KR20160076734A - Method for rf beamforming, and apparatuses operating the same - Google Patents

Abstract

Disclosed are a method for RF beamforming and an apparatuses operating the same. A communications device according to an embodiment of this invention comprises: a digital RF beamformer which performs beamforming for a sample digital signal based on a weight; an oscillator which generates an oscillation signal in response to a carrier frequency; and a radio frequency (RF) modulator which generates a sending signal based on the oscillation signal and an output signal of the digital RF beamformer.

Description

METHOD FOR RF BEAMFORMING, AND APPARATUS OPERATING THE SAME,

The following embodiments relate to an RF beamforming method and apparatuses for performing the same.

Conventional multi-beam RF beamforming schemes use K RF beamformers to transmit K signals and each RF beamformer requires M phase shifters and attenuators The complexity of the image is very large. This is because each RF beamformer is made up of M branches, and the number of total branches is K x M, and one beamformer is used for each branch using one phase shifter and one attenuator.

For example, in an existing RF beamforming system that transmits one signal sequence for each beam using 64 transmit antennas and 16 beams, 1024 phase shifters and attenuators are required because there are 1024 branches An upconversion RF chain comprising 64 power amplifiers, 32 D / A converters, and an analog mixer and filters is needed.

The high complexity of these existing RF beamformer structures increases the implementation cost and the power efficiency of the system due to the use of a large number of RF devices.

Embodiments can provide a technique for improving the complexity of an RF beamformer by using a digital RF beamformer.

In addition, embodiments use a gain controller that can use a high input voltage to upconvert a signal to be transmitted, thereby placing the position of the power amplifier at the output terminal of the oscillator, not the terminal end of the transmission circuit, It is possible to provide a technique capable of reducing the amount of the light.

A communication apparatus according to an exemplary embodiment includes a digital RF beam former for beamforming a digital sample signal based on a weight, an oscillator for generating an oscillation signal in accordance with a carrier frequency, And an RF (Radio Frequency) modulator that generates a transmission signal based on an output signal of the RF beam former.

The RF modulator may generate the transmission signal by modulating the oscillation signal based on an output signal of the digital RF beam former.

The RF modulator comprising: a gain controller for controlling a gain of the oscillation signal based on the magnitude of the output signal of the digital RF beam former; and a gain controller for controlling the gain controlled oscillator based on the phase of the output signal of the digital RF beam former, And may include a phase shifter for phase shifting.

The apparatus may further comprise a signal distribution circuit for distributing the oscillation signal to generate distribution signals comprising the oscillation signal.

The RF modulator includes a multiplication circuit multiplying the distribution signals with a sign of a real part and an imaginary part respectively of an output signal of the digital RF beam former and a multiplier circuit for multiplying the real part and the imaginary part of the output signal of the digital RF beam former, A gain control circuit for controlling the gain of the output signals of the multiplication circuit based on the respective magnitudes, and an adder for adding the output signals of the gain control circuit.

The RF modulator may further include an analysis module for analyzing real and imaginary parts of the output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part.

The RF modulator includes a selection circuit for selecting two signals from the distribution signals and for multiplying each of the selected signals by a sign of a real part and an imaginary part of an output signal of the digital RF beam former, A gain control circuit for controlling the gain of the output signals of the selection circuit based on the magnitudes of the real and imaginary parts of the output signal of the RF beam former and an adder for adding the output signals of the gain control circuit .

The RF modulator may further include an analysis module for analyzing real and imaginary parts of the output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part.

The signal distribution circuit may include a phase shifter that phase shifts the oscillation signal by a first phase.

A first phase shifter for phase shifting the oscillation signal by a first phase; a second phase shifter for phase shifting the oscillation signal by a second phase; and a phase shifter for phase shifting the oscillation signal by a third phase And a third phase shifter.

The apparatus may further comprise a weight generation module for generating the weight for the digital sample signal.

The gain controller may be implemented as a digital attenuator.

The apparatus may further include a power amplifier connected to an output terminal of the oscillator.

An RF beamforming method, according to an embodiment, includes the steps of: a digital RF beamformer beamforming a digital sample signal based on a weight; generating an oscillating signal in accordance with a carrier frequency; And generating a transmission signal based on the signal and an output signal of the digital RF beam former.

The generating of the transmission signal may include generating the transmission signal by modulating the oscillation signal based on an output signal of the digital RF beam former.

Wherein generating the transmit signal comprises: controlling the gain of the oscillation signal based on the magnitude of the output signal of the digital RF beam former; determining a gain controlled oscillation based on the phase of the output signal of the digital RF beam former And phase shifting the signal.

The method may further include dividing the oscillation signal to generate distribution signals including the oscillation signal.

Wherein generating the transmit signal comprises: multiplying the split signals by a sign of a real part and an imaginary part respectively of an output signal of the digital RF beam former; and a gain control circuit outputting the output of the digital RF beam former Controlling the gain of the output signals of the multiplication circuit based on the magnitudes of the real and imaginary parts of the signal, and adding the output signals of the gain control circuit.

The generating of the transmission signal may further include analyzing a real part and an imaginary part of an output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part.

The generating of the transmit signal may include selecting a signal among the plurality of split signals by a selection circuit, multiply each of the selected signals by a sign of a real part and an imaginary part of an output signal of the digital RF beam former, Controlling the gain of the output signals of the selection circuit based on the magnitude of each of the real and imaginary parts of the output signal of the digital RF beam former; And a step of adding the signal.

The generating of the transmission signal may further include analyzing a real part and an imaginary part of an output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part.

The method may further comprise generating the weight for the digital sample signal.

A multi-stream RF beamformer in accordance with another embodiment includes a plurality of beamformers, and a plurality of adders, each of which adds an output signal of each of the plurality of beamformers to produce a transmit signal, The number of formers may be equal to the number of the plurality of adders.

1 shows a communication apparatus for forming a single beam using M antennas to transmit one signal.
Fig. 2 shows the structure of the RF beam former shown in Fig.
3 shows a communication apparatus for forming multiple beams.
Figure 4 shows an embodiment of a communication device for improving the complexity of a power amplifier included in a multi-stream RF beamformer.
FIG. 5 is a schematic diagram illustrating an example of a transmission circuit for equivalently implementing the transmission signal of FIG. 4. Referring to FIG.
6 is a schematic structural diagram according to another example of a transmission circuit for equivalently implementing the transmission signal of FIG.
FIG. 7 is a schematic structural diagram according to another example of a transmission circuit for equivalently implementing the transmission signal of FIG.
FIG. 8 is a schematic structural view of the analysis module shown in FIGS. 6 and 7. FIG.
FIG. 9 is a schematic block diagram of an example of a communication device including the RF modulator shown in FIG. 5, FIG. 6, or FIG. 7;
FIG. 10 is a schematic block diagram of another example of a communication device including the RF modulator shown in FIG. 5, FIG. 6, or FIG.
FIG. 11 is a schematic block diagram of another example of a communication device including the RF modulator shown in FIG. 5, FIG. 6, or FIG.
FIG. 12 is a flowchart for explaining an operation method of the communication apparatus shown in FIG. 9, FIG. 10, or FIG.

It is to be understood that the specific structural or functional descriptions of embodiments of the present invention disclosed herein are presented for the purpose of describing embodiments only in accordance with the concepts of the present invention, May be embodied in various forms and are not limited to the embodiments described herein.

Embodiments in accordance with the concepts of the present invention are capable of various modifications and may take various forms, so that the embodiments are illustrated in the drawings and described in detail herein. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms disclosed, but includes all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

The terms first, second, or the like may be used to describe various elements, but the elements should not be limited by the terms. The terms may be named for the purpose of distinguishing one element from another, for example without departing from the scope of the right according to the concept of the present invention, the first element being referred to as the second element, Similarly, the second component may also be referred to as the first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises ", or" having ", and the like, are used to specify one or more of the features, numbers, steps, operations, elements, But do not preclude the presence or addition of steps, operations, elements, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

A module in this specification may mean hardware capable of performing the functions and operations according to the respective names described in this specification and may mean computer program codes capable of performing specific functions and operations , Or an electronic recording medium, e.g., a processor or a microprocessor, equipped with computer program code capable of performing certain functions and operations.

In other words, a module may mean a functional and / or structural combination of hardware for carrying out the technical idea of the present invention and / or software for driving the hardware.

FIG. 1 shows a communication apparatus for forming a single beam using M antennas to transmit one signal, and FIG. 2 shows a structure of the RF beam former shown in FIG.

Referring to Figures 1 and 2, the communication device 10 may perform RF beamforming. The communication device 10 may be a beam forming system that forms a single beam. For example, the communication device 10 may be a transmitter or a receiver.

RF beamforming is a wireless communication technique that uses a plurality of transmit antennas and an RF beamformer to form a spatial beam with directivity in a particular receiver direction.

The communication device 10 includes a single beam RF beam former.

The transmit symbol s _k (n) may be a time-domain digital signal corresponding to the output of the baseband module. The transmission symbol s _k (n) is upconverted to an RF carrier frequency via a pulse shaping and a digital-to-analog (D / A) converter and then transmitted through an RF beam former And may be transmitted over the wireless channel to the receiver antenna.

The output signal of the D / A converter can be expressed by Equation (1).

로 표현할 경우에 j번째 수신 안테나에 수신되는 신호

는 수학식 2와 같이 표현될 수 있다.
Weights of the RF beamformer for the signal s _k (n) are denoted by M x 1 vectors

, The signal received at the j < th >

Can be expressed by Equation (2).

In Equation (1), g (t) may be a function that integrally expresses phase shaping, oversampling, and baseband filtering.

가 곱해진 형태로 표현될 수 있다. 따라서, 신호 s_k(n)을 위한 RF 빔포머의 각 브랜치는 도 2와 같이 별도의 RF 빔포밍 알고리즘에 의하여 계산된 RF 빔포머의 가중치를 입력으로 동작하는 감쇠기(attenuator)와 페이즈 시프터(phase shifter)로 구현될 수 있다.
As shown in FIG. 1, the RF beamformer for the signal s _k (n) has M branches, and the output signal of the i-th branch can be expressed as Equation (3). That is, the i-th output signal of the RF beam former has a phase shifted version of a _k (t) expressed by Equation (4)

Can be expressed in the multiplied form. Therefore, each branch of the RF beamformer for the signal s _k (n) is composed of an attenuator and a phase shifter (phase shifter), which operate as input, the weights of the RF beam former calculated by a separate RF beamforming algorithm, shifter.

3 shows a communication apparatus for forming multiple beams.

Referring to FIG. 3, the communication device 20 may perform RF beamforming. The communication device 20 may be a beam forming system that forms multiple beams. For example, the communication device 20 may be a transmitter or a receiver.

The communication device 20 can simultaneously transmit K signals {s _k (n), k = 1, 2, ..., K}. The communication device 20 may include a multi-stream RF beamformer including K in parallel of the single RF beamformer of FIG. As shown in FIG. 3, a multi-stream RF beamformer that includes K RF beamformers may include K x M branches. This requires the number of attenuators, phase shifters, and power amplifiers to be K x M, respectively, so that the hardware complexity of the communication device 20, e.g., a multi-stream RF beamformer, for transmitting RF beamforming It can be very large.

Figure 4 shows an embodiment of a communication device for improving the complexity of a power amplifier included in a multi-stream RF beamformer.

Referring to FIG. 4, the communication device 30 may perform RF beamforming. The communication device 30 may be a transmitter or a receiver.

를 다른 방식으로 표현하여 이 송신 신호

를 등가적으로 구현하는 방법을 도출할 수 있다. 예를 들어, 멀티-스트림 RF 빔포머는 다중 빔 RF 빔포머일 수 있다.In the present invention, a communication apparatus 30 having improved complexity of a multi-stream RF beamformer, for example, a transmission signal transmitted from a transmission antenna in order to derive a transmitter structure,

Lt; RTI ID = 0.0 > signal < / RTI >

Can be derived equivalently. For example, a multi-stream RF beamformer may be a multi-beam RF beamformer.

는 수학식 5와 같이 표현될 수 있다.
Assuming the transmitter structure of FIG. 3, the signal received at the j < th >

Can be expressed by Equation (5).

는 도 4의 등가적인 송신기 구조를 통해서도 동일한 값을 얻을 수 있다. 이것은 도 4에서 i번째 송신되는 신호를

라고 정의하면, 신호

는 수학식 6과 같이 표현될 수 있고, 이때,

는 수학식 7과 같이 유도되어 수학식 5와 동일한 값이 될 수 있다.
signal

The same value can be obtained through the equivalent transmitter structure of FIG. This means that the i < th >

By definition,

Can be expressed as Equation (6), where < RTI ID = 0.0 >

Can be derived as shown in Equation (7) and can be the same value as Equation (5).

As shown in FIG. 4, the structure of the multi-stream RF beamformer can reduce the number of power amplifiers from M to M in the power amplifier K x M included in the multi-stream RF beamformer shown in FIG. However, the multi-stream RF beam former of Fig. 4 also includes K x M phase shifters and attenuators.

를 등가적으로 구현하고 동시에 구현 복잡도를 개선할 수 있는 새로운 송신 회로의 구조를 설명한다.
Hereinafter, a transmitter for improving the complexity of a multi-stream RF beamformer, i. E. A multi-beam RF beamformer, for example a transmit signal

And a structure of a new transmission circuit capable of improving the implementation complexity will be described.

는 수학식 9와 같이 정의될 수 있다.
In order to improve the complexity of the multi-stream RF beamformer including K x M phase shifters and attenuators, the transmission symbol s _k (t) is obtained by multiplying the digital sample ) Can be approximated as a function of the signal s _k ^D (m) and the step response u (t). The output signal of the digital RF beam former

Can be defined as: " (9) "

는 수학식 10과 같이 다시 표현될 수 있다.
Therefore,

Can be re-expressed as Equation (10).

Here, T _S may mean a sample duration of the RF stage, i.e., a sample rate.

는 수학식 11과 수학식 12와 같이 다시 표현될 수 있다.
In Equation (10)

Can be expressed again as Equations (11) and (12).

를 등가적으로 구현하는 송신 회로는 수학식 11과 수학식 12으로부터 도출된다. Transmission signal

Are derived from equations (11) and (12).

는 수학식 11로부터 신호(cos w_ct)에

의 크기(magnitude), 예를 들어 절대값을 곱하고,

의 위상(phase)만큼 위상 시프트(phase shift)시킨 것과 동일할 수 있다.Referring to Equation 11,

(Cos < RTI ID = _0.0 > wct) <

For example, an absolute value,

Phase shifted by the phase of the phase shifter.

는 신호들(cos w_ct 및 sin w_ct) 각각에

의 실수부(real part)와 허수부(imaginary part) 각각이 곱해진 형태로 표현될 수 있다. 또한, 수학식 12의 셋째 줄을 참조하면,

의 실수부와 허수부 각각은 크기(magnitude)와 부호(sign)로 분해가 가능할 수 있다.Referring to the first line of Equation 12,

(Cos w _c t and sin w _c t)

The real part and the imaginary part of the real part can be expressed by multiplying each other. Also, referring to the third line of Equation 12,

Each of the real part and the imaginary part of the symbol can be decomposed into a magnitude and a sign.

In Fig. 5, the transmission circuit derived from Equation (11) will be described, and in Fig. 6 and Fig. 7, the transmission circuit derived from Equation (12) will be described.

FIG. 5 is a schematic diagram illustrating an example of a transmission circuit for equivalently implementing the transmission signal of FIG. 4. Referring to FIG.

Referring to FIG. 5, the transmission circuit 100A may include an oscillator 150 and an RF modulator 190A.

The oscillator 150 may transmit an oscillation signal, i.e., an output signal cos w _c t, to the RF modulator 190A. For example, the oscillator 150 may be a local oscillator having a carrier frequency (w _c ).

에 기초하여 송신 신호

를 생성할 수 있다.The RF modulator 190A receives the output signal (cos w _c t) of the oscillator 150 and

Lt; RTI ID = 0.0 >

Lt; / RTI >

The RF modulator 190A may include a gain controller and a phase shifter.

의 크기(magnitude)에 기초하여 발진기(150)의 출력 신호(cos w_ct)의 이득을 제어할 수 있다. 보다 구체적으로, 이득 컨트롤러는 출력 신호(cos w_ct)에

의 크기(magnitude)를 곱할 수 있다. 예를 들어, 이득 컨트롤러는 수학식 10의 u(t)를 반영하여 구현될 수 있다. 이득 컨트롤러는 디지털 감쇠기(digital attenuator)로 구현될 수 있다.The gain controller

(Cos w _c t) of the oscillator 150 based on the magnitude of the output signal of the oscillator 150. More specifically, the gain controller outputs the output signal (cos w _c t)

Can be multiplied by the magnitude of the output signal. For example, the gain controller may be implemented to reflect u (t) in equation (10). The gain controller may be implemented as a digital attenuator.

Instead of using a mixer circuit vulnerable to high input power, a gain controller implemented with a digital attenuator can use high input power to uncover the signal to transmit. Thus, the position of the power amplifier can be located at the output of the oscillator 150, rather than at the output (or terminal) of the transmitter circuit, reducing the number of power amplifiers required.

의 위상(phase)에 기초하여 이득 컨트롤러의 출력 신호, 예를 들어 이득이 제어된 출력 신호(cos w_ct)를 위상 시프트할 수 있다. 예를 들어, 페이즈 시프터는 이득 컨트롤러의 출력 신호를

의 위상(phase)만큼 위상 시프트할 수 있다.The phase shifter

For example, a gain controlled output signal (cos w _c t) based on the phase of the output signal of the gain controller. For example, the phase shifter can be used to

Phase by the phase of the phase shifter.

의 크기(magnitude)와 위상(phase)을 분석하고, 이를 전송하기 위한 분석 모듈이 RF 변조기(190A) 내에 구현될 수 있다.According to one example,

An analysis module for analyzing the magnitude and phase of the RF modulator 190A may be implemented in the RF modulator 190A.

The RF modulator 190A uses the output signal cos w _c t of the oscillator 150 as a desired input signal to estimate the magnitude and phase of the output signal cos w _c t of the oscillator 150 at each sample time May be modulated. Thus, the RF modulator 190A can operate at a sample rate of a high rate digital RF beam former.

6 is a schematic structural diagram according to another example of a transmission circuit for equivalently implementing the transmission signal of FIG.

Referring to FIG. 6, the transmission circuit 100B may include an oscillator 150, a signal distribution circuit 170A, and an RF modulator 190B.

The oscillator 150 can transmit an oscillation signal, that is, an output signal (cos w _c t), to the signal distribution circuit 170A. For example, the oscillator 150 may be a local oscillator having a carrier frequency (w _c ).

The signal distribution circuit 170A may generate the distribution signals cos w _c t and -sin w _c t based on the output signal cos w _c t of the oscillator 150. For example, the signal distribution circuit 170A may divide the output signal (cos w _c t) to produce a bypassed signal, an output signal (cos w _c t) and a phase-shifted signal (-sin w _c t) . The signal distribution circuit 170A may include a phase shifter 171 for phase-shifting the output signal cos w _c t. The phase shifter 171 may phase shift the output signal cos w _c t by a first phase, e.g., (-) 90 degrees.

에 기초하여 송신 신호

를 생성할 수 있다. The RF modulator 190B receives the distribution signals (cos w _c t and -sin w _c t) of the signal distribution circuit 170A and

Lt; RTI ID = 0.0 >

Lt; / RTI >

The RF modulator 190B may include an analysis module 191, a multiplying circuit 193, a gain control circuit 195, and an adder 197.

의 실수부와 허수부를 분석하고, 실수부와 허수부 각각의 크기(magnitude)와 부호(sign)를 생성할 수 있다. 예를 들어, 분석 모듈(191)은

의 실수부와 허수부 각각의 부호를 곱셈 회로(193)로 전송하고,

의 실수부와 허수부 각각의 크기를 이즉 제어 회로(195)로 전송할 수 있다. 분석 모듈(191)은 도 8에 도시된 바와 같이 구현될 수 있다.The analysis module 191

The magnitude and sign of each of the real part and the imaginary part can be generated. For example, the analysis module 191 may

The sign of each of the real part and the imaginary part of the multiplication circuit 193,

The magnitude of each of the real part and the imaginary part of the signal can be transmitted to the control circuit 195. The analysis module 191 may be implemented as shown in FIG.

의 실수부와 허수부 각각의 부호와 곱할(multiply) 수 있다. 곱셈 회로(193)는 제1 곱셈기(first multiplier; 193-3)와 제2 곱셈기(second multiplier; 193-5)를 포함할 수 있다.The multiplication circuit 193 multiplies each of the distribution signals (cos w _c t and -sin w _c t) by

And multiply the sign of each of the real part and the imaginary part of the symbol. The multiplication circuit 193 may include a first multiplier 193-3 and a second multiplier 193-5.

의 실수부의 부호

를 곱할 수 있다. 제2 곱셈기(193-5)는 제2 분배 신호(-sin w_ct)와

의 허수부의 부호

를 곱할 수 있다.The first multiplier 193-3 multiplies the first distribution signal cos w _c t and

The sign of the real part of

Lt; / RTI > The second multiplier 193-5 multiplies the second distribution signal (-sin w _c t)

The sign of the imaginary part of

Lt; / RTI >

의 실수부와 허수부 각각의 크기에 기초하여 곱셈 회로(193)의 출력 신호들의 이득을 제어할 수 있다. 이득 제어 회로(195)는 제1 이득 컨트롤러(first gain controller; 195-3) 및 제2 이득 컨트롤러(second gain controller; 195-5)를 포함할 수 있다.The gain control circuit 195

The gain of the output signal of the multiplication circuit 193 can be controlled based on the size of each of the real part and imaginary part of the multiplication circuit 193. The gain control circuit 195 may include a first gain controller 195-3 and a second gain controller 195-5.

의 실수부 크기

에 기초하여 제1 곱셈기(193-3)의 출력 신호의 이득을 제어할 수 있다. 예를 들어, 제1 이득 컨트롤러(195-3)는 제1 곱셈기(193-3)의 출력 신호와

의 실수부 크기

를 곱할 수 있다.The first gain controller 195-3

The real part size

The gain of the output signal of the first multiplier 193-3 can be controlled. For example, the first gain controller 195-3 receives the output signal of the first multiplier 193-3

The real part size

Lt; / RTI >

의 허수부 크기

에 기초하여 제2 곱셈기(193-5)의 출력 신호의 이득을 제어할 수 있다. 예를 들어, 제2 이득 컨트롤러(195-5)은 제2 곱셈기(193-5)의 출력 신호와

의 허수부 크기

를 곱할 수 있다.The second gain controller 195-5

Imaginary part size of

The gain of the output signal of the second multiplier 193-5 can be controlled. For example, the second gain controller 195-5 outputs the output signal of the second multiplier 193-5

Imaginary part size of

Lt; / RTI >

For example, each of the gain controllers 195-3 and 195-5 may be implemented to reflect u (t) in Equation (10). In addition, each gain controller 195-3 and 195-5 may be implemented in the form of a digital attenuator. Instead of using a mixer circuit vulnerable to high input power, each of the gain controllers 195-3 and 195-5 implemented with a digital attenuator is used to unconverge the signal to transmit High input power can be used. Thus, the position of the power amplifier can be located at the output of the oscillator 150, rather than at the output (or terminal) of the transmitter circuit, reducing the number of power amplifiers required.

The RF modulator 190B may use two gain controllers 195-3 and 195-5 for one transmit antenna. That is, the number of branches of the RF modulation circuit including M RF modulators 190B can be reduced to 2M.

The adder 197 may add the output signals of the gain control circuit 195.

The RF modulator 190B uses the output signal cos w _c t of the oscillator 150 as a desired input signal to estimate the magnitude and phase of the output signal cos w _c t of the oscillator 150 at each sample time May be modulated. Thus, RF modulator 190B can operate at a sample rate of a high rate digital RF beam former.

FIG. 7 is a schematic structural diagram according to another example of a transmission circuit for equivalently implementing the transmission signal of FIG.

7, the transmission circuit 100C may include an oscillator 150, a signal distribution circuit 170B, and an RF modulator 190C.

The signal distribution circuit 170B divides the distribution signals (cos w _c t, -cos w _c t, sin w _c t and -sin w _c t) based on the output signal (cos w _c t) of the oscillator 150 Can be generated. For example, the signal distribution circuit 170B divides the output signal cos w _c t and outputs the bypassed signal cos w _c t and the phase-shifted signals -cos w _c t, sin w _c t, -sin w _c t).

The signal distribution circuit 170B may include phase shifters 173, 175, and 177 for phase shifting the output signal cos w _c t.

For example, the first phase shifter 173 may phase shift the output signal cos w _c t by a first phase, e.g., 180 degrees. The second phase shifter 175 may phase shift the output signal cos w _c t by a second phase, e.g., 90 degrees. The third phase shifter 177 may phase shift the output signal cos w _c t by a third phase, e.g., 270 degrees.

에 기초하여 송신 신호

를 생성할 수 있다.The RF modulator 190B receives the distribution signals (cos w _c t, -cos w _c t, sin w _c t, and -sin w _c t) of the signal distribution circuit 170A and

Lt; RTI ID = 0.0 >

Lt; / RTI >

The RF modulator 190C may include an analysis module 191, a gain control circuit 195, an adder 197, and a selection circuit 199.

의 실수부와 허수부 각각의 부호와 곱할(multiply) 수 있다. 선택회로(199)는 제1 선택기(first selector; 199-3) 및 제2 선택기(second selector; 199-5)를 포함할 수 있다.The selection circuit 199 selects two signals out of the distribution signals (cos w _c t, -cos w _c t, sin w _c t, and -sin w _c t)

And multiply the sign of each of the real part and the imaginary part of the symbol. The selection circuit 199 may include a first selector 199-3 and a second selector 199-5.

의 실수부의 부호와 곱할(multiply) 수 있다. 제2 선택기(199-5)는 제2 분배 신호들(sin w_ct 및 -sin w_ct) 중에서 하나의 신호를 선택하고, 선택된 신호를

의 허수부의 부호와 곱할(multiply) 수 있다.For example, the first selector 199-3 may select one of the first distribution signals (cos w _c t and -cos w _c t)

And multiply by the sign of the real part of. The second selector 199-5 selects one of the second distribution signals sin w _c t and -sin w _c t,

With the sign of the imaginary part of < / RTI >

The structure and operation of the analysis module 191, the gain control circuit 195 and the adder 197 of the oscillator 150 and the RF modulator 190C of FIG. 7 are similar to those of the oscillator 150 and the RF modulator 190B of FIG. The gain control circuit 195, and the adder 197 of the analysis module 191 of FIG. Therefore, detailed description is omitted.

과 반송파 주파수(carrier frequency)가 주어질 때, 도 5, 도 6 또는 도 7에 도시된 송신 회로를 통해서 i번째 안테나의 송신신호

를 등가적으로 구현할 수 있다.
As described above,

And a carrier frequency, the transmission signal of the i < th > antenna through the transmission circuit shown in Fig. 5, Fig. 6,

Can be equivalently implemented.

Hereinafter, another embodiment of a communication apparatus for improving the complexity of a power amplifier included in a multi-stream RF beamformer will be described with reference to Figs. 9 to 11. Fig.

FIG. 9 is a schematic block diagram of an example of a communication device including the RF modulator shown in FIG. 5, FIG. 6, or FIG. 7;

9, the communication device 40A includes a digital RF beam former 110, a weight generation module 130, an oscillator 150, a signal distribution circuit 170, and an RF modulator circuit 190, as shown in FIG. For example, the communication device 40A may be a transmitter or a receiver.

The digital RF beam former 110 may beamform digital sample signals based on the weights generated from the weight generation module 130. [ The digital RF beam former 110 may output the output signals to the RF modulation circuitry 190. [

The weight generation module 130 may generate weights for the digital sample signals and transmit the weights to the digital RF beamformer 110.

The oscillator 150 may generate an oscillating frequency signal, e.g., cos w _c t. The oscillator 150 may transmit the oscillation frequency signal to the signal distribution circuit 170. [ For example, the oscillator 150 may be a local oscillator having a carrier frequency (w _c ).

The signal distribution circuit 170 may generate the distribution signals based on the oscillation frequency signal of the oscillator 150. [ For example, the signal distribution circuit 170 may be implemented as the signal distribution circuit 170A or 170B shown in Fig. 6 or Fig. The structure and operation of the signal distribution circuit 170 may be substantially the same as the structure and operation of the signal distribution circuit 170A or 170B shown in Fig. 6 or Fig. Therefore, detailed description of the structure and operation of the signal distributing circuit 170 of FIG. 9 will be omitted.

The RF modulation circuit 190 may include a plurality of RF modulators 190-1 through 190-M (M is a natural number greater than one).

Each of the RF modulators 190-1 to 190-M can modulate the output signal of the oscillator 150 based on the output signal of the digital RF beam former 110. [ For example, each of the RF modulators 190-1 to 190-M modulates the distribution signal (s) of the signal distribution circuit 170 based on the output signal of the digital RF beam former 110 to generate a transmission signal . At this time, the distribution signal of the signal distribution circuit 170 may be an output signal of the oscillator 150 or an output signal of the phase-shifted oscillator 150.

For example, each of the RF modulators 190-1 to 190-M may be implemented by an RF modulator 190A, 190B or 190C shown in FIG. 5, FIG. 6, or FIG. The structure and operation of each RF modulator 190-1 through 190-M may be substantially the same as the structure and operation of the RF modulator 190A, 190B, or 190C illustrated in FIG. 5, FIG. 6, or FIG. Therefore, detailed description of the structure and operation of the RF modulators 190-1 to 190-M of FIG. 9 will be omitted.

By implementing the digital RF beam former 110, the communications device 40A can remove the K x M phase shifters and attenuators, and one RF modulator 190-1, 190-2, ..., or 190-M). ≪ / RTI > Therefore, the communication device 40A can improve the complexity of the RF modulation circuit 190, for example, each RF modulator 190-1 to 190-M.

FIG. 10 is a schematic block diagram of another example of a communication device including the RF modulator shown in FIG. 5, FIG. 6, or FIG.

Referring to FIGS. 9 and 10, each of the power amplifiers 210 may be positioned at the output of each of the RF modulators 190-1 through 190-M.

The structure and operation of the communication device 40B of FIG. 10 are identical to those of the communication device 40A of FIG. 9 except that each of the power amplifiers 210 is located at the output end of each of the RF modulators 190-1 to 190- Can be substantially the same as structure and operation.

The communication device 40B of FIG. 10 includes but is not limited to M power amplifiers as in FIG. 4, but may remove K x M phase shifters and attenuators. By implementing the digital RF beam former 110, the communication device 40B can improve the complexity of the RF modulation circuit 190, e.g., each RF modulator 190-1 through 190-M.

FIG. 11 is a schematic block diagram of another example of a communication device including the RF modulator shown in FIG. 5, FIG. 6, or FIG.

Referring to FIG. 11, the power amplifier 210 may be connected to the output terminal of the oscillator 150.

The structure and operation of the communication device 40C of Fig. 11 are the same as those of the communication device 40A of Fig. 9 or the communication device 40B of Fig. 10 except that the power amplifier 210 is located at the output terminal of the oscillator 150. [ Can be substantially the same as structure and operation.

By implementing the digital RF beam former 110, the communication device 40C can remove K x M phase shifters and attenuators. Thus, the communication device 40C can improve the complexity of the RF modulation circuit 190, for example, each of the RF modulators 190-1 to 190-M.

In addition, the communication device 40C can reduce the number of power amplifiers 210 required for multi-beam RF beamforming to one. The output signal of the oscillator 150 is input as the input signal of the power amplifier 210 so that the PAPR of the input signal of the power amplifier 210 becomes 0 dB and the communication device 40C has high power efficiency power efficiency.

10 and 11, the communication devices 40B and 40C include a communication device 40B such as an impedance matching circuit and a circulator for preventing a reflected current at the output terminal of the power amplifier 210 And 40C), e.g., additional circuitry required by the transmitter.

FIG. 12 is a flowchart for explaining an operation method of the communication apparatus shown in FIG. 9, FIG. 10, or FIG.

Referring to FIG. 12, the digital RF beam former 110 may beam-form a digital sample signal based on the weights (S1210).

The oscillator 150 may generate an oscillation signal according to the carrier frequency (S1230).

Based on the oscillation signal and the output signal of the digital RF beam former 110, the RF modulation circuit 190, for example, the RF modulator 190-1, 190-2, ..., or 190- (S1250).

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA) , A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (23)

A digital RF beam former for beamforming a digital sample signal based on a weight;
An oscillator for generating an oscillation signal according to a carrier frequency; And
An RF (Radio Frequency) modulator for generating a transmission signal based on the oscillation signal and the output signal of the digital RF beam former
.
The method according to claim 1,
Wherein the RF modulator modulates the oscillation signal based on an output signal of the digital RF beam former to generate the transmission signal.
The method according to claim 1,
The RF modulator includes:
A gain controller for controlling a gain of the oscillation signal based on a magnitude of an output signal of the digital RF beam former; And
A phase shifter for phase-shifting an oscillation signal whose gain is controlled based on a phase of an output signal of the digital RF beam former;
.
The method according to claim 1,
A signal distribution circuit for distributing the oscillation signal and generating distribution signals including the oscillation signal;
Further comprising:
5. The method of claim 4,
The RF modulator includes:
A multiplying circuit multiplying each of the distribution signals by a sign of a real part and an imaginary part of an output signal of the digital RF beam former;
A gain control circuit for controlling gains of the output signals of the multiplication circuit based on magnitudes of the real and imaginary parts of the output signal of the digital RF beam former; And
An adder for adding the output signals of the gain control circuit
.
6. The method of claim 5,
The RF modulator includes:
Analyzing the real and imaginary parts of the output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part,
Further comprising:
5. The method of claim 4,
The RF modulator includes:
A selection circuit for selecting two signals from the distribution signals and for multiplying each of the selected signals by a sign of a real part and an imaginary part of an output signal of the digital RF beam former;
A gain control circuit for controlling gains of the output signals of the selection circuit based on magnitudes of the real and imaginary parts of the output signal of the digital RF beam former; And
An adder for adding the output signals of the gain control circuit
.
8. The method of claim 7,
The RF modulator includes:
Analyzing the real and imaginary parts of the output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part,
Further comprising:
5. The method of claim 4,
Wherein the signal distribution circuit comprises:
A phase shifter for phase shifting the oscillation signal by a first phase;
.
5. The method of claim 4,
Wherein the signal distribution circuit comprises:
A first phase shifter for phase shifting the oscillation signal by a first phase;
A second phase shifter for phase shifting the oscillation signal by a second phase; And
A third phase shifter for phase-shifting the oscillation signal by a third phase,
.
The method according to claim 1,
A weight generation module for generating the weight for the digital sample signal;
Further comprising:
The method of claim 3,
Wherein the gain controller is implemented as a digital attenuator.
The method according to claim 1,
A power amplifier connected to an output terminal of the oscillator,
Further comprising:
The digital RF beamformer beamforming a digital sample signal based on a weight;
Generating an oscillation signal according to a carrier frequency; And
Generating a transmission signal based on the oscillation signal and the output signal of the digital RF beam former;
/ RTI >
15. The method of claim 14,
The generating of the transmission signal includes:
Modulating the oscillation signal based on an output signal of the digital RF beam former to generate the transmission signal
/ RTI >
15. The method of claim 14,
The generating of the transmission signal includes:
Controlling a gain of the oscillation signal based on a magnitude of an output signal of the digital RF beam former; And
Phase shifting the gain controlled oscillation signal based on the phase of the output signal of the digital RF beam former
/ RTI >
15. The method of claim 14,
Dividing the oscillation signal to generate distribution signals including the oscillation signal
Wherein the RF beamforming method further comprises:
18. The method of claim 17,
The generating of the transmission signal includes:
Multiplying each of the distribution signals by a sign of a real part and an imaginary part of an output signal of the digital RF beam former;
Controlling a gain of the output signals of the multiplication circuit based on a magnitude of each of a real part and an imaginary part of an output signal of the digital RF beam former; And
Adding the output signals of the gain control circuit
/ RTI >
19. The method of claim 18,
The generating of the transmission signal includes:
Analyzing the real and imaginary parts of the output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part,
Wherein the RF beamforming method further comprises:
18. The method of claim 17,
The generating of the transmission signal includes:
Wherein the selection circuit selects two signals from the distribution signals and multiply each of the selected signals with a sign of a real part and an imaginary part of an output signal of the digital RF beam former;
Controlling a gain of the output signals of the selection circuit based on a magnitude of each of a real part and an imaginary part of an output signal of the digital RF beam former; And
Adding the output signals of the gain control circuit
/ RTI >
21. The method of claim 20,
The generating of the transmission signal includes:
Analyzing the real and imaginary parts of the output signal of the digital RF beam former and generating the magnitude and the sign of each of the real part and the imaginary part,
Wherein the RF beamforming method further comprises:
15. The method of claim 14,
Generating the weight for the digital sample signal
Wherein the RF beamforming method further comprises:
A plurality of beam formers; And
A plurality of adders for generating transmission signals by adding output signals of the plurality of beam formers,
Lt; / RTI >
Wherein the number of the plurality of beamformers is equal to the number of the plurality of adders.

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