broadband radio frequency signal from the modulation module to obtain broadband radio frequency signal 2.

7. The frequency shift tag circuit as described in claim 6, characterized in that, In Scheme 1, the frequency selection module 1 includes a reflective band-stop filter, an LC series resonant circuit, and an LC parallel resonant circuit; In Scheme 2, the frequency selection module 1 includes a through-pass bandpass filter, an LC series resonant circuit, and an LC parallel resonant circuit; In the first to third schemes, the frequency selection module two includes a passive piezoelectric resonator, an LC parallel resonant circuit, or an LC series resonant circuit.

8. The frequency shift tag circuit as described in claim 7, characterized in that, The passive piezoelectric resonators include passive crystal resonators, passive ceramic resonators, passive surface acoustic wave resonators, and passive MEMS piezoelectric resonators.

9. A link monitoring method, applied to base station equipment, characterized in that, Includes the following steps: The signal source generates a downlink target signal, which is then transmitted by the transceiver isolation unit to the indoor distributed signal feedback device, enabling the indoor distributed signal feedback device to generate uplink target signal status information that characterizes the downlink target signal. The process of generating uplink target signal state information that characterizes the features of downlink target signals includes the following steps: It receives downlink target signals and generates broadband radio frequency signals with a frequency range covering DC to the downlink target signal frequency; Frequency selection is performed on the broadband radio frequency signal to obtain a narrowband radio frequency signal, and the narrowband radio frequency signal is mixed with the downlink target signal to obtain the uplink target signal; The transceiver isolation unit receives uplink target signal status information and sends it to the monitoring unit; The monitoring unit receives the uplink target signal from each antenna unit, and then determines whether the signal link of the corresponding antenna unit is faulty based on the status information of the uplink target signal received from the corresponding antenna unit.

10. A link monitoring method, applied to an indoor distributed antenna system (DAS) signal feedback device, characterized in that, Includes the following steps: The downlink target signal is received, and the distribution unit distributes the downlink target signal to the indoor distributed antenna unit; The indoor distributed antenna unit generates uplink target signal status information that characterizes the downlink target signal and transmits the uplink target signal; The process of generating uplink target signal state information that characterizes the features of downlink target signals includes the following steps: It receives downlink target signals and generates broadband radio frequency signals with a frequency range covering DC to the downlink target signal frequency; Frequency selection is performed on the broadband radio frequency signal to obtain the narrowband radio frequency signal, and the narrowband radio frequency signal is mixed with the downlink target signal to obtain the uplink target signal.

11. The method as described in claim 1, 9, or 10, characterized in that, The downlink target signal is a channel guard band signal or a signal within the channel band; the uplink target signal is a channel guard band signal or a signal within the channel band.

12. The method as described in claim 1, 9, or 10, characterized in that, The uplink target signal carries the identification information of the corresponding indoor distributed antenna.

13. The method as described in claim 12, wherein the identity information includes the indoor distributed antenna number and the cell number where the indoor distributed antenna is located; or, it includes the channel frequency information corresponding to the indoor distributed antenna.

14. A link monitoring system, characterized in that, include: The signal source transmits downlink target signals; Indoor distributed antenna units generate uplink target signal state information that characterizes the downlink target signal features; The process of generating uplink target signal state information that characterizes the features of downlink target signals includes the following steps: It receives downlink target signals and generates broadband radio frequency signals with a frequency range covering DC to the downlink target signal frequency; Frequency selection is performed on the broadband radio frequency signal to obtain a narrowband radio frequency signal, and the narrowband radio frequency signal is mixed with the downlink target signal to obtain the uplink target signal; The monitoring unit determines the operating status of the signal link between the signal source and each indoor distributed antenna based on the status information of the received uplink target signal.

15. The system as described in claim 14, characterized in that, The downlink target signal is a channel guard band signal or a signal within the channel band; the uplink target signal is a channel guard band signal or a signal within the channel band.

16. The system as described in claim 14 or 15, characterized in that, The indoor distributed antenna unit includes an indoor distributed antenna and a frequency shift tag; The frequency shift tag is located inside or outside the indoor distributed antenna; The frequency shift tag stores the identity information of the corresponding antenna unit.

17. The system of claim 16, wherein the identity information includes the indoor distributed antenna number and the cell number where the indoor distributed antenna is located; or, includes the channel frequency information corresponding to the indoor distributed antenna.

Images