WO2017146278A1

WO2017146278A1 - Transmission device for performing selective beamforming by using multi-stream transmission circuit and transmission method thereof

Info

Publication number: WO2017146278A1
Application number: PCT/KR2016/001798
Authority: WO
Inventors: 최일도; 이경태; 이주용
Original assignee: 한국과학기술원
Priority date: 2016-02-24
Filing date: 2016-02-24
Publication date: 2017-08-31

Abstract

Disclosed is a wireless transmission device including one or more parasitic antennas and one or more active antennas for a beamspace MIMO system. The wireless transmission device comprises: a modem circuit for outputting a signal to be transmitted through multi-stream transmission or beamforming; a control circuit for selectively applying a control signal for generating a multi-stream signal or a beamforming signal, according to a transmission mode of the modem circuit; and an impedance loading circuit for loading impedance corresponding to a plurality of parasitic antennas in order to transmit the beamforming signal or loading impedance corresponding to one or more active antennas in order to transmit the multi-stream signal, according to the applied control signal.

Description

Transmission apparatus and selective transmission method for performing selective beamforming using multi-stream transmission circuit

The present invention relates to a radio transmitting apparatus and a method thereof. More specifically, the present invention relates to a wireless transmission apparatus and method for performing selective beamforming using a multi-stream transmission circuit.

In general, a communication system based on a voice communication service has used a single input single output (SISO) system using only a single antenna element for narrowband channel characteristics within a limited frequency range, but a narrowband SISO system using a single antenna is used. There have been many difficulties in transferring large amounts of data at high speeds within a channel.

Therefore, MIMO (Multiple Input Multiple Output) technology, which is a next generation wireless transmission technology that allows each antenna to be driven independently using multiple antennas and transmits data transmission / reception rates faster and with a lower error probability, has emerged.

However, MIMO technology, which uses a common array antenna to improve the data rate, increases the RF rate along with the increase in RF complexity when extending the antenna to improve the data rate.

This makes it difficult to expand the MIMO system given the limited size and power consumption requirements of the mobile terminal.

Accordingly, beamspace MIMO technology using an electronically steerable passive array radiator (ESPAR) has emerged, which is based on an ESPAR antenna having a parasitic element around an active element It is to overcome the limitations of the MIMO system.

In a beamspace MIMO system, one active antenna and a plurality of parasitic antennas are basically coupled to each other to form a beam pattern. Specifically, the power is applied to an active antenna using only a power amplifier for feeding one active antenna, and transfers power through a mutual coupling to a parasitic antenna disposed around the active antenna, and to an impedance value loaded in the parasitic antenna. Therefore, the signal is radiated. At this time, an impedance value for flowing a desired current must be loaded into an antenna, and in particular, an impedance value loaded into an active antenna needs to be always maintained at 50 Ω.

As described above, the beamspace MIMO system uses a single RF and has several advantages. However, since the system operates based on the coupling between the antennas, the performance is determined according to the sensitivity of the coupling between the antennas. There is this. Coupling between antennas can be defined as a parameter called Z-matrix, and this value can be easily changed according to the environment around the antenna, which has the disadvantage that the stability of the antenna stage is not guaranteed.

Accordingly, in the beamspace MIMO system, a load-modulated beamspace-MIMO in which an RF stage is connected to not only an active antenna but also a parasitic antenna, and the impedance loading circuits all share one power amplifier. The system is emerging. In this case, the coupling between the antennas can be reduced as much as possible and the isolation can be increased as compared to the beamspace (MIMO) method in which the antenna must maintain a coupling state that is neither too large nor too small. .

However, a load-modulated beamspace (MIMO) system requires an additional matching network between the power amplifier and the impedance loading circuit. This is because the impedance loading circuit changes impedance, but the impedance seen from the parasitic antenna must be maintained at 50 ohms.

Accordingly, the load-modulated beamspace (MIMO) system secures antenna stability, but increases the complexity of the system implementation due to an additional matching network and increases the difficulty and price of the implementation. have.

In addition, in a load-modulated beamspace (MIMO) system, the increase in complexity of the RF stage due to the matching network as described above is fundamental in that it is impossible to implement additional functions using the antenna stage. I have a problem.

The present invention is to solve the above problems, and through the impedance loading control for the active antenna and the parasitic antenna, beam space multi-stream transmission using the active antenna and beamforming function using a plurality of parasitic antennas selectively It is an object of the present invention to provide a radio transmitting apparatus and a method thereof that can be performed.

A wireless transmission apparatus including at least one parasitic antenna and at least one active antenna for a beam space MIMO system for achieving the above object, a modem circuit for outputting a signal to be transmitted by multi-stream transmission or beamforming (beamforming) A control circuit for selectively applying a control signal for generating a multi-stream signal or a beamforming signal according to the transmission mode of the modem circuit, and the beamforming signal according to the applied control signal. And an impedance loading circuit for loading impedances corresponding to the plurality of parasitic antennas for transmission or for loading the impedances corresponding to one or more active antennas for transmitting the multi-stream signal.

Here, the modem circuit may determine the transmission mode as a multi-stream transmission or beamforming transmission mode according to the update of the channel information.

The control circuit may include a multi-stream impedance converter for generating an impedance code corresponding to the multi-stream signal received from the modem circuit and outputting the impedance code to the impedance loading circuit.

The control circuit may generate a control signal for loading impedances corresponding to the parasitic antennas from a signal to be transmitted by beamforming received by the modem circuit, and output the control signal to the impedance loading circuit. It may include a forming impedance controller.

The impedance loading circuit may control one or more switches to load impedances corresponding to each of the plurality of parasitic antennas according to an impedance loading value for outputting a beamforming signal applied from the control circuit. One or more beamforming impedance loading circuits may be included.

Here, the one or more switches, a plurality of switch array for controlling the capacitor array in accordance with the impedance loading value, a first switch for adjusting the reactance area of the output signal output to the parasitic antenna and the inductor of the output signal interlocked It may include a second switch to determine the.

In addition, the impedance loading circuit controls the one or more variable resistors according to an impedance code for outputting the multi-stream signal applied from the control circuit, respectively, and loads a load modulated impedance corresponding to the active antenna, respectively. One or more load modulated impedance loading circuits may be included.

Meanwhile, a wireless transmission method using a wireless transmission apparatus including one or more parasitic antennas and one or more active antennas for a beam space MIMO system according to an embodiment of the present invention includes a signal to be transmitted by multi-stream transmission or beamforming. Outputting, selectively applying a control signal for generating a multi-stream signal or a beamforming signal according to the output signal, and transmitting a plurality of parasitics for transmitting the beamforming signal according to the applied control signal Loading an impedance corresponding to an antenna, or loading an impedance corresponding to one or more active antennas for transmitting the multi-stream signal.

In the outputting of the signal, the multi-stream transmission signal or the beamforming transmission signal may be output according to the update of the channel information.

The applying may further include generating an impedance code corresponding to the multi-stream signal and applying a control signal including the generated impedance code.

The applying may include applying a control signal for loading impedances corresponding to the plurality of parasitic antennas from the beamforming signal.

In the loading of the impedance, the impedance corresponding to each of the parasitic antennas may be loaded by controlling one or more switches according to the impedance loading value for the beamforming signal output.

In the loading of the impedance, the load modulated impedance corresponding to the active antenna may be loaded by controlling one or more variable resistors according to the impedance code for outputting the multi-stream signal. .

According to various embodiments of the present disclosure as described above, since the multi-stream signal is transmitted through a single RF, it is advantageous to integrate, reduce the cost, and ensure the stability of the antenna stage.

1 is a block diagram showing a configuration of a transmitting apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the detailed configuration of the transmitter shown in FIG.

3 is a block diagram illustrating a detailed configuration of a multi-stream impedance converter according to an exemplary embodiment of the present invention.

4 is a diagram illustrating a detailed configuration of a load modulating impedance loading unit according to an exemplary embodiment of the present invention.

5 is a circuit diagram illustrating a detailed configuration of a beamforming impedance loading unit according to an embodiment of the present invention.

6 is a flowchart illustrating a transmission method of a transmission apparatus according to an embodiment of the present invention.

The following merely illustrates the principles of the invention. Therefore, those skilled in the art, although not explicitly described or illustrated herein, can embody the principles of the present invention and invent various devices that fall within the spirit and scope of the present invention. In addition, all conditional terms and embodiments listed herein are in principle clearly intended to be understood only for the purpose of understanding the concept of the invention and are not to be limited to the specifically listed embodiments and states. do.

In addition, it is to be understood that all detailed descriptions, including the specific embodiments, as well as the principles, aspects, and embodiments of the present invention, are intended to include structural and functional equivalents thereof. In addition, these equivalents should be understood to include not only equivalents now known, but also equivalents to be developed in the future, that is, all devices invented to perform the same function regardless of structure.

Thus, for example, it should be understood that the block diagrams herein represent a conceptual view of example circuitry embodying the principles of the invention. Similarly, all flowcharts, state transitions, pseudocodes, and the like are understood to represent various processes performed by a computer or processor, whether or not the computer or processor is substantially illustrated on a computer readable medium and whether the computer or processor is clearly shown. Should be.

The functionality of the various elements shown in the figures, including functional blocks represented by a processor or similar concept, can be provided by the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functionality may be provided by a single dedicated processor, by a single shared processor or by a plurality of individual processors, some of which may be shared.

In addition, the explicit use of terms presented in terms of processor, control, or similar concept should not be interpreted exclusively as a citation to hardware capable of running software, and without limitation, ROM for storing digital signal processor (DSP) hardware, software. (ROM), RAM, and non-volatile memory are to be understood to implicitly include. Other hardware for the governor may also be included.

In the claims of this specification, components expressed as means for performing the functions described in the detailed description include all types of software including, for example, a combination of circuit elements or firmware / microcode, etc. that perform the functions. It is intended to include all methods of performing a function which are combined with appropriate circuitry for executing the software to perform the function. The invention, as defined by these claims, is equivalent to what is understood from this specification, as any means capable of providing such functionality, as the functionality provided by the various enumerated means are combined, and in any manner required by the claims. It should be understood that.

The above objects, features, and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a block diagram illustrating a transmitter according to an embodiment of the present invention.

Referring to FIG. 1, a transmission device 100 according to an embodiment of the present invention may include a modem circuit 110, a control circuit 120, an impedance loading circuit 130, an antenna unit 140, and a power distribution circuit 150. ).

The modem circuit 110 may output a signal to be transmitted by multi-stream transmission or beamforming. Here, the signal transmitted by multi-stream transmission or beamforming may be a complex signal. The modem circuit 110 may be implemented as an LTE modem or an LTE-A modem, but is not limited thereto.

In addition, the modem circuit 110 may determine the transmission mode of the output signal in the multi-stream transmission mode or the beamforming transmission mode according to the update of the channel information.

The control circuit 120 selectively applies a control signal for generating the multi-stream signal or the beamforming signal to the impedance loading circuit 130 according to the transmission mode of the modem circuit 110. In the multi-stream transmission mode, a control signal for generating a multi-stream signal may be applied, and in the beam-forming transmission mode, a control signal for generating a beamforming signal may be applied.

In addition, the control circuit 120 may change the I / Q signal transmitted from the modem circuit 110 to an impedance loading value. In this case, the impedance loading value may be the magnitude of the impedance required to deliver a specific magnitude of current to the antenna unit 140. In detail, a method of converting an I / Q signal into an impedance loading value will be described later with reference to FIG. 3.

The impedance loading circuit 130 may load an impedance corresponding to an active antenna or an impedance corresponding to a parasitic antenna according to a control signal applied from the control circuit 120.

In detail, when the transmission mode of the modem circuit is the multi-stream transmission mode according to the channel information, the impedance loading circuit 130 may load an impedance corresponding to at least one active antenna to transmit the multi-stream signal. Also, when the transmission mode of the modem circuit is the beamforming transmission mode, the impedance loading circuit 130 may load impedances corresponding to the plurality of parasitic antennas in order to transmit the beamforming signal.

Also, when the transmission mode of the modem circuit 110 is all beamforming, the impedance loading circuit 130 may control at least one switch to set an impedance loading value for outputting the beamforming signal. A detailed operation of the impedance loading circuit 130 will be described later with reference to FIG. 5.

The antenna unit 140 transmits a signal to the outside. The antenna unit 140 may include at least one active antenna and a plurality of parasitic antennas, and electromagnetic fields radiated through the active antennas may be induced through mutual coupling to the plurality of parasitic antennas.

In addition, the antenna unit 140 may be implemented as a printed circuit board (PCB) such as a motherboard, an integrated circuit (IC), a system on chip (SoC), or the like.

The power distribution circuit 150 supplies power to the impedance loading circuit 130. In detail, the power distribution circuit 150 may supply different power to each impedance loading unit of the impedance loading circuit 130 based on the control signal applied from the control circuit 120. However, the power supplied to each impedance loading unit of the impedance loading circuit 130 may be the same value.

According to FIG. 2, the transmitter 100 ′ includes a baseband modem 110, a multi-stream impedance converter 121, a beamforming impedance controller 122, a beamforming impedance loading unit 131, and a load modulation impedance loading unit. 132, an antenna 141, and a power distribution unit 150. Detailed description of parts overlapping with those shown in FIG. 1 among the elements shown in FIG. 2 will be omitted.

When the transmission mode of the modem circuit 110 is determined as the multi-stream transmission mode, the multi-stream impedance converter 121 generates an impedance code corresponding to the multi-stream signal received by the modem circuit 110 to generate an impedance loading circuit 130. Can be printed as

In this case, the impedance loading circuit 130 loads the first to nth load modulation impedance loading units 132-1, 132-2,..., 132-n so that the antennas 141-1, 141-2, 141-n) may transmit a multi-stream signal.

When the transmission mode of the modem circuit 110 is determined as the beamforming transmission mode, the beamforming impedance control unit 122 receives a control signal for loading an impedance corresponding to the parasitic antenna from the beamforming signal received by the modem circuit 110. It may be generated and output to the impedance loading circuit 130.

In this case, the impedance loading circuit 130 loads the first to nth beamforming impedance loading units 131-1, 131-2,..., 131-n to the antennas 141-1, 141-2, 141-n) may transmit a beamforming signal.

According to FIG. 3, the multi-stream impedance converter 121 may include a code generator 310, an interface 320, and a look-up table 330.

When the multi-stream impedance converter 121 receives the multi-stream signal from the modem circuit 110, the multi-stream impedance converter 121 may generate an impedance code corresponding to the multi-stream signal. In detail, the code generator 310 generates an impedance code corresponding to the I / Q signal received from the modem circuit 110. In this case, the code generator 310 may separate the I and Q values from the received I / Q signal and generate an impedance code based on the I and Q values in the pre-stored lookup table 130. Thereafter, the interface unit 320 may transmit the generated impedance code to the load modulation impedance loading unit 132.

The load modulation impedance loading unit 132 includes a 90

degree hybrid coupler

411, 412, 413, and a Wilkinson power combiner 420.

The load modulating impedance loading unit 132 may change the amplitude and phase of the current flowing through the active antenna by adjusting the loaded impedance value of the active antenna. As a result, the load modulation impedance loading unit 132 may adjust the impedance value of the active antenna so that a signal corresponding to the multi-stream signal output from the modem circuit 110 is transmitted from the active antenna.

The beamforming impedance loading unit 131 includes a first switch 510, a second switch 520, and a plurality of

switch arrays

531 and 532.

The first switch 510 may adjust the sound volume of the reactance region of the output signal output to the parasitic antenna. Specifically, when the first switch 510 is turned on upward, the reactance of the output signal may have a positive value, and when the first switch 510 is turned on downward, the reactance of the output signal is negative Can have

In addition, the second switch 520 may determine whether the output signal is inductor interlocked. In detail, the inductor is interlocked when the second switch 520 is turned on, and the inductor is not interlocked when the second switch 520 is turned off.

In addition, the plurality of

switch arrays

531 and 532 may control the capacitor array according to the impedance loading value.

However, the circuit shown in FIG. 5 is only an embodiment of the beamforming impedance loading unit according to the present invention, and the beamforming impedance loading unit may be implemented by various other circuits, but is not limited thereto.

According to the transmitting method of the transmitting apparatus shown in FIG. 6, first, a signal to be transmitted by multi-stream transmission or beamforming is output (S610). Here, the output signal may be determined as a multi-stream transmission signal or a beamforming transmission signal according to the update of the channel information.

Subsequently, according to the output signal, a control signal for generating a multi-stream signal or a beamforming signal is selectively applied (S620). In detail, an impedance code corresponding to the multi-stream signal may be generated to apply a control signal corresponding to the multi-stream signal, or a control signal for loading impedances corresponding to the plurality of parasitic antennas from the beamforming signal may be applied.

Subsequently, according to the applied control signal, an impedance corresponding to a plurality of parasitic antennas is loaded to transmit a beamforming signal, or an impedance corresponding to at least one active antenna is loaded to transmit a multi-stream signal (S630).

As described above, according to various embodiments of the present disclosure, since the multi-stream signal is transmitted through a single RF, it is advantageous to integrate, reduce the cost, and ensure the stability of the antenna stage.

Meanwhile, the above-described method according to various embodiments of the present disclosure may be implemented in program code and provided to each server or devices in a state of being stored in various non-transitory computer readable mediums.

The non-transitory readable medium refers to a medium that stores data semi-permanently and is readable by a device, not a medium storing data for a short time such as a register, a cache, a memory, and the like. Specifically, the various applications or programs described above may be stored and provided in a non-transitory readable medium such as a CD, a DVD, a hard disk, a Blu-ray disk, a USB, a memory card, a ROM, or the like.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the above-described specific embodiment, the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims

A radio transmitting apparatus comprising at least one parasitic antenna and at least one active antenna for a beam space MIMO system, comprising:

A modem circuit for outputting a signal to be transmitted by multi-stream transmission or beamforming;

A control circuit for selectively applying a control signal for generating a multi-stream signal or a beamforming signal according to the transmission mode of the modem circuit; And

Load impedances corresponding to a plurality of parasitic antennas for transmitting the beamforming signal or load impedances corresponding to one or more active antennas for transmitting the multi-stream signal according to the applied control signal Impedance loading circuit; wireless transmission device comprising a.
The method of claim 1,

The modem circuit,

And transmitting the transmission mode to a multi-stream transmission or beamforming transmission mode according to the update of channel information.
The method of claim 1,

The control circuit,

And a multi-stream impedance converter for generating an impedance code corresponding to the multi-stream signal received from the modem circuit and outputting the impedance code to the impedance loading circuit.
The method of claim 1,

The control circuit,

And a beamforming impedance controller configured to generate a control signal for loading impedances corresponding to the plurality of parasitic antennas from a signal to be transmitted by beamforming received by the modem circuit, and output the control signal to the impedance loading circuit. Transmitting device.
The method of claim 1,

The impedance loading circuit,

At least one beamforming impedance loading circuit for controlling one or more switches to load impedances corresponding to each of the plurality of parasitic antennas according to an impedance loading value for beamforming signal output from the control circuit; Wireless transmitting device comprising.
The method of claim 5,

The one or more switches,

A plurality of switch arrays for controlling the capacitor array according to the impedance loading value;

A first switch adjusting a reactance region yin-yang of the output signal outputted to the parasitic antenna; And

And a second switch to determine whether the output signal is inductor-linked.
The method of claim 1,

The impedance loading circuit,

At least one load modulated impedance loading circuit for respectively controlling a load modulated impedance corresponding to the active antenna by controlling at least one variable resistor according to an impedance code for outputting a multi-stream signal applied from the control circuit; Wireless transmitting device comprising.
A wireless transmission method using a wireless transmission device comprising at least one parasitic antenna and at least one active antenna for a beam space MIMO system,

Outputting a signal to be transmitted by multi-stream transmission or beamforming;

Selectively applying a control signal for generating a multi-stream signal or a beamforming signal according to the output signal; And

Loading an impedance corresponding to a plurality of parasitic antennas for transmitting the beamforming signal or loading an impedance corresponding to one or more active antennas for transmitting the multi-stream signal according to the applied control signal; Wireless transmission method comprising.
The method of claim 8,

The step of outputting the signal,

A wireless transmission method for outputting a multi-stream transmission signal or a beamforming transmission signal in accordance with the update of the channel information.
The method of claim 8,

The applying step,

Generating an impedance code corresponding to the multi-stream signal; And

And applying a control signal including the generated impedance code.
The method of claim 8,

The applying step,

And a control signal for loading impedances corresponding to the plurality of parasitic antennas from the beamforming signal.
The method of claim 8,

Loading the impedance,

And controlling the one or more switches to load impedances corresponding to each of the plurality of parasitic antennas according to the impedance loading value for the beamforming signal output.
The method of claim 12,

The one or more switches,

A plurality of switch arrays for controlling the capacitor array according to the impedance loading value;

A first switch adjusting a reactance region yin-yang of the output signal outputted to the parasitic antenna; And

And a second switch to determine whether the output signal is inductor-linked.
The method of claim 8,

Loading the impedance,

And a load modulated impedance corresponding to the active antenna, respectively, by controlling one or more variable resistors according to an impedance code for outputting an applied multi-stream signal.