Wireless communication signal distribution system and method, frequency shifter, access and radio frequency unit

Abstract

The present application relates to a method for a wireless communication signal distribution system, characterized in that it includes: obtaining a first I / Q baseband signal; orthogonally modulating the first I / Q baseband signal to obtain a second modulated signal; transmitting the second modulated signal through a twisted pair channel; receiving the second modulated signal from the twisted pair channel; and orthogonally demodulating the second modulated signal to obtain the first I / Q baseband signal.

Description

Technical Field

[0001] The present application belongs to the field of mobile communications, and in particular relates to a method, an orthogonal frequency shifter, an access unit, a radio frequency unit, and a wireless communication signal distribution system. Background Art

[0002] It's estimated that 70% of 5G data traffic and services will occur indoors, in locations such as train stations, airports, stadiums, hospitals, subways, shopping malls, hotels, and office buildings. Furthermore, 80% of 5G users will spend their working time indoors. The primary 5G frequency bands in China are 2.6GHz and 3.5GHz, which are higher than the mainstream 2G, 3G, and 4G bands. This increases transmission and penetration losses, making it difficult to achieve indoor coverage from outdoor locations. 5G signal coverage is crucial for 5G services.

[0003] Based on the existing passive indoor distribution system, 5G RRU (Remote Radio Unit) signals can be combined into the passive indoor distribution system through POI. The inventors of this application found that the existing passive indoor distribution system is mainly targeted at 2G, 3G, and 4G frequency bands, but has a high loss problem in the higher frequency bands of 5G.

[0004] On the other hand, in the existing technology, the active digital indoor distribution system based on micro base stations has defects such as large system scale, high cost, and high power consumption requirements. Summary of the Invention

[0005] The present application aims to provide a method, an orthogonal frequency shifter, an access unit, a radio frequency unit and a wireless communication signal distribution system for a wireless communication signal distribution system, which are low in cost and good in flexibility.

[0006] According to one aspect of the present application, a method for a wireless communication signal distribution system is provided, comprising: acquiring a first I / Q baseband signal; orthogonally modulating the first I / Q baseband signal to obtain a second modulated signal; transmitting the second modulated signal through a twisted pair channel; receiving the second modulated signal from the twisted pair channel; and orthogonally demodulating the second modulated signal to obtain the first I / Q baseband signal.

[0007] Another embodiment of the present application provides an orthogonal down-shifter, comprising: an orthogonal demodulator, which orthogonally demodulates a first modulation signal to obtain an I / Q baseband signal; an orthogonal modulator, which orthogonally modulates the I / Q baseband signal to obtain a second modulation signal; and a low-pass filter, which is connected between the orthogonal modulator and the orthogonal demodulator, and performs out-of-band suppression on the I / Q baseband signal.

[0008] Another embodiment of the present application provides an orthogonal up-shifter, comprising: an orthogonal demodulator, which orthogonally demodulates a second modulation signal to obtain an I / Q baseband signal; an orthogonal modulator, which orthogonally modulates the I / Q baseband signal to obtain a first modulation signal; and a low-pass filter, which is connected between the orthogonal demodulator and the orthogonal modulator, and performs out-of-band suppression on the I / Q baseband signal.

[0009] Another aspect of the present application provides an access unit including: a downlink orthogonal modulator, which orthogonally modulates the downlink I / Q baseband signal to obtain a downlink second modulated signal; a second modulated signal transmitter, which sends the downlink second modulated signal to a twisted pair channel; a second modulated signal receiver, which receives an uplink second modulated signal from the twisted pair channel; and an uplink orthogonal demodulator, which orthogonally demodulates the uplink second modulated signal to obtain an uplink I / Q baseband signal.

[0010] Another aspect of the present application provides a radio frequency unit, comprising: a second modulation signal receiver, receiving a downlink second modulation signal from a twisted pair channel; a downlink orthogonal demodulator, orthogonally demodulating the downlink second modulation signal to obtain a downlink I / Q baseband signal; a downlink orthogonal modulator, orthogonally modulating the downlink I / Q baseband signal to obtain a downlink second modulation signal; an uplink orthogonal demodulator, orthogonally demodulating the uplink first modulation signal to obtain an uplink I / Q baseband signal; an uplink orthogonal modulator, orthogonally modulating the uplink I / Q baseband signal to obtain an uplink second modulation signal; and a second modulation signal transmitter, transmitting the uplink second modulation signal to the twisted pair channel.

[0011] Another aspect of the present application provides a wireless communication signal distribution system, comprising: any one of the aforementioned access units; at least one radio frequency unit of any one of the aforementioned units; and a twisted pair system for distributing and connecting the radio frequency units to the access units.

[0012] Using any of the aforementioned methods, orthogonal frequency shifters, access units, radio frequency units, and systems, mobile communication signal distribution, including 5G communications, can be achieved relatively simply using twisted-pair cables. In this system, micro base stations generate cell signals, and twisted-pair cables are used for signal transmission and coverage, thereby reducing networking costs and being particularly suitable for indoor signal coverage.

[0013] The orthogonal frequency shifter provided in this application can be used to implement frequency shifting operations on mobile communication signals, including 5G communication signals, using a relatively simple topology. This operation can downconvert mobile communication signals, including 5G communication signals, to a frequency band that can be transmitted by twisted pair cables.

[0014] Channel compensation or signal pre-emphasis can be used to ensure that twisted-pair channels have wider available bandwidth and transmit over longer distances. This allows the use of twisted-pair cables to transmit 2G, 3G, 4G, and 5G communication signals. This reduces system deployment costs and increases system flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram showing the composition of a passive indoor distribution system for mobile communications based on prior art is shown.

[0016] Figure 2 A schematic diagram showing the composition of an active indoor distribution system for mobile communications based on prior art is shown.

[0017] Figure 3 A schematic diagram of the composition of a down converter based on the prior art is shown.

[0018] Figure 4 A schematic diagram of the composition of an up-converter based on the prior art is shown.

[0019] Figure 5 Show Figure 3 Signal characteristics of the downconverter shown.

[0020] Figure 6 A flowchart illustrating a method for a wireless communication distribution system according to an exemplary embodiment of the present application is shown.

[0021] Figure 7 A schematic diagram showing the circuit principles of the filtering module according to an exemplary embodiment of the present application is shown.

[0022] Figure 8 Show Figure 7 The amplitude-frequency characteristic curve of the filtering module is shown.

[0023] Figure 9 A schematic diagram showing the principle of a high-pass filter according to an exemplary embodiment of the present application.

[0024] Figure 10 Show Figure 9 The amplitude-frequency characteristic curve of the high-pass filter is shown.

[0025] Figure 11 A schematic diagram showing the composition of an orthogonal down-shifter according to an exemplary embodiment of the present application is shown.

[0026] Figure 12 A schematic diagram showing the composition of an orthogonal up-shifter according to another embodiment of the present application is shown.

[0027] Figure 13 A schematic diagram showing the composition of an access unit according to another embodiment of the present application is shown.

[0028] Figure 14A schematic diagram illustrating frequency range configuration in a 4G downlink fourth modulation signal and a 5G downlink second modulation signal in an example embodiment is shown.

[0029] Figure 15 A schematic diagram showing the composition of a radio frequency unit according to another embodiment of the present application is shown.

[0030] Figure 16 A schematic diagram showing the composition of a wireless communication distribution system according to another embodiment of the present application. DETAILED DESCRIPTION

[0031] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. In the figures, identical or similar reference numerals indicate identical or similar parts, and thus repeated descriptions thereof may sometimes be omitted. The figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0032] The described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices or steps may be employed. In these cases, well-known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0033] The block diagrams shown in the accompanying drawings do not necessarily correspond to physically independent entities. These functional entities or parts of these functional entities can be implemented in software, or in one or more hardware modules and / or programmable modules, or in different networks and / or processor devices and / or microcontrollers.

[0034] The following is an explanation of the implementation methods of the method, orthogonal down-shifter, orthogonal up-shifter, access unit, radio frequency unit and wireless communication distribution system disclosed in the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted in actual size. It is stated in advance. The following implementation methods will further explain the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. Although the technical solution of the present application is mainly explained below with 5G applications as an example, it is easy to understand that the technical solution of the present application can also be applied to other communication systems other than 5G communications, including other similar wireless communication application scenarios that may appear in the future.

[0035] It should be understood that the terms "first," "second," "third," and "fourth," etc. in the claims, specification, and drawings of this application are used to distinguish different objects rather than to describe a specific order. The terms "comprise" and "comprising" used in the specification and claims of this application indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0036] It should also be understood that the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this specification and claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" as used in this specification and claims refers to any and all possible combinations of one or more of the associated listed items, including and including these combinations.

[0037] Figure 1 A schematic diagram showing the composition of a passive indoor distribution system for mobile communications based on prior art is shown.

[0038] like Figure 1As shown, in the passive indoor distribution system of mobile communication based on the prior art, the 5G RRU (Remote Radio Unit) signal can be combined into the passive indoor distribution system through POI. The inventors of the present application found that the passive indoor distribution system of mobile communication based on the prior art is mainly aimed at 2G, 3G, and 4G frequency bands. The system has a large loss when passing through higher frequencies and is difficult to adapt to the transmission of 5G communication signals. Therefore, if the system is applied to the 5G communication networking project, it is necessary to carry out spectrum spread modification on the system, or increase the number and power of signal sources. If 2T2R is to be realized, another signal distribution system must be added. The system construction scale is large, the cost is high, and the flexibility is insufficient.

[0039] Figure 2 A schematic diagram showing the composition of an active indoor distribution system for mobile communications based on prior art is shown.

[0040] like Figure 2 As shown, in existing active digital indoor distribution systems based on micro base stations, the BBU (baseband processing unit) generates cell baseband signals, the hub distributes downlink signals and aggregates uplink signals, and the indoor distributed micro base stations transmit and receive RF signals. Data is transmitted between network elements using the CPRI protocol, and the micro base stations use optoelectronic composite cables or 10G network cables for signal extension and power. Active digital indoor distribution systems enable multimode transmission and simultaneous coverage of 2G, 3G, 4G, and 5G networks, as well as 2T2R and 4T4R MIMO capabilities, making them a key approach for future indoor distribution systems. However, 10G network or optical ports can only support 2T2R functionality with a 100MHz bandwidth signal. Category 6 shielded network cables have a maximum reach of 100 meters. The need to transmit and receive broadband signals requires high-speed ADCs, DACs, and FPGAs, resulting in high equipment cost and power consumption.

[0041] Conventional technology also utilizes twisted-pair cables to transmit mobile communication signals. This solution typically uses a downconverter to convert the mobile communication signal to a lower frequency. This lower-frequency signal is then transmitted to a predetermined indoor area via the twisted-pair cable. An upconverter then converts the lower-frequency signal back to the original mobile communication RF signal, achieving coverage for the predetermined indoor area.

[0042] Figure 3 A schematic diagram of the composition of a down converter based on the prior art is shown. Figure 4 A schematic diagram of the composition of an up-converter based on the prior art is shown. Figure 5 Show Figure 3 Signal characteristics of the downconverter shown.

[0043] like Figure 3The downconverter shown can use a mixer to mix the higher frequency carrier signal fc with the local oscillator signal fo to obtain a lower frequency carrier signal fs. The frequency relationship between the three signals is:

[0044] fs=fc-fo (a)

[0045] like Figure 5 As shown, using Figure 3 During the downconversion process of the downconverter shown in the figure, fs has an image signal 2fo - fc. The converted signal of this image signal is also superimposed on fs, causing interference. To prevent this image signal interference, a bandpass filter is required. The design of this bandpass filter must not affect the signal (fc) while simultaneously suppressing the image signal (2fo - fc).

[0046] In use Figure 3 When the downconverter shown in the figure handles 5G signal transmission over twisted-pair cables, the 5G signal frequency fc is relatively high, primarily 2.6 to 4.9 GHz in FR1. The twisted-pair operating frequency fs is relatively low, less than 200 MHz. According to equation (a), in this solution, the local oscillator frequency fo will be very close to the 5G signal frequency fc. Consequently, the image signal frequency 2fo-fc will be very close to the 5G signal frequency fc. This poses a significant challenge to the design of the bandpass filter, making its implementation difficult and costly.

[0047] Likewise, see Figure 4 After the twisted pair transmits the signal to the remote radio unit, the 5G signal is restored through the up-converter. At the output of the mixer, an out-of-band signal is generated that is aliased on the target modulation signal (fo+fs). This out-of-band signal includes the local oscillator signal (fo) and the signal fo-fs. Due to the numerical relationship between the local oscillator frequency fo of the 5G signal and the twisted pair operating frequency fs, the out-of-band signals of the two frequencies are very close to the target modulation signal frequency fo+fs. Therefore, when passing through Figure 4 When the upconverter shown in the figure processes 5G signals, the bandpass filter used to suppress out-of-band signals is difficult to implement and the cost is relatively high.

[0048] In order to solve the above problems, the inventors of this application have proposed a new technical solution, which uses an orthogonal frequency converter to realize the relay transmission of 5G signals via twisted pair at a lower cost. According to the technical concept of this application, in the downlink direction, the access unit first extracts the I / Q baseband signal of the 5G signal fc through an orthogonal demodulator, suppresses the out-of-band signal with a low-pass filter, and then modulates the I / Q baseband signal to the frequency fs that can be transmitted by the twisted pair through an orthogonal modulator, thereby realizing the transfer of the 5G broadband signal to the twisted pair for transmission. The remote radio frequency unit uses an orthogonal frequency converter to convert the signal transmitted by the twisted pair into a normal 5G signal, amplifies it and transmits it to achieve signal coverage. For signal transmission in the uplink direction, the reverse direction processing of the above method can be adopted.

[0049] The technical solution of the present application is described in detail below with reference to exemplary embodiments.

[0050] Figure 6 A flowchart illustrating a method for a wireless communication distribution system according to an exemplary embodiment of the present application is shown.

[0051] like Figure 6 As shown, in S110, a first modulated signal s1(t) is received. The first modulated signal s1(t) may be a mobile communication signal including a 5G communication signal. Optionally, the first modulated signal s1(t) may include one or more of 2G, 3G, 4G, and 5G. Optionally, the first modulated signal s1(t) may be received in the downlink direction from an RRU or an integrated small base station. Alternatively, in the uplink direction, the first modulated signal s1(t) may be obtained from at least one mobile communication terminal.

[0052] s1(t)=a(t)cos(2πf o1 t+2πf b t) (1)

[0053] Formula (1) shows the signal expression of the first modulated signal s1(t) in the exemplary embodiment. As shown in Formula (1), s1(t) can be the first modulated signal. Wherein, a(t) can be the baseband signal amplitude of the first modulated signal s1(t), and f o1 can be the local oscillator frequency of the first modulation signal s1(t), f b can be the baseband signal frequency of the first modulation signal s1(t), f o1 >>f b .

[0054] In S120, quadrature demodulation is performed on the first modulated signal s1(t) to obtain a first I / Q baseband signal, wherein the first I / Q baseband signal may include a baseband signal I(t) and a baseband signal Q(t).

[0055] First, the first local oscillation signal I can be generatedb1 (t) and the first local oscillator imaginary signal Q b1 (t). The first real part signal I b1 (t) and the first local oscillator imaginary signal Q b1 (t) are all single-frequency signals with a phase difference of 90°. The first local oscillation real part signal I b1 (t) and the first local oscillator imaginary signal Q b1 The frequencies of (t) are all the local oscillator frequency f of the first modulation signal s1(t) o1 Optionally, the first local vibration part signal I b1 (t) and the first local oscillator imaginary signal Q b1 (t) can be expressed as formula (2) or formula (3).

[0056] I b1 (t) = cos(2πf o1 t) (2)

[0057] Q b1 (t)=sin(2πf o1 t) (3)

[0058] As shown in equations (4) and (5), the first local oscillation signal I can be used to b1 (t) and the first local oscillator imaginary signal Q b1 (t) is multiplied by the first modulated signal s1(t) to obtain the baseband signal I(t) / Q(t).

[0059]

[0060]

[0061] Among them, the baseband signal I(t) can be expressed as:

[0062] I(t)=1 / 2a(t)cos(2πf b t),

[0063] The baseband signal Q(t) can be expressed as:

[0064] Q(t)=1 / 2a(t)sin(2πf b t).

[0065] As in formula (4) and formula (5), 1 / 2a(t)cos(2πf b t+4πf o1 t) and 1 / 2a(t)sin(2πf b t+4πf o1 t) is noise, i.e. out-of-band signal.

[0066] Optionally, after S120 , the step of performing low-pass filtering on the first I / Q baseband signal may be included to suppress out-of-band signals.

[0067] Since the out-of-band components in equations (4) and (5) do not contain low-frequency components, only a low-pass filter is needed to effectively suppress the out-of-band signal. o1 >>f b , so the frequency of the out-of-band signal is much greater than the frequency f of the baseband signal I(t) / Q(t) b Therefore, a relatively common low-pass filter can suppress the aforementioned out-of-band signal. This filter is relatively easy to implement and has low implementation cost.

[0068] The specific implementation of orthogonal demodulation can be achieved by using FFT method, Hilbert transform method, digital interpolation method, direct digital mixing method, direct analog mixing method, etc., and this application has no special restrictions on this.

[0069] Optionally, S110 and S120 may be replaced by directly acquiring the baseband signal I(t) and baseband signal Q(t) from the RRU or integrated small base station. Alternatively, the baseband signal I(t) and baseband signal Q(t) may be acquired from the RRU or integrated small base station via a CPRI / eCPRI interface.

[0070] In S130 , the baseband signal I(t) / Q(t) may be orthogonally modulated to obtain a second modulated signal s2 ( t ).

[0071] The second local oscillation signal I can be generated first b2 (t) and the second local oscillator imaginary signal Q b2 (t).

[0072] Among them, the second local oscillation signal I b2 (t) and the second local oscillator imaginary part signal are both single frequency signals with a phase difference of 90°. The second local oscillator real part signal I b2 (t) and the second local oscillator imaginary signal Q b2 The frequencies of (t) are all the local oscillator frequency f of the second modulation signal s2(t) o2 .

[0073] Wherein, the frequency f o2 It can be a frequency within the transmission bandwidth of the twisted pair channel. o2 Can be in the range of 10-200MHz.

[0074] Optionally, the second local oscillation real part signal I b2 (t) and the second local oscillator imaginary signal Q b2 (t) can be expressed as formula (6) or formula (7).

[0075] Ib2 (t)=2 cos(2πf o2 t) (6)

[0076] Q b2 (t)=-2 sin(2πf o2 t) (7)

[0077] As shown in equations (8) and (9), the second local oscillation real part signal I b2 (t) and the baseband signal I(t) are multiplied, and the second local oscillator imaginary signal Q b2 (t) is multiplied by the baseband signal Q(t). Equations (8) and (9) can be summed to obtain the second modulated signal s2(t). The implementation of quadrature modulation is similar to that of quadrature demodulation and will not be described in detail here.

[0078]

[0079]

[0080] s2(t)=I(t)×I b2 (t)+Q(t)×Q b2 (t)=a(t)cos(2πf o2 t+2πf b t) (10)

[0082] Optionally, the frequency f can be properly configured o2 , so that the frequency f of the second modulation signal s2(t) o2 +f b In the range of 10-200MHz.

[0083] In S140 , the second modulated signal s2 ( t ) may be transmitted via the twisted pair channel.

[0084] In some application scenarios, the second modulated signal s2(t) can be transmitted from a first preset area to a second preset area via a twisted pair channel. Direct wireless communication between the first and second preset areas via a preset communication method may not be feasible. Optionally, the preset communication method may include at least one of 2G, 3G, 4G, and 5G. Optionally, there may be obstructions between the first and second preset areas, such as walls, metal objects, or other objects that may affect wireless signal propagation. Optionally, at least one of the first and second preset areas is not covered by an existing wireless communication network. Optionally, the area not covered by the existing wireless communication network may be a relatively enclosed area, such as an indoor area or an underground area. Optionally, the area not covered by the existing wireless communication network may be an open area not yet covered by the existing wireless communication network. Optionally, at least one of the first and second preset areas may be an area with a high density of wireless communication terminals, such as certain factory areas or schools.

[0085] Optionally, the twisted pair channel may include a network cable, which may be a Category 5 cable, a Category 6 cable, a Category 7 cable, or other types of network cables. Optionally, the length of the network cable may be 100-200 meters.

[0086] In S150 , a second modulated signal s2 ( t ) may be received from a twisted pair channel.

[0087] In S160, the second modulated signal s2(t) can be used to restore the first modulated signal s1(t). Optionally, the second modulated signal s2(t) can be orthogonally demodulated to obtain the baseband signal I(t) / Q(t). Optionally, in S160, the baseband signal I(t) / Q(t) can also be orthogonally modulated to restore the first modulated signal s1(t). This process is similar to S120-S130 and is not further described here.

[0088] Optionally, after orthogonally demodulating the second modulated signal s2(t) to obtain the baseband signal I(t) / Q(t), the baseband signal I(t) / Q(t) may be low-pass filtered to suppress out-of-band signals.

[0089] Optionally, after S160 , the process may further include power amplifying the first modulated signal s1 ( t ) and transmitting the first modulated signal s1 ( t ). For example, the first modulated signal s1 ( t ) may be transmitted to at least one mobile communication terminal.

[0090] Optionally, in the uplink direction, the first modulated signal s1(t) can also be coupled to the RRU or the integrated small base station, or the baseband signal I(t) / Q(t) can be sent to the RRU or the integrated small base station. The RRU or the integrated small base station uses the baseband signal I(t) / Q(t) to restore the first modulated signal s1(t). The first modulated signal s1(t) can also be sent by the RRU or the integrated small base station. Optionally, the baseband signal I(t) / Q(t) can be sent to the RRU or the integrated small base station via the CPRI / eCPRI interface.

[0091] Optionally, after S150 , the method may further include: performing amplitude-frequency characteristic compensation on the second modulated signal s2 ( t ) according to the attenuation characteristic of the twisted pair channel.

[0092] Optionally, a filter may be used to compensate for the amplitude-frequency characteristics of the second modulated signal s2(t). The amplitude-frequency characteristics of the filter match those of the twisted-pair channel, such that the overall amplitude-frequency characteristics of the twisted-pair channel and the filter cascade are relatively flat within a preset frequency range.

[0093] Optionally, the filter may be composed of a plurality of cascaded filter modules. Optionally, the filter may be composed of at least two cascaded high-pass filter modules. Optionally, the transfer function of each high-pass filter module may be as shown in formula (11):

[0094]

[0095] Among them, R2, R3 and C2 can all be preset constants, f is the frequency, Vin is the input voltage of the filter module, V out It can be the output voltage of the filter module, and j can be an imaginary unit.

[0096] Optionally, the method according to the example embodiment may also include a multi-mode transmission mode, for example, the method may also include: obtaining a second I / Q baseband signal; orthogonally modulating the second I / Q baseband signal to obtain a fourth modulation signal; transmitting the fourth modulation signal in a frequency division multiplexing manner, sharing the twisted pair channel with the second modulation signal, with a protection interval of 5-20 MHz between the fourth modulation signal and the second modulation signal; receiving the fourth modulation signal from the twisted pair channel; and orthogonally demodulating the fourth modulation signal to obtain the second I / Q baseband signal.

[0097] Furthermore, the method according to this example embodiment may further include: receiving a third modulated signal, orthogonally demodulating the third modulated signal to obtain the second I / Q baseband signal. Furthermore, the method according to this example embodiment may further include: orthogonally modulating the second I / Q baseband signal to recover the third modulated signal. Furthermore, the method according to this example embodiment may further include: transmitting the third modulated signal.

[0098] For example, the first modulated signal may be a 5G signal, and the third modulated signal may be a 4G signal. In this way, the second modulated signal and the fourth modulated signal corresponding to 4G and 5G may be simultaneously combined and transmitted on the same twisted pair channel, thereby improving equipment utilization.

[0099] Figure 7 A schematic diagram showing the circuit principles of a filtering module according to an exemplary embodiment of the present application is shown.

[0100] like Figure 7 As shown, the filtering module may include: an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a varactor diode C2 and an inductor L. Among them, the capacitor C1 can be used to isolate the bias voltage V T , the inductor L can be used to provide the bias voltage V T , resistor R1 can be used for impedance matching. The influence of resistor R1, capacitor C1 and inductor L on the transmission characteristics of the filter module can be ignored. Figure 7 The transfer function of the filtering module can be shown as formula (11).

[0101] Figure 8 Show Figure 7 The amplitude-frequency characteristic curve of the filtering module is shown.

[0102] like Figure 8 As shown, Figure 7 The amplitude-frequency characteristics of the filter module shown have two inflection points, namely (FL, 1) and (FC, Ac).

[0103]

[0104]

[0105]

[0106] like Figure 7 As shown, the bias voltage V T Adjust the capacitance of the varactor diode C2. Then, the bias voltage V T Adjusting parameters adjusts the amplitude-frequency characteristics of the filter module, and adjusts the inflection point parameters FL and FC of the filter module.

[0107] Figure 9 A schematic diagram showing the principle of a high-pass filter according to an exemplary embodiment of the present application is shown.

[0108] like Figure 9As shown, the high-pass filter may include three cascaded filter modules 111, 112, and 113. The filter modules 111, 112, and 113 may be the filter modules shown in FIG7. The corresponding filter inflection point parameters are (Ac1, FL1, FC1), (Ac2, FL2, FC2), and (Ac3, FL3, FC3). The bias voltage V T1 、V T2 and V T3 The filtering parameters of the filtering modules 111 , 112 and 113 are adjusted respectively to match the attenuation characteristics of the twisted pair channel.

[0109] Figure 10 Show Figure 9 The amplitude-frequency characteristic curve of the high-pass filter is shown.

[0110] like Figure 10 As shown, 121 is the amplitude-frequency characteristic curve of the filter module 111, 122 is the amplitude-frequency characteristic curve of the filter module 112, and 123 is the amplitude-frequency characteristic curve of the filter module 113. Figure 9 124 is the amplitude-frequency characteristic curve of the high-pass filter, and 125 is the attenuation characteristic curve of the twisted-pair channel.

[0111] The bias voltage V T1 、V T2 and V T3 The product of the amplitude-frequency characteristic of the high-pass filter and the attenuation characteristic of the twisted pair channel is a relatively flat curve within the preset frequency range. Curve 125 is the superposition curve of curve 120 and curve 124, that is, Figure 9 The total gain curve of the filter cascaded with the twisted pair channel is shown.

[0112] As shown in the exemplary embodiment, the curve 125 is relatively flat between O-FN, thereby extending the available bandwidth of the twisted pair channel.

[0113] Since the attenuation characteristics of twisted pair cables are related to the type and length of twisted pair cables, it is possible to adjust the V T1 、V T2 and V T3 Adjust the transmission characteristics of the high-pass filter so that the overall gain characteristic of the filter and the twisted pair channel cascade is relatively flat within a preset frequency range. In the exemplary embodiment, the high-pass filter includes three stages of filter modules. Optionally, the filter may also include other numbers of filter modules.

[0114] Optionally, before S140, the second modulated signal s2(t) can also be amplitude-frequency pre-emphasized according to the attenuation characteristics of the twisted pair channel, so that after the second modulated signal s2(t) is sequentially subjected to amplitude-frequency pre-emphasis and twisted pair transmission, the overall amplitude-frequency characteristic is relatively flat within a preset frequency range.

[0115] Optionally, a filter may be used to pre-emphasize the amplitude-frequency characteristics of the second modulated signal s2(t). According to some embodiments, the filter may be as follows: Figure 9 As shown, no further details are given here.

[0116] Optionally, either or both of the amplitude-frequency characteristic pre-emphasis and the amplitude-frequency characteristic compensation may be used.

[0117] Figure 11 The diagram shows the composition of the orthogonal down-shifter according to an exemplary embodiment of the present application. The orthogonal down-shifter according to this embodiment can be used in the processing method of the aforementioned wireless communication distribution system.

[0118] like Figure 11 As shown, the orthogonal down-shifter 2000 can be used to convert the first modulated signal s1(t) into the second modulated signal s2(t). The first modulated signal can be a mobile communication radio frequency signal, which can include 2G, 3G, 4G, and 5G radio frequency signals. The second modulated signal can be a signal transmittable over a twisted pair cable.

[0119] According to an example embodiment, the quadrature down shifter 2000 may include a quadrature demodulator 210 , a quadrature modulator 220 , and low-pass filters 231 and 232 connected between the quadrature demodulator 210 and the quadrature modulator 220 .

[0120] Referring to the above description, the quadrature demodulator 210 can utilize the first local oscillation part signal I b1 (t) and the first local oscillator imaginary signal Q b1 (t) are multiplied with the first modulated signal s1(t) to obtain the baseband signal I(t) / Q(t). The first local oscillation real part signal I b1 (t) and the first local oscillator imaginary signal Q b1 (t) can be a stable, single-frequency signal with equal amplitude. The first real part signal I b1 (t) and the first local oscillator imaginary signal Q b1 The frequencies of (t) can be the local oscillator frequency f of the first modulation signal s1(t) o1 The first real part signal I b1 (t) and the first local oscillator imaginary signal Q b1 The phase difference between (t) can be 90°.

[0121] The filter 231 may be connected to the baseband signal I(t) to filter out out-of-band components in the baseband signal I(t). The filter 232 may be connected to the baseband signal Q(t) to filter out out-of-band signals in the baseband signal Q(t).

[0122] The quadrature modulator 220 can be connected to the low-pass filters 231 and 232 respectively, and generate the second modulation signal s2(t) using the filtered baseband signal I(t) / Q(t). b2 (t) is multiplied by the baseband signal I(t), and the second local oscillator imaginary part signal Q b2 (t) is multiplied by the baseband signal Q(t), and the two product signals are superimposed to obtain the second modulated signal s2(t).

[0123] The second real part signal I b2 (t) and the second local oscillator imaginary signal Q b2 (t) can be a stable, single-frequency signal with equal amplitude. The second local oscillation real part signal I b2 (t) and the second local oscillator imaginary signal Q b2 The frequency of (t) can be the local oscillator frequency f of the second modulation signal s2(t) o2 The second real part signal I b2 (t) and the second local oscillator imaginary signal Q b2 The phase of (t) can be different by 90°.

[0124] Figure 12 A schematic diagram showing the composition of an orthogonal up-frequency shifter according to another embodiment of the present application is shown. The orthogonal up-frequency shifter according to this embodiment can be used in the processing method of the aforementioned wireless communication distribution system.

[0125] like Figure 12 As shown, the orthogonal up-shifter 3000 can be used to restore the second modulated signal s2(t) to the first modulated signal s1(t). The first modulated signal can be a mobile communication radio frequency signal, which can include 2G, 3G, 4G, and 5G radio frequency signals. The second modulated signal can be a twisted pair transmission signal.

[0126] According to example embodiments, the quadrature up-shifter 3000 may include a quadrature demodulator 310 , a quadrature modulator 320 , and low-pass filters 331 and 332 .

[0127] As described above, the quadrature demodulator 310 can be used to quadrature-demodulate the second modulated signal to obtain the baseband signal I(t) / Q(t). The low-pass filters 331 and 332 can be used to suppress out-of-band signals in the baseband signal I(t) and the baseband signal Q(t), respectively. The quadrature modulator 320 can be used to modulate the baseband signal I(t) / Q(t) to restore the first modulated signal s1(t). Optionally, the above components can be respectively connected to Figure 11 The components with the same name are similar and will not be described here.

[0128] Figure 13 A schematic diagram showing the composition of an access unit according to an exemplary embodiment of the present application.

[0129] The access unit 4000 can be connected between the source RRU or integrated small base station and the twisted-pair channel, and can cooperate with the radio frequency unit connected to the other end of the twisted-pair channel to achieve communication between wireless communication terminals in a preset area and the source RRU or integrated small base station. The access unit 4000 can be connected to the RRU or integrated small base station by wireless coupling or by digital connection.

[0130] Access unit 4000 can be used to process the conversion between uplink / downlink first modulated signals (RF signals) and uplink / downlink second modulated signals (twisted pair transmittable signals), or can be used to process the conversion between uplink / downlink I / Q baseband signals and uplink / downlink second modulated signals. This allows for the conversion of communication signals between wireless transmission and twisted pair transmission at the end where the wireless communication signal has been covered.

[0131] According to an example embodiment, in the downlink direction, access unit 4000 may include a downlink orthogonal modulator 414 and a second modulated signal transmitter 418. Optionally, the upstream stage of downlink orthogonal modulator 414 may further include a downlink orthogonal demodulator 412. In the uplink direction, access unit 4000 may include a second modulated signal receiver 428 and an uplink orthogonal demodulator 424. Optionally, the downstream stage of uplink orthogonal demodulator 424 may also include an uplink orthogonal modulator 422.

[0132] Optionally, the access unit 4000 may also include a coupler (not shown) and may be wirelessly coupled to the RRU or the integrated small base station through the coupler. The access unit 4000 may receive a downlink first modulated signal from the RRU or the integrated small base station through the coupler, or may transmit an uplink first modulated signal to the RRU or the integrated small base station through the coupler. At least one of the downlink first modulated signal and the uplink first modulated signal may be a radio frequency signal for mobile communication. Optionally, the radio frequency signal may be one of 2G, 3G, 4G and 5G radio frequency signals, or a superposition of at least two of them.

[0133] like Figure 13 As shown, the downlink orthogonal demodulator 412 can be used to orthogonally demodulate the downlink first modulated signal to obtain the aforementioned downlink I / Q baseband signal. Optionally, a downlink low-pass filter (not shown) can also be included between the orthogonal demodulator 412 and the downlink orthogonal modulator 414 to perform out-of-band suppression on the downlink I / Q baseband signal.

[0134] like Figure 13 As shown, downlink quadrature modulator 414 can be used to quadrature-modulate the downlink I / Q baseband signal to generate a downlink second modulated signal. The downlink second modulated signal can be used for twisted-pair transmission. The frequency of the downlink second modulated signal can be within the transmission bandwidth of twisted-pair channel 430. Optionally, the frequency range of the downlink second modulated signal can be within 10-200 MHz.

[0135] like Figure 13 As shown, the second modulated signal transmitter 418 can be connected between the downlink quadrature modulator 414 and the twisted pair channel 430, and is configured to transmit the downlink second modulated signal to the twisted pair channel 430. The second modulated signal transmitter 418 can be directly connected to the twisted pair channel 430. Alternatively, the twisted pair channel 430 can include at least one twisted pair. The second modulated signal transmitter 418 can be connected to at least one twisted pair in the twisted pair channel 430. Optionally, the second modulated signal transmitter 418 can also perform power amplification on the downlink second modulated signal before transmitting the signal.

[0136] At the other end of twisted pair channel 430, a radio frequency unit can be used to convert the downlink second modulated signal transmitted downlink via twisted pair channel 430 into a downlink first modulated signal. The radio frequency unit can also be used to transmit the downlink first modulated signal to mobile communication terminals within a predetermined area. The radio frequency unit can also receive uplink first modulated signals from mobile communication terminals, convert the uplink first modulated signal into an uplink second modulated signal, and transmit the uplink second modulated signal uplink via the twisted pair channel to access unit 4000.

[0137] like Figure 13 As shown, the second modulated signal receiver 428 can be used to receive the uplink second modulated signal transmitted uplink via the twisted pair channel 430. The second modulated signal receiver 428 can be directly connected to the twisted pair channel 430. Alternatively, the second modulated signal receiver 428 can be connected to at least one twisted pair in the twisted pair channel 430.

[0138] According to an example embodiment, the second modulated signal receiver 428 may be connected to the same twisted pair as the second modulated signal transmitter 418. The second modulated signal receiver 428 and the second modulated signal transmitter 418 perform duplex transmission and / or multi-mode transmission and reception via a frequency division duplexing (FDD) mode or a time division duplexing (TDD) mode. The second modulated signal receiver 428 and the second modulated signal transmitter 418 may be connected to different twisted pairs, and perform duplex transmission and / or multi-mode transmission and reception via the different twisted pairs.

[0139] like Figure 13 As shown, the uplink quadrature demodulator 424 can be coupled to the second modulated signal receiver 428 to quadrature-demodulate the uplink second modulated signal to obtain an uplink I / Q baseband signal. The uplink quadrature modulator 422 can be configured to quadrature-modulate the uplink I / Q baseband signal to obtain an uplink first modulated signal. Optionally, an uplink low-pass filter can be included between the uplink quadrature demodulator 424 and the uplink quadrature modulator 422 to suppress out-of-band signals from the uplink I / Q baseband signal.

[0140] Optionally, the access unit 4000 may not include the downlink orthogonal demodulator 412 and the uplink orthogonal modulator 422. Optionally, the access unit 4000 may include a CPRI / eCPRI interface (not shown) and may be digitally connected to the RRU or integrated small base station via the CPRI / eCPRI interface. Optionally, uplink I / Q baseband and downlink I / Q baseband signals may be directly exchanged with the RRU or integrated small base station via the CPRI / eCPRI interface.

[0141] Optionally, the downlink I / Q baseband signal may be a downlink baseband signal of at least one of 2G communication, 3G communication, 4G communication, and 5G communication. The uplink I / Q baseband signal may also be an uplink baseband signal of at least one of 2G communication, 3G communication, 4G communication, and 5G communication.

[0142] Optionally, the access unit 4000 may further include a first high-pass filter (not shown). Optionally, the first high-pass filter may be used to pre-emphasize the downlink second modulated signal. The first high-pass filter may be the one previously described. Figure 9 The filters described above are not described in detail here. Optionally, the first high-pass filter can be provided between the second modulated signal transmitter 418 and the twisted pair channel 430, or between the downlink quadrature modulator 414 and the second modulated signal transmitter 418. Optionally, the first high-pass filter can also be provided in the front stage of the downlink quadrature modulator 414 to directly pre-emphasize the downlink I / Q baseband signal.

[0143] Optionally, the access unit 4000 may further include a second high-pass filter (not shown). Optionally, the second high-pass filter may be used to compensate the amplitude-frequency characteristic of the uplink first modulated signal. The second high-pass filter may be as described in Figure 9 The filters described above are not described in detail here. The second high-pass filter can be provided between the second modulated signal receiver 428 and the uplink quadrature demodulator 424, or between the second modulated signal receiver 428 and the twisted pair channel 430. Optionally, the second high-pass filter can also be provided after the uplink quadrature demodulator 424 and can compensate for the amplitude-frequency characteristics of the uplink I / Q baseband signal.

[0144] Optionally, the access unit 4000 can also be used for multi-mode transmission of communication signals. For example, the signal received from the RRU or the integrated small base station can be a superposition signal of at least two downlink first modulated signals, such as the superposition of at least two of the 2G, 3G, 4G and 5G radio frequency signals. Optionally, the access unit 4000 may include at least two downlink orthogonal demodulators, which respectively orthogonally demodulate the at least two downlink first modulated signals and obtain at least two pairs of downlink I / Q baseband signals. Optionally, the access unit 4000 can also directly obtain at least two pairs of downlink I / Q baseband signals from the RRU or the integrated small base station directly through the CPRI / eCPRI interface.

[0145] Optionally, access unit 4000 may further include at least two downlink quadrature modulators 414, each configured to quadrature-modulate two pairs of downlink I / Q baseband signals to generate at least two downlink second modulated signals. Optionally, the frequency ranges of the at least two downlink second modulated signals are both within the transmission bandwidth of the twisted-pair channel and do not overlap. Optionally, the at least two downlink second modulated signals may be combined and transmitted in a frequency-division multiplexing manner over twisted-pair channel 430.

[0146] For example, according to some embodiments, the access unit 4000 may include a first and a second downlink orthogonal modulator, and the first and the second downlink orthogonal modulator may be used to respectively perform orthogonal modulation on the first (e.g., 5G) downlink I / Q baseband signal and the second (e.g., 4G) downlink I / Q baseband signal, thereby obtaining a first (e.g., 5G) downlink second modulated signal and a second (e.g., 4G) downlink second modulated signal. A guard interval of a preset frequency width may be left between the first downlink second modulated signal and the second downlink second modulated signal, so that their frequency ranges may not overlap with each other, such as Figure 14 See Figure 14The frequency range of the 5G downlink second modulation signal (5G signal) can be 100-200 MHz. The frequency range of the 4G downlink second modulation signal (4G signal) can be 70-90 MHz. 90 MHz-100 MHz is the guard interval. The frequency ranges of other signals, such as the 2G downlink second modulation signal and the 3G downlink second modulation signal, can be similarly configured.

[0147] Optionally, the access unit 4000 may further include a second modulated signal combiner for combining the at least two downlink second modulated signals.

[0148] In the uplink path, the signal received from the twisted pair channel 430 may also be at least two uplink second modulated signals transmitted in combination in a frequency division multiplexing manner. Optionally, the access unit 4000 may include a signal separator to separate the at least two uplink second modulated signals transmitted in combination. Optionally, the frequency configuration of the at least two uplink second modulated signals transmitted in combination in a frequency division multiplexing manner may be as follows: Figure 14 The description is not repeated here.

[0149] Access unit 4000 may also include at least two uplink orthogonal demodulators, each configured to orthogonally demodulate the at least two uplink second modulated signals to obtain at least two pairs of uplink I / Q baseband signals. The at least two pairs of uplink I / Q baseband signals may be directly transmitted to an RRU or integrated small base station via a CPRI / eCPRI interface. The at least two pairs of uplink I / Q baseband signals may also be orthogonally modulated using the at least two uplink orthogonal modulators to obtain at least two uplink first modulated signals. The at least two uplink first modulated signals may then be coupled and transmitted to the RRU or integrated small base station.

[0150] Figure 15 A schematic diagram showing the composition of a radio frequency unit according to another embodiment of the present application is shown.

[0151] The RF unit 5000 can be similar to a micro base station, located within a preset area to provide communication signal coverage for the preset area. The RF unit 5000 can be connected to a twisted pair channel and can cooperate with any of the aforementioned access units located at the other end of the twisted pair channel. The RF unit 5000 can also wirelessly couple with at least one mobile communication terminal within the preset area to establish a mobile communication connection between the at least one mobile communication terminal within the preset area and the source RRU or integrated small base station.

[0152] See also Figure 15 In the downlink direction, the RF unit 5000 may include: a second modulated signal receiver 512, a downlink orthogonal demodulator 514, and a downlink orthogonal modulator 516. In the uplink direction, the RF unit 5000 may include: an uplink orthogonal demodulator 526, an uplink orthogonal modulator 524, and a second modulated signal transmitter 522.

[0153] In the downlink direction, the second modulated signal receiver 512 can be used to receive a downlink second modulated signal. This downlink second modulated signal can be generated by any of the aforementioned access units based on a signal transmitted by the RRU or the integrated small base station, and can be transmitted downlink to the RF unit 5000 via the twisted pair channel 530. The downlink orthogonal demodulator 514 can be used to orthogonally demodulate the downlink second modulated signal to obtain a downlink I / Q baseband signal. The downlink orthogonal modulator 516 can be used to orthogonally modulate the downlink I / Q baseband signal to restore the downlink first modulated signal.

[0154] Optionally, a first modulated signal transmitter (not shown) may be included after the downlink quadrature modulator 516 to transmit the downlink first modulated signal to at least one mobile communication terminal within a preset area. A downlink low-pass filter (not shown) may also be included between the downlink quadrature demodulator 514 and the downlink quadrature modulator 516 to suppress out-of-band downlink I / Q baseband signals. Optionally, a first high-pass filter (not shown) may also be included after the second modulated signal receiver 512 to compensate for the downlink second modulated signal.

[0155] In the uplink direction, the uplink orthogonal demodulator 526 can be used to orthogonally demodulate the uplink first modulated signal from at least one mobile terminal in a preset area to obtain an uplink I / Q baseband signal. The uplink orthogonal modulator 524 can be used to orthogonally modulate the uplink I / Q baseband signal to obtain an uplink second modulated signal. The second modulated signal transmitter 522 can be used to send the uplink second modulated signal to the twisted pair channel 530. Any of the aforementioned access units connected to the other end of the twisted pair channel 530 can receive and restore the uplink second modulated signal, and can send the restored signal to the RRU or integrated small base station.

[0156] Optionally, a first modulation signal receiver (not shown) may be included before the uplink quadrature demodulator 526 to receive the uplink first modulation signal from at least one mobile terminal. An uplink low-pass filter (not shown) may also be included between the uplink quadrature demodulator 526 and the uplink quadrature modulator 524 to perform out-of-band suppression on the uplink I / Q baseband signal. A second high-pass filter (not shown) may also be included before the second modulation signal transmitter 522 to perform pre-emphasis on the uplink second modulation signal.

[0157] Easy to understand, Figure 15 The RF unit shown is Figure 13 The access units shown in the figure operate in a similar manner in terms of frequency shifting, filtering, etc., and their detailed description is omitted here.

[0158] Figure 16 A schematic diagram showing the composition of a wireless communication distribution system according to an exemplary embodiment of the present application.

[0159] like Figure 16 As shown, the system 6000 may include: an access unit 610 , at least one radio frequency unit 621 , 622 , and 623 , and a twisted pair system 630 .

[0160] The access unit 610 can be a reference Figure 13 The radio frequency units 621, 622 and 623 can be referenced. Figure 15 What has been described will not be repeated here.

[0161] Optionally, the access unit 610 may be located within a first preset area, and the radio frequency units 621, 622, and 623 may be located within a second preset area, a third preset area, and a fourth preset area, respectively. It may be difficult for the second preset area, the third preset area, and the fourth preset area to directly communicate with the first preset area via a preset wireless communication method. The preset wireless communication method may include at least one of 2G, 3G, 4G, and 5G.

[0162] Optionally, the first preset area may be an open area that can be covered by a preset public mobile communication signal. At least one of the second preset area, the third preset area, and the fourth preset area may be an area to be covered or strengthened by a preset public mobile communication signal. Optionally, at least one of the second preset area, the third preset area, and the fourth preset area may be a closed area or a semi-closed area. Optionally, the closed area or semi-closed area may include areas such as indoor areas and basements that are difficult to be covered by the preset public mobile communication signal. Optionally, at least one of the second preset area, the third preset area, and the fourth preset area may be an open area that is not yet covered by an existing preset public mobile communication signal. Optionally, at least one of the second preset area, the third preset area, and the fourth preset area may be an area with an excessively high density of mobile communication terminals, such as a factory area, a school, or a hospital.

[0163] Optionally, at least two of the RF units 621, 622, and 623 may be located at different positions in the same preset area to jointly cover the same preset area. As shown in the example embodiment, the system 6000 includes three RF units. Optionally, the system 6000 may also include other numbers of RF units.

[0164] According to the technical solution of the present application, system 6000 can be used to achieve full or partial mobile communication coverage in the second, third, and fourth preset areas. That is, system 6000 can be used to include the second, third, and fourth preset areas in the coverage of the public mobile communication network.

[0165] Optionally, twisted-pair system 630 may include at least one twisted-pair pair. Optionally, at least one of radio frequency units 621, 622, and 623 may be connected point-to-point to access unit 610 via at least one twisted-pair pair in twisted-pair system 630. Optionally, twisted-pair system 630 may include a network cable. Optionally, the network cable may be a Category 5, Category 6, Category 7, or other type of network cable. Optionally, the length of the network cable does not exceed 200 meters. Furthermore, the length of the network cable is 100-200 meters. Optionally, at least one radio frequency unit may be connected to access unit 610 via four twisted-pair pairs in the network cable to achieve 2T2R or 4T4R MIMO capabilities. Optionally, at least one radio frequency unit may be connected to access unit 610 via two or more network cables to improve information throughput.

[0166] Optionally, the system 6000 may further include an RRU or an integrated small base station 640 , coupled to the access unit 610 .

[0167] According to some embodiments, the wireless communication distribution system 6000 utilizes the twisted pair system to implement 2T2R or 4T4R MIMO capabilities.

[0168] The above describes the system according to the embodiment of the present application. Through the above detailed description, those skilled in the art can easily understand that the technical solution according to the embodiment of the present application has one or more of the following advantages.

[0169] The distribution of mobile communication signals, including 5G communications, can be achieved using twisted pair cables in a relatively simple manner.

[0170] According to some embodiments, indoor mobile terminals can be covered; using twisted pair cables to connect with access units and RRUs or integrated small base stations can reduce networking costs.

[0171] According to example embodiments, the orthogonal frequency shifter provided herein can be used to implement frequency shifting operations on mobile communication signals, including 5G communication signals, using a relatively simple topology. This operation can downconvert mobile communication signals, including 5G communication signals, to a frequency band that can be transmitted over twisted pair cables.

[0172] According to an example embodiment, channel compensation or signal pre-emphasis can be used to ensure that a twisted pair channel has a wider available bandwidth and transmits over a longer distance.

[0173] According to example embodiments, 2G, 3G, 4G, and 5G communication signals may be transmitted using a twisted pair combination, thereby reducing the network deployment cost of the system and improving the flexibility of the system.

[0174] The above are only some embodiments of the present application and are not intended to limit the present application in any form. These exemplary embodiments are not intended to be exhaustive or to limit the present application to the precise forms disclosed, and it is obvious that, given the inspiration of the above teachings, those of ordinary skill in the art can make many modifications and variations. Therefore, the scope of the present application is not intended to be limited to the aforementioned embodiments, but is intended to be defined by the claims and their equivalents.

[0175] The present application is not limited to any specific structure in this regard. The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept. For example, the above-mentioned features are replaced with (but not limited to) technical features with similar functions disclosed in this application by each other to form a technical solution.

Claims

1. A method for a wireless communication signal distribution system, characterized in that: A cell signal is generated by a micro base station and transmitted by a twisted pair cable to achieve indoor signal coverage. The method includes: Acquire a first I / Q baseband signal; Quadrature-modulate the first I / Q baseband signal to obtain a second modulated signal; transmitting the second modulated signal through a twisted pair channel; receiving the second modulated signal from the twisted pair channel; orthogonally demodulating the second modulated signal to obtain the first I / Q baseband signal, The acquiring of the first I / Q baseband signal includes: Receive a first modulated signal from an RRU or an integrated small base station, where the first modulated signal is a 5G signal; generating a first local oscillation real part signal and a first local oscillation imaginary part signal, wherein the first local oscillation real part signal and the first local oscillation imaginary part signal are both single-frequency signals with a phase difference of 90 degrees, and the frequencies of the first local oscillation real part signal and the first local oscillation imaginary part signal are both the local oscillation frequency of the first modulation signal; performing multiplication operations on the first modulated signal using the first local oscillator real part signal and the first local oscillator imaginary part signal respectively to obtain the first I / Q baseband signal; Low-pass filtering is performed on the first I / Q baseband signal to suppress out-of-band signals.

2. The method according to claim 1, wherein After quadrature demodulating the second modulated signal to obtain the first I / Q baseband signal, the method further includes: The first I / Q baseband signal is low-pass filtered to suppress out-of-band signals.

3. The method according to claim 1, wherein After quadrature demodulating the second modulated signal to obtain the first I / Q baseband signal, the method further includes: The first I / Q baseband signal is orthogonally modulated to obtain a first modulated signal.

4. The method according to claim 3, after quadrature modulating the first I / Q baseband signal to obtain a first modulated signal, further comprising: power amplifying the first modulated signal; The first modulated signal is transmitted.

5. The method according to claim 3, after quadrature modulating the first I / Q baseband signal to obtain a first modulated signal, further comprising: The first modulated signal is coupled to the RRU or the integrated small base station.

6. The method according to claim 1, after quadrature demodulating the second modulated signal to obtain the first I / Q baseband signal, further comprising: The first I / Q baseband signal is sent to the RRU or the integrated small base station through the CPRI / eCPRI interface.

7. The method according to claim 1, before transmitting the second modulated signal through the twisted pair channel, further comprising: Amplitude-frequency pre-emphasis is performed on the second modulated signal according to the attenuation characteristics of the twisted pair channel.

8. The method according to claim 7, wherein: The performing amplitude-frequency pre-emphasis on the second modulated signal according to the attenuation characteristic of the twisted pair channel includes: A high-pass filter is used to pre-emphasize the amplitude-frequency characteristic of the second modulated signal.

9. The method according to claim 1, after receiving the second modulated signal from the twisted pair channel, further comprising: Amplitude-frequency characteristic compensation is performed on the second modulated signal according to the attenuation characteristic of the twisted pair channel.

10. The method according to claim 9, wherein: The compensating the amplitude-frequency characteristic of the second modulated signal according to the attenuation characteristic of the twisted pair channel includes: A high-pass filter is used to compensate the amplitude-frequency characteristic of the second modulated signal.

11. The method according to any one of claims 8 and 10, wherein: The high-pass filter comprises: At least two high-pass filter modules are cascaded.

12. The method according to claim 11, wherein The gain of at least one of the at least two high-pass filtering modules is: Among them, R2, R3 and C2 are preset constants, f is the frequency, Vin is the input voltage of the filter module, V out is the output voltage of the filter module, and j is an imaginary unit.

13. The method according to claim 1, wherein The second modulation signal is a twisted pair transmission signal, and the frequency range of the second modulation signal is 10-200 MHz.

14. The method according to claim 1, wherein The twisted pair channel includes: at least one pair of twisted pairs; The at least one twisted pair includes at least one of a Category 5 cable, a Category 6 cable, and a Category 7 cable; The twisted pair channel is a channel that uses the at least one twisted pair to perform bidirectional transmission and / or MIMO transmission.

15. The method according to claim 14, wherein The length of the at least one twisted pair is 100-200 meters.

16. The method according to claim 1, further comprising: Acquire a second I / Q baseband signal; Quadrature-modulating the second I / Q baseband signal to obtain a fourth modulated signal; Transmitting the fourth modulated signal by sharing the twisted pair channel with the second modulated signal in a frequency division multiplexing manner, with a guard interval of 5-20 MHz between the fourth modulated signal and the second modulated signal; receiving the fourth modulated signal from the twisted pair channel; The fourth modulated signal is orthogonally demodulated to obtain the second I / Q baseband signal.

17. An orthogonal down-shifter, characterized in that: include: A quadrature demodulator, configured to quadrature-demodulate a first modulated signal to obtain an I / Q baseband signal, wherein the first modulated signal is a 5G signal; A quadrature modulator, configured to quadrature-modulate the I / Q baseband signal to obtain a second modulated signal; A low-pass filter is connected between the quadrature modulator and the quadrature demodulator to suppress the I / Q baseband signal out of band. The orthogonal down-shifter is used to transmit signals using twisted-pair cables to achieve indoor signal coverage. Wherein, the orthogonal demodulator is configured as follows: Receiving the first modulated signal from the RRU or the integrated small base station; generating a first local oscillation real part signal and a first local oscillation imaginary part signal, wherein the first local oscillation real part signal and the first local oscillation imaginary part signal are both single-frequency signals with a phase difference of 90 degrees, and the frequencies of the first local oscillation real part signal and the first local oscillation imaginary part signal are both the local oscillation frequency of the first modulation signal; The first local oscillator real part signal and the first local oscillator imaginary part signal are respectively multiplied by the first modulation signal to obtain the I / Q baseband signal.

18. An access unit, characterized in that include: A downlink quadrature demodulator, configured to quadrature-demodulate a first downlink modulated signal to obtain a downlink I / Q baseband signal, wherein the first modulated signal is a 5G signal; A downlink quadrature modulator, configured to quadrature-modulate the downlink I / Q baseband signal to obtain a downlink second modulated signal; a downlink low-pass filter, connected between the downlink quadrature demodulator and the downlink quadrature modulator, for performing out-of-band suppression on the downlink I / Q baseband signal; A second modulated signal transmitter transmits the downlink second modulated signal to the twisted pair channel; A second modulated signal receiver receives an uplink second modulated signal from the twisted pair channel; an uplink quadrature demodulator, for quadrature demodulating the uplink second modulated signal to obtain an uplink I / Q baseband signal, The access unit is used to transmit signals using twisted pair cables to achieve indoor signal coverage. Wherein, the downlink orthogonal demodulator is configured as follows: Receiving the downlink first modulated signal from the RRU or the integrated small base station; generating a first local oscillation real part signal and a first local oscillation imaginary part signal, wherein the first local oscillation real part signal and the first local oscillation imaginary part signal are both single-frequency signals with a phase difference of 90 degrees, and the frequencies of the first local oscillation real part signal and the first local oscillation imaginary part signal are both the local oscillator frequency of the downlink first modulated signal; The first local oscillator real part signal and the first local oscillator imaginary part signal are respectively multiplied with the downlink first modulated signal to obtain the downlink I / Q baseband signal.

19. The access unit according to claim 18, characterized in that: Also includes: an uplink quadrature modulator, for quadrature-modulating the uplink I / Q baseband signal to obtain an uplink first modulated signal; An uplink low-pass filter is connected between the uplink quadrature demodulator and the uplink quadrature modulator, and is used to suppress the uplink I / Q baseband signal out of band.

20. The access unit according to claim 18, characterized in that Also includes: A first high-pass filter is used to pre-emphasize the downlink second modulated signal, wherein the amplitude-frequency characteristic of the first high-pass filter matches the attenuation characteristic of the twisted pair channel.

21. The access unit according to claim 18, characterized in that Also includes: The second high-pass filter compensates for the uplink second modulated signal, and the amplitude-frequency characteristic of the second high-pass filter matches the attenuation characteristic of the twisted pair channel.

22. A radio frequency unit, characterized in that: include: A second modulated signal receiver receives a downlink second modulated signal from the twisted pair channel; A downlink quadrature demodulator, for quadrature demodulating the downlink second modulated signal to obtain a downlink I / Q baseband signal; A downlink quadrature modulator, configured to quadrature-modulate the downlink I / Q baseband signal to obtain a downlink second modulated signal; An uplink first modulated signal receiver, receiving an uplink first modulated signal, wherein the uplink first modulated signal is a 5G signal; an uplink quadrature demodulator for quadrature demodulating the uplink first modulated signal to obtain an uplink I / Q baseband signal; an uplink quadrature modulator, for quadrature-modulating the uplink I / Q baseband signal to obtain an uplink second modulated signal; A second modulated signal transmitter transmits the uplink second modulated signal to the twisted pair channel, The radio frequency unit is used to transmit signals using twisted pair cables to achieve indoor signal coverage. Wherein, the uplink orthogonal demodulator is configured as follows: generating a first local oscillation real part signal and a first local oscillation imaginary part signal, wherein the first local oscillation real part signal and the first local oscillation imaginary part signal are both single-frequency signals and have a phase difference of 90 degrees, and the frequencies of the first local oscillation real part signal and the first local oscillation imaginary part signal are both the local oscillator frequency of the uplink first modulated signal; The uplink I / Q baseband signal is obtained by performing a multiplication operation on the uplink first modulated signal using the first local oscillator real part signal and the first local oscillator imaginary part signal respectively.

23. The radio frequency unit according to claim 22, characterized in that: Also includes: A first high-pass filter is used to compensate for the downlink second modulated signal, wherein the amplitude-frequency characteristic of the first high-pass filter matches the attenuation characteristic of the twisted pair channel.

24. The radio frequency unit according to claim 22, characterized in that Also includes: The second high-pass filter performs pre-emphasis on the uplink second modulated signal, and the amplitude-frequency characteristic of the second high-pass filter matches the attenuation characteristic of the twisted pair channel.

25. The radio frequency unit according to claim 22, characterized in that Also includes: A downlink low-pass filter, configured to suppress the downlink I / Q baseband signal out of band; An uplink low-pass filter performs out-of-band suppression on the uplink I / Q baseband signal.

26. The radio frequency unit according to claim 22, characterized in that Also includes: The downlink first modulated signal transmitter amplifies the power of the downlink first modulated signal and transmits it.

27. A wireless communication signal distribution system, characterized in that: include: The access unit according to any one of claims 18 to 21; At least one radio frequency unit according to any one of claims 22 to 26; A twisted pair system connects the radio frequency unit to the access unit in a distributed manner.

28. The wireless communication signal distribution system according to claim 27, wherein: Also includes: The RRU or integrated small base station is wirelessly coupled to the access unit or digitally connected to the access unit via CPRI / eCPRI.

29. The wireless communication signal distribution system according to claim 27, wherein: The radio frequency unit is arranged indoors or outdoors.

30. The wireless communication signal distribution system according to claim 27, wherein: The wireless communication signal distribution system utilizes the twisted pair system to achieve 2T2R or 4T4R MIMO capabilities.

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