WO2022111308A1

WO2022111308A1 - Frequency-division multiplexing unit, apparatus and method

Info

Publication number: WO2022111308A1
Application number: PCT/CN2021/130370
Authority: WO
Inventors: 李欧鹏
Original assignee: 华为技术有限公司
Priority date: 2020-11-24
Filing date: 2021-11-12
Publication date: 2022-06-02
Also published as: CN114553653A

Abstract

Provided by the present application are a frequency-division multiplexing unit, apparatus and method. The frequency-division multiplexing unit comprises a first frequency mixer, a second frequency mixer, and a radio frequency synthesis unit connected to the first frequency mixer and the second frequency mixer. The first frequency mixer is used to mix a first signal and a local oscillator signal to obtain a first output signal, and the second frequency mixer is used to mix a second signal and the local oscillator signal to obtain a second output signal. Moreover, the radio frequency synthesis unit is used to synthesize the first output signal and the second output signal to obtain a synthesized signal. In the synthesized signal, a first input signal and a second input signal are located in different sidebands of the local oscillator signal, respectively. By using the frequency-division multiplexing scheme of the present application, the number of frequencies of the local oscillator signal is reduced, a large number of combiners and filters corresponding to frequencies are not required, and the structure is simple.

Description

Frequency division multiplexing unit, device and method

This application claims the priority of the Chinese patent application with the application number 202011335706.5 and the invention title "Frequency Division Multiplexing Unit, Apparatus and Method", which was filed with the State Intellectual Property Office of China on November 24, 2020, the entire contents of which are incorporated by reference in this application.

technical field

The present application relates to the field of communication technologies, and in particular, to a frequency division multiplexing unit, apparatus and method.

Background technique

With the evolution of wireless technology, the demand for bandwidth continues to increase. In the future, ultra-wideband signals above 20 GHz will be required to support ultra-large-capacity transmission at the terabit per second (Tbps) level. Ultra-wideband signals have reached the limit of analog-to-digital converter (ADC)/digital-to-analog converter (DAC) processing, using frequency-division multiplexing (FDM) Implementation is one possible solution.

FDM is a multiplexing technology that modulates multiple signals onto different frequency carriers and then superimposes them to form a composite signal. FDM provides the function of transmitting multiple data simultaneously on the same channel, greatly increasing the capacity. However, in the prior art, when multiplexing N-channel signals, it is necessary to use local oscillator signals of N frequencies to move the N-channel signals to different radio frequencies, and use a synthesizer for synthesis, which requires a large number of combiners and filters corresponding to frequencies. device, etc., increasing the complexity of the structure.

SUMMARY OF THE INVENTION

The present application provides a frequency division multiplexing unit, device and method to save the number of frequencies of local oscillator signals.

In a first aspect, a frequency division multiplexing unit is provided, including a first mixer, a second mixer, and a radio frequency synthesis unit connected to the first mixer and the second mixer;

The first mixer is used for mixing and outputting the first signal and the local oscillator signal to obtain a first output signal, and the second mixer is used for mixing the second signal and the local oscillator signal and outputting the obtained The second output signal; wherein, the first signal is a second input signal after adding a 90° phase shift to the first input signal, and the second signal is the second input signal adding a 90° phase shift to the second input signal a first input signal; the first input signal and the second input signal are input signals of the frequency division multiplexing unit;

The radio frequency synthesis unit is used for synthesizing the first output signal and the second output signal to obtain a synthesized signal, and in the synthesized signal, the first input signal and the second input signal are respectively located in the different sidebands of the local oscillator signal.

In this aspect, frequency division multiplexing of more intermediate frequency signals can be realized with the same number of frequencies of local oscillator signals, which saves the number of frequencies of local oscillator signals, and does not require a large number of combiners and filters corresponding to frequencies, Simple structure.

In a possible implementation, the frequency division multiplexing unit further includes a signal quadrature unit, the first output end of the signal quadrature unit is connected to the first mixer, and the first output end of the signal quadrature unit is connected to the first mixer. The two output ends are connected to the second mixer;

The signal quadrature unit is configured to perform equal-amplitude quadrature synthesis output on the first input signal and the second input signal to obtain the first signal and the second signal.

In this implementation, the signal quadrature unit may perform equal-amplitude quadrature synthesis output on the first input signal and the second input signal, so as to provide the first mixer and the second mixer for frequency mixing output.

In yet another possible implementation, the signal quadrature unit is a branch line bridge.

In this implementation, the signal quadrature unit can be implemented by using an analog circuit, for example, the signal quadrature unit is a branch line bridge. By adopting the branch line bridge, 90-degree power division can be realized, and the equal-amplitude quadrature synthesis output can be realized.

In yet another possible implementation, the signal quadrature unit is a digital signal processor.

In this implementation, the signal quadrature unit may also be implemented using a digital circuit.

In yet another possible implementation, the relationship between the first signal V _a1 and the second signal V _a2 is as follows:

in,

Wherein, V ₁ is the first input signal, and V ₂ is the second input signal.

In this implementation, the first signal and the second signal are quadrature signals of equal amplitude, ie V _a1 =V ₁ -jV ₂ , V _b1 =V ₂ -jV ₁ .

In another implementation, it can also be V _a1 = -V ₁ +jV ₂ , Vb1 = jV ₁ -V ₂ .

In another implementation, V _a1 =V ₁ +jV ₂ , V _b1 =V ₂ +jV ₁ may also be used.

In another implementation, V _a1 =-V ₁ -jV ₂ , V _b1 =-jV ₁ -V ₂ may also be used.

In yet another possible implementation, the first output end of the radio frequency synthesis unit is used to output the synthesized signal, and the frequency division multiplexing unit further includes a directional connection connected to the first output end of the radio frequency synthesis unit a coupler, the directional coupler is also connected to the digital signal processor;

The directional coupler is used for extracting and outputting the signal of the first power in the composite signal, and also for extracting the signal of the second power in the composite signal, and inputting the signal of the second power to the the digital signal processor;

The digital signal processor is configured to adjust the H according to the signal-to-noise ratio of the signal of the second power.

In this implementation, the extracted signal of the second power in the synthesized signal is input to the digital signal processor, which can be used to detect the signal-to-noise ratio of the feedback signal, thereby adjusting the value of the [H] matrix in the DSP to compensate for the power The non-ideal characteristics of splitters and bridges are used to achieve the lowest detected signal-to-noise ratio.

In yet another possible implementation, the frequency division multiplexing unit further includes a power divider, and the power divider is configured to output the local oscillator signal by power division of equal amplitude and in phase; the radio frequency synthesis unit includes any one of the following : Lange bridge, branch line bridge, ring bridge.

In another possible implementation, the frequency division multiplexing unit further includes an electric bridge, and the electric bridge is configured to output the local oscillator signal by equal-amplitude quadrature power division, and the electric bridge includes any one of the following: Langer bridge, branch line bridge, ring bridge; the radio frequency synthesis unit is a power divider.

In yet another possible implementation, the power divider is a Wilkinson power divider or a Gysel power divider.

In yet another possible implementation, when the harmonic component of the first input signal is 1, the first output signal is located in the upper sideband of the local oscillator signal, and the harmonic component of the second input signal is -1, the second output signal is located in the lower sideband of the local oscillator signal; or

When the harmonic component of the first input signal is -1, the first output signal is located in the lower sideband of the local oscillator signal, and when the harmonic component of the second input signal is 1, the second output signal The signal is in the upper sideband of the local oscillator signal.

In this implementation, the first output signal and the second output signal output by the radio frequency synthesis unit are located in different sidebands of the local oscillator signal, and the harmonic components of the first input signal and the second input signal are suppressed, so that less interference can be obtained. output signal.

In a second aspect, a frequency division multiplexer is provided, the frequency division multiplexer includes a multi-stage cascaded frequency division multiplexing unit, wherein each stage includes one or more of the first aspect or the first Any one of the aspects realizes the frequency division multiplexing unit;

Wherein, the input signal of the first-stage frequency division multiplexing unit is an intermediate frequency signal;

The input signal of the frequency division multiplexing unit of the other stage includes the intermediate frequency signal and/or the synthesized signal output by the two frequency division multiplexing units of the previous stage.

In this aspect, using the frequency division multiplexer, the frequency division multiplexing of more intermediate frequency signals can be realized by the same number of local oscillator signals, which saves the number of frequencies of the local oscillator signals, and does not require a large number of corresponding frequencies. Combiners and filters with simple structure. Preferably, N local oscillators implement FDM with 2 ^N intermediate frequencies.

In a third aspect, a frequency division multiplexing method is provided, including:

mixing and outputting the first signal and the local oscillator signal to obtain a first output signal, and mixing and outputting the second signal and the local oscillator signal to obtain a second output signal;

Wherein, the first signal is a second input signal obtained by adding a 90° phase shift to the first input signal, and the second signal is the first input signal obtained by adding a 90° phase shift to the second input signal;

performing radio frequency synthesis on the first output signal and the second output signal to output a synthesized signal, in which the first input signal and the second input signal are respectively located on different sides of the local oscillator signal bring.

In a possible implementation, the method further includes:

The equal-amplitude quadrature synthesis output is performed on the first input signal and the second input signal to obtain the first signal and the second signal.

in,

Wherein, V ₁ is the first input signal, and V ₂ is the second input signal.

In yet another possible implementation, the method further includes:

extracting the signal of the first power and the signal of the second power in the composite signal;

outputting a signal of the first power;

The H is adjusted according to the signal-to-noise ratio of the signal of the second power.

For the beneficial effects of the method, reference may be made to the first aspect or the related beneficial effects achieved by any one of the first aspects.

In a fourth aspect, a computer-readable storage medium is provided, and a computer program or instruction is stored in the computer-readable storage medium. When the computer program or instruction is executed, the above third aspect or the third aspect is realized. any of the methods described.

In a fifth aspect, there is provided a computer program product comprising instructions, which when run on a computer, cause the computer to execute the above third aspect or any one of the third aspects to implement the method.

In a sixth aspect, a chip is provided, the chip is coupled with a memory, and implements any three of the third aspect or the first aspect of the embodiments of the present application to implement the communication method.

It should be noted that, "coupled" in the embodiments of the present application means that two components are directly or indirectly combined with each other.

Description of drawings

1 is a schematic diagram of a communication system involved in the application;

Fig. 2 is the principle schematic diagram of FDM;

Fig. 3 is a schematic diagram of a traditional analog FDM technology implementation scheme;

FIG. 4 is a schematic diagram of the radio frequency front-end architecture of the device;

FIG. 5 is a schematic structural diagram of a frequency division multiplexer provided by an embodiment of the present application;

6 is a schematic structural diagram of a module of an FDM unit provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of an FDM unit of a specific example provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of the principle of the branch line bridge in the FDM unit;

Fig. 9 is a schematic diagram of the principle of the Wilkinson power divider in the FDM unit;

10 is a schematic diagram of the Lange bridge principle in the FDM unit;

11 is a schematic structural diagram of another FDM unit of a specific example provided by an embodiment of the present application;

12 is a schematic structural diagram of another FDM unit of a specific example provided by an embodiment of the present application;

FIG. 13 is a schematic structural diagram of another FDM unit of a specific example provided by an embodiment of the present application;

14 is a schematic structural diagram of another FDM unit of a specific example provided by an embodiment of the application;

FIG. 15 is a schematic diagram of the principle of a directional coupler in an FDM unit provided by an embodiment of the present application;

16 is a schematic flowchart of a frequency division multiplexing method provided by an embodiment of the present application;

FIG. 17 is a schematic structural diagram of a signal orthogonalization apparatus provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

FIG. 1 is a schematic diagram of a communication system involved in the present application. The communication system may include at least one network device 100 (only one is shown) and one or more terminal devices 200 connected to the network device 100 . The frequency division multiplexer of the present application can be applied to the terminal device 200 and the network device 100 . The communication system may be a long term evolution (LTE) system, a fifth generation (5G) communication system (such as a new radio (NR) system, a communication system that integrates multiple communication technologies (such as A communication system in which LTE technology and NR technology are integrated), or a subsequent evolved communication system.

The network device 100 may be a device capable of communicating with the terminal device 200 . The network device 100 may be any device with a wireless transceiver function. Including but not limited to: evolved base station eNodeB, base station in 5G communication system, base station or network equipment in future communication system, access node in WiFi system, wireless relay node, wireless backhaul node, etc. The network device 100 may also be a wireless controller in a cloud radio access network (CRAN) scenario, a device-to-device (device-to-device, D2D), a vehicle-to-everything (V2X) connection ), a device that undertakes the function of a base station in machine-to-machine (M2M) communication, and the like. The network device 100 may also be a small station, a transmission reference point (transmission reference point, TRP) or the like. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device.

The terminal device 200 is a device with wireless transceiver function, which can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted; it can also be deployed on water, such as ships; it can also be deployed in the air, such as aircraft , balloons, and satellites. The terminal device can be a mobile phone (mobile phone), a tablet computer (pad), a computer with wireless transceiver function, a virtual reality (virtual reality, VR) terminal device, an augmented reality (augmented reality, AR) terminal device, industrial control ( Wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grid, transportation safety wireless terminals in smart cities, wireless terminals in smart homes, and so on. The embodiments of the present application do not limit application scenarios. Terminal equipment may also sometimes be referred to as user equipment (UE), access terminal equipment, UE unit, mobile station, mobile station, remote station, remote terminal equipment, mobile device, terminal, wireless communication device, UE Proxy or UE device etc.

It should be noted that the terms "system" and "network" in the embodiments of the present application may be used interchangeably. "Plurality" refers to two or more than two, and in view of this, "plurality" may also be understood as "at least two" in the embodiments of the present application. "And/or", which describes the association relationship of the associated objects, means that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/", unless otherwise specified, generally indicates that the related objects are an "or" relationship.

As shown in Figure 2, it is a schematic diagram of the principle of frequency-division multiplexing (FDM). FDM is a method of modulating multiple signals (the signals on channel 1, channel 2, and channel 3 in Figure 1). A multiplexing technology that superimposes on different frequency carriers to form a composite signal. FDM provides the function of transmitting multiple data simultaneously on the same channel, greatly increasing the capacity.

As shown in FIG. 3, the schematic diagram of the traditional analog FDM technology implementation scheme, if there are N intermediate frequency (intermediate frequency, IF) signals to be multiplexed, the local oscillator (local oscillator, LO) signal of N frequencies is used: Ω ₁ , Ω ₂ ,Ω ₃ ...Ω _N , move the N intermediate frequency signals to different radio frequencies, and then combine them with a combiner to form a broadband signal for transmission. During reception, N band pass filters (BPF) are used to filter out each radio frequency signal, and then the corresponding local oscillator signal is used to move it to an intermediate frequency for reception. However, every time a signal is added, an additional local oscillator signal of one frequency is required. N local oscillators can only provide FDM of N frequency bands, and a large number of combiners and filters corresponding to frequencies need to be used, which makes the structure complicated.

Aiming at the above-mentioned traditional analog FDM solution, the structure is complex, and the local oscillator signals of N frequencies can only perform frequency shifting for N intermediate frequency signals, the embodiments of the present application provide a frequency division multiplexing unit, device and method, The first signal and the second signal are mixed and output by the same local oscillator signal, and the same number of local oscillator signals can realize the frequency division multiplexing of more intermediate frequency signals, which does not require a large number of combiners and filters corresponding to frequencies, Simple structure.

The frequency division multiplexer provided by the embodiment of the present application may be applicable to a front-end system of a radio frequency transceiver of a terminal device and a network device. As shown in the schematic diagram of the radio frequency front-end architecture of the device as shown in Figure 4, the M signals output by the intermediate frequency channel are aggregated into a large bandwidth signal through the frequency division multiplexer 301 (through the N first-stage local oscillator signals 302), which are amplified and entered into The RF mixer moves to the high frequency through the second-stage local oscillator signal, and transmits it through the transmitting antenna. After space transmission, it is received by the receiving antenna, down-converted by the radio frequency mixer, and then entered into the frequency division multiplexer to deaggregate and restore the large-bandwidth signal into M intermediate frequency signals for demodulation. Among them, M﹥N. Exemplarily, in the architecture shown in FIG. 4 , M=2 ^N , that is, N first-stage local oscillator signals may be used to perform frequency shifting on 2 ^N intermediate frequency signals. Exemplarily, the traditional FDM method shown in FIG. 2 may also be used for part of the intermediate frequency signal, and the FDM method of the embodiment of the present application is used for part of the intermediate frequency signal, so M is greater than N and less than or equal to 2 ^N .

Specifically, the frequency division multiplexer 301 includes multiple stages of cascaded FDM units, and each stage includes one or more FDM units. The input signal of the FDM unit of the first stage is an intermediate frequency signal; the input signal of the FDM unit of other stages includes the intermediate frequency signal and/or the composite signal output by the two FDM units of the previous stage.

In an implementation manner, as shown in FIG. 5 , which is a schematic structural diagram of a frequency division multiplexer provided by an embodiment of the present application, the input signals of the first-stage FDM unit are ^2N intermediate frequency At the beginning, to the Nth stage, the input signal of the FDM unit is the composite signal output by the two FDM units of the previous stage, at this time, M=2 ^N . That is, each FDM unit in the frequency division multiplexer realizes the aggregated output of 2 intermediate frequency signals. In the case of aggregation of 2 ^N intermediate frequency signals, the FDM units are arranged in N levels. The first-level FDM unit aggregates ^2N intermediate frequency signals into ^2N-1 signals, the second-level FDM unit aggregates ^2N-1 signals into ^{2N-2 signals..., the Nth-level FDM unit aggregates 2 N-} 1 signals Signals are aggregated into one signal. The frequencies of the local oscillator signals used by the mixers in the FDM units of the same stage are the same; the frequencies of the local oscillator signals used by the mixers in the FDM units of different stages may be the same or different.

In another implementation, each stage includes one or more FDM units. Wherein, the input signal of each FDM can be two intermediate frequency signals, or a composite signal of the intermediate frequency signal and the output of one FDM unit of the previous stage, or the composite signal output by two FDM units of the previous stage, or an intermediate frequency signal (using the FDM technique shown in Figure 2).

In the frequency division multiplexer shown in FIG. 5, the module structure of any one of the FDM units is shown in FIG. 6, and the FDM unit 400 includes a first mixer 401, a second mixer 402, and a first mixer A radio frequency synthesis unit 403 of a mixer 401 and a second mixer 402; wherein:

The first mixer 401 is used to mix and output the first signal and the local oscillator signal to obtain the first output signal, and the second mixer 402 is used to mix the second signal and the local oscillator signal to output the second signal. output signal; wherein, the first signal is the second input signal after the first input signal is added with a 90° phase shift, and the second signal is the first input signal after the second input signal is added with a 90° phase shift; the first input signal and The second input signal is the input signal of the frequency division multiplexing unit;

The radio frequency synthesis unit 403 is used for synthesizing the first output signal and the second output signal to obtain a synthesized signal. In the synthesized signal, the first input signal and the second input signal are respectively located in different sidebands of the local oscillator signal.

Specifically, the first mixer 401 and the second mixer 402 use the same local oscillator signal (which may be a signal with a higher frequency than the first input signal and the second input signal, for example, the local oscillator signal is 2 GHz) The first signal and the second signal are mixed and output, and the same local oscillator signal can realize the frequency transfer of the two intermediate frequency signals, and transfer the two intermediate frequency signals to high frequencies. By performing radio frequency synthesis on the first output signal and the second output signal, a wider signal can be output, and through the above mixing process, the first input signal and the second input signal are located in different sidebands of the local oscillator signal respectively . The first input signal and the second input signal are respectively located in different sidebands of the local oscillator signal, which may be that the first input signal is located in the upper sideband of the local oscillator signal, and the second input signal is located in the lower sideband of the local oscillator signal; or It is that the first input signal is located in the lower sideband of the local oscillator signal, and the second input signal is located in the upper sideband of the local oscillator signal.

Further, the FDM unit 400 may further include a signal quadrature unit 404, the first output end of the signal quadrature unit is connected to the first mixer 401, and the second output end of the signal quadrature unit 404 is connected to the second mixer 402 ;

The signal quadrature unit 404 is configured to perform equal-amplitude quadrature synthesis output on the first input signal and the second input signal to obtain the first signal and the second signal.

In this embodiment, the first input signal and the second input signal are intermediate frequency signals. For example, its frequency is 20MHz. The equal-amplitude quadrature synthesis output is performed on the first input signal and the second input signal to obtain the first signal and the second signal, wherein the first signal is the first input signal and the second input signal after 90° phase shift , the second signal is the first input signal after adding a 90° phase shift to the second input signal.

The above-mentioned first signal and second signal can also be obtained in other manners. Therefore, the signal orthogonalization unit 404 is optional, which is represented by a dotted line in the figure.

In this embodiment, the same number of local oscillator signal frequencies can realize frequency division multiplexing of more intermediate frequency signals, which saves the number of local oscillator signal frequencies, and does not require a large number of combiners and filters corresponding to frequencies. Simple.

The FDM unit shown in Figure 6 is described in detail below:

As shown in FIG. 7 , it is a schematic structural diagram of an FDM unit of a specific example. In this example, two intermediate frequency signals V ₁ and V ₂ pass through a 90-degree bridge 1 and are fed into two up-conversion mixers ( Mixer 1, mixer 2), wherein the parameters of mixer 1 and mixer 2 are the same, and the parameters include: frequency conversion loss and phase shift, driving frequency and power of the local oscillator signal, input and output frequencies and power, etc.; the mixer is driven by an in-phase local oscillator signal whose frequency is Ω ₁ ; the outputs of the two mixers are then synthesized by a 90-degree bridge 2; finally a broadband signal is output, V ₁ and V ₂ are in the upper and lower sidebands of the local oscillator frequency Ω ₁ , respectively.

Specifically, the intermediate frequency 90° bridge 1 can use a branch line bridge to achieve 90° power division. The schematic diagram of the branch line bridge shown in Figure 8, the branch line bridge belongs to a four-port directional coupler, which is composed of two pairs of transmission lines connected by a coupling device. 4. The physical connection of the coupling line with a length of λ/4 realizes the coupling. The transmission line and coupling line impedance is the system impedance Z0

The 4 ports are divided into power input port, through port, coupling port, and isolation port. Coupling port and through port realize equal-amplitude quadrature output. The isolation port is terminated with a resistance equal to the system impedance to absorb reflection. power.

Each FDM unit includes a Wilkinson power divider, which inputs a local oscillator signal to the Wilkinson power divider of the FDM unit, and the Wilkinson power divider realizes equal-amplitude in-phase power division of the local oscillator signal. The schematic diagram of the Wilkinson power divider as shown in Figure 9, the Wilkinson power divider is a three-port power distribution device.

A transmission line of length λ/4 that splits the power in two. The end of the power division transmission line is terminated with an absorbing resistor of 2Z ₀ to absorb the mismatched reflected wave.

In another embodiment, a Gysel power divider may also be used. The Gysel power divider is used for equal-amplitude and in-phase power division of the local oscillator signal, and its principle is similar to that of the Wilkinson power divider.

In addition, it should be noted that the frequency of the local oscillator signal used by the mixers in the FDM unit of the same stage is the same. The Wilkinson power divider realizes equal-amplitude and in-phase power division of the local oscillator signal, and provides it to the two mixers in the FDM unit.

The radio frequency synthesis bridge (ie, the above-mentioned 90-degree bridge 2 ) adopts a Lange bridge. As shown in Figure 10, the schematic diagram of the lange bridge principle, the lange bridge uses multiple parallel lines with a length of λ/4 tightly coupled, and connects alternate lines. Its four ports are power input port, through port, coupling port, and isolation port. Coupling port and through port realize equal-amplitude quadrature output, and the resistance of isolation port end connected to system impedance absorbs reflected power. In addition, the RF synthesis bridge can also be replaced with a ring bridge, a branch line bridge, and the like.

Using the above device, a schematic structural diagram of another FDM unit of a specific example as shown in FIG. 11 can be obtained. The two sets of intermediate frequency signals V ₁ and V ₂ are fed through the input terminal a1 and the isolation terminal a2 of the branch line bridge, and are fed into two

identical mixers

1 and 2 through the straight-through terminal b1 and the coupling terminal b2. The local oscillator signals of the two mixers are fed through a Wilkinson power divider. The output ends of the mixer 1 and the mixer 2 are respectively connected to the input end c1 and the isolation end c2 of the lange bridge. The coupling end d2 of the lange bridge is connected to the system resistance absorbing load (the resistance value of the system resistance can be, for example, 50 ohms), and the straight end d1 is the system output port, from which the aggregated signal is output.

The signal analysis of each node in Figure 11 is as follows:

V _b1 =V ₁ -jV ₂ , V _b2 =V ₂ -jV ₁

Among them, V _LO is the local oscillator signal input to the mixer after power division, V _a1 is the signal of node a1, V _a2 is the signal of node a2, V _b1 is the signal of node b1, V _b2 is the signal of node b2, V _c1 is the signal of node c1, V _c2 is the signal of node c2, V _d1 is the signal of node d1, V _d2 is the signal of node d2, m is the harmonic component of intermediate frequency signal V ₁ , k is the signal of intermediate frequency signal V ₂ Harmonic components, n Harmonic components of the local oscillator signal.

1) When m=1, n=1, k=0, the frequency of mixing is V ₁ ·V _LO , that is, V ₁ is in the upper sideband of the local oscillator signal, at this time

V _d1 =[1-j·(-j)]·[V ₁ ·V _LO ]=0

That is, V ₁ is suppressed in the upper sideband of the local oscillator signal;

2) When m=-1, n=1, k=0

V _d1 =[1-j·(-j) ^-1 ]·[V ₁ ^-1 ·V _LO ]=2·V ₁ ^-1 ·V _LO

That is, V ₁ is output in the lower sideband of the local oscillator signal;

3) When m=0, n=1, k=1

V _d1 =[(-j)-j]·[V ₂ ·V _LO ]=j·2·V ₂ ·V _LO

That is, V ₂ is output in the upper sideband of the local oscillator signal;

4) When m=0, n=1, k=-1

V _d1 =[(-j) ^-1 -j]·[V ₂ ^-1 ·V _LO ]=0

That is, V2 is suppressed in the lower _sideband of the LO signal.

In specific implementation, according to the above 1) and 4), V ₁ is suppressed in the upper sideband of the local oscillator signal, while V ₂ is suppressed in the lower sideband of the local oscillator signal, so that V ₁ and V ₂ are respectively located in the local oscillator signal. Upper sideband, lower sideband; or according to ₂ ) and ₃ ) above, V1 is output in the lower sideband _of the local oscillator signal, while V2 is output in the upper sideband _of the local oscillator signal, so that V1 and V2 are respectively located in the local oscillator signal The lower and upper sidebands.

As shown in FIG. 12 , which is a schematic structural diagram of another FDM unit as a specific example, the difference from the FDM unit shown in FIG. 7 or FIG. 11 is that a 90° bridge 3 is used to equalize the input local oscillator signal. Orthogonal power division. As shown in Figure 12, the local oscillator signal V _LO is input from the input end of the bridge 3, the bridge 3 divides the power of V _LO into two, the straight end of the bridge 3 is connected to the mixer 3, and the straight end outputs V _LO goes to mixer 3, the coupling end of bridge 3 is connected to mixer 4, and the coupling end outputs -j*V _LO to mixer 4. V _LO and -j*V _LO are equal-amplitude quadrature signals. Alternatively, V _LO can also be input from the isolated end of bridge 3, bridge 3 divides the power of V _LO into two, the straight end of bridge 3 is connected to mixer 3, and the straight end outputs -j*V _LO goes to mixer 3, the coupling end of bridge 3 is connected to mixer 4, and the coupling end outputs V _LO to mixer 4.

Another difference is that the radio frequency synthesis unit is implemented by a 1:1 power divider, which can be the aforementioned Wilkinson power divider or a Geisel power divider, which is used for the mixer 3 The output V _c1 " and the V _c2 " signal output by the mixer 4 are radio-frequency synthesized to be V _d ".

After the above analysis, it can be seen that the two intermediate frequency signals of the same frequency are respectively moved to the upper and lower sidebands of the local oscillator frequency Ω1, and the FDM of two frequencies is realized with one local oscillator signal. If this structure is connected in series, FDM of 2 ^N intermediate frequencies can be realized with N local oscillator frequencies. However, if the FDM solution shown in FIG. 2 is adopted, ^2N local oscillator signals are required for FDM with ^2N intermediate frequencies. Therefore, the embodiment of the present application greatly simplifies the front-end architecture.

The above describes how to aggregate into a large bandwidth signal through the frequency division multiplexer during the transmission process. After the above-mentioned large-bandwidth signal synthesized by radio frequency is transmitted in space, it is received by the receiving antenna. The receiving process and the sending process are inverse processes. The specific receiving process is as follows: the received large-bandwidth signal V _d1 is input into the d1 node of the Lange bridge, and the Lange bridge c1 and c2 nodes output V _c1 and V _c2 respectively; V _c1 enters the first down-conversion mixer , V _c2 enters the second down-conversion mixer, the first down-conversion mixer moves V _c1 to the intermediate frequency according to the local oscillator signal and V _c1 , and obtains V _b1 , and the second down-conversion mixer according to the local oscillator signal and V _c2 , move V _c2 to the intermediate frequency to obtain V _b2 ; V _b1 and V _b2 are input to the branch line bridge to realize equal-amplitude quadrature outputs V _a1 and V _a2 . The parameters of the first and second down-conversion mixers may be the same or different from the first and second up-conversion mixers used in the transmission process.

As shown in FIG. 13 , it is a schematic structural diagram of another FDM unit of a specific example. In this example, a digital phase shift scheme is used to replace the intermediate frequency 90-degree bridge shown in FIG. 7 . Specifically, the intermediate frequency signals V ₁ and V ₂ are processed by a digital signal processor (DSP), and the intermediate frequency signal V ₁ is added to the intermediate frequency signal V ₂ after 90° phase shift to obtain V _a1 ′, and Adding the intermediate frequency signal V ₂ to the intermediate frequency signal V ₁ after being phase-shifted by 90°, V _a2 ' is obtained. The two signals V _a1 ' and V _a2 ' output by the DSP are respectively subjected to digital-to-analog conversion by the digital-to-analog converters DAC1 and DAC2 to output V _a1 , V _a2 . The output terminal a1 of DAC1 is connected to the intermediate frequency terminal of mixer 1, and the output port a2 of DAC2 is connected to the intermediate frequency terminal of mixer 2. The RF output of mixer 1 is connected to the input end b1 of the lange bridge, the RF output of mixer 2 is connected to the isolation end b2 of the lange bridge, and the coupling end c2 of the lange bridge is connected to the system resistance (for example, the resistance of the system resistance). The value can be 50 ohms) to absorb the load, the straight-through terminal c1 is the system output port, and the aggregated signal is output from this.

In the DSP, the following operations are performed on the two channels of intermediate frequency signals V ₁ and V ₂ , and the output V _a1 and V _a2 are:

in

That is, in digital processing, a 90-degree bridge effect is achieved.

In another embodiment, V _a1 = -V ₁ +jV ₂ , V _b1 =jV ₁ -V ₂ , ie

The output V _a1 and V _a2 are equal in magnitude and quadrature.

In another embodiment, V _a1 =V ₁ +jV ₂ , V _b1 =V ₂ +jV ₁ , ie

The output V _a1 and V _a2 are equal in magnitude and quadrature.

In another embodiment, V _a1 =-V ₁ -jV ₂ , V _b1 =-jV ₁ -V ₂ , ie

The output V _a1 and V _a2 are equal in magnitude and quadrature.

In this example, better amplitude and phase characteristics can be achieved by replacing the analog IF bridge with digital phase shifting.

As shown in FIG. 14 , which is a schematic structural diagram of another FDM unit of a specific example, the FDM scheme adopts a digital phase-shifting scheme with a feedback branch. In this example, a digital phase-shifting scheme is used to replace the IF 90-degree bridge shown in Figure 7. Specifically, the intermediate frequency signals V ₁ and V ₂ are processed by DSP, and the intermediate frequency signal V ₁ is added to the intermediate frequency signal V ₂ after the 90° phase shift to obtain V _a1 ′, and the intermediate frequency signal V ₂ is added to the 90° shifted intermediate frequency signal V 2 . The intermediate frequency signal V ₁ after the phase is obtained to obtain V _a2 '. The two signals V _a1 ' and V _a2 ' output by the DSP are respectively subjected to digital-to-analog conversion by DAC1 and DAC2 to output V _a1 , V _a2 . The output terminal a1 of DAC1 is connected to the intermediate frequency terminal of mixer 1, and the output port a2 of DAC2 is connected to the intermediate frequency terminal of mixer 2. The RF output of mixer 1 is connected to the input end b1 of the lange bridge, the RF output of mixer 2 is connected to the isolation end b2 of the lange bridge, the coupling end c2 of the lange bridge is connected to the 50ohm absorbing load, and the straight end c1 is the system output port, from which the aggregated signal is output.

in

A directional coupler is connected to the output port c1 of the lange bridge, and the directional coupling is terminated with a band-pass filter (BPF) and mixer 3, which are fed into the ADC of the digital intermediate frequency. The schematic diagram of the directional coupler can be seen in Figure 15. The signal input from the input end is extracted with a certain power and distributed to the coupling end and the output end. Usually, the signal with most power is output through the output terminal (specifically, the output terminal outputs the first power signal in the composite signal), and the signal with a small part of power is output at the coupling terminal (specifically, the coupling terminal outputs the second power signal in the composite signal) power signal), used for feedback detection of signal quality, power, etc. Wherein, the second power is less than or equal to the first power, and the ratio of the second power to the first power may generally be 1:10˜1:100.

Through the directional coupler, the signal with a small amount of power is coupled from the synthesized signal V _c1 , and then enters the band-pass filter, selects a part of the narrow-band signal in the frequency band, enters the mixer 3, and converts the frequency to low frequency and sends it to the ADC. The use of band-pass filters and mixers can reduce the signal bandwidth and signal frequency, avoid the use of wideband ADCs, and reduce costs. The feedback signal after the ADC is sent to the processor. The processor detects the signal-to-noise ratio of the feedback signal, and adjusts the value of the [H] matrix in the DSP through an algorithm to compensate for the non-ideal characteristics of the power divider and the bridge to achieve the lowest detected signal-to-noise ratio.

The feedback signal enters the digital intermediate frequency for processing and analyzes the signal-to-noise ratio of the signal. Feedback compensation is performed by adjusting the [H] matrix in the digital IF to compensate for the amplitude or phase distortion that may be caused by non-ideal power dividers and bridges, and to improve the signal-to-noise ratio of the synthesized signal.

In addition, the feedback branch can also be applied to the 90-degree bridge 1 shown in FIG. 7 .

This scheme moves the two same-frequency intermediate frequency signals to the upper and lower sidebands of the same local oscillator by shifting, mixing, and synthesizing the input signal, and suppresses its leakage at the image frequency. Finally, N local oscillator frequencies can realize FDM aggregation of 2 ^N intermediate frequencies, which greatly simplifies the FDM system architecture. At the same time, a digital intermediate frequency and a feedback loop are introduced, and the algorithm is used to adjust the signal-to-noise ratio of the feedback output signal in real time to compensate for the non-ideality of the analog device and improve the system performance.

Based on the same concept of the above frequency division multiplexing unit, the present application also provides a frequency division multiplexing method. As shown in FIG. 16 , which is a schematic flowchart of a frequency division multiplexing method provided by an embodiment of the present application, the method may include the following steps:

S101. Perform equal-amplitude quadrature synthesis output on a first input signal and a second input signal to obtain a first signal and a second signal.

In this embodiment, the first input signal and the second input signal are intermediate frequency signals. For example, its frequency is 20MHz. The equal-amplitude quadrature synthesis output is performed on the first input signal and the second input signal to obtain the first signal and the second signal, wherein the first signal is the second input signal after the first input signal is added with a 90° phase shift, The second signal is the first input signal obtained by adding a 90° phase shift to the second input signal.

The above-mentioned first signal and second signal may also be obtained in other manners. Therefore, this step S101 is optional, which is represented by a dotted line in the figure.

S102 , mixing and outputting the first signal and the local oscillator signal to obtain a first output signal, and mixing and outputting the second signal and the local oscillator signal to obtain a second output signal.

In this step, the same local oscillator signal (which may be a signal with a higher frequency than the first input signal and the second input signal, for example, the local oscillator signal is 2 GHz) is used to mix the first signal and the second signal respectively and output , the same local oscillator signal can realize the frequency transfer of two intermediate frequency signals, and move the two intermediate frequency signals to high frequency.

S103. Perform radio frequency synthesis on the first output signal and the second output signal to output a synthesized signal, where the first input signal and the second input signal are located in different sidebands of the local oscillator signal respectively.

By performing radio frequency synthesis on the first output signal and the second output signal, a wider signal can be output. Here, RF synthesis means that the output is a synthesized RF signal that can be transmitted.

Through the above mixing process, the first input signal and the second input signal are respectively located in different sidebands of the local oscillator signal. Specifically, when the harmonic component of the first input signal is 1, the first output signal is located in the upper sideband of the local oscillator signal, and when the harmonic component of the second input signal is -1, the second output signal is located at the lower side of the local oscillator signal or when the harmonic component of the first input signal is -1, the first output signal is located in the lower sideband of the local oscillator signal, and when the harmonic component of the second input signal is 1, the second output signal is located on the upper side of the local oscillator signal bring.

In one example, the relationship between the first signal V _a1 and the second signal V _a2 is as follows:

in,

Wherein, V ₁ is the first input signal, and V ₂ is the second input signal.

Further, the method can also include the following steps:

outputting a signal of the first power;

Adjust H according to the signal-to-noise ratio of the signal of the second power.

Specifically, the signal of the second power extracted from the composite signal is used to feed back the quality and power of the detected signal. By detecting the signal-to-noise ratio of the signal of the second power, the value of the above [H] matrix can be adjusted according to an algorithm to compensate for the non-ideal characteristics of the power divider and the bridge to achieve the lowest detected signal-to-noise ratio.

According to a frequency division multiplexing method provided by the embodiment of the present application, the first signal and the second signal are mixed and output by the same local oscillator signal, and the same number of local oscillator signals can realize the frequency division multiplexing of more intermediate frequency signals. use.

An embodiment of the present application further provides a chip, including: at least one processor and an interface, the at least one processor is coupled to a memory through an interface, and when the at least one processor executes a computer program or instruction in the memory, the above-mentioned figure is made Step S101 in the embodiment shown in 16 is performed. Optionally, the chip system may be composed of chips, or may include chips and other discrete devices, which are not specifically limited in this embodiment of the present application.

Embodiments of the present application further provide a computer-readable storage medium, where a computer program may be stored thereon, and when the program is executed by a processor, step S101 described in the embodiment shown in FIG. 16 of the present disclosure is implemented.

Embodiments of the present application further provide a computer program product including instructions, which, when run on a computer, cause the computer to execute step S101 described in the embodiment shown in FIG. 16 of the present disclosure.

The signal quadrature unit described in the above embodiments may be implemented by a branch line bridge and a DSP, and may also be implemented by a signal quadrature device as shown in FIG. 17 . The signal quadrature device 500 includes a logic circuit 501 and an input and output interface 502 . The input/output interface 502 may be an independent input interface and an output interface, or may be a combined input/output interface. The input and output interface 502 is used to receive the first input signal and the second input signal; the logic circuit 501 is used to perform equal-amplitude quadrature synthesis output on the first input signal and the second input signal to obtain the first signal and the second signal ; The input and output interface 502 is also used to output the first signal and the second signal.

Wherein, the logic circuit 501 may be a central processing unit (central processing unit, CPU). The central processing unit may further include a hardware chip. The above-mentioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above-mentioned PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a general array logic (generic array logic, GAL) or any combination thereof.

The input/output interface 502 may be an interface circuit, an output circuit, an input circuit, a pin or a related circuit, etc. on the signal quadrature device 500 .

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above may refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the division of the unit is only for one logical function division, and there may be other division methods in actual implementation, for example, multiple units or components may be combined or integrated into another system, or some features may be ignored, or not implement. The shown or discussed mutual coupling, or direct coupling, or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

Units described as separate components may or may not be physically separated, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the procedures or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted over a computer-readable storage medium. The computer instructions can be sent from one website site, computer, server, or data center to another by wire (eg, coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.) A website site, computer, server or data center for transmission. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that includes an integration of one or more available media. The available media may be read-only memory (ROM), or random access memory (RAM), or magnetic media, such as floppy disks, hard disks, magnetic tapes, magnetic disks, or optical media, such as , digital versatile disc (digital versatile disc, DVD), or semiconductor media, for example, solid state disk (solid state disk, SSD) and the like.

Claims

A frequency division multiplexing unit, characterized in that it includes a first mixer, a second mixer, and a radio frequency synthesis unit connected to the first mixer and the second mixer;

The first mixer is used for mixing and outputting the first signal and the local oscillator signal to obtain a first output signal, and the second mixer is used for mixing the second signal and the local oscillator signal and outputting the obtained The second output signal; wherein, the first signal is the second input signal after adding a 90° phase shift to the first input signal, and the second signal is the second input signal adding a 90° phase shift to the second input signal a first input signal; the first input signal and the second input signal are input signals of the frequency division multiplexing unit;

The radio frequency synthesis unit is used for synthesizing the first output signal and the second output signal to obtain a synthesized signal, and in the synthesized signal, the first input signal and the second input signal are respectively located in the different sidebands of the local oscillator signal.
The frequency division multiplexing unit according to claim 1, wherein the frequency division multiplexing unit further comprises a signal quadrature unit, and a first output end of the signal quadrature unit is connected to the first mixer , the second output end of the signal quadrature unit is connected to the second mixer;

The signal quadrature unit is configured to perform equal-amplitude quadrature synthesis output on the first input signal and the second input signal to obtain the first signal and the second signal.
The frequency division multiplexing unit according to claim 2, wherein the signal quadrature unit is a branch line bridge.
The frequency division multiplexing unit according to claim 2, wherein the signal quadrature unit is a digital signal processor.
The frequency division multiplexing unit according to claim 4, wherein the relationship between the first signal V a1 and the second signal V a2 is as follows:

in,

Wherein, V 1 is the first input signal, and V 2 is the second input signal.
The frequency division multiplexing unit according to claim 4 or 5, wherein the first output end of the radio frequency synthesis unit is used for outputting the synthesized signal, and the frequency division multiplexing unit further comprises a a directional coupler connected to the first output end of the synthesis unit, the directional coupler is also connected to the digital signal processor;

The directional coupler is used for extracting and outputting a signal of a first power in the composite signal, and also for extracting a signal of a second power in the composite signal and inputting the signal of the second power to the digital signal processor;

The digital signal processor is configured to adjust the H according to the signal-to-noise ratio of the signal of the second power.
The frequency division multiplexing unit according to any one of claims 1 to 6, characterized in that, the frequency division multiplexing unit further comprises a power divider, and the power divider is used for equal-amplitude and in-phase power division to output the local oscillator signal;

The radio frequency synthesis unit includes any one of the following: a Lange bridge, a branch line bridge, and a ring bridge.
The frequency division multiplexing unit according to any one of claims 1 to 6, wherein the frequency division multiplexing unit further comprises an electric bridge, and the electric bridge is used for equal-amplitude quadrature power division to output the Local oscillator signal, the bridge includes any one of the following: Lange bridge, branch line bridge, ring bridge;

The radio frequency synthesis unit is a power divider.
The frequency division multiplexing unit according to any one of claims 1 to 8, wherein when the harmonic component of the first input signal is 1, the first output signal is located in the middle of the local oscillator signal. upper sideband, when the harmonic component of the second input signal is -1, the second output signal is located in the lower sideband of the local oscillator signal; or

When the harmonic component of the first input signal is -1, the first output signal is located in the lower sideband of the local oscillator signal, and when the harmonic component of the second input signal is 1, the second output signal The signal is in the upper sideband of the local oscillator signal.
A frequency division multiplexing device, characterized in that the frequency division multiplexer includes a multi-stage cascaded frequency division multiplexing unit, wherein each stage includes one or more of the frequency division multiplexing units according to any one of claims 1 to 9. The frequency division multiplexing unit described in item;

Wherein, the input signal of the first-stage frequency division multiplexing unit is an intermediate frequency signal;

The input signal of the frequency division multiplexing unit of the other stage includes the intermediate frequency signal and/or the synthesized signal output by the two frequency division multiplexing units of the previous stage.
A frequency division multiplexing method, comprising:

mixing and outputting the first signal and the local oscillator signal to obtain a first output signal, and mixing and outputting the second signal and the local oscillator signal to obtain a second output signal;

Wherein, the first signal is a second input signal obtained by adding a 90° phase shift to the first input signal, and the second signal is the first input signal obtained by adding a 90° phase shift to the second input signal;

performing radio frequency synthesis on the first output signal and the second output signal to output a synthesized signal, in which the first input signal and the second input signal are respectively located on different sides of the local oscillator signal bring.
The frequency division multiplexing method according to claim 11, wherein the method further comprises:

The equal-amplitude quadrature synthesis output is performed on the first input signal and the second input signal to obtain the first signal and the second signal.
The frequency division multiplexing method according to claim 11 or 12, wherein the relationship between the first signal V a1 and the second signal V a2 is as follows:

in,

Wherein, V 1 is the first input signal, and V 2 is the second input signal.
The frequency division multiplexing method according to claim 13, wherein the method further comprises:

extracting the signal of the first power and the signal of the second power in the composite signal;

outputting a signal of the first power;

The H is adjusted according to the signal-to-noise ratio of the signal of the second power.
The frequency division multiplexing method according to any one of claims 11 to 14, characterized in that, when the harmonic component of the first input signal is 1, the first output signal is located in the middle of the local oscillator signal. upper sideband, when the harmonic component of the second input signal is -1, the second output signal is located in the lower sideband of the local oscillator signal; or

When the harmonic component of the first input signal is -1, the first output signal is located in the lower sideband of the local oscillator signal, and when the harmonic component of the second input signal is 1, the second output signal The signal is in the upper sideband of the local oscillator signal.
A computer-readable storage medium on which a computer program is stored, characterized in that, when the program is executed by a processor, the method according to any one of claims 11 to 15 is implemented.
A computer program product for performing the method of any of claims 11-15 when executed on a computing device.
A communication device, characterized in that it includes an input and output interface and a logic circuit,

the input and output interface is used for receiving the first input signal and the second input signal;

The logic circuit is configured to perform equal-amplitude quadrature synthesis output on the first input signal and the second input signal according to the method according to any one of claims 11 to 15 to obtain the first signal and the second signal ;

The input and output interface is also used for outputting the first signal and the second signal.