A method and system for multi-point positioning signal transmission in a room division system

Abstract

The application provides a kind of room distribution system multi-point positioning signal transmission method and system, belong to satellite positioning technical field.The method includes: obtaining multiple mobile communication signals and multiple positioning signals;According to multiple positioning signals and preset positioning signal parameters, obtain time division combined signal;The time division combined signal is combined with multiple mobile communication signals to obtain mixed transmission signal;The mixed transmission signal is transmitted to at least one receiving point of room distribution system;The mixed transmission signal is separated at the receiving point to obtain multiple separated positioning signals and multiple mobile communication signals;Multiple separated positioning signals are subjected to time delay compensation processing to obtain multiple delayed compensation positioning signals;Multiple delayed compensation positioning signals are combined to obtain output positioning signals and emit through positioning antenna.The scheme realizes the time division multiplexing transmission and accurate positioning of multi-point same frequency satellite signals of room distribution system.

Description

Technical Field

[0001] This invention relates to the field of satellite positioning technology, and in particular to a method and system for transmitting multi-point positioning signals in an indoor distribution system. Background Technology

[0002] With the iterative upgrades of mobile communication technology and the continuous growth in demand for high-precision location services in indoor scenarios, indoor distribution systems have become the core infrastructure for indoor mobile communication signal coverage in various buildings. These systems combine multi-band mobile communication signals through combining equipment and transmit them to various indoor locations via feeder cables. Signal transmission and reception are then completed through antennas, effectively solving the problems of severe signal attenuation and numerous coverage blind spots indoors. Related technologies have formed a mature standardized system and have been deployed on a large scale in scenarios such as commercial complexes, underground spaces, and industrial plants. Meanwhile, Global Navigation Satellite System (GNSS), as the mainstream positioning technology, suffers from severe signal attenuation in indoor scenarios, failing to directly meet indoor positioning needs. Indoor positioning solutions based on pseudo-satellite technology to simulate GNSS signals at different locations have become a key focus of industry research and application. This solution is compatible with general GNSS terminals, requires no additional terminal adaptation, and possesses strong universality. However, due to the technical characteristics of GNSS analog signals, GNSS analog signals from different locations operate in the same frequency band and use the same spread spectrum sequence. The only difference is the arrival time of the satellite signals. It is impossible to separate the signals after transmission over the same cable using conventional filtering methods. It is also impossible to directly reuse the existing indoor distribution system to complete the transmission of GNSS positioning signals at multiple points. Existing solutions mostly use separate transmission cables to distribute signals or use frequency division multiplexing technology to combine the signals from different locations after spectrum shifting.

[0003] The solution of laying separate transmission cables cannot reuse existing indoor distributed antenna system (DAS) infrastructure, resulting in high construction difficulty, high deployment costs, and long transformation cycles, making it difficult to achieve large-scale indoor coverage applications. On the other hand, the transmission solution using frequency division multiplexing (FDM) technology requires allocating independent spectrum resources for each GNSS signal, occupying a large amount of spectrum space, which conflicts with the current scarcity of spectrum resources in indoor DAS systems and poses a risk of interference with existing mobile communication signals. Furthermore, each signal requires two spectrum shifts, leading to complex signal processing circuit designs and significantly increased hardware costs, further limiting the large-scale deployment of the solution. Existing technologies have consistently failed to achieve an effective technical balance between compatibility with existing indoor DAS systems, controlling deployment costs, reducing spectrum occupancy, and ensuring positioning accuracy, making it difficult to meet the large-scale deployment requirements of indoor GNSS positioning coverage and becoming a core technical bottleneck restricting the large-scale application of indoor GNSS positioning technology. Summary of the Invention

[0004] This invention provides a method and system for transmitting multi-point positioning signals in an indoor distribution system, which solves the problem of combining and separating multi-point co-frequency satellite positioning signals in an indoor distribution system.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] This invention provides a method for transmitting multi-point positioning signals in an indoor distribution system, comprising:

[0007] The system acquires multiple mobile communication signals and multiple positioning signals transmitted from multiple analog points located in different indoor locations. Each positioning signal has the same center frequency and spreading sequence, but different signal arrival times.

[0008] Based on the multi-channel positioning signals and preset positioning signal parameters, the multi-channel positioning signals are subjected to time-division and merging processing to obtain time-division and merging signals;

[0009] The time-division multiplexed signal and the multiplexed mobile communication signal are combined to obtain a hybrid transmission signal;

[0010] The hybrid transmission signal is transmitted to at least one receiving point of the indoor distribution system;

[0011] The mixed transmission signal is separated at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals.

[0012] The multi-channel separated positioning signals are subjected to time delay compensation processing to obtain the delay-compensated multi-channel positioning signals;

[0013] The delayed-compensated multi-channel positioning signals are combined to obtain an output positioning signal, which is then transmitted through a positioning antenna. The multi-channel mobile communication signals are also transmitted through an indoor communication antenna.

[0014] Optionally, acquire multiple positioning signals transmitted from multiple analog points located at different indoor locations, including:

[0015] By using a positioning signal generator to simulate signals for different simulated locations, multiple positioning signals corresponding to different simulated locations are obtained. The multiple positioning signals have the same center frequency and spread spectrum sequence, and the signals of the same satellite corresponding to different simulated locations have a time difference of arrival related to the spatial location difference of the simulated locations.

[0016] Optionally, based on the multiple positioning signals and preset positioning signal parameters, the multiple positioning signals are subjected to time-division and combining processing to obtain time-division and combining signals, including:

[0017] Obtain preset positioning signal parameters;

[0018] Based on the preset positioning signal parameters, the spread spectrum signal period of the positioning signal, as well as the number of chips and chip rate contained in one spread spectrum signal period, are determined.

[0019] Based on the multi-channel positioning signals, determine the number of channels of the multi-channel positioning signals;

[0020] according to: Determine the duration of the time slot division; among which Divide the time slot into durations. For the number of chips, For chip rate, The number of multiple positioning signals;

[0021] Based on the time slot division duration, the time slot selection timing is determined, which is the timing sequence of sequentially selecting each positioning signal in chronological order within one spread spectrum signal period;

[0022] According to the time slot selection timing, each positioning signal is sequentially selected within one spread spectrum signal cycle, so that each positioning signal passes through the corresponding time slot, forming a time-division and combining signal that is staggered in time.

[0023] Optionally, the time-division multiplexed signal and the multiplexed mobile communication signal are combined to obtain a hybrid transmission signal, including:

[0024] The time-division combined signal is analyzed to determine the first frequency spectrum interval;

[0025] The multiple mobile communication signals are analyzed to determine a second spectrum interval, wherein the first spectrum interval and the second spectrum interval are independent of each other;

[0026] The signal components in the first frequency range and the signal components in the second frequency range are superimposed in the frequency domain to obtain a hybrid transmission signal that simultaneously contains the time-division multiplexing signal and the multi-channel mobile communication signal.

[0027] Optionally, the mixed transmission signal is separated at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals, including:

[0028] The hybrid transmission signal is subjected to power division processing to obtain a first transmission signal and a second transmission signal;

[0029] The first transmitted signal is subjected to bandpass filtering to obtain the extracted time-division and combining signal;

[0030] Based on the time slot selection timing sequence, the extracted time-division combined signal is subjected to time-division separation processing, and the signal segments in each time slot are selected and output separately to obtain multi-channel separation positioning signals.

[0031] The second transmitted signal is filtered to obtain multiple mobile communication signals.

[0032] Optionally, the multi-channel separated positioning signals are subjected to time delay compensation processing to obtain delay-compensated multi-channel positioning signals, including:

[0033] Obtain the spatial distance difference between the current receiving point and the analog points corresponding to each positioning signal;

[0034] Obtain the elevation angle of the satellite corresponding to each positioning signal at the current receiving point;

[0035] according to: Determine the time delay compensation amount corresponding to each separated signal; among which, For the first The time delay compensation amount corresponding to the path separation signal. For the first The spatial distance difference between the analog point corresponding to the road positioning signal and the current receiving point. For the first The road positioning signal corresponds to the elevation angle of the satellite at the current receiving point. The speed of light;

[0036] Based on the time delay compensation amount, a time delay is applied to the multi-channel separation signal to obtain the delay-compensated multi-channel positioning signal.

[0037] Optionally, the delayed-compensated multi-channel positioning signals are combined to obtain an output positioning signal, which is then transmitted through a positioning antenna, including:

[0038] The delay-compensated multi-channel positioning signals are linearly added in the time domain to obtain a complete output positioning signal. The output positioning signal contains all satellite signal components required for the current receiving point. The delay-compensated multi-channel positioning signal corresponds to the signal components of different satellites.

[0039] The output positioning signal is broadcast through the positioning antenna so that the terminal device at the current receiving point can perform positioning calculations.

[0040] This invention also provides a multi-point positioning signal transmission system for an indoor distribution system, comprising:

[0041] The positioning signal generation module includes multiple analog positioning signal generation units, which are used to generate multiple analog point transmissions at different indoor locations. Each positioning signal has the same center frequency and spread spectrum sequence, and has different signal arrival times.

[0042] A first time-division multiplexing module connected to the positioning signal generation module is used to perform time-division multiplexing processing on the multiple positioning signals according to the multiple positioning signals and preset positioning signal parameters to obtain a time-division multiplexed signal.

[0043] The first combining module has a first input terminal connected to the first time division multiplexing module and a second input terminal connected to multiple mobile communication signals. The first combining module is used to combine the time division multiplexing signal and the multiple mobile communication signals to obtain a hybrid transmission signal.

[0044] A transmission link connected to the first combining module, the transmission link being used to transmit the mixed transmission signal to at least one receiving point of the indoor distribution system;

[0045] A signal separation module coupled to the transmission link is used to separate the mixed transmission signal at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals.

[0046] A delay compensation module connected to the signal separation module includes multiple delay compensation units, which are used to perform time delay compensation processing on the multi-channel separated positioning signals to obtain delay-compensated multi-channel positioning signals.

[0047] A second combining module connected to the delay compensation module is used to combine the delay-compensated multi-channel positioning signals to obtain an output positioning signal.

[0048] A positioning antenna connected to the second combining module is used to transmit the output positioning signal.

[0049] Optionally, the signal separation module includes:

[0050] A first bandpass filter, the input of which is coupled to the transmission link;

[0051] A second time-division multiplexing module is connected to the output of the first bandpass filter, and the input of the second time-division multiplexing module is connected to the output of the bandpass filter.

[0052] Optionally, the multi-point positioning signal transmission system of the indoor distribution system further includes:

[0053] A second bandpass filter, the input of which is coupled to the transmission link, is used to extract the target mobile communication signal from the mixed transmission signal;

[0054] An indoor communication antenna is connected to the output of the second bandpass filter, and the indoor communication antenna is used to transmit the target mobile communication signal.

[0055] The technical solution of the present invention has at least the following effects:

[0056] The above-described solution of the present invention acquires multiple mobile communication signals and multiple positioning signals transmitted from multiple simulated points located at different indoor locations. Each positioning signal has the same center frequency and spreading sequence, but different signal arrival times. Based on the multiple positioning signals and preset positioning signal parameters, the multiple positioning signals are time-division multiplexed to obtain a time-division multiplexed signal. The time-division multiplexed signal is then combined with the multiple mobile communication signals to obtain a hybrid transmission signal. The hybrid transmission signal is transmitted to at least one receiving point of the indoor distributed antenna system (DAS). At the receiving point, the hybrid transmission signal is separated to obtain multiple separate positioning signals and multiple mobile communication signals. The multiple separate positioning signals are time-delay compensated to obtain delay-compensated multiple positioning signals. The delay-compensated multiple positioning signals are then combined to obtain an output positioning signal, which is transmitted through a positioning antenna. The multiple mobile communication signals are also transmitted through an indoor communication antenna. This solution achieves time-division multiplexing transmission and precise positioning of multi-point co-frequency satellite signals in an indoor DAS. Attached Figure Description

[0057] Figure 1 This is a flowchart of the multi-point positioning signal transmission method for an indoor distribution system provided in an embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram of the combination of a navigation satellite system simulation positioning system and an indoor distribution system provided in an embodiment of the present invention;

[0059] Figure 3 This is a schematic diagram of the structure of the multi-point positioning signal transmission system of the indoor distribution system provided in an embodiment of the present invention. Detailed Implementation

[0060] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0061] like Figure 1 As shown, an embodiment of the present invention proposes a multi-point positioning signal transmission method for an indoor distribution system, comprising:

[0062] Step 11: Acquire multiple mobile communication signals and multiple positioning signals transmitted from multiple simulated points in different indoor locations. Each positioning signal has the same center frequency and spreading sequence, and different signal arrival times.

[0063] Step 12: Based on the multi-channel positioning signals and preset positioning signal parameters, perform time-division and merging processing on the multi-channel positioning signals to obtain time-division and merging signals;

[0064] Step 13: Combine the time-division multiplexed signal with the multiplexed mobile communication signal to obtain a hybrid transmission signal;

[0065] Step 14: Transmit the hybrid transmission signal to at least one receiving point of the indoor distribution system;

[0066] Step 15: Separate the mixed transmission signal at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals;

[0067] Step 16: Perform time delay compensation processing on the multi-channel separated positioning signals to obtain the delay-compensated multi-channel positioning signals;

[0068] Step 17: Combine the delay-compensated multi-channel positioning signals to obtain an output positioning signal and transmit it through the positioning antenna, and transmit the multi-channel mobile communication signals through the indoor communication antenna.

[0069] The embodiments of the present invention, by time-division multiplexing positioning signals with different arrival times but the same center frequency and spreading sequence within a single spreading signal period, and then combining them with multiple mobile communication signals in the frequency domain, transmit them together via a co-cable to various receiving points indoors. After the receiving points separate the signals synchronously in a time-division manner, independent time delay compensation is applied to each separated signal based on the spatial distance difference between the receiving point and the simulated point and the satellite elevation angle information. Finally, the compensated positioning signals are combined and transmitted through an indoor positioning antenna, thereby achieving transparent transmission of multiple co-frequency positioning signals on a single indoor frequency point, effectively saving spectrum resources and simplifying the circuit complexity of the signal transmission link. Simultaneously, by applying differentiated and precise time delay compensation to each signal at the end point, realistic simulated positioning signals can be reproduced at different receiving points, meeting the need for simultaneous independent positioning in multiple indoor areas, and ensuring that the positioning signals and mobile communication signals are transmitted compatiblely within the same indoor distribution system without mutual interference.

[0070] In an optional embodiment of the present invention, step 11, acquiring multiple positioning signals transmitted from multiple simulated points located at different indoor locations, may include:

[0071] Step 111: Use a positioning signal generator to simulate signals for different simulated locations to obtain multiple positioning signals corresponding to different simulated locations; the multiple positioning signals have the same center frequency and spread spectrum sequence, and the signals of the same satellite corresponding to different simulated locations have an arrival time difference related to the spatial location difference of the simulated locations.

[0072] In this embodiment, each positioning signal is simulated and generated separately by a GNSS signal generator for different spatial locations, and has the same center frequency and spreading sequence. Signals from the same satellite corresponding to different simulated locations have different time differences of arrival (TDAs), determined by the simulated spatial distance from each simulated location to the satellite. Each positioning signal is a complete spreading signal cycle, with a cycle length denoted as T. The multiple mobile communication signals are wireless communication signals in different frequency bands, each occupying a different frequency range, and their frequency ranges do not overlap with those of the time-division multiplexing (TDM) combined signal.

[0073] In step 111 of this embodiment, based on the signal system of a real satellite navigation system, for a specific spatial point, navigation signals from multiple satellites that can theoretically be received at that point are simulated. The simulation process requires obtaining satellite ephemeris parameters and the precise coordinates of the simulated point, calculating the spatial distance from each satellite to the simulated point, and then determining the propagation delay of each satellite signal. Based on the propagation delay, the generated spread spectrum signal is subjected to corresponding delay processing to obtain the positioning signal for the simulated point.

[0074] For different simulated locations, the positioning signal generator generates corresponding positioning signals, thus obtaining multiple positioning signals. Each positioning signal follows the same signaling system, possessing the same center frequency and the same spreading sequence. Taking the BeiDou Navigation Satellite System as an example, the center frequency can be the B1 frequency point, and the spreading sequence is the pseudo-random noise code corresponding to each satellite. Although the signals from the same satellite corresponding to different simulated locations use the same spreading sequence, due to the different spatial locations of each simulated location, the spatial distance from the same satellite to each simulated location varies. Therefore, the signals from the same satellite corresponding to different simulated locations have different propagation delays, i.e., they have arrival time differences related to the spatial location differences of the simulated locations.

[0075] The arrival time difference is determined by the simulated spatial distance from the simulated point to the satellite. Specifically, for the i-th and j-th simulated points, the time delay difference between the arrival of the signal from the same satellite at the two points is... This time delay can be expressed as the difference in distance from two points to the satellite divided by the speed of light. This time delay difference is an important reference for subsequent delay compensation calculations at the receiving point. Each positioning signal is a complete spread spectrum signal cycle, with a cycle length denoted as T. This cycle contains M chips, and the chip rate is... These parameters provide the basic data for subsequent time slot allocation.

[0076] In an optional embodiment of the present invention, step 12, which involves performing time-division and combining processing on the multiple positioning signals based on the multiple positioning signals and preset positioning signal parameters to obtain a time-division and combined signal, may include:

[0077] Step 121: Obtain the preset positioning signal parameters;

[0078] Step 122: Determine the spread spectrum period of the positioning signal, the number of chips and the chip rate contained in one spread spectrum period, based on the preset positioning signal parameters.

[0079] Step 123: Determine the number of the multiple positioning signals based on the multiple positioning signals;

[0080] Step 124, according to: Determine the duration of the time slot division; among which Divide the time slot into durations. For the number of chips, For chip rate, The number of multiple positioning signals;

[0081] Step 125: Determine the time slot selection timing according to the time slot division duration. The time slot selection timing is the timing sequence of selecting each positioning signal in chronological order within one spread spectrum signal period.

[0082] Step 126: According to the time slot selection timing, each positioning signal is sequentially selected within one spread spectrum signal cycle, so that each positioning signal passes through the corresponding time slot, forming a time-division combined signal that is staggered in time.

[0083] In this embodiment, based on the signal structure of the positioning signal, the number of chips and chip rate within the spread spectrum signal period T are determined, the spread spectrum signal period T is taken as the preset signal period, and the time slot division parameters are determined; the spread spectrum signal period is divided into multiple time slots according to the time slot division parameters, and the time slot selection sequence is determined to select each positioning signal in chronological order within the preset signal period.

[0084] According to the timing sequence of the time slot selection, each positioning signal is selected sequentially within one spread spectrum signal cycle, and each positioning signal passes through the corresponding time slot to form a time-division multiplexing signal.

[0085] In step 121 of this embodiment, the preset positioning signal parameters are derived from the signal system definition of the adopted global satellite navigation system, mainly including the duration of the spread spectrum signal period, the chip rate of the spread spectrum code, and the number of chips contained in one spread spectrum signal period. Taking the BeiDou satellite navigation system as an example, the spread spectrum signal period of its B1 frequency point signal is 1ms, the chip rate is 2.046MHz, and one spread spectrum signal period contains 2046 chips.

[0086] In step 122, the spread spectrum period T of the positioning signal is determined according to the preset positioning signal parameters, as well as the number of chips contained in one spread spectrum period. and chip rate The spread spectrum signal period T is one complete spread spectrum code period, which is the time unit required for the positioning signal to transmit one data bit. Number of chips The total number of chips in the spreading code within this period, and the chip rate. This represents the number of chips transmitted per unit of time.

[0087] In steps 1, 2, and 3, the number of paths The configuration can be tailored to the number of different simulated locations that need to be covered, based on the positioning requirements of the indoor distribution system's coverage area. Generally, to achieve 3D positioning of a single location, signals from at least four satellites are required. The value of is usually not less than 4, but it can also be 5, 6 or larger integers depending on actual needs.

[0088] In step 124, according to Determine the duration of the time slot allocation;

[0089] in Divide the time slot into durations. For the number of chips, For chip rate, This refers to the number of multiple positioning signals. This allows for the even distribution of all chips within a complete spread spectrum period T to the multiple positioning signals, with each signal receiving a certain amount of chips within each spread spectrum period. The transmission time of each chip.

[0090] In step 125, the time slot selection timing is the sequence of selecting each positioning signal sequentially within a spread spectrum signal period T. Specifically, the spread spectrum signal period T is divided sequentially into the first time slot, the second time slot, and so on. There are 1 time slot, and the duration of each time slot is 1. , No. The first time slot corresponds to the gating of the first... The timing sequence for time slot selection repeats cyclically after the end of one spread spectrum signal cycle to form continuous time-division transmission of multiple signals.

[0091] In step 126, according to the time slot selection timing, each positioning signal is sequentially selected within one spread spectrum signal cycle. In the first time slot, the first positioning signal is selected and transmitted within that time slot; in the second time slot, the second positioning signal is selected and transmitted; and so on, until the... The first time slot is selected. The positioning signals pass through their respective time slots, forming a time-division multiplexing signal that is staggered in time. This time-division multiplexing signal contains all the positioning signals within one spread spectrum period. The positioning signal segments are arranged sequentially in time and occupy the same center frequency in the frequency domain, thus achieving the purpose of transmitting multiple positioning signals on the same frequency.

[0092] In an optional embodiment of the present invention, step 13, combining the time-division multiplexed signal with the multiplexed mobile communication signal to obtain a hybrid transmission signal, may include:

[0093] Step 131: Analyze the time-division multiplexing signal to determine the first frequency spectrum interval;

[0094] Step 132: Analyze the multiple mobile communication signals to determine the second spectrum interval, wherein the first spectrum interval and the second spectrum interval are independent of each other;

[0095] Step 133: The signal components in the first frequency range and the signal components in the second frequency range are superimposed in the frequency domain to obtain a hybrid transmission signal that simultaneously includes the time-division multiplexing signal and the multi-channel mobile communication signal.

[0096] In this embodiment, the time-division combined signal is fed into the first input terminal of the combiner, and the multiple mobile communication signals are fed into the second input terminal of the combiner. The combiner superimposes the signal components in the first frequency range of the time-division combined signal and the signal components in the second frequency range of the multiple mobile communication signals in the frequency domain to obtain a hybrid transmission signal that simultaneously contains the time-division combined signal and the multiple mobile communication signals.

[0097] In step 131 of this embodiment, the time-division combined signal is formed by time-division gating multiple positioning signals. Each positioning signal has the same center frequency f0, therefore the center frequency of the time-division combined signal is also f0. The time-division combined signal occupies a finite bandwidth in the frequency domain with f0 as its center frequency. This bandwidth is determined by the chip rate of the spreading code. According to the power spectrum characteristics of the spreading signal, the main energy of the signal is concentrated in the bandwidth range on both sides of the center frequency; this bandwidth range is the first spectral range.

[0098] In step 132, multiple mobile communication signals refer to wireless communication signals of different standards carried in the indoor distributed antenna system (DAS) system. These signals may include various types of communication signals such as GSM signals, Code Division Multiple Access (CDMA) signals, Wideband CDMA signals, and Long Term Evolution (LTE) signals. Each mobile communication signal operates at a different carrier frequency and has its own independent spectrum range, which do not overlap with each other.

[0099] The second spectrum interval is a set of spectrum intervals occupied by each of the multiple mobile communication signals. Each sub-interval within this set is independent of the others, as well as with the first spectrum interval, and there is no spectral overlap. Taking the GSM 900MHz signal and the LTE 2500MHz signal as examples, the former occupies a frequency band around 900MHz, and the latter occupies a frequency band around 2500MHz. Both maintain sufficient frequency spacing from the first spectrum interval where the time-division multiplexed signal is located, allowing them to be separated at the receiving end through filtering.

[0100] In step 133, the signal components within the first spectral interval and the signal components within the second spectral interval are superimposed in the frequency domain. This superposition process is achieved through a combiner, which linearly adds the time-division combined signal from the first input and the multiplexed mobile communication signal from the second input in the frequency domain. Since the first and second spectral intervals are independent of each other, the two signals do not interfere with each other in the frequency domain. The resulting hybrid transmission signal exhibits a composite distribution of multiple independent spectral intervals in the frequency domain. This hybrid transmission signal simultaneously contains all the information of both the time-division combined signal and the multiplexed mobile communication signal, and each signal component retains its original spectral characteristics in the frequency domain.

[0101] In an optional embodiment of the present invention, step 14, transmitting the hybrid transmission signal to at least one receiving point of the indoor distribution system, may include:

[0102] The mixed transmission signal is transmitted through the feeder cable transmission link of the indoor distribution system to at least one receiving point. The receiving point is a spatial location within the coverage area of ​​the indoor distribution system that requires location services.

[0103] In an optional embodiment of the present invention, step 15, separating the mixed transmission signal at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals, may include:

[0104] Step 151: Perform power division processing on the hybrid transmission signal to obtain a first transmission signal and a second transmission signal;

[0105] Step 152: Perform bandpass filtering on the first transmission signal to obtain the extracted time-division combined signal;

[0106] Step 153: According to the time slot selection timing, perform time-division separation processing on the extracted time-division combined signal, and select and output the signal segments in each time slot to obtain multi-channel separation positioning signals;

[0107] Step 154: Filter the second transmission signal to obtain multiple mobile communication signals.

[0108] In this embodiment, the mixed transmission signal is bandpass filtered to remove signal components with different spectra from the time-division combined signal, resulting in the extracted time-division combined signal. The time slot selection timing sequence synchronized with the transmitting end is acquired, and the extracted time-division combined signal is time-division separated according to this timing sequence, selecting and outputting the signal segments within each time slot to obtain a multi-path separation positioning signal.

[0109] In step 151 of this embodiment, power division processing is implemented through a power divider, which is a microwave device that distributes the energy of one input signal to multiple output ports in a certain proportion. After the mixed transmission signal is fed into the input of the power divider, the power divider splits the signal into two outputs: the first output is the first transmission signal, and the second output is the second transmission signal. The first and second transmission signals are identical in signal composition to the input mixed transmission signal, both containing both time-division multiplexing (TDM) signal components and multiple mobile communication signal components, only with correspondingly reduced signal power according to the distribution ratio. The function of power division processing is to duplicate the mixed transmission signal into two paths so that the positioning signal and mobile communication signal can be extracted separately subsequently. The two processing processes are independent of each other and do not affect each other.

[0110] In step 152 of this embodiment, the first transmission signal simultaneously includes a time-division multiplexing signal and a multiplex mobile communication signal in the frequency domain. The time-division multiplexing signal occupies a first frequency range centered on the center frequency f0, and the multiplex mobile communication signal occupies a second frequency range that is independent of the first frequency range.

[0111] The bandpass filtering process employs a bandpass filter with a center frequency of f0 and a passband bandwidth that matches the bandwidth of the time-division combined signal. This bandpass filter covers the first spectral interval, exhibiting low attenuation characteristics for signal components within this interval, allowing them to pass smoothly. Conversely, it exhibits high suppression characteristics for multiple mobile communication signal components located outside the passband in the second spectral interval, effectively filtering them out. After bandpass filtering, a clean time-division combined signal is extracted from the mixed transmission signal. This signal retains the original structure of the location signal segments arranged in a time-sequential manner in the time domain, with each signal segment temporally separated, thus providing the conditions for subsequent time-division separation processing.

[0112] In step 153, the time slot gating timing is synchronized with the timing used by the transmitting end during time-division gating, and this synchronization is uniformly coordinated by the switch controller. Time-division separation processing is implemented through a receiving end multiplexer with the same structure as the transmitting end multiplexer. Within one spread spectrum signal period T, the receiving end multiplexer sequentially switches the gating channels according to the time slot gating timing. In the first time slot, the multiplexer connects to the first output channel, selecting and outputting the first positioning signal segment within the first time slot; in the second time slot, the multiplexer connects to the second output channel, selecting and outputting the second positioning signal segment within the second time slot; and so on, until the nth positioning signal segment is selected and output in the nth time slot. Since the order and duration of each time slot within each spread spectrum signal period are consistent with those of the transmitting end, each positioning signal segment is accurately assigned to its corresponding output channel, thereby restoring the time-division combined signal to an n-channel separated signal. Each separated signal exhibits a discontinuous characteristic in the time domain, with signal segments existing only within its corresponding time slot. However, since each spread spectrum signal period T is only on the order of 1ms, this discontinuity has a limited impact on subsequent signal reception and demodulation, and the receiving terminal can still complete signal acquisition and tracking based on partial chip information.

[0113] In step 154, the second transmitted signal also simultaneously contains time-division multiplexing (TDM) signals and multiple mobile communication signals in the frequency domain. Filtering can employ one or more bandpass filters, each with its passband corresponding to the respective frequency range occupied by the multiple mobile communication signals. These filters remove TDM components and other non-target frequency band signal components, extracting each mobile communication signal. Since the multiple mobile communication signals operate at different carrier frequencies and their frequency bands do not overlap, each signal can be extracted separately using its corresponding bandpass filter. The extracted multiple mobile communication signals retain their original modulation schemes and information content and can be broadcast separately through corresponding indoor distributed antennas for normal signal reception and demodulation by the communication terminal.

[0114] Through the above processing, the mixed transmission signal is separated into two types of signals at the receiving point: a multi-channel positioning signal and a multi-channel mobile communication signal, which are used for positioning services and communication services respectively, without interfering with each other.

[0115] In an optional embodiment of the present invention, step 16, performing time delay compensation processing on the multi-channel separated signals to obtain delay-compensated multi-channel signals, may include:

[0116] Step 161: Obtain the spatial distance difference between the current receiving point and the analog points corresponding to each positioning signal;

[0117] Step 162: Obtain the elevation angle of the satellite corresponding to each positioning signal at the current receiving point;

[0118] Step 163, according to: Determine the time delay compensation amount corresponding to each separated signal; among which, For the first The time delay compensation amount corresponding to the path separation signal. For the first The spatial distance difference between the analog point corresponding to the road positioning signal and the current receiving point. For the first The road positioning signal corresponds to the elevation angle of the satellite at the current receiving point. The speed of light;

[0119] Step 164: Apply a time delay to the multi-channel separation signal according to the time delay compensation amount to obtain the delay-compensated multi-channel positioning signal.

[0120] In this embodiment, the spatial distance difference between the current receiving point and the simulated points corresponding to each positioning signal is obtained, as well as the elevation angle of the satellite corresponding to each positioning signal at the current receiving point. Based on the above parameters, the time delay compensation amount corresponding to each separated signal is determined; based on the time delay compensation amount corresponding to each separated signal, a corresponding time delay is applied to each separated signal to obtain the multi-channel positioning signal after delay compensation.

[0121] In step 161 of this embodiment, during the deployment of the indoor distribution system, each positioning signal is generated by a GNSS signal generator for different simulated locations. Each simulated location corresponds to a known spatial position, which can be denoted as P. i Where i is the serial number of the simulated point. The current receiving point is the spatial location within the coverage area of ​​the indoor distribution system that needs to provide positioning services, denoted as P. m For the k-th positioning signal, its corresponding analog point is P. k Current receiving point P m With the simulated point P k Spatial distance difference between This spatial distance difference can be expressed as the Euclidean distance between two points. It can be obtained by pre-measuring each point in the indoor distribution system, or calculated based on the coordinates of the system's design drawings. The spatial distance difference between different receiving points and the same simulated point varies, as does the spatial distance difference between the same receiving point and different simulated points. These differences form the basis for subsequent time delay compensation calculations.

[0122] In step 162, each positioning signal contains signal components from multiple satellites. For each satellite in the k-th positioning signal, its position at the current receiving point P... m Angle of elevation at the location The elevation angle can be calculated based on satellite ephemeris data and the coordinates of the receiving point. The satellite elevation angle is defined as the angle between a line pointing from the receiving point to the satellite and the local horizontal plane. The elevation angle is 90° when the satellite is directly above the receiving point and 0° when it is on the horizon. Different satellites have different elevation angles at the same receiving point, and the same satellite also has different elevation angles at different receiving points. Therefore, it is necessary to obtain the corresponding satellite elevation angle value for each positioning signal and the specific conditions of the current receiving point.

[0123] In step 163, according to: Determine the time delay compensation amount corresponding to each separated signal, where, For the first The time delay compensation amount corresponding to the path separation signal. For the first The spatial distance difference between the analog point corresponding to the road positioning signal and the current receiving point. For the first The road positioning signal corresponds to the elevation angle of the satellite at the current receiving point. The speed of light is used as the equation. This equation projects the spatial distance difference between the simulated and received points onto the propagation direction of the satellite signal, obtaining the equivalent path difference along the satellite's line-of-sight. Dividing this path difference by the speed of light yields the corresponding propagation delay difference. When the received and simulated points coincide, the spatial distance difference is zero, and the delay compensation is also zero, meaning no additional delay compensation is needed. When the received and simulated points do not coincide, this delay compensation accurately compensates for the signal propagation delay differences introduced by changes in point location.

[0124] In step 164, a time delay is applied to the multiple separated signals according to the time delay compensation amount corresponding to each separated signal, resulting in a multi-channel signal with time delay compensation. The time delay is applied using configurable delay units, with each delay unit corresponding to one separated signal, and the delay value of the delay unit set to the time delay compensation amount corresponding to that separated signal. When the k-th separated signal passes through the corresponding delay unit, the delay unit performs a time delay on the entire signal, keeping the waveform and spectral characteristics unchanged, only shifting it backward on the time axis. The k-th signal after delay compensation is equivalent to the signal from the k-th satellite that should theoretically be received at the current receiving point. After all n separated signals are processed by their respective delay units, multiple delay-compensated signals are obtained, and the relative arrival time difference between each signal matches the actual spatial location of the current receiving point.

[0125] In an optional embodiment of the present invention, step 17, which involves merging the delayed-compensated multiple signals to obtain an output positioning signal and broadcasting it, may include:

[0126] Step 171: Linearly add the delay-compensated multi-channel positioning signals in the time domain to obtain a complete output positioning signal. The output positioning signal contains all satellite signal components required for the current receiving point. The delay-compensated multi-channel positioning signal corresponds to the signal components of different satellites.

[0127] Step 172: The output positioning signal is broadcast through the positioning antenna so that the terminal device at the current receiving point can perform positioning calculation.

[0128] In this embodiment, delay-compensated multi-channel positioning signals are fed into multiple inputs of a combiner, with each signal corresponding to a signal component from a different satellite. The combiner linearly adds the multiple signals in the time domain to synthesize a single composite signal waveform. In this composite signal waveform, each satellite signal component retains its respective spreading code characteristics and the delay-compensated time difference of arrival. This composite signal waveform serves as the output positioning signal, broadcast via a GNSS antenna for positioning calculation by the terminal equipment at the current receiving point.

[0129] In step 171 of this embodiment, the multiple separated signals have undergone time delay compensation processing according to their respective time delay compensation amounts. The relative positions of each signal on the time axis have been adjusted to match the actual spatial position of the current receiving point. Each signal after delay compensation corresponds to the signal component of a satellite at the current receiving point, and each signal maintains the same center frequency and the spreading sequence corresponding to its respective satellite. Since each signal has undergone time-division gating processing at the transmitting end, each signal exhibits discontinuous characteristics in the time domain, with signal segments existing only within its corresponding time slot. However, the spreading code information and arrival time information carried by these signal segments are complete and sufficient to support the receiving terminal in subsequent signal processing and positioning calculations. The multiple signals after delay compensation accurately reflect the geometric distance relationship between the current receiving point and each satellite in terms of time relationship.

[0130] This linear addition process is implemented using a combiner, which has multiple inputs and one output. The delayed-compensated signals from each input are fed into their respective inputs. The combiner sums the instantaneous amplitude values ​​of each input signal in the time domain, and the voltage waveform of the output signal is the sum of the instantaneous values ​​of the voltage waveforms of each input signal at the same moment. Since the arrival time differences between the signals are matched to the current receiving point after delay compensation, the combined output positioning signal is structurally equivalent to the natural superposition of navigation signals actually received from multiple satellites at the current receiving point. This output positioning signal contains all the satellite signal components required for the current receiving point, and the spreading code characteristics, carrier phase relationships, and relative arrival time differences of each satellite signal component remain correct, enabling the terminal equipment to perform signal acquisition, tracking, and calculation according to the conventional satellite navigation and positioning process.

[0131] In step 172, the antenna is a GNSS antenna located at the current receiving point. Its operating frequency band covers the center frequency of the output positioning signal, enabling it to radiate the output positioning signal into the surrounding space in the form of electromagnetic waves. The terminal device at the current receiving point receives the output positioning signal broadcast by the antenna through its built-in GNSS receiving module. The terminal device sequentially performs down-conversion, analog-to-digital conversion, acquisition, tracking, and navigation message demodulation on the received signal, measures the pseudorange of each satellite signal, and establishes a set of positioning equations using the satellite orbit parameters parsed from the navigation message. Finally, it calculates the three-dimensional position coordinates of the terminal device itself. Since the output positioning signal has undergone precise time delay compensation processing before transmission, the position coordinates calculated by the terminal device will match the actual spatial position of the current receiving point, thus achieving accurate positioning of that point. At the same time, the mobile communication signal at the original indoor antenna location is broadcast as usual after the positioning signal component is filtered out by another bandpass filter. The communication signal and the positioning signal coexist at the receiving point without interfering with each other.

[0132] The multi-point positioning signal transmission method for indoor distribution systems provided in this invention is based on, for example, Figure 2 The GNSS analog positioning system and indoor distribution system shown herein include the following specific transmission process:

[0133] Step 1: Generate multiple analog positioning signals.

[0134] pass Figure 2The GNSS satellite 1, GNSS satellite 2, GNSS satellite 3 to GNSS satellite n signal generators generate analog signals GS1, GS2, GS3, ..., GSn corresponding to different navigation satellites. All signals use the same center frequency f0, such as the BeiDou B1 band or the GPS L1 band. In the BeiDou / GPS signal, 1 bit of information is transmitted every 1ms. This 1ms duration contains 1023 or 2046 spread spectrum chips. Even if only a portion of the chips are transmitted, the receiver can still complete the signal demodulation.

[0135] Step 2: Calculate the time slot division duration and perform time-division processing.

[0136] Based on the total number of indoor positioning points n, the transmission duration of a single time slot is calculated to be 1 / nms. Figure 2 The switching controller generates periodic gating control signals based on the transmission duration of each single time slot, controlling the multiplexer S to select only one GNSS signal for transmission in each time slot. The transmission segments of multiple GNSS signals at the same frequency are staggered in time and merged to form a time-division multiplexed signal.

[0137] Step 3: Combine the time-division multiplexed signal with the multi-channel mobile communication signal of the indoor distribution system.

[0138] The generated time-division multiplexing signal is input into the POI combining device of the indoor distribution system and combined with the 3G / 4G / 5G communication signal to obtain a mixed transmission signal containing communication and positioning signals. If the POI combining device does not have an access port that matches the frequency band of the time-division multiplexing signal, an external combiner is connected to the output of the POI combining device to superimpose the time-division multiplexing signal with the communication signal output by the POI.

[0139] Step 4: Transmit the hybrid transmission signal through the indoor distribution system feeder cable (i.e., the transmission link). The hybrid transmission signal is transmitted through... Figure 2 Indoor feeder cables 1, 2, ..., m transmit signals to various indoor positioning points. The combined signal is represented as (Tf1 + Tf2 + Tf3 + ... + Tfn), and is transmitted to GNSS antennas 1 to GNSS antenna m via feeder cables 1 to m for broadcasting. Multiple 3G / 4G / 5G communication signals and time-division multiplexing signals of different frequency bands are simultaneously transmitted in the indoor feeder cables. The spectra of each signal do not overlap, and there is no mutual interference during transmission.

[0140] Step 5: Separate the mixed transmission signals.

[0141] Connect a power divider to the end of each indoor feeder cable, such as... Figure 2As shown, the first indoor distribution feeder cable is connected to power divider 1 at its end, and the m-th indoor distribution feeder cable is connected to power divider m at its end; the power divider splits the mixed transmission signal into two paths. The first path signal input... Figure 2 Bandpass filters such as filters 1-2 and m-2 in the system filter out composite positioning signals, retaining 3G / 4G / 5G communication signals, which are then broadcast through the original indoor distributed antennas (DAS) 1, ..., m, etc. The second signal input is a dedicated GNSS bandpass filter, such as... Figure 2 The filters 1, ..., m in the filter array filter out all 3G / 4G / 5G communication signals and then extract the time-separation and combination signals.

[0142] Step 6: Demultiplex and demultiplex the time-division multiplexing signal.

[0143] The switch controller generates a time-slot selection timing control signal, controlling multiplexers 1, ..., m to select each time slot sequentially according to the time-slot selection sequence. Within each time slot, multiplexers 1, ..., m only allow the corresponding positioning signal segment to pass through, separating the temporally interleaved composite positioning signal into multiple independent signal segments. All time-slot segments corresponding to the same source signal are then concatenated in chronological order to obtain the multi-channel separated signal.

[0144] Step 7: Calculate the delay compensation for each positioning signal.

[0145] Obtain the elevation angle parameters of each navigation satellite relative to the target positioning point. Based on the linear distance between the signal simulation origin and the target positioning point, and the propagation speed of electromagnetic waves in free space, calculate the delay compensation amount. The calculation formula is as follows: ;

[0146] in, For the first The time delay compensation amount corresponding to the path separation signal. For the first The spatial distance difference between the analog point corresponding to the road positioning signal and the current receiving point. For the first The road positioning signal corresponds to the elevation angle of the satellite at the current receiving point. It is the speed of light.

[0147] Step 8: Perform delay compensation processing on the restored multi-channel separated signals. Configure the calculated delay compensation amounts for each channel to... Figure 2In the delay units 1-1, 1-2, 1-3, ..., 1-n, ..., m-1, m-2, m-3, ..., mn, each restored GNSS positioning signal is input to its corresponding delay unit, and a precise time delay is applied. After delay compensation, the time parameters of each signal are consistent with the actual time parameters of the real satellite signals received by the target positioning point.

[0148] Step 9: Combine and broadcast the compensated signals. Input the multi-channel GNSS positioning signals after delay compensation. Figure 2 The combiner 1, ..., combiner m, etc., are linearly superimposed, and each signal maintains its amplitude, phase, and time-domain characteristics during the superposition process. The combined signal is broadcast through a dedicated GNSS antenna such as GNSS antenna m, for indoor terminal equipment to receive and perform positioning calculations. The original indoor distributed antenna simultaneously broadcasts communication signals, and the two do not interfere with each other.

[0149] The method of the present invention combines the same-frequency positioning signals of multiple GNSS simulators located at different indoor locations and transmits them to various receiving points indoors. At the receiving points, frequency filtering and time-division delay compensation are applied to enable the transmission of multiple simulated GNSS signals from different locations within the indoor distributed antenna system. These signals are then separated at the antenna at the end of the system. This solves the problem that indoor distributed antenna systems cannot directly transmit simulated GNSS signals from multiple locations.

[0150] like Figure 3 As shown, this embodiment of the invention also provides a multi-point positioning signal transmission system 30 for an indoor distribution system, comprising:

[0151] The positioning signal generation module 31 includes multiple analog positioning signal generation units, which are used to generate multiple analog point transmissions at different indoor locations. Each positioning signal has the same center frequency and spread spectrum sequence, and has different signal arrival times.

[0152] A first time-division multiplexing module 32 connected to the positioning signal generation module is used to perform time-division multiplexing processing on the multiple positioning signals according to the multiple positioning signals and preset positioning signal parameters to obtain a time-division multiplexing signal.

[0153] The first combining module 33 has a first input terminal connected to the first time division multiplexing module 32, and a second input terminal connected to multiple mobile communication signals. The first combining module 33 is used to combine the time division multiplexing signal and the multiple mobile communication signals to obtain a hybrid transmission signal.

[0154] A transmission link 34 connected to the first combining module 33 is used to transmit the mixed transmission signal to at least one receiving point of the indoor distribution system.

[0155] A signal separation module 35 coupled to the transmission link 34 is used to separate the mixed transmission signal at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals.

[0156] A delay compensation module 36 connected to the signal separation module 35 includes a plurality of delay compensation units, which are used to perform time delay compensation processing on the multi-channel separated positioning signals to obtain delay-compensated multi-channel positioning signals.

[0157] The second combining module 37, which is connected to the delay compensation module 36, is used to combine the delay-compensated multi-channel positioning signals to obtain an output positioning signal.

[0158] The positioning antenna 38 is connected to the second combining module 37 and is used to transmit the output positioning signal.

[0159] In this embodiment, the positioning signal generation module 31 includes multiple analog positioning signal generation units, each generating a positioning signal for a specific analog point. The analog positioning signal generation unit can be a GNSS signal generator, which calculates the spatial distance from each satellite to the analog point based on satellite ephemeris parameters and the spatial coordinates of the analog point, thereby determining the propagation delay of each satellite signal and generating a positioning signal containing multiple satellite signal components. The positioning signals corresponding to different analog points all follow the same signal system, having the same center frequency f0 and the same spreading sequence. However, due to the different spatial locations of the analog points, the distance from the same satellite to each analog point varies. Therefore, the signals from the same satellite corresponding to different analog points have an arrival time difference related to the spatial location difference of the analog points.

[0160] The first time-division multiplexing module 32 is connected to the positioning signal generation module 31 and is used to perform time-division processing based on multiple positioning signals and preset positioning signal parameters. The first time-division multiplexing module 32 acquires the number of multiple positioning signals, as well as the number of chips and chip rate within the spread spectrum signal period. The first time-division multiplexing module 32 divides the spread spectrum signal period T into n time slots and determines the time slot selection sequence to sequentially select each positioning signal in chronological order within one spread spectrum signal period. Within one spread spectrum signal period, the first time-division multiplexing module 32 selects the first positioning signal in the first time slot, selects the second positioning signal in the second time slot, and so on, with each positioning signal passing through its corresponding time slot, forming a time-division combined signal that is staggered in time. This time-division combined signal occupies the first spectral interval centered at f0 in the frequency domain.

[0161] The first input terminal of the first combining module 33 is connected to the first time-division multiplexing module 32 to receive the time-division multiplexing signal. The second input terminal of the first combining module 33 receives multiple mobile communication signals, which occupy a second frequency range independent of the first frequency range. The first combining module 33 superimposes the signal components in the first frequency range and the signal components in the second frequency range in the frequency domain to obtain a hybrid transmission signal. This hybrid transmission signal presents a composite distribution of multiple independent frequency ranges in the frequency domain, simultaneously containing all the information of the time-division multiplexing signal and the multiple mobile communication signals. The first combining module 33 can be a POI device or an external combiner.

[0162] Transmission link 34 is connected to the output of the first combiner module 33 and is used to transmit the mixed transmission signal to at least one receiving point. Transmission link 34 is the feeder cable of the indoor distribution system and can simultaneously carry multiple signals in different frequency ranges, delivering the mixed transmission signal from the combiner point to various spatial locations requiring location services within the coverage area of ​​the indoor distribution system.

[0163] The signal separation module 35 is coupled to the transmission link 34 and is used to extract and separate the mixed transmission signal. The signal separation module 35 first filters the mixed transmission signal through a bandpass filter with a center frequency of f0, filtering out the multiple mobile communication signal components within the second frequency range and extracting the time-division multiplexing signal. Subsequently, the signal separation module 35, through a second time-division multiplexing module synchronized with the first time-division multiplexing module 32, performs time-division separation processing on the extracted time-division multiplexing signal according to the same time slot gating sequence as the transmitting end, selecting and outputting the signal segments within each time slot to obtain the multiplexed signal.

[0164] The delay compensation module 36 is connected to the signal separation module 35 and includes multiple delay compensation units, each corresponding to one separated signal. For the k-th separated signal, the delay compensation unit obtains the spatial distance difference between the current receiving point and the analog point corresponding to that positioning signal, as well as the elevation angle of the satellite corresponding to that positioning signal at the current receiving point, to calculate the delay compensation amount. The delay compensation unit applies a delay to the separated signal according to the delay compensation amount, obtaining the delay-compensated signal. After processing by their respective delay compensation units, the relative arrival time differences between each separated signal match the actual spatial position of the current receiving point.

[0165] The second combining module 37 is connected to the delay compensation module 36 and has multiple input terminals and one output terminal. The delayed-compensated signals from each input are fed into their respective input terminals of the second combining module 37. The second combining module 37 linearly adds the instantaneous amplitude values ​​of each input signal in the time domain, and the voltage waveform of the output signal is the sum of the instantaneous values ​​of the voltage waveforms of each input signal at the same moment, resulting in a complete output positioning signal. This output positioning signal contains all the satellite signal components required for the current receiving point, and the spreading code characteristics and relative arrival time relationships of each signal component are matched to the actual position of the current receiving point.

[0166] The positioning antenna 38 is connected to the output terminal of the second combining module 37 and is used to radiate the output positioning signal into the surrounding space in the form of electromagnetic waves. The positioning antenna 38 is a GNSS antenna, and its operating frequency band covers the center frequency of the output positioning signal. After receiving the output positioning signal broadcast by this antenna, the terminal equipment at the current receiving point can perform signal acquisition, tracking, and positioning calculation to obtain the position coordinates that match the actual spatial position of the current receiving point.

[0167] This invention proposes the above-mentioned technical solution, which generates multiple co-frequency positioning signals for different simulated locations through a positioning signal generation module. A first time-division multiplexing module divides the time slots within a spreading cycle and sequentially selects each signal to form a time-division combined signal. The first combining module merges the time-division combined signal with multiple mobile communication signals in the frequency domain and transmits them via a shared cable through a transmission link. At the receiving end, a signal separation module recovers each separated signal in a synchronous time-division manner. A delay compensation module then applies independent time delay compensation to each signal based on the spatial distance difference between the receiving point and the simulated point and the satellite elevation angle. Finally, the signals are combined by a second combining module and broadcast through an antenna. This achieves the transmission of multiple co-frequency positioning signals on a single frequency point, saving spectrum resources and simplifying the system circuit structure. Simultaneously, through precise time delay compensation for each signal at the end point, different receiving points can obtain realistic positioning signals that match their actual locations, meeting the need for simultaneous independent positioning in multiple indoor areas. Furthermore, the positioning signals and mobile communication signals coexist compatiblely within the same indoor distribution system without mutual interference.

[0168] In an optional embodiment of the present invention, the signal separation module includes:

[0169] A first bandpass filter, the input of which is coupled to the transmission link;

[0170] A second time-division multiplexing module is connected to the output of the first bandpass filter, and the input of the second time-division multiplexing module is connected to the output of the bandpass filter.

[0171] In this embodiment, the input of the first bandpass filter is coupled to the transmission link and is used to extract the time-division combined signal from the mixed transmission signal. The mixed transmission signal simultaneously contains the time-division combined signal and multiple mobile communication signals in the frequency domain. The time-division combined signal occupies a first spectral interval centered at a center frequency f0, while the multiple mobile communication signals occupy a second spectral interval independent of the first spectral interval. The first bandpass filter is a frequency-selective device with its passband center frequency set to f0, and its passband bandwidth matching the bandwidth of the time-division combined signal. The bandwidth of the time-division combined signal is determined by the chip rate of the spreading code, and its main lobe width is twice the chip rate. Therefore, the passband width of the first bandpass filter should at least cover this main lobe width range to ensure that the main energy of the time-division combined signal can pass through, while effectively suppressing signal components outside the passband. When the mixed transmission signal passes through the first bandpass filter, the time-division combined signal components within the first spectral interval experience minimal attenuation and can pass smoothly; while the multiple mobile communication signal components within the second spectral interval are filtered out due to greater attenuation because their frequency position is far from the passband range. After processing by the first bandpass filter, the output signal is a time-division multiplexing signal extracted from the mixed transmission signal. This signal still retains the structural characteristics of the positioning signal segments being arranged in a time-sequential manner in the time domain.

[0172] The input of the second time-division multiplexing module is connected to the output of the first bandpass filter. It is used to perform time-division separation processing on the extracted time-division combined signal to obtain a multi-channel separated signal. The second time-division multiplexing module includes a multiplexer with one input and n outputs, where n is the same as the number of input channels of the transmitting end's first time-division multiplexing module. The switching action of the second time-division multiplexing module is uniformly controlled by a switch controller, ensuring that its gating timing is synchronized with the time slot gating timing of the transmitting end's first time-division multiplexing module. Within one spread spectrum signal cycle, the second time-division multiplexing module switches the gating channels according to the same time slot division method as the transmitting end: in the first time slot, the multiplexer connects to the first output channel; in the second time slot, the multiplexer connects to the second output channel; and so on, until the nth time slot connects to the nth output channel. After one spread spectrum signal cycle ends, the switch restarts its cycle from the first output channel. In this way, signal segments within each time slot of the extracted time-division combined signal are selected and routed to their corresponding output channels, thus separating the time-division combined signal into n independent discrete signals. Each discrete signal exhibits a discontinuous characteristic in the time domain, with signal segments existing only within its corresponding time slot. Since the spread spectrum signal period is only on the order of 1 ms, each signal receives only T / n of the transmission time within one spread spectrum period, resulting in some signal energy loss. However, the receiving terminal can still utilize some chip information to complete signal acquisition and tracking; therefore, this discontinuity does not affect the final positioning function.

[0173] In an optional embodiment of the present invention, the multi-point positioning signal transmission system of the indoor distribution system further includes:

[0174] A second bandpass filter, the input of which is coupled to the transmission link, is used to extract the target mobile communication signal from the mixed transmission signal;

[0175] An indoor communication antenna is connected to the output of the second bandpass filter, and the indoor communication antenna is used to transmit the target mobile communication signal.

[0176] In this embodiment, the input of the second bandpass filter is coupled to the transmission link and is used to extract the target mobile communication signal from the mixed transmission signal. The mixed transmission signal simultaneously contains a time-division multiplexing (TDM) signal and multiple mobile communication signals in the frequency domain. The TDM signal occupies a first spectral interval centered at frequency f0, while the multiple mobile communication signals occupy a second spectral interval independent of the first. The second bandpass filter and the first bandpass filter are complementary in the frequency domain: the first bandpass filter, with f0 as its center frequency, covers the first spectral interval and is used to extract the TDM signal; the second bandpass filter's passband covers the target frequency band in the second spectral interval and is used to extract the mobile communication signal of the desired frequency band. The specific passband frequency and bandwidth of the second bandpass filter are determined based on the carrier frequency and signal standard of the target mobile communication signal to be extracted. For example, when extracting a LTE 2500MHz signal, the center frequency of the second bandpass filter is set to 2500MHz, and its bandwidth matches the bandwidth of the LTE signal. The second bandpass filter exhibits low attenuation for target mobile communication signals within its passband, allowing them to pass smoothly. However, it exhibits high suppression for other frequency components outside the passband, including time-division multiplexing signals within the first frequency range and other frequency band communication signals within the second frequency range, effectively filtering them out. After processing by the second bandpass filter, a clean target mobile communication signal is extracted from the mixed transmission signal. This signal retains its original modulation scheme and information content, allowing the communication terminal to perform normal signal reception and demodulation.

[0177] The indoor communication antenna is connected to the output of the second bandpass filter and is used to broadcast the target mobile communication signal. The indoor communication antenna is the same antenna deployed at the receiving point in the original indoor distributed antenna system. Its operating frequency band covers the carrier frequency range of the target mobile communication signal, enabling it to radiate the target mobile communication signal extracted by the second bandpass filter into the surrounding space in the form of electromagnetic waves. The indoor communication antenna and the positioning antenna 38 can be deployed adjacent to each other in space, but they operate in different frequency bands, broadcasting mobile communication signals and positioning signals respectively. The two signals do not overlap in the frequency domain and do not interfere with each other in the spatial domain. The communication terminal at the current receiving point receives the target mobile communication signal broadcast by the indoor communication antenna through its own receiving antenna, thus enabling normal communication services. Through the aforementioned configuration of the second bandpass filter and the indoor communication antenna, the indoor distributed antenna system provides positioning signals to the current receiving point without affecting the original mobile communication signal coverage, achieving a compatible coexistence scheme where positioning signals and mobile communication signals are transmitted together in the same indoor distributed antenna system and broadcast separately after separation at the receiving end.

[0178] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for transmitting multi-point positioning signals in an indoor distribution system, characterized in that, include: The system acquires multiple mobile communication signals and multiple positioning signals transmitted from multiple analog points located in different indoor locations. Each positioning signal has the same center frequency and spreading sequence, but different signal arrival times. Based on the multi-channel positioning signals and preset positioning signal parameters, the multi-channel positioning signals are subjected to time-division and merging processing to obtain time-division and merging signals; The time-division multiplexed signal and the multiplexed mobile communication signal are combined to obtain a hybrid transmission signal; The hybrid transmission signal is transmitted to at least one receiving point of the indoor distribution system; The mixed transmission signal is separated at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals. The multi-channel separated positioning signals are subjected to time delay compensation processing to obtain the delay-compensated multi-channel positioning signals; The delayed-compensated multi-channel positioning signals are combined to obtain an output positioning signal, which is then transmitted through a positioning antenna. The multi-channel mobile communication signals are also transmitted through an indoor communication antenna. Specifically, based on the multiple positioning signals and preset positioning signal parameters, the multiple positioning signals are subjected to time-division and combining processing to obtain a time-division and combining signal, including: Obtain preset positioning signal parameters; Based on the preset positioning signal parameters, the spread spectrum signal period of the positioning signal, as well as the number of chips and chip rate contained in one spread spectrum signal period, are determined. Based on the multi-channel positioning signals, determine the number of channels of the multi-channel positioning signals; according to: Determine the duration of the time slot division; among which Divide the time slot into durations. For the number of chips, For chip rate, The number of multiple positioning signals; Based on the time slot division duration, the time slot selection timing is determined, which is the timing sequence of sequentially selecting each positioning signal in chronological order within one spread spectrum signal period; According to the time slot selection timing, each positioning signal is sequentially selected within one spread spectrum signal cycle, so that each positioning signal passes through the corresponding time slot, forming a time-division and combining signal that is staggered in time.

2. The multi-point positioning signal transmission method for an indoor distribution system according to claim 1, characterized in that, Acquire multiple positioning signals transmitted from simulated points located at different indoor locations, including: By using a positioning signal generator to simulate signals for different simulated locations, multiple positioning signals corresponding to different simulated locations are obtained. The multiple positioning signals have the same center frequency and spread spectrum sequence, and the signals of the same satellite corresponding to different simulated locations have a time difference of arrival related to the spatial location difference of the simulated locations.

3. The multi-point positioning signal transmission method for an indoor distribution system according to claim 1, characterized in that, The time-division multiplexing signal and the multiplexed mobile communication signal are combined to obtain a hybrid transmission signal, including: The time-division combined signal is analyzed to determine the first frequency spectrum interval; The multiple mobile communication signals are analyzed to determine a second spectrum interval, wherein the first spectrum interval and the second spectrum interval are independent of each other; The signal components in the first frequency range and the signal components in the second frequency range are superimposed in the frequency domain to obtain a hybrid transmission signal that simultaneously contains the time-division multiplexing signal and the multi-channel mobile communication signal.

4. The multi-point positioning signal transmission method for an indoor distribution system according to claim 1, characterized in that, The mixed transmission signal is separated at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals, including: The hybrid transmission signal is subjected to power division processing to obtain a first transmission signal and a second transmission signal; The first transmitted signal is subjected to bandpass filtering to obtain the extracted time-division and combining signal; Based on the time slot selection timing sequence, the extracted time-division combined signal is subjected to time-division separation processing, and the signal segments in each time slot are selected and output separately to obtain multi-channel separation positioning signals. The second transmitted signal is filtered to obtain multiple mobile communication signals.

5. The multi-point positioning signal transmission method for an indoor distribution system according to claim 1, characterized in that, The multi-channel separated positioning signals are subjected to time delay compensation processing to obtain delay-compensated multi-channel positioning signals, including: Obtain the spatial distance difference between the current receiving point and the analog points corresponding to each positioning signal; Obtain the elevation angle of the satellite corresponding to each positioning signal at the current receiving point; according to: Determine the time delay compensation amount corresponding to each separated signal; among which, For the first The time delay compensation amount corresponding to the path separation signal. For the first The spatial distance difference between the analog point corresponding to the road positioning signal and the current receiving point. For the first The road positioning signal corresponds to the elevation angle of the satellite at the current receiving point. The speed of light; Based on the time delay compensation amount, a time delay is applied to the multi-channel separation signals to obtain the multi-channel positioning signals after delay compensation.

6. The multi-point positioning signal transmission method for an indoor distribution system according to claim 1, characterized in that, The delayed-compensated multi-channel positioning signals are combined to obtain an output positioning signal, which is then transmitted through a positioning antenna. This process includes: The delay-compensated multi-channel positioning signals are linearly added in the time domain to obtain a complete output positioning signal. The output positioning signal contains all satellite signal components required for the current receiving point. The delay-compensated multi-channel positioning signal corresponds to the signal components of different satellites. The output positioning signal is broadcast through the positioning antenna so that the terminal device at the current receiving point can perform positioning calculations.

7. A multi-point positioning signal transmission system for an indoor distribution system, characterized in that, include: The positioning signal generation module includes multiple analog positioning signal generation units, which are used to generate multiple positioning signals transmitted from multiple analog points in different indoor locations. Each positioning signal has the same center frequency and spread spectrum sequence, and has different signal arrival times. A first time-division multiplexing module connected to the positioning signal generation module is used to perform time-division multiplexing processing on the multiple positioning signals according to the multiple positioning signals and preset positioning signal parameters to obtain a time-division multiplexed signal. The first combining module has a first input terminal connected to the first time division multiplexing module and a second input terminal connected to multiple mobile communication signals. The first combining module is used to combine the time division multiplexing signal and the multiple mobile communication signals to obtain a hybrid transmission signal. A transmission link connected to the first combining module, the transmission link being used to transmit the mixed transmission signal to at least one receiving point of the indoor distribution system; A signal separation module coupled to the transmission link is used to separate the mixed transmission signal at the receiving point to obtain multiple separate positioning signals and multiple mobile communication signals. A delay compensation module connected to the signal separation module includes multiple delay compensation units, which are used to perform time delay compensation processing on the multi-channel separated positioning signals to obtain delay-compensated multi-channel positioning signals. A second combining module connected to the delay compensation module is used to combine the delay-compensated multi-channel positioning signals to obtain an output positioning signal. A positioning antenna connected to the second combining module, the positioning antenna being used to transmit the output positioning signal; Specifically, based on the multiple positioning signals and preset positioning signal parameters, the multiple positioning signals are subjected to time-division and combining processing to obtain a time-division and combining signal, including: Obtain preset positioning signal parameters; Based on the preset positioning signal parameters, the spread spectrum signal period of the positioning signal, as well as the number of chips and chip rate contained in one spread spectrum signal period, are determined. Based on the multi-channel positioning signals, determine the number of channels of the multi-channel positioning signals; according to: Determine the duration of the time slot division; among which Divide the time slot into durations. For the number of chips, For chip rate, The number of multiple positioning signals; Based on the time slot division duration, the time slot selection timing is determined, which is the timing sequence of sequentially selecting each positioning signal in chronological order within one spread spectrum signal period; According to the time slot selection timing, each positioning signal is sequentially selected within one spread spectrum signal cycle, so that each positioning signal passes through the corresponding time slot, forming a time-division and combining signal that is staggered in time.

8. The multi-point positioning signal transmission system for an indoor distribution system according to claim 7, characterized in that, The signal separation module includes: A first bandpass filter, the input of which is coupled to the transmission link; A second time-division multiplexing module is connected to the output of the first bandpass filter, and the input of the second time-division multiplexing module is connected to the output of the bandpass filter.

9. The multi-point positioning signal transmission system for an indoor distribution system according to claim 7, characterized in that, Also includes: A second bandpass filter, the input of which is coupled to the transmission link, is used to extract the target mobile communication signal from the mixed transmission signal; An indoor communication antenna is connected to the output of the second bandpass filter, and the indoor communication antenna is used to transmit the target mobile communication signal.

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