WO2013097395A1

WO2013097395A1 - Active antenna device and signal transmission and reception method thereof

Info

Publication number: WO2013097395A1
Application number: PCT/CN2012/075328
Authority: WO
Inventors: 傅焕展; 王鹏; 王芳
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-12-31
Filing date: 2012-05-11
Publication date: 2013-07-04
Also published as: CN102570064B; CN102570064A

Abstract

An active antenna device comprises digital processing modules, transmission and reception radio-frequency modules and an antenna array in sequence. The device further comprises combiners, a passive antenna feeder phase-shift network and ANT (Antenna) air interfaces. A signal transmission and reception method for the active antenna device comprises the following steps: the active antenna device receives active antenna signals through OPT (Optical fiber Transformer) ports, while receives RRU (Radio Remote Unit) radio-frequency signals via ANT air interfaces; the active antenna signals are processed to be active antenna radio-frequency signals, and the RRU radio-frequency signals are power distributed to multi-path; and the active antenna device combines the active antenna radio-frequency signals and the each path RRU radio-frequency signals which had been performed power distribution separately and then outputs the combined signals. The active antenna device provides external interfaces to connect with the RRUs, realizes the multiplexed antenna array in the device, therefore making the network collocation convenient, improving the device utilization ratio and reducing the cost.

Description

Active antenna device and method for transmitting and receiving signals

Technical field

The present invention relates to the field of mobile communications, and in particular, to an active antenna device and a method for transmitting and receiving signals.

Background technique

In the field of civil mobile communication, the mainstream architecture of the current cell network is the Base Baseband Unite (BBU) + Radio Remote Unite (RRU), as shown in Figure 1, the baseband pool unit (BBU) completes the baseband signal interaction with the radio remote unit (RRU) through the optical fiber transmission, the RRU completes the digital intermediate frequency processing and realizes the conversion with the radio frequency signal, and connects with the antenna array through the radio frequency jumper, and the signal is transmitted by the antenna. Receive work. In actual field engineering, the architecture typically requires racking RRUs and antenna arrays at high points, such as the top of a residential tower. In this architecture, the RRU and the antenna array are independent physical entities, and the RF jumpers are used to complete the signal transmission. The insertion loss of the jumper consumes a large amount of power consumption, which directly affects the working efficiency of the RRU. Based on the reduction of operation and maintenance costs, and the flexibility of installation and operation and network upgrade, a variety of radio access network base station architectures have emerged. Active antennas, which are in the form of next-generation base stations, are receiving widespread attention.

The active antenna is a new architecture in the form of a next-generation base station. The external field engineering is set up as shown in Figure 2. Physically, it realizes the integration of the RRU and the antenna array. The multi-channel signal is usually provided with multiple antenna oscillators. Each antenna vibrator works in parallel, and each antenna vibrator is usually configured with two processing modules: a transceiver RF module and a baseband processing module. The active antenna divides the transceiver channel to the antenna oscillator level, and the granularity is more detailed. In addition to reducing the insertion loss caused by the jumper, the active antenna can realize beam flexible control and multiple-input multiple-output (MIMO) of the actual communication network by different configurations of the active antenna elements. And other functions, to achieve more flexible resource dynamic configuration and sharing, to achieve the goal of the network's best performance and low network-wide networking costs. At the same time, the integration of the RRU into the antenna saves the installation area of the antenna field and reduces the labor cost of installation and maintenance. Considering the actual use of the commercial network base station model, there will be a coexistence of the BBU+RRU architecture and the active antenna architecture for a long period of time in the future. When a cell needs to add new active antenna equipment, the installation location of the tower is likely to have been occupied by the previous RRU base station and passive antenna, and the antenna array is integrated inside the active antenna. If the antenna is used, it will inevitably lead to waste of resources. . Summary of the invention

The embodiments of the present invention provide an active antenna device and a method for transmitting and receiving signals thereof, so as to solve the problem that the installation location is scarce and the antenna resources are wasted during the use of the two communities in the common cell.

An embodiment of the present invention provides an active antenna device, including a digital processing module, a transceiver RF module, and an antenna array, which are sequentially connected, and the device further includes a combiner, a passive antenna feed phase shift network, and an antenna (ANT) air interface. among them:

The combiner is configured to: be located between the transceiver RF module and the antenna array, and have an active antenna RF signal from the transceiver RF module and a radio remote unit from the passive antenna feed phase shift network ( RRU) the RF signal is combined, the combined signal is provided to a corresponding antenna element in the antenna array; and the signal from the antenna element is received, and the signal is divided into an active antenna and an RRU signal. And respectively sent to the transceiver RF module and the passive antenna feed phase shift network;

The passive antenna-feeding phase-shifting network is configured to: connect to the plurality of combiners, and divide the RRU transmission signals received through the ANT air interface into multiple channels and respectively send the signals to the plurality of combiners; The RRU receiving signals from the plurality of combiners are combined and output to the RRU through the ANT air interface.

Preferably, the passive antenna-fed phase shifting network is further configured to: implement beamforming on the RRU side. Preferably, the device further includes an electrical adjustment port (AISG); the passive antenna-fed phase shifting network is configured to: implement a downtilt adjustment of a beam on the RRU side by using the AISG.

Preferably, the passive antenna-fed phase shifting network comprises a passive antenna network and a phase shifting network, and the passive antenna network is a Wilkinson and a 1/4 wavelength transform principle, and the microstrip a passive antenna feeder network implemented by lines and strip lines; the passive antenna feeder network is set to: by changing the line width and The line length controls amplitude and phase weighting respectively to implement beamforming on the RRU side; the phase shifting network is configured to: achieve phase change by changing the physical length or dielectric constant of the line.

Preferably, the combiner is a combiner implemented in the form of a microstrip printed circuit board or a cavity; and/or the antenna array is in the form of a bandwidth, supporting at least an active antenna signal band and an RRU The antenna frame of the signal band.

Preferably, the device further includes a power division network; the power division network is configured to be located between the combiner and the antenna element, and the power dividing network is connected to multiple antenna elements by changing a line width And the line length provides amplitude and phase weighting for a plurality of antenna elements corresponding to the power division network.

Preferably, the apparatus further comprises a plurality of optical fiber converter (OPT) ports;

The digital processing module is configured to: receive an active antenna signal sent by the baseband processing unit (BBU) through the OPT port, and send an active antenna signal that is subjected to digital down-conversion processing to the BBU through the OPT port.

Preferably, the BBU is arranged to be located outside the active antenna device or inside the active antenna device.

Preferably, the BBU is configured to: connect to the active antenna device and the RRU through a plurality of OPT ports to form a chain network, a ring network, or a star network; or, the BBU is configured to: The active antenna device and the RRU are respectively connected through a plurality of OPT ports.

The embodiment of the invention further provides a method for transmitting and receiving signals by an active antenna device, the method comprising: the active antenna device receiving an active antenna signal through an optical fiber converter (OPT) port, and receiving the radio remote unit through the ANT air interface ( RRU) a radio frequency signal; processing the active antenna signal into an active antenna radio frequency signal, and dividing the RRU radio frequency signal into multiple channels;

The active antenna device combines the active antenna radio frequency signal and each RRU radio frequency signal after the power split to output.

Preferably, the method further comprises:

The active antenna device receives a signal and divides the signal into an active antenna signal and an RRU signal;

The active antenna device transmits the active antenna signal through the OPT port, and transmits the RRU signal to the RRU through an ANT air interface. The above-mentioned active antenna device is connected to the RRU and provides multiplexing of the antenna array inside the device, thereby improving the utilization rate of the device and reducing the cost while facilitating the actual network deployment. BRIEF abstract

Figure 1 is a schematic diagram of the external field engineering of the existing BBU+RRU architecture;

2 is a layout diagram of an existing active antenna external field engineering;

3 is a schematic diagram of a common antenna device of the present invention and an external field project of a BBU+RRU architecture; FIG. 4 is a schematic diagram of an external interface provided by the active antenna device of the present invention;

FIG. 5 is a schematic structural diagram of Embodiment 1 of an active antenna device according to the present invention; FIG.

6 is a schematic structural diagram of Embodiment 2 of an active antenna device according to the present invention;

7 is a schematic structural diagram of Embodiment 3 of an active antenna device according to the present invention;

8a is a first application scenario of the active antenna device and the BBU and the RRU; FIG. 8b is a second application scenario of the active antenna device and the BBU and the RRU; FIG. 8c is an active antenna device of the present invention; The application scenario of the BBU and the RRU is as follows: Figure 8 is a fourth application scenario of the active antenna device and the BBU and the RRU.

Preferred embodiment of the invention

In order to make the objects, the technical solutions and the advantages of the present invention more clearly, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments of the present application may be arbitrarily combined with each other.

The embodiment of the invention provides an active antenna device. Compared with the existing active antenna device, the device provides a plurality of external interfaces connected to the RF output port of the RRU to achieve the purpose of sharing the antenna array between the device and the RRU. In addition, the device provides M optical fiber converters (OPT) ports to implement joint networking applications with current BBUs and RRUs.

The external field engineering erection diagram of the active antenna device provided by the embodiment of the present invention is as shown in FIG. 3, and the active part of the device realizes the function of the active antenna itself (connecting with the BBU to realize the uplink and downlink digital signal processing function and the wireless transceiver function of the radio frequency signal) , beamforming function of uplink and downlink signals, under the uplink and downlink antennas The function of the tilting angle is adjusted to meet the function of the expansion of the cell network service. In addition, the device provides an external radio interface to be connected to the RRU to ensure the normal operation of the original network.

Specifically, the active antenna device includes a digital processing module, a transceiver RF module, and an antenna array, which are sequentially connected, and a combiner, a passive antenna feed phase shift network, and an ANT air interface, where:

The combiner is located between the transceiver RF module and the antenna array, and is configured to transmit an active antenna radio frequency signal from the transceiver RF module and a radio remote unit from the passive antenna feeder phase shift network ( RRU) the RF signal is combined, the combined signal is provided to a corresponding antenna element in the antenna array; and the signal from the antenna element is received, and the signal is divided into an active antenna and an RRU signal. And sent to the transceiver RF module and the passive antenna feeder phase shift network; the passive antenna feeder phase shift network is connected to the plurality of combiners for receiving through an antenna (ANT) air interface The RRU transmission signal is divided into multiple channels and sent to the plurality of combiners respectively; and the RRU receiving signals from the plurality of combiners are combined and output to the RRU through the ANT air interface.

As shown in FIG. 4, a schematic diagram of an external interface provided by the active antenna device of the present invention, wherein ANT 1 - ANT N is connected to an RRU air interface (N depends on the number of built-in antenna arrays) to implement interaction of radio frequency signals; The device may further include an AISG, which is an electrical regulation port of the RRU passive antenna array, and controls a downtilt adjustment of the RRU antenna array; further, the optical fiber converter (OPT) 1-OPTM port is the optical fiber of the device itself. The interface is connected to the BBU, RRU or other active antenna to complete the baseband signal to implement the hybrid networking function.

As shown in FIG. 5 , it is a schematic structural diagram of Embodiment 1 of an active antenna device according to the present invention. The device includes a digital processing module 11 , a transceiver RF module 12 , an antenna array 13 , a combiner 14 , and a passive antenna feed phase shift network 15 . . Active antenna One antenna oscillator corresponds to a set of transceiver links. The number of antenna elements and the corresponding relationship of the paths determine the number of transceiver links.

The digital processing module 11 is configured to convert the signal transmitted from the baseband processing unit to the IQ digital transmission signal and provide the RF transceiver module to the transceiver module during downlink. When uplinking, the IQ analog reception signal obtained by the down conversion is converted into IQ. The digital received signal is digitally processed. The digital processing module can be subdivided into M digital processing modules corresponding to the respective antenna elements, and each module completes the digital processing tasks of the respective transceiver links. In addition, the digital processing module also performs functions such as amplitude, phase calibration, beamforming, downtilt adjustment, subcarrier or submode downtiling through related algorithms. The transmitting and receiving radio frequency modules 12 respectively correspond to each antenna vibrator. Each module can be subdivided into transmit, receive, and feedback channels. The transmitting channel up-converts the intermediate frequency signal provided by the digital processing module to the radio frequency signal through the up-conversion modulator, and further amplifies the transmitting signal through the multi-stage amplifier. The receiving channel receives the RF small signal received from the antenna array, is amplified by a device such as a low noise amplifier (LNA), and is converted into an intermediate frequency signal by a downconverting mixer to be supplied to the digital processing module. The feedback channel performs two functions: (1) coupling the relevant signal from the output of the transmitting power amplifier (PA), and providing the digital processing module with digital predistortion processing (DPD) to optimize the adjacent channel leakage suppression ratio of the transmitting link; As a calibration channel, the amplitude and phase calibration of each channel can be transmitted and received.

The antenna array 13 is composed of an antenna vibrator to realize conversion of electromagnetic wave signals and radio frequency signals, and completes spatial radiation and reception functions of transmitting and receiving signals.

There are a total of M combiners 14 described above. In the downlink, it completes the combination of the active antenna RF signal and the RRU RF signal, and supplies it to each antenna oscillator; in the uplink, it receives the small signal received by the antenna oscillator, and the power is divided into the active antenna and the RRU two-way. signal.

The above passive antenna-fed phase shifting network 15 is composed of a passive antenna feeder network and a phase shifting network. The passive antenna feeder network completes the function of combining the power of the RRU transmission signal and the RRU reception signal, and assigns a certain amplitude and phase difference to each channel to realize antenna beamforming on the RRU side. The phase-shifting network is controlled by AISG, and the down-tilt angle adjustment of the beam on the RRU side is realized by changing the phase of each channel by the motor drive.

If the device shown in Figure 5 is used as a subsystem, the whole machine can also realize the integration of N subsystems, so that the external interfaces of the whole machine and the RRU air interface are ANT 1 - ANT N , a total of N.

The device shown in FIG. 5 realizes the power splitting and combining of the active antenna signal and the RRU signal through the combiner, and achieves the purpose of multiplexing the antenna array. The following describes the specific functions of the device from the perspective of the signal:

In the downlink, the device receives the active antenna IQ digital signal at the OPT port, and receives the RF analog downlink signal of the external RRU at the ANT 1 port. The active antenna IQ digital signal is converted into an IQ analog signal by the digital processing module 11, and is frequency-converted into an active antenna RF signal through the transceiver RF module 12; the RRU RF signal is divided into M-channel signals through a passive antenna-fed phase shifting network. The combiner provides the two signals together to the antenna element for energy radiation.

When uplinking, the antenna oscillator of the device receives a small space signal, and the active antenna RF is transmitted through the combiner. The signal and RRU RF signal are split into two paths. The active antenna RF signal is converted by the RF signal to the IQ analog signal and the IQ digital signal via the transceiver RF module 12 and the digital processing module 11, and is provided to the BBU for processing; the RF signals of the RRU are implemented by the passive antenna feed phase shift network 15 Combine the road, and send the RF analog signal after the combination to the RRU to complete the uplink signal processing function.

It should be noted that: the spatial radiation of each signal, the reception needs beamforming and downtilt adjustment, and the beamforming of the active antenna signal and the RRU signal is implemented by different methods. In the active antenna part, the whole machine uses a feedback link or a dedicated calibration channel to collect the amplitude and phase information of each channel for transmission and reception. The digital processing unit performs correlation processing to obtain the amplitude, phase difference and delay information of each channel, and finally by the number. The processing unit gives the correction factor for each channel to achieve beamforming and downtilt adjustment. In the RRU part, the passive antenna network realizes beamforming by assigning different amplitudes and phase differences to each channel through physical traces, and further adjusts the phase of each channel through the phase shift network through the AISG ESC to complete the downtilt adjustment.

Passive antenna feeder networks can be implemented by Wilkinson, 1/4 wavelength conversion, etc., by means of microstrip lines and strip lines, and further change the line width and line length to control the amplitude and phase performance.

Phase shifting networks primarily achieve phase changes by changing the physical length or dielectric constant of the line. The combiner can be implemented in the form of a microstrip printed circuit board or cavity, and the two signals of the combine are separated from each other in frequency. In order to improve the efficiency, the combiner insertion loss is required to be as small as possible, and certain suppression and isolation indicators are maintained between the ports to prevent mutual interference between the two signals.

The antenna element is in the form of a broadband, and at least the working frequency band supporting the active and passive parts is required.

FIG. 6 is a schematic structural diagram of Embodiment 2 of an active antenna device according to the present invention. Compared with the device shown in FIG. 5, FIG. 6 additionally adds a power division network 16 to implement a transceiver RF module and K antenna oscillators. Connection (K usually takes 2 or 3). The power distribution network 16 can be physically implemented using Wilkinson or other types of microstrip printed circuit board power splitters, providing a fixed amplitude and phase weighting for each vibrator by varying the line width and line length to provide active antenna side Beamforming on the RRU side provides another way of physical compensation.

The introduction of the power division network 16 reduces the number of active antenna side transceiver channels to some extent, thereby effectively reducing cost and power consumption. On the basis of Fig. 5 and Fig. 6, the active antenna can also realize the integration of the BBU, and its internal structure is shown in Fig. 7. The power division network 16 is removed, that is, the integration of FIG. 5 and the BBU is achieved.

The above-mentioned active antenna device can also provide M OPT external interfaces (M > 2), and the OPT interface can be combined with the existing BBUs and RRUs. The specific scenario is as follows:

Hybrid chain type: A chain network in which a BBU is simultaneously cascaded with K active antenna devices (hereinafter referred to as AAS) and L RRUs can be realized. Where K+L=Y, and the position and number of AAS and RRU in the chain network can be flexibly changed, as shown in Figure 8a.

Hybrid ring type: A ring network in which a BBU is simultaneously cascaded with K AASs and L RRUs is implemented, and the Yth base station is connected to the BBU to implement a loop. Where K+L=Y, and the position and number of AAS and RRU in the chain network can be flexibly changed, as shown in Figure 8b.

Hybrid star: It can realize the star networking mode of K AAS and L RRU connecting the same BBU at the same time. Among them, K+L=Y, and the configuration ratio of AAS and RRU in the star network can also be flexibly configured, as shown in Figure 8c.

Separate type: K AAS and L RRUs can be connected to the independent BBUs, as shown in Figure 8d.

In the above application scenario, the RRU air interface can be connected to the adjacent active antenna device of the present invention to realize multiplexing of the built-in antenna array while implementing the joint networking of the RRU and the device of the present invention.

The active antenna device of the present invention can also be applied in a cooperative radio access (CRAN) architecture of a cloud computing architecture.

The active antenna device is connected to the RRU through the external interface to implement multiplexing of the antenna array inside the device, thereby improving the utilization rate of the device and reducing the cost while facilitating the actual network deployment.

The embodiment of the present invention further provides a method for transmitting and receiving signals by an active antenna device. The method is applicable to the apparatus shown in FIG. 5 to FIG. 7, and is also applicable to the architecture shown in FIG. 8a-8d. The method includes:

Step 11. The active antenna device receives the active antenna signal through the optical fiber converter (OPT) port, and simultaneously receives the radio frequency remote unit (RRU) radio frequency signal through the ANT air interface; and processes the active antenna signal into the active antenna radio frequency signal. , dividing the RRU radio frequency signal into multiple channels;

Step 12: The active antenna device separately performs RF signal and power splitting on the active antenna The RRU RF signal is combined and output.

The above process is a process of transmitting signals by the active antenna device of the present invention. In addition, the process of receiving signals by the active antenna device is as follows:

Step 21: The active antenna device receives a signal, and divides the signal into an active antenna signal and an RRU signal.

Step 22: The active antenna device transmits the active antenna signal through the OPT port, and transmits the RRU signal to the RRU through an ANT air interface.

The active antenna device provided by the invention can multiplex the antenna array to transmit and receive signals, thereby improving device utilization and reducing cost.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program that instructs the associated hardware to be stored in a computer readable storage medium, such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above embodiments are only intended to illustrate the technical solutions of the present invention and are not to be construed as limiting the invention. It should be understood by those skilled in the art that the present invention may be modified or equivalently substituted without departing from the spirit and scope of the invention.

Industrial Applicability The above-mentioned active antenna device provides an external interface to the RRU to realize multiplexing of the antenna array inside the device, thereby improving the utilization rate of the device and reducing the cost while facilitating the actual deployment.

Claims

Claim

An active antenna device comprising a digital processing module, a transceiving radio frequency module and an antenna array connected in sequence, wherein the device further comprises a combiner, a passive antenna feed phase shift network and an antenna (ANT) air interface, wherein:

The passive antenna-feeding phase-shifting network is configured to be connected to the plurality of combiners, and divide the RRU transmission signals received through the ANT air interface into multiple channels and then separately send the signals to the plurality of combiners. And combining the RRU reception signals from the plurality of combiners and outputting to the RRU through the ANT air interface.

2. The apparatus according to claim 1, wherein

The passive antenna-fed phase shifting network is further configured to: implement beamforming on the RRU side.

3. The apparatus according to claim 2, wherein the apparatus further comprises an electrical regulation port (AISG); the passive antenna-fed phase shifting network is configured to: implement a downtilt adjustment of a beam on the RRU side by the AISG .

4. The apparatus according to claim 2, wherein

The passive antenna-fed phase shifting network comprises a passive antenna feeder network and a phase shifting network, and the passive antenna feeder network is a Wilkinson and 1/4 wavelength conversion principle, and passes through a microstrip line and a belt. Passive antenna feeder network realized by a line;

The passive antenna feeder network is configured to: control the amplitude and phase weighting by changing the line width and the line length, respectively, to realize the beam on the RRU side!

The phase shifting network is configured to: effect a phase change by changing the physical length or dielectric constant of the line.

5. The apparatus according to claim 1, wherein

The combiner is a combiner implemented in the form of a microstrip printed circuit board or a cavity; and/or the antenna array is in the form of a bandwidth, and supports at least an antenna of an active antenna signal band and an RRU signal band. A while.

6. Apparatus according to any of claims 1-5, wherein the apparatus further comprises a power network;

The power dividing network is configured to be located between the combiner and the antenna element, and the power dividing network is connected to a plurality of antenna elements, and the line width and the line length are changed to correspond to the power dividing network. Multiple antenna elements provide amplitude and phase weighting.

7. The apparatus according to claim 6, wherein the apparatus further comprises a plurality of fiber converters

( OPT ) mouth;

8. The apparatus according to claim 7, wherein

The BBU is configured to be located external to the active antenna device or internal to the active antenna device.

9. The apparatus according to claim 8, wherein

The BBU is configured to be connected to the active antenna device and the RRU through multiple OPT ports to form a chain network, a ring network, or a star network; or

The BBU is configured to be connected to the active antenna device and the RRU through a plurality of OPT ports.

10. A method for transmitting and receiving signals by an active antenna device, the method comprising:

The active antenna device receives the active antenna signal through the optical fiber converter (OPT) port, and simultaneously receives the radio frequency remote unit (RRU) radio frequency signal through the antenna (ANT) air interface; and processes the active antenna signal into the active antenna radio frequency signal , dividing the RRU radio frequency signal into multiple channels;

The active antenna device respectively pairs the active antenna radio frequency signal and each RRU after the power division The RF signal is combined and output.

The method according to claim 10, wherein the method further comprises:

The active antenna device transmits the active antenna signal through the OPT port, and transmits the RRU signal to the RRU through the ANT air interface.