CN111866898A

CN111866898A - Wireless communication signal distribution system and method, frequency shifter, access unit and radio frequency unit

Info

Publication number: CN111866898A
Application number: CN202010500766.1A
Authority: CN
Inventors: 郑思杰
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-05-29
Filing date: 2020-06-04
Publication date: 2020-10-30
Also published as: CN213586303U

Abstract

The present application relates to a method for a wireless communication signal distribution system, comprising: acquiring a first I/Q baseband signal; quadrature modulating the first I/Q baseband signal to obtain a second modulation signal; transmitting the second modulated signal over a twisted pair channel; receiving the second modulated signal from the twisted pair channel; and quadrature demodulating the second modulation signal to obtain the first I/Q baseband signal.

Description

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

Technical Field

The present application relates to the field of mobile communications, and in particular, to 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.

Background

70% of the data traffic and services of 5G communications are expected to occur in indoor scenarios such as stations, airports, stadiums, hospitals, subways, shopping malls, hotels, office buildings, etc. Furthermore, 80% of the working hours of 5G communication users will be in indoor environments. The domestic 5G main frequency band is 2.6GHz and 3.5GHz, the frequency is higher than that of 2G, 3G and 4G main frequency bands, the transmission loss and the penetration loss are increased, and the indoor coverage is difficult to pass through outdoors. The signal coverage of 5G signals is the key of 5G services.

Based on the passive indoor distribution system in the prior art, 5G RRU (Remote Radio Unit) signals can be combined to the passive indoor distribution system through the POI. The inventor of the application finds that the existing passive indoor distribution system mainly aims at 2G, 3G and 4G frequency bands, and has the problem of large loss for a higher frequency band of 5G.

On the other hand, in the prior art, an active digital indoor distribution system based on a micro base station has the defects of large system scale, high cost, large power consumption requirement and the like.

Disclosure of Invention

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

According to an aspect of the application, there is provided a method for a wireless communication signal distribution system, comprising: acquiring a first I/Q baseband signal; quadrature modulating the first I/Q baseband signal to obtain a second modulation signal; transmitting the second modulated signal over a twisted pair channel; receiving the second modulated signal from the twisted pair channel; and quadrature demodulating the second modulation signal to obtain the first I/Q baseband signal.

Another embodiment of the present application provides a quadrature down-shifter, including: the quadrature demodulator is used for quadrature demodulating the first modulation signal to obtain an I/Q baseband signal; the orthogonal modulator is used for orthogonally modulating the I/Q baseband signal to obtain a second modulation signal; and a low pass filter connected between the quadrature modulator and the quadrature demodulator for out-of-band rejection of the I/Q baseband signal.

Another embodiment of the present application provides a quadrature up-shifter, including: the quadrature demodulator is used for quadrature demodulating the second modulation signal to obtain an I/Q baseband signal; the orthogonal modulator is used for orthogonally modulating the I/Q baseband signal to obtain a first modulation signal; and a low pass filter connected between the quadrature demodulator and the quadrature modulator for out-of-band rejection of the I/Q baseband signal.

Another aspect of the present application provides an access unit including: the downlink orthogonal modulator is used for orthogonally modulating the downlink I/Q baseband signal to obtain a downlink second modulation signal; a second modulation signal transmitter for transmitting the downlink second modulation signal to a twisted-pair channel; a second modulated signal receiver for receiving an upstream second modulated signal from the twisted-pair channel; and the uplink orthogonal demodulator is used for orthogonally demodulating the uplink second modulation signal to obtain an uplink I/Q baseband signal.

Another aspect of the present application provides a radio frequency unit, including: a second modulation signal receiver which receives a downstream second modulation signal from the twisted-pair channel; the downlink orthogonal demodulator is used for orthogonally demodulating the downlink second modulation signal to obtain a downlink I/Q baseband signal; the downlink orthogonal modulator is used for orthogonally modulating the downlink I/Q baseband signal to obtain a downlink second modulation signal; the uplink orthogonal demodulator is used for orthogonally demodulating the uplink first modulation signal to obtain an uplink I/Q baseband signal; the uplink orthogonal modulator is used for orthogonally modulating the uplink I/Q baseband signal to obtain an uplink second modulation signal; and the second modulation signal transmitter is used for transmitting the uplink second modulation signal to the twisted-pair channel.

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

Any one of the above methods, orthogonal frequency shifters, access units, radio frequency units and systems are utilized. The distribution of mobile communication signals including 5G communication using twisted pair lines can be achieved in a relatively simple manner. In the system, a cell signal is generated by using the micro station, and signal transmission and coverage are carried out by using the twisted pair, so that the networking cost can be reduced, and the system is particularly suitable for indoor signal coverage.

The orthogonal frequency shifter provided by the application can be utilized to realize frequency shifting operation of mobile communication signals including 5G communication signals by utilizing a relatively simple topology. This operation may down-convert mobile communication signals, including 5G communication signals, to a frequency band transmittable over a twisted pair.

The twisted pair channel can be ensured to have wider available bandwidth and transmit for a longer distance through channel compensation or signal pre-emphasis. So that 2G, 3G, 4G and 5G communication signals can be transmitted using twisted pair combinations. Thereby reducing the netting cost of the system and providing flexibility to the system.

Drawings

Fig. 1 shows a schematic composition diagram of a passive indoor distribution system based on mobile communication of the prior art.

Fig. 2 shows a schematic composition diagram of an active indoor distribution system based on mobile communication of the prior art.

Fig. 3 shows a block schematic diagram of a down converter based on the prior art.

Fig. 4 shows a schematic diagram of the composition of an up-converter based on the prior art.

Fig. 5 shows signal characteristics of the down converter shown in fig. 3.

Fig. 6 shows a flow diagram of a method for a wireless communication distribution system according to an example embodiment of the present application.

Fig. 7 shows a schematic circuit diagram of a filter module according to an exemplary embodiment of the present application.

Fig. 8 shows the amplitude-frequency characteristic of the filter module shown in fig. 7.

Fig. 9 shows a schematic diagram of a high-pass filter of an exemplary embodiment of the present application.

Fig. 10 shows the amplitude-frequency characteristic of the high-pass filter shown in fig. 9.

Fig. 11 shows a schematic diagram of a quadrature down-shifter according to an exemplary embodiment of the present application.

Fig. 12 shows a schematic diagram of a quadrature upconverter according to another embodiment of the present application.

Fig. 13 shows a schematic diagram of the components of an access unit according to another embodiment of the present application.

Fig. 14 shows a schematic diagram of frequency range configurations in the 4G downstream fourth modulation signal and the 5G downstream second modulation signal in the example embodiment.

Fig. 15 is a schematic diagram illustrating a radio frequency unit according to another embodiment of the present application.

Fig. 16 is a schematic diagram showing a configuration of a wireless communication distribution system according to another embodiment of the present application.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different 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 concept of example embodiments to those skilled in the art. The same or similar reference numerals denote the same or similar parts in the drawings, and thus their repetitive description may sometimes be omitted. The drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the embodiments of the disclosure can be practiced without one or more of the specific details, or with other means, components, materials, devices, or steps. In such cases, well-known structures, methods, devices, implementations, materials, or operations are not shown or described in detail.

The block diagrams shown in the figures do not necessarily correspond to physically separate entities. These functional entities or parts of functional entities may be implemented in software or in one or more hardware modules and/or programmable modules or in different networks and/or processor means and/or micro-control means.

The following are embodiments of the method for a wireless communication distribution system, an orthogonal frequency down-shifter, an orthogonal frequency up-shifter, an access unit, a radio frequency unit and a wireless communication distribution system disclosed in the present invention, and those skilled in the art can understand the advantages and effects of the present invention from the disclosure of the present specification. The invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. The drawings of the present invention are for illustrative purposes only and are not intended to be drawn to scale. The following embodiments will further explain the related art of the present invention in detail, but the disclosure is not intended to limit the scope of the present invention. Although the technical solution of the present application is mainly described below by taking a 5G application as an example, it is easily understood that the technical solution of the present application can also be applied to other communication systems other than 5G communication, including other similar wireless communication application scenarios that may appear later.

It should be understood that the terms "first," "second," "third," and "fourth," etc. in the claims, description, and drawings of the present application are used for distinguishing between different objects and not for describing a particular order. The terms "comprises" and "comprising," when used in the specification and claims of this application, specify the presence of stated 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 groups thereof.

It is also to be understood that the terminology used in the description of the present application herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the application. As used in the specification and claims of this application, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the term "and/or" as used in the specification and claims of this application refers to any and all possible combinations of one or more of the associated listed items and includes such combinations.

As shown in fig. 1, in a passive indoor distribution system based on mobile communication in the prior art, a 5G RRU (Remote Radio Unit) signal may be combined into the passive indoor distribution system through a POI. The inventor of the present application found that the passive indoor distribution system based on the mobile communication of the prior art mainly aims at the 2G, 3G, 4G frequency bands. When the system passes through higher frequency, the loss is larger, and the system is difficult to adapt to the transmission of 5G communication signals. Therefore, if the system is applied to the 5G communication networking engineering, the system needs to be subjected to spread spectrum modification, or the number of the information sources and the power are increased. If 2T2R is to be realized, another signal distribution system is added. The system has large construction scale, high cost and insufficient flexibility.

As shown in fig. 2, in the active digital indoor distribution system based on the micro base station in the prior art, a BBU (baseband processing unit) may generate a cell baseband signal, and a HUB may complete downlink signal distribution and uplink signal aggregation, and an indoor distribution micro station may complete radio frequency signal transceiving. Data are transmitted between network elements through a CPRI protocol, and the micro station uses a photoelectric composite cable or a 10G network cable to carry out signal remote and power supply. The active digital indoor distribution system can realize 2G, 3G, 4G and 5G multimode transmission and synchronous coverage; 2T2R and 4T4R MIMO functions can be realized, and the method is a main mode of a future indoor distribution system. However, the network port or optical port of 10G can only realize the 2T2R function of the signal with the bandwidth of 100 Mhz. Six types of shielding net wires with the maximum pulling distance of 100 meters. Because the broadband signal is transmitted and received, a high-speed ADC, a DAC and an FPGA need to be configured, the equipment cost is high, and the power consumption is high.

In the prior art, there are also schemes for transmitting mobile communication signals using twisted pair wires. In this scheme, a down converter is generally used to convert the mobile communication signal to a lower frequency, and the communication signal of the lower frequency is transmitted to a predetermined indoor area by using a twisted pair, and then the communication signal of the lower frequency is reduced to the original mobile communication radio frequency signal by an up converter, so as to realize the coverage of the predetermined indoor area.

Fig. 3 shows a block schematic diagram of a down converter based on the prior art. Fig. 4 shows a schematic diagram of the composition of an up-converter based on the prior art. Fig. 5 shows signal characteristics of the down converter shown in fig. 3.

The down converter shown in fig. 3 may use a mixer to perform mixing processing on the carrier signal fc with a higher frequency and the local oscillator signal fo to obtain a carrier signal fs with a lower frequency. The frequency relationship of the three signals is:

fs＝fc-fo (a)

as shown in FIG. 5, during downconversion by the downconverter of FIG. 3, fs has an image signal 2fo-fc whose frequency converted signal is also superimposed on fs, causing interference. In order to avoid image signal interference, a band-pass filter is added. The bandpass filter is designed to avoid affecting the signal (fc) while suppressing the image signal (2 fo-fc).

When the down converter shown in fig. 3 is used for processing the problem of twisted pair transmission of 5G signals, the frequency fc of the 5G communication signals is higher, and is mainly 2.6 to 4.9GHz in FR 1; the operating frequency fs of the twisted pair is relatively very low, and is only less than 200 MHz. According to equation (a), in this scheme, the frequency fo of the local oscillator signal is very close to the frequency fc of the 5G communication signal. Resulting in the image signal frequency 2fo-fc being very close to the frequency fc of the 5G communication signal. This has led to a great examination on the design of band-pass filters, which is difficult to implement and costly to implement.

Similarly, referring to fig. 4, after the twisted pair cable transmits the signal to the remote rf unit, the 5G signal is recovered by the up-converter. An out-of-band signal aliased above the target modulated signal (fo + fs) is generated at the output of the mixer, which includes the local oscillator signal (fo) and the signal fo-fs. Due to the numerical relationship between the local oscillation frequency fo of the 5G signal and the working frequency fs of the twisted pair, out-of-band signals of the two frequencies are very close to the frequency fo + fs of the target modulation signal. Thus, when the 5G signal is processed by the up-converter shown in fig. 4, the implementation difficulty and cost of the band-pass filter for suppressing the out-of-band signal are also relatively large.

In order to solve the above problems, the inventor of the present application proposes a new technical solution, which can implement twisted pair relay transmission of 5G signals at a lower cost by using a quadrature frequency converter. According to the technical concept of the application, in the downlink direction, the access unit extracts the I/Q baseband signal of the 5G signal fc through the quadrature demodulator, suppresses the out-of-band signal by using the low-pass filter, and modulates the I/Q baseband signal to the frequency fs which can be transmitted by the twisted pair through the quadrature modulator, so that the 5G broadband signal is transferred to the twisted pair for transmission. The far-end radio frequency unit uses a quadrature frequency converter to convert the signals transmitted by the twisted pair into normal 5G signals, and the signals are amplified and transmitted to realize signal coverage. The reverse direction processing in the above manner may be adopted for the signal transmission in the uplink direction.

Hereinafter, the technical solution of the present application will be described in detail with reference to example embodiments.

Fig. 6 shows a flowchart of a method for a wireless communication distribution system according to an example embodiment of the present application.

As shown in fig. 6, in S110, a first modulation signal S is received₁(t) of (d). First modulation signal s₁(t) may be a mobile communication signal including a 5G communication signal. Optionally, the first modulation signal s ₁(t) may include one or more of 2G, 3G, 4G, and 5G. Optionally, the first modulation signal s may be received from an RRU or an integrated small base station in the downlink direction₁(t) of (d). Alternatively, in the uplink direction, the first modulation signal s may be acquired from at least one mobile communication terminal₁(t)。

s₁(t)＝a(t)cos(2πf_o1t+2πf_bt) (1)

Equation (1) shows that in an exemplary embodiment, the first modulation signal s₁(t) signal expression. As shown in formula (1), s₁(t) may be the first modulation signal. Wherein a (t) can be the first modulation signal s₁(t) amplitude of the baseband signal, f_o1May be the first modulation signal s₁(t) local oscillation frequency, f_bMay be the first modulation signal s₁(t) frequency of baseband signal, f_o1＞＞f_b。

In S120, the first modulation signal S is subjected to₁And (t) carrying out quadrature demodulation to obtain a first I/Q baseband signal. The first I/Q baseband signal may include a baseband signal I (t) and a baseband signal Q (t).

First, a first local oscillator real part signal I can be generated_b1(t) and a first local oscillator imaginary signal Q_b1(t) of (d). Wherein the first local oscillator real part signal I_b1(t) and a first local oscillator imaginary signal Q_b1(t) are both single frequency signals and are 90 ° out of phase. First local oscillator real part signal I_b1(t) and a first local oscillator imaginary signal Q_b1(t) are each a first modulation signal s₁(t) local oscillation frequency f _o1. Optionally, the first local oscillator real part signal I_b1(t) and a first local oscillator imaginary signal Q_b1(t) may be represented by the formula (2) or (3).

I_b1(t)＝cos(2πf_o1t) (2)

Q_b1(t)＝sin(2πf_o1t) (3)

As shown in equations (4) and (5), the first local oscillator real part signal I may be utilized respectively_b1(t) and a first local oscillator imaginary signal Q_b1(t) and a first modulation signal s₁(t) performing multiplication to obtain baseband signals I (t)/Q (t).

The baseband signal i (t) can be represented as:

I(t)＝1/2a(t)cos(2πf_bt)，

the baseband signal q (t) can be expressed as:

Q(t)＝1/2a(t)sin(2πf_bt)。

1/2a (t) cos (2 π f) as in formula (4) or formula (5)_bt+4πf_o1t) and 1/2a (t)sin(2πf_bt+4πf_o1t) is noise, i.e. an out-of-band signal.

Optionally, low pass filtering the first I/Q baseband signal to suppress out-of-band signals may be further included after S120.

Since the out-of-band components in equations (4) and (5) do not contain low-frequency components, only a low-pass filter is required to effectively suppress the out-of-band signal. Due to f_o1＞＞f_bTherefore, the frequency of the out-of-band signal is much greater than the frequency f of the baseband signal I (t)/Q (t)_b. The out-of-band signal can be suppressed using a relatively common low-pass filter. The filter is low in implementation difficulty and low in implementation cost.

The specific implementation manner of the quadrature demodulation may be implemented by FFT, hilbert transform, digital interpolation, direct digital mixing, direct analog mixing, and the like, which is not particularly limited in the present application.

Alternatively, S110 and S120 may be replaced by: and directly acquiring a baseband signal I (t) and a baseband signal Q (t) from the RRU or the integrated small base station. Optionally, the baseband signal i (t) and the baseband signal q (t) may be acquired from the RRU or the integrated small base station through a CPRI/eccri interface.

In S130, the baseband signal i (t)/q (t) may be quadrature modulated to obtain a second modulation signal S₂(t)。

A second local oscillator real part signal I may be generated first_b2(t) and a second local oscillator imaginary part signal Q_b2(t)。

Wherein the second local oscillator real part signal I_b2And (t) and the second local oscillator imaginary part signal are both single-frequency signals, and the phase difference is 90 degrees. Second local oscillator real part signal I_b2(t) and a second local oscillator imaginary part signal Q_b2(t) are each a second modulation signal s₂(t) local oscillation frequency f_o2。

Wherein, the frequency f_o2May be a frequency within the transmission bandwidth of the twisted pair channel. Alternatively, the frequency f_o2May be in the range of 10-200 MHz.

Optionally, the second local oscillator real part signal I_b2(t) and a second local oscillator imaginary signalQ_b2(t) may be represented by the formula (6) or the formula (7).

I_b2(t)＝2 cos(2πf_o2t) (6)

Q_b2(t)＝-2 sin(2πf_o2t) (7)

As shown in equations (8) and (9), the second local oscillator real part signal I may be processed_b2(t) multiplying the baseband signal I (t) by the imaginary signal Q of the second local oscillator_b2(t) is multiplied by the baseband signal Q (t). The second modulation signal s can be obtained by summing equation (8) and equation (9) ₂(t) of (d). The implementation of quadrature modulation is similar to that of quadrature demodulation, and is not described herein.

s₂(t)＝I(t)×I_b2(t)+Q(t)×Q_b2(t)＝a(t)cos(2πf_o2t+2πf_bt)

(10)

Alternatively, the frequency f can be configured appropriately_o2So that the second modulation signal s₂Frequency f of (t)_o2+f_bIn the range of 10-200 MHz.

In S140, the second modulated signal S may be transmitted through the twisted pair channel₂(t)。

In some application scenarios, the second modulated signal s may be transmitted over a twisted-pair channel₂(t) from the first preset area to the second preset area, wireless communication between the first preset area and the second preset area may not be facilitated directly through a preset communication means. Optionally, the preset communication means may include at least one of 2G, 3G, 4G, and 5G. Optionally, a shelter may be present between the first predetermined area and the second predetermined area, the shelter may comprise a wall, a metal object or other object that may affect the propagation of the wireless signal. Optionally, a first presetAt least one of the area and the second predetermined area is an uncovered area of the existing wireless communication network. Alternatively, the uncovered area of the existing wireless communication network may be a relatively closed area, such as an indoor area, an underground area, etc. Alternatively, the uncovered area of the original wireless communication network may be an open area that is not covered by the original wireless communication network. Alternatively, at least one of the first preset area and the second preset area may also be an area where the wireless communication terminals are too dense, such as some factory areas, schools, and the like.

Alternatively, the twisted pair channel may comprise a mesh, which may be a category five wire, a category six wire, a category seven wire, or other type of mesh. Alternatively, if the length of the net line can be 100-200 meters.

In S150, a second modulated signal S may be received from the twisted pair channel₂(t)。

In S160, a second modulation signal S may be utilized₂(t) recovering the first modulated signal s₁(t) of (d). Alternatively, the second modulated signal s may be quadrature-demodulated₂(t) obtaining a baseband signal I (t)/Q (t). Optionally, in S160, the baseband signal i (t)/q (t) may be quadrature-modulated, and the first modulation signal S is obtained by reduction₁(t) of (d). The process is similar to S120-S130 and will not be described herein.

Optionally, the second modulated signal s is demodulated in quadrature₂(t), after obtaining the baseband signal i (t)/q (t), low pass filtering may be further included to suppress the out-of-band signal.

Optionally, power amplifying the first modulation signal S may be further included after S160₁(t) and transmitting the first modulated signal s₁(t) of (d). For example, the first modulated signal s may be transmitted to at least one mobile communication terminal₁(t)。

Optionally, in the uplink direction, the first modulation signal s may also be coupled to the RRU or the integrated small base station ₁And (t), or sending a baseband signal I (t)/Q (t) to the RRU or the integrated small base station. And the RRU or the integrated small base station utilizes the baseband signal I (t)/Q (t) to restore and obtain the first modulation signal s₁(t) of (d). And the RRU or the integrated small base station can be utilized to send the first modulation signal s₁(t) of (d). Optionally, the baseband signal i (t)/q (t) may be sent to the RRU or the integrated small base station through a CPRI/eccri interface.

Optionally, after S150, the method may further include: modulating a second modulated signal s according to attenuation characteristics of the twisted pair channel₂(t) compensating for the amplitude-frequency characteristics.

Alternatively, the second modulation signal s may be filtered using a filter₂(t) compensating for the amplitude-frequency characteristics. The amplitude-frequency characteristic of the filter is matched with the amplitude-frequency characteristic of the twisted-pair channel, so that the total amplitude-frequency characteristic of the twisted-pair channel and the filter cascade is relatively flat in a preset frequency range.

Alternatively, the filter may be composed of a plurality of filtering modules in cascade. Alternatively, the filter may be composed of at least two high-pass filtering modules cascaded to each other. Alternatively, the transfer function of each high-pass filtering module may be as shown in equation (11)

Wherein R is₂、R₃And C₂All can be preset constants, f is frequency, Vin can be input voltage of the filter module, and V _outMay be the filter module output voltage and j may be an imaginary unit.

Optionally, the method according to the example embodiment may further include a multimode transmission mode, for example, the method may further include: acquiring a second I/Q baseband signal; quadrature modulating the second I/Q baseband signal to obtain a fourth modulation signal; sharing the twisted-pair channel with the second modulation signal in a frequency division multiplexing mode, and transmitting the fourth modulation signal, wherein a guard interval of 5-20MHz is arranged between the fourth modulation signal and the second modulation signal; receiving the fourth modulated signal from the twisted pair channel; and quadrature demodulating the fourth modulation signal to obtain the second I/Q baseband signal.

Further, the method according to an example embodiment may further include: and receiving a third modulation signal, and performing quadrature demodulation on the third modulation signal to obtain a second I/Q baseband signal. And may further comprise: and quadrature modulating the second I/Q baseband signal, and recovering to obtain a third modulation signal. Still further, a method according to an example embodiment may further include: and transmitting the third modulation signal.

For example, the first modulation signal may be a 5G signal and the third modulation signal may be a 4G signal, such that the second modulation signal and the fourth modulation signal corresponding to 4G and 5G may be simultaneously combined for transmission on the same twisted pair channel, providing device utilization.

As shown in fig. 7, the filtering module may include: operational amplifier U1, resistance R1, resistance R2, resistance R3, electric capacity C1, varactor diode C2 and inductance L. Among other things, the capacitor C1 may be used to isolate the bias voltage V_TThe inductor L may be used to provide a bias voltage V_TThe resistor R1 may be used for impedance matching. The resistor R1, the capacitor C1 and the inductor L have negligible influence on the transmission characteristic of the filter module. The transfer function of the filtering module shown in fig. 7 may be as shown in equation (11).

As shown in fig. 8, the amplitude-frequency characteristic of the filter module shown in fig. 7 has two inflection points. Respectively, (FL, 1) and (FC, Ac). Wherein:

as shown in fig. 7, the bias voltage V can be controlled_TThe capacitance of the varactor C2 is adjusted. And then canTo control the bias voltage V_TAnd adjusting the amplitude-frequency characteristic of the parameter adjusting filter module, and adjusting the inflection point parameters FL and FC of the filter module.

Fig. 9 shows a schematic diagram of a high pass filter according to an exemplary embodiment of the present application.

As shown in fig. 9, the high pass filter may include three

filtering modules

111, 112, and 113 in cascade. Among them, the

filtering modules

111, 112 and 113 may be the filtering module shown in fig. 7. The corresponding filter inflection point parameters are (Ac1, FL1, FC1), (Ac2, FL2, FC2) and (Ac3, FL3, FC3), respectively. Can be controlled by controlling the bias voltage V _T1、 V_T2And V_T3The filtering parameters of the

filtering modules

111, 112 and 113 are adjusted to match the attenuation characteristics of the twisted pair channels, respectively.

As shown in fig. 10, 121 is the amplitude-frequency characteristic curve of the

filtering module

111, 122 is the amplitude-frequency characteristic curve of the

filtering module

112, and 123 is the amplitude-frequency characteristic curve of the filtering module 113. 120 is the amplitude-frequency characteristic of the high pass filter of fig. 9, and 124 is the attenuation characteristic of the twisted pair channel.

Can be controlled by controlling the bias voltage V_T1、V_T2And V_T3The product of the amplitude-frequency characteristic of the high-pass filter and the attenuation characteristic of the twisted-pair channel is relatively flat curve in a preset frequency range. Curve 125 is the superimposed curve of curve 120 and curve 124, i.e., the total gain curve of the filter cascaded with the twisted pair channel shown in fig. 9.

As shown in the exemplary embodiment, the curve 125 is relatively flat between 0-FN. Thereby expanding the available bandwidth of the twisted pair channel.

Since the attenuation characteristics of a twisted pair are related to the type and length of the twisted pair. Therefore, V can be controlled according to the type and the length of the twisted pair_T1、V_T2And V_T3The transmission characteristic of the high-pass filter is adjusted. So that the overall gain characteristic of the filter cascade with twisted pair channels is relatively flat over a predetermined frequency range. The high pass filter in the exemplary embodiment includes a three stage filtering module. Alternatively, The filter may also include other numbers of filtering modules.

Optionally, before S140, the second modulation signal S may also be modulated according to the attenuation characteristics of the twisted-pair channel₂(t) performing amplitude-frequency characteristic pre-emphasis so that the second modulation signal s₂(t) after the pre-emphasis of the amplitude-frequency characteristic and the transmission of the twisted pair, the total amplitude-frequency characteristic is relatively flat in a preset frequency range.

Alternatively, a pair of filters may be employed such that the second modulated signal s₂And (t) carrying out amplitude-frequency characteristic pre-emphasis. According to some embodiments, the filter may be as shown in fig. 9, which is not described herein.

Alternatively, either or both of the amplitude-frequency characteristic pre-emphasis and the amplitude-frequency characteristic compensation may be set to be used.

Fig. 11 shows a schematic diagram of a quadrature down-shifter according to an exemplary embodiment of the present application. The orthogonal frequency down-shifter according to this embodiment can be used for the processing method of the aforementioned wireless communication distribution system.

As shown in fig. 11, a quadrature down-shifter 2000 may be used to shift the first modulated signal s₁(t) into a second modulated signal s₂(t) of (d). The first modulation signal may be a mobile communication radio frequency signal, which may include 2G, 3G, 4G, and 5G radio frequency signals. The second modulated signal may be a twisted pair transmissible signal.

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.

Referring to the foregoing description, quadrature demodulator 210 may utilize a first local real part signal I_b1(t) and a first local oscillator imaginary signal Q_b1(t) are respectively associated with the first modulated signal s₁(t) performing multiplication to obtain baseband signals I (t)/Q (t). First local oscillator real part signal I_b1(t) and a first local oscillator imaginary signal Q_b1(t) may be an equal amplitude, stable, single frequency signal. First local oscillator real part signal I_b1(t) and a first local oscillator imaginary signal Q_b1Frequency of (t)May all be the first modulation signal s₁(t) local oscillation frequency f_o1. First local oscillator real part signal I_b1(t) and a first local oscillator imaginary signal Q_b1The phase difference between (t) may be 90 °.

The filter 231 may be connected to the baseband signal i (t) for filtering out-of-band components of the baseband signal i (t). The filter 232 may be connected to the baseband signal q (t) for filtering out-of-band signals in the baseband signal q (t).

Quadrature modulator 220 may be coupled to low pass filters 231 and 232, respectively, and may generate a second modulation signal s using the filtered baseband signals i (t)/q (t) ₂(t) of (d). Can pass through a second local oscillator real part signal I_b2(t) multiplying the baseband signal I (t) by a second local oscillator imaginary signal Q_b2(t) multiplying the baseband signal Q (t), and adding the two product signals to obtain a second modulation signal s₂(t)。

Second local oscillator real part signal I_b2(t) and a second local oscillator imaginary part signal Q_b2(t) may be an equal amplitude, stable, single frequency signal. Second local oscillator real part signal I_b2(t) and a second local oscillator imaginary part signal Q_b2The frequency of (t) may be the second modulation signal s₂(t) local oscillation frequency f_o2. Second local oscillator real part signal I_b2(t) and a second local oscillator imaginary part signal Q_b2The phase of (t) may differ by 90 °.

Fig. 12 shows a schematic diagram of a quadrature upconverter according to another embodiment of the present application. The quadrature upconverter according to this embodiment can be used in the processing method of the aforementioned wireless communication distribution system.

As shown in fig. 12, a quadrature up-shifter 3000 may be used to shift the second modulated signal s₂(t) reduction to the first modulated signal s₁(t) of (d). The first modulation signal may be a mobile communication radio frequency signal, which may include 2G, 3G, 4G, and 5G radio frequency signals. The second modulated signal may be a twisted pair transmission signal.

According to an example embodiment, the quadrature up-shifter 3000 may include: quadrature demodulator 310, quadrature modulator 320, low pass filters 331 and 332.

Referring to the foregoing description, quadrature demodulator 310 may be used to quadrature demodulate the second modulated signal to obtain baseband signal i (t)/q (t). The low pass filters 331 and 332 may be used to reject out-of-band signals in the baseband signal i (t) and the baseband signal q (t), respectively. The quadrature modulator 320 may be configured to modulate the baseband signal i (t)/q (t) to obtain a first modulation signal s₁(t) of (d). Optionally, each of the above components may be similar to the components with the same name in fig. 11, and are not described herein again.

Fig. 13 shows a schematic composition diagram of an access unit according to an exemplary embodiment of the present application.

The access unit 4000 may be connected between the source end RRU or the integrated small base station and the twisted pair channel, and may be matched with a radio frequency unit connected to the other end of the twisted pair channel to implement communication connection between the wireless communication terminal in the preset area and the source end RRU or the integrated small base station. The access unit 4000 may be wirelessly coupled with an RRU or an integrated small base station, or may be digitally connected with the RRU or the integrated small base station.

The access unit 4000 may be used to process conversion between an uplink/downlink first modulation signal (radio frequency signal) and an uplink/downlink second modulation signal (twisted pair transmittable signal), or may be used to process conversion between an uplink/downlink I/Q baseband signal and an uplink/downlink second modulation signal. Therefore, the communication signals can be converted between wireless transmission and twisted pair transmission at the covered end of the wireless communication signals.

According to an example embodiment, in the downlink direction, the access unit 4000 may include: a downlink quadrature modulator 414 and a second modulated signal transmitter 418. Optionally, the front stage of the downlink orthogonal modulator 414 may further include a downlink orthogonal demodulator 412. In the uplink direction, the access unit 4000 may include: a second modulated signal receiver 428 and an uplink quadrature demodulator 424. Optionally, an uplink quadrature modulator 422 may also be included at a stage subsequent to the uplink quadrature demodulator 424.

Optionally, the access unit 4000 may also include a coupler (not shown), and may be wirelessly coupled and connected with an RRU or an integrated small base station through the coupler. The access unit 4000 may receive the downlink first modulation signal from the RRU or the integrated small base station through the coupler, or may transmit the uplink first modulation 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 of mobile communication. Alternatively, the radio frequency signal may be one item including 2G, 3G, 4G and 5G radio frequency signals, or a superposition of at least two items thereof.

As shown in fig. 13, the downlink quadrature demodulator 412 may be configured to quadrature demodulate the downlink first modulated signal to obtain the aforementioned downlink I/Q baseband signal. Optionally, a downstream low pass filter (not shown) may also be included between quadrature demodulator 412 and downstream quadrature modulator 414 for out-of-band rejection of the downstream I/Q baseband signals.

As shown in fig. 13, the downlink quadrature modulator 414 may be configured to quadrature modulate the downlink I/Q baseband signal to obtain a downlink second modulated signal. Wherein the downstream second modulated signal is usable for twisted pair transmission. The frequency of the downstream second modulated signal may be within the transmission bandwidth of twisted-pair channel 430. Alternatively, the frequency range of the downstream second modulation signal may be within 10-200 MHz.

As shown in fig. 13, a second modulated signal transmitter 418 may be connected between the downstream quadrature modulator 414 and the twisted-pair channel 430 for transmitting the downstream second modulated signal to the twisted-pair channel 430. Second modulated signal transmitter 418 may be directly connected to twisted-pair channel 430. Alternatively, twisted-pair channel 430 may include at least one twisted pair. The second modulated signal transmitter 418 may be coupled to at least one twisted pair of the twisted pair channels 430. Optionally, the second modulation signal transmitter 418 may also power amplify the downlink second modulation signal before transmitting the signal.

At the other end of twisted-pair channel 430, the radio frequency unit may be used to convert the downstream second modulated signal transmitted downstream through twisted-pair channel 430 into the downstream first modulated signal. And the radio frequency unit can be used for transmitting the downlink first modulation signal to the mobile communication terminal in the preset area. The rf unit may also receive an uplink first modulated signal from the mobile communication terminal, convert the uplink first modulated signal into an uplink second modulated signal, and transmit the uplink second modulated signal to the access unit 4000 in uplink via the twisted-pair channel.

As shown in fig. 13, second modulated signal receiver 428 may be configured to receive an upstream second modulated signal transmitted upstream over twisted-pair channel 430. The second modulated signal receiver 428 may be directly connected to the twisted pair channel 430. Optionally, a second modulated signal receiver 428 may be connected to at least one twisted pair of the twisted pair channels 430.

According to an example embodiment, the second modulated signal receiver 428 may be connected to the same pair of twisted pairs as the second modulated signal transmitter 418. The second modulated signal receiver 428 and the second modulated signal transmitter 418 perform duplex transceiving and/or multimode transceiving through a frequency division multiplexing (FDD) mode or a time division multiplexing (TDD) mode. The second modulated signal receiver 428 may be coupled to the second modulated signal transmitter 418 by a different twisted pair line for duplex and/or multimode transmission and reception.

As shown in fig. 13, the uplink quadrature demodulator 424 may be coupled to a second modulated signal receiver 428. The method can be used for quadrature demodulation of the uplink second modulation signal to obtain an uplink I/Q baseband signal. The uplink quadrature modulator 422 may be configured to quadrature modulate the uplink I/Q baseband signal to obtain an uplink first modulation signal. Optionally, an upstream low pass filter may also be included between upstream quadrature demodulator 424 and upstream quadrature modulator 422 for out-of-band rejection of the upstream I/Q baseband signals.

Alternatively, 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/eccri interface (not shown), and may be digitally connected to the RRU or the integrated small base station through the CPRI/eccri interface. Optionally, the uplink I/Q baseband and the downlink I/Q baseband signals may be directly exchanged with the RRU or the integrated small base station through a CPRI/eccri interface.

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 be an uplink baseband signal of at least one of 2G communication, 3G communication, 4G communication, and 5G communication.

Optionally, the access unit 4000 may further comprise a first high pass filter (not shown). Optionally, a first high-pass filter may be used to pre-emphasize the downstream second modulated signal. The first high-pass filter may be the filter described above with reference to fig. 9, and will not be described herein. Alternatively, the first high pass filter may be disposed between the second modulated signal transmitter 418 and the twisted pair channel 430, or between the downstream quadrature modulator 414 and the second modulated signal transmitter 418. Optionally, the first high-pass filter may be further disposed at a front stage of the downstream quadrature modulator 414 to directly pre-emphasize the downstream I/Q baseband signal.

Optionally, the access unit 4000 may further comprise a second high pass filter (not shown). Optionally, the second high-pass filter may be used to compensate the amplitude-frequency characteristic of the upstream first modulated signal. The second high-pass filter may be a filter as described with reference to fig. 9, which is not described herein. The second high pass filter may be disposed between the second modulated signal receiver 428 and the upstream quadrature demodulator 424 or between the second modulated signal receiver 428 and the twisted pair channel 430. Optionally, the second high-pass filter may be further disposed at a post-stage of the uplink quadrature demodulator 424, and may perform amplitude-frequency characteristic compensation on the uplink I/Q baseband signal.

Optionally, the access unit 4000 may also be used for multi-mode transmission of communication signals. For example, the signal coupled and received from the RRU or the integrated small cell may be a superimposed signal of at least two downlink first modulation signals, such as a superimposed signal of at least two of 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 modulation signals and respectively obtain at least two pairs of downlink I/Q baseband signals. Optionally, the access unit 4000 may further directly obtain at least two pairs of downlink I/Q baseband signals from the RRU or the integrated small base station through the CPRI/eccri interface.

Optionally, the access unit 4000 may further include at least two downlink orthogonal modulators 414, respectively configured to orthogonally modulate the two pairs of downlink I/Q baseband signals, so as to obtain at least two downlink second modulation signals. Optionally, the frequency ranges of the at least two downlink second modulation signals are within the transmission bandwidth of the twisted-pair channel and do not overlap with each other. Alternatively, the at least two downstream second modulated signals may be combined and transmitted in a frequency division multiplexed manner in twisted pair channel 430.

For example, according to some embodiments, the access unit 4000 may include first and second downlink quadrature modulators, and the first and second downlink quadrature modulators may be configured to perform quadrature modulation on a first (e.g., 5G) downlink I/Q baseband signal and a second (e.g., 4G) downlink I/Q baseband signal, respectively, so as to obtain a first (e.g., 5G) downlink second modulation signal and a second (e.g., 4G) downlink second modulation signal. A guard interval with a preset frequency width may be left between the first downlink second modulation signal and the second downlink second modulation signal, so that frequency ranges of the guard interval may not overlap with each other, as shown in fig. 14. Referring to fig. 14, the frequency range of the 5G downstream second modulation signal (5G signal) may be 100-200 MHz. The frequency range of the 4G downstream second modulation signal (4G signal) may be 70-90 MHz. 90MHz-100MHz 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, may also be configured similarly.

Optionally, the access unit 4000 may further include a second modulation signal combiner, which combines the at least two downlink second modulation signals.

In the uplink path, the received signals from twisted-pair channels 430 may also be at least two uplink second modulated signals that are transmitted in a frequency division multiplexing manner. Optionally, the access unit 4000 may comprise a signal splitter for splitting the at least two upstream second modulated signals transmitted in combination. Optionally, the frequency configuration of the at least two uplink second modulation signals that are combined and transmitted in the frequency division multiplexing manner may be as described in fig. 14, which is not described herein again.

The access unit 4000 may also include at least two uplink orthogonal demodulators, which are respectively configured to orthogonally demodulate the at least two uplink second modulation signals to obtain at least two pairs of uplink I/Q baseband signals. The at least two pairs of uplink I/Q baseband signals can be directly sent to the RRU or the integrated small base station through a CPRI/eCPRI interface. Or at least two uplink orthogonal modulators are used for orthogonally modulating the at least two pairs of uplink I/Q baseband signals to obtain at least two paths of uplink first modulation signals. And the at least two paths of uplink first modulation signals can be coupled and sent to the RRU or the integrated small base station.

The rf unit 5000 may be similar to a micro base station, and may be disposed in a predetermined area to perform communication signal coverage on the predetermined area. The rf unit 5000 may be connected to the twisted pair channel and may be configured to cooperate with any of the access units disposed at the other end of the twisted pair channel. The radio frequency unit 5000 may also be wirelessly coupled to at least one mobile communication terminal in a preset area, so as to implement mobile communication connection between the at least one mobile communication terminal in the preset area and the source RRU or the integrated small base station.

Referring to fig. 15, in the downlink direction, the radio frequency unit 5000 may include: a second modulated signal receiver 512, a downlink quadrature demodulator 514, and a downlink quadrature modulator 516. The uplink direction radio frequency unit 5000 may include: an uplink quadrature demodulator 526, an uplink quadrature modulator 524, and a second modulated signal transmitter 522.

In the downlink direction, the second modulated signal receiver 512 is operable to receive a downlink second modulated signal. The downlink second modulation signal may be generated by any of the foregoing access units according to signal conversion issued by the RRU or the integrated small base station, and may be transmitted to the radio frequency unit 5000 by the twisted pair channel 530 in a downlink. The downlink quadrature demodulator 514 may be configured to quadrature demodulate the downlink second modulated signal to obtain a downlink I/Q baseband signal. The downlink quadrature modulator 516 may be configured to quadrature modulate the downlink I/Q baseband signal to obtain a downlink first modulation signal.

Optionally, a first modulation signal transmitter (not shown) may be included at a stage subsequent to the downlink quadrature modulator 516 to transmit the downlink first modulation signal to at least one mobile communication terminal within the predetermined area. A downstream low pass filter (not shown) may also be included between downstream quadrature demodulator 514 and downstream quadrature modulator 516 to perform out-of-band rejection of the downstream I/Q baseband signals. Optionally, a first high-pass filter (not shown) may be included at a later stage of the second modulation signal receiver 512 to compensate the downstream second modulation signal.

In the uplink direction, the uplink quadrature demodulator 526 may be configured to quadrature demodulate an uplink first modulation signal from at least one mobile terminal in the predetermined area, so as to obtain an uplink I/Q baseband signal. The uplink quadrature modulator 524 may be configured to quadrature modulate the uplink I/Q baseband signal to obtain an uplink second modulated signal. A second modulated signal transmitter 522 may be used to transmit the upstream second modulated signal to twisted-pair channel 530. Any of the foregoing access units connected to the other end of the twisted-pair channel 530 may receive and recover the uplink second modulated signal, and may send the recovered signal to the RRU or the integrated small base station.

Optionally, the upstream stage of the upstream quadrature demodulator 526 may also include a first modulated signal receiver (not shown) for receiving the upstream first modulated signal from at least one mobile terminal. An upstream low pass filter (not shown) may also be included between upstream quadrature demodulator 526 and upstream quadrature modulator 524 to perform out-of-band rejection of the upstream I/Q baseband signals. A second high pass filter (not shown) may also be included in a preceding stage of the second modulated signal transmitter 522 to pre-emphasize the upstream second modulated signal.

It is easily understood that the radio frequency unit shown in fig. 15 operates in a similar manner in frequency shift, filtering, etc. to the access unit shown in fig. 13, and a detailed description thereof is omitted.

Fig. 16 is a schematic diagram showing a configuration of a wireless communication distribution system according to an exemplary embodiment of the present application.

As shown in fig. 16, the system 6000 may include: an access unit 610, at least one

radio unit

621, 622, and 623, and a twisted pair system 630.

The access unit 610 may be as described with reference to fig. 13, and will not be described in detail. The

rf units

621, 622 and 623 may be those described with reference to fig. 15, and will not be described herein.

Alternatively, the access unit 610 may be disposed in a first predetermined area, and the

rf units

621, 622, and 623 may be disposed in a second predetermined area, a third predetermined area, and a fourth predetermined area, respectively. The second preset area, the third preset area and the fourth preset area are difficult to directly communicate with the first preset area in a preset wireless communication mode. The preset wireless communication manner may include at least one of 2G, 3G, 4G, and 5G.

Alternatively, the first predetermined area may be an open area, and may be covered by a predetermined public mobile communication signal. At least one of the second preset area, the third preset area and the fourth preset area may be a preset area to be covered by the public mobile communication signal or an area to be enhanced. 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. Alternatively, the closed or semi-closed area may include an indoor area, a basement area, or the like, which is difficult to be covered 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 also be an open area which is not covered by the 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 also be an area where the mobile communication terminals are too dense, such as a factory floor, a school, a hospital, and the like.

Optionally, at least two of the

rf units

621, 622, and 623 may be disposed at different positions of the same predetermined area, and jointly cover the same predetermined area. As shown in the exemplary embodiment, the system 6000 includes 3 radio frequency units, and optionally, the system 6000 may include other numbers of radio frequency units.

According to the technical scheme of the application, the system 6000 can be utilized to realize the whole coverage or partial coverage of the mobile communication in the second preset area, the third preset area and the fourth preset area. That is, the second preset area, the third preset area and the fourth preset area can be included in the coverage of the public mobile communication network by the system 6000.

Alternatively, twisted pair system 630 may include at least one twisted pair. Optionally, at least one of the

radio units

621, 622, and 623 may be point-to-point connected to the access unit 610 via at least one twisted pair of the twisted pair system 630. Optionally, twisted pair system 630 may include a mesh wire. Alternatively, the network cable may be a five-type, six-type, seven-type or other type network cable. Optionally, the length of the mesh wire does not exceed 200 meters. Further, the length of the net wire is 100-200 meters. Optionally, at least one radio unit and the access unit 610 may implement MIMO capability of 2T2R or 4T4R through 4 twisted pairs in the network cable. Optionally, at least one radio access unit and the access unit 610 may be connected by two or more network cables to improve information throughput.

Optionally, the system 6000 may further include an RRU or an integrated small cell 640 coupled to the access unit 610.

According to some embodiments, the wireless communication distribution system 6000 utilizes the twisted pair system to implement MIMO capabilities of 2T2R or 4T 4R.

The foregoing describes a system in accordance with an embodiment of the present application. From the above detailed description, those skilled in the art will readily appreciate that the technical solutions according to the embodiments of the present application have one or more of the following advantages.

The distribution of mobile communication signals including 5G communication using twisted pair lines can be achieved in a relatively simple manner.

According to some embodiments, mobile terminals indoors may be covered; and the twisted pair is connected with the access unit and the RRU or the integrated small base station, so that the networking cost can be reduced.

According to an example embodiment, a frequency shift operation for mobile communication signals including 5G communication signals may be implemented using a relatively simple topology using the quadrature frequency shifter provided herein. This operation may down-convert mobile communication signals, including 5G communication signals, to a frequency band transmittable over a twisted pair.

According to an example embodiment, twisted pair channels may be guaranteed to have a wider available bandwidth for transmission over greater distances through channel compensation or signal pre-emphasis.

According to example embodiments, 2G, 3G, 4G, and 5G communication signals may be transmitted using twisted pair combinations, which may reduce the networking cost of the system and provide flexibility to the system.

The foregoing is merely exemplary of the present application and is not intended to limit the present application in any manner. The exemplary embodiments are not intended to be exhaustive or to limit the application to the precise forms disclosed, and obviously many modifications and variations are possible to those skilled in the art in light of the above teachings. Accordingly, the scope of the present application is not intended to be limited to the foregoing embodiments, but is intended to be defined by the claims and their equivalents.

The present application is not limited in this regard to any particular configuration. The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention herein disclosed is not limited to the particular combination of features described above, but also encompasses other arrangements formed by any combination of the above features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. A method for a wireless communication signal distribution system, comprising:

acquiring a first I/Q baseband signal;

quadrature modulating the first I/Q baseband signal to obtain a second modulation signal;

transmitting the second modulated signal over a twisted pair channel;

receiving the second modulated signal from the twisted pair channel;

and quadrature demodulating the second modulation signal to obtain the first I/Q baseband signal.

2. The method of claim 1, wherein the obtaining a first I/Q baseband signal comprises:

receiving a first modulation signal;

and quadrature demodulating the first modulation signal to obtain the first I/Q baseband signal.

3. The method of claim 2, wherein the receiving a first modulated signal comprises:

and receiving the first modulation signal from the RRU or the integrated small base station.

4. The method of claim 1, wherein the obtaining a first I/Q baseband signal comprises:

and acquiring the first I/Q baseband signal from the RRU or the integrated small base station through a CPRI/eCPRI interface.

5. The method of claim 2, wherein after quadrature demodulating the first modulated signal to obtain a first I/Q baseband signal, further comprising:

Low pass filtering the first I/Q baseband signal to suppress out-of-band signals.

6. The method of claim 1, wherein after quadrature demodulating the second modulated signal to obtain the first I/Q baseband signal, further comprising:

7. The method of claim 1, wherein after quadrature demodulating the second modulated signal to obtain the first I/Q baseband signal, further comprising:

and quadrature modulating the first I/Q baseband signal to obtain a first modulation signal.

8. The method of claim 7, further comprising, after said quadrature modulating said first I/Q baseband signal to obtain a first modulated signal:

power amplifying the first modulated signal;

and transmitting the first modulation signal.

9. The method of claim 7, after quadrature modulating the first I/Q baseband signal to obtain a first modulated signal, further comprising:

and coupling the first modulation signal to the RRU or the integrated small base station.

10. The method of claim 1, further comprising, after said quadrature demodulating said second modulated signal to obtain said first I/Q baseband signal:

And sending the first I/Q baseband signal to the RRU or the integrated small base station through the CPRI/eCPRI interface.