KR101506842B1 - Apparatus for extending MIMO signal - Google Patents

Abstract

The present invention relates to an apparatus for extending a multiple input multiple output (MIMO) signal (or a relay) for extending a specific distance by using the MIMO signal applied to a wireless communication system or the like in a multi-access method with a signal of a different frequency band such as LTE, WCDMA, CDMA 1X, etc. or a signal in a different communication method by using a single cable. The present invention can transmit the MIMO signal of a base station or a relay to an antenna for service by using one cable while making a transmission channel matrix of 2X2 between the antenna for service and a terminal. The present invention has two or more individual different paths within one cable by separating a frequency down part and a frequency up part of a transceiver from each other within the relay for making two or more paths within one cable and implementing to a donor side (main unit) and a service side (service unit) to be connected to each base station or each relay in wired and wireless communications. Also, according to an embodiment of the present invention, the present invention can reduce manufacturing costs of the relay by implementing a reverse path within a MIMO path to be nonexistent.

Description

[0001] Apparatus for extending MIMO signal [

The present invention relates to a system and method for transmitting a Multiple Input Multiple Output (MIMO) signal, which is applied in a wireless communication system of a multiple access system such as an LTE (Long Term Evolution) communication system, to another frequency band such as LTE, WCDMA, CDMA 1X, To a MIMO signal expander for extending a certain distance using a single cable.

Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Such multiple access systems may include, for example, a Code Division Multiple Access (CDMA) system, a Time Division Multiple Access (TDMA) system, a Frequency Division Multiple Access (FDMA) system, a 3GPP Long Term to LTE system, (OFDMA) system, and the like.

Generally, a wireless multiple access communication system can simultaneously support communication for a plurality of wireless terminals. Each terminal communicates with one or more base stations via transmissions on the forward link and the reverse link. The forward link (or downlink or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (also referred to as the uplink or uplink) refers to the communication link from the terminals to the base stations do. Such a communication link may be established through a single input single output (SISO) scheme, a multiple input single output (MISO) scheme, or a multiple input multiple output (MIMO) scheme.

MIMO systems use multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. The MIMO channel formed by the NT transmit antennas and the NR receive antennas may be decomposed into NS independent channels, and the independent channels may be referred to as spatial channels. Each of the N independent channels corresponds to a dimension. If additional dimensions generated by multiple transmit and receive antennas are used, a MIMO system can provide improved performance (e.g., higher throughput and / or greater reliability).

On the other hand, it is necessary to construct a repeater (or a MIMO signal expander) in a region where the installation cost of the base station is limited by covering the propagation shaded area in the MIMO communication system.

However, a plurality of transmission cables corresponding to the number of MIMO antennas are required to extend or transmit the MIMO signal by a certain distance from the base station or the repeater to the plurality of antennas. Due to the installation of the plurality of transmission cables, There is a problem that the installation cost is increased and the installation space is also limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a MIMO (Multiple Input Multiple Output) signal applied to a multiple access wireless communication system such as an LTE (Long Term Evolution) , CDMA 1X, or the like, or a signal of another communication system, so that the MIMO signal can be effectively relayed by extending a certain distance to a plurality of service antennas through one cable.

According to an aspect of the present invention, there is provided a MIMO signal extending apparatus including: a first input / output port for inputting / outputting (up / down) main signals of a first base station apparatus; (Up / down) main signal of (up / down) main signal from / to the first base station apparatus (up / down) main signals of A second input / output port for inputting and outputting a main signal; A signal combiner for combining and outputting a MIMO signal from the first base station apparatus and a MIMO signal input from at least one of the second base station apparatus through a third input / A first downlink signal amplifying unit for down-frequency-amplifying the downlink MIMO signal output from the signal combining unit; And a downlink MIMO signal output from the first downlink signal amplifying unit and a downlink (combined) main signal input through the second input / output port to output through a fourth input / output port connected to one end of a single cable, And a MUX for outputting an upward main signal inputted through the fourth input / output port from the cable through the second input / output port, wherein the main unit The base station apparatus includes a main signal processing unit for processing a main signal up or down, a signal separation unit connected between the main signal processing unit and the first input / output port to divide the main signal into uplink main signals and downlink main signals, And a MIMO signal processing unit for down-processing the MIMO signal.

Also, the MIMO signal expander according to the present invention may include: a fifth input / output port to which the other ends of the single cable are connected; A sixth input / output port for connecting the main antenna; A seventh input / output port for connecting the MIMO antenna; A second signal separator connected to the fifth input / output terminal for separating the main signal and the MIMO signal; A bypass line connecting between the second signal separator and the sixth input / output port; And a second downlink signal amplifying unit connected between the second signal separating unit and the seventh input / output port to amplify and amplify a downlink MIMO signal by up-sampling can do.

Also, a MIMO signal extending apparatus according to the present invention includes: a first portion in which a frequency down-converter and an amplifier are sequentially connected in series; Wherein the first down-signal amplifier comprises a second portion connected in series with the frequency up-converter and the amplifier, and the first portion and the second portion are connected in series, wherein the first down-signal amplifier amplifies the super- And the second downstream signal amplifying unit may be composed of the second portion of the superheterodyne type amplifier.

The first base station apparatus may include a base station apparatus or a relay apparatus of an LTE system and may be a micro cell, a pico cell, a femto cell, or a macro cell service Area.

The second base station device may include using a different communication scheme or using a different frequency band than the first base station device.

As described above, according to various aspects of the present invention, a MIMO (Multiple Input Multiple Output) signal applied to a wireless communication system of a multiple access method such as an LTE (Long Term Evolution) communication system is transmitted to LTE, WCDMA, It is possible to effectively relay the signals of different frequency bands or other communication methods by extending a certain distance to a plurality of service antennas through one cable.

That is, signals of various communication methods and bands (base stations or repeaters) used by different communication carriers or the same communication service provider can be relayed using a single relay device (that is, a MIMO signal expansion device) of a single cable, The facility cost of the repeater can be greatly reduced.

In addition, it is possible to effectively relay the MIMO scheme signal applied in the multiple access method wireless communication system such as the LTE (Long Term Evolution) communication system without distortion.

In addition, when a MIMO signal is extended or transmitted from a base station or a repeater to a plurality of antennas by a predetermined distance, a plurality of transmission cables corresponding to the number of MIMO antennas can be shared by one transmission cable, .

Also, since the relay path of the upstream signal is formed only in one main signal path without the MIMO signal path in the relay apparatus, the manufacturing cost of the relay apparatus can be remarkably reduced.

1 is a diagram for explaining a transmission / reception system of a MIMO signal in a multiple access wireless communication system,
2 is a diagram for explaining a general wireless repeater,
3 is a configuration diagram of a MIMO signal expander (MIMO relay apparatus) according to an embodiment of the present invention,
FIG. 4 is a detailed configuration diagram of the first downstream signal amplifying unit of FIG. 3,
FIG. 5 is a detailed configuration diagram of the second downstream signal amplifying unit of FIG. 3,
6 is a configuration diagram of a general superheterodyne type amplifier.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals are used to denote like elements in the drawings, even if they are shown in different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Although the phenomenon caused by one or more reflected waves in the period of wireless signal transmission is a main factor that deteriorates the reception performance of the communication system, it is possible to raise the frequency efficiency by using this multi-reflected wave phenomenon. Multi Input Multi Output) system. As can be seen from the name, MIMO is a method for improving the performance of transmission speed, capacity increase, and coverage increase by using a plurality of antennas on both the transmitting side and the receiving side.

Is simply the antenna to the transmitting side 2, the characteristics of a channel between the antenna to the reception-side two examples the 2X2 system, g., Once received and the transmission antenna # 1, as the antenna shown in Figure 1 with h _11, H ₁₂ is the channel characteristic between the transmitting antenna 2 and the receiving antenna 1, h ₂₁ is the characteristic of the channel between the transmitting antenna 1 and the receiving antenna 2, and the characteristic of the channel between the transmitting antenna 2 and the receiving antenna 2 Is h ₂₂ , and a channel matrix as shown in Equation (1) is created by combining the channel characteristics in this case.

[Equation 1]

In this case, x ₁ and x ₂ are transmission signals transmitted from the transmission antennas 1 and 2, n ₁ and n ₂ are the noise existing in the reception antennas 1 and 2, respectively, and y 1 and y 2 are reception signals.

Based on the above basic equations, we can see two examples as follows.

&Quot; (2) "

&Quot; (3) "

The matrix of equation (2) can be analyzed as 6 = 1 x ₁ + 2 x ₂ and 12 = 2 x ₁ + 4 x ₂ . On the other hand, since the matrixes of Equation (3) are different from each other, the values of the different transmission signals x ₁ and x ₂ can be obtained by solving the matrix or simultaneous equations. In the linear algebra, the 2X2 matrix of Equation (2) has a rank of 1 and the matrix of Equation (3) has a rank of 2.

In Equation (4), in a system having two transmit antennas and two receive antennas and having a channel matrix of 2x2 and maintaining the condition of rank 2, an inverse matrix of a channel matrix is applied, Is extracted.

&Quot; (4) "

과

는 각 안테나 별 전송된 것으로 추정되는 신호를 복조 해낸 값에 해당한다.In equations (1) and (4)

and

Corresponds to a value obtained by demodulating a signal estimated to be transmitted for each antenna.

Such a MIMO scheme is referred to as a MIMO SM (Spatial Multiplexing) scheme, and the number of different data streams that can be simultaneously transmitted is limited by the smaller number of transmit antennas M and receive antennas N The general MIMO type has the same number of transmission / reception antennas.

2, a typical repeater 210 includes a base station 220 having two transmit and receive antennas, a user terminal 230 having two transmit and receive antennas, A reception antenna 210a for receiving a signal transmitted from the base station 220 for a downlink MIMO signal transmitting a MIMO communication signal toward a user terminal 230 and a transmission antenna 210b ), And the received signal is amplified by the downstream signal amplifying section 213 and retransmitted.

In this case, since the number of mutually connected antennas is two and one (that is, 2x1) on the link between the base station and the repeater, and the number of mutually connected antennas on the link between the repeater and the terminal is one and two, , Transmission and restoration of the MIMO signal becomes impossible. This is also the case when the uplink signal from the user terminal 230 to the base station 220 is a MIMO scheme.

In FIG. 2, reference numerals 211 to 212 denote a duplexer for separating an uplink signal and a downlink signal, and reference numeral 214 denotes an uplink signal amplifier.

As described above, the basic principle of MIMO is to transmit different data to a mobile station through two or more different paths (including antennas) from a base station or a repeater using a reflected wave signal in a space, thereby increasing transmission efficiency at the same frequency within the same time. In order to transmit two or more MIMO signals from the base station or the repeater to two or more service antennas and to have the effect of MIMO between the service antennas and the terminals, two or more mutually nonmultiplied paths must be created. If two or more cables are installed, the cost is greatly increased.

According to the embodiment of the present invention, as shown in Equation (1), the transmission channel matrix between the service antennas and the terminal is made 2x2, and signals of the MIMO base station or the repeater can be transmitted to the service antenna using one cable And one or more transceivers (or a downstream signal amplifying unit) are provided in a repeater to make two or more paths in the one cable, and a frequency down portion and a frequency up portion of the transceiver are provided By separating each other from the main unit side and the service unit side, it is possible to have two or more independent different paths in one cable. Also, according to the embodiment of the present invention, since the reverse path in the MIMO path does not exist, the manufacturing cost of the repeater itself can be further reduced.

As a result, according to the embodiment of the present invention, by having two completely independent channels between the service antennas in the donor and the service antennas connected to the base station or the repeater for MIMO communication, A specific embodiment will be described as follows.

3 is a block diagram of a MIMO signal extending apparatus (or MIMO relay apparatus) according to an embodiment of the present invention. As shown in the drawing, a main unit (MU) 300 And a service unit (SU) 400 installed on the service side.

First, the main unit 300 of FIG. 3 will be described.

The main unit 300 may include a plurality of input and output ports 301 to 304, a base station 310, a signal combiner 320, a downlink signal amplifier 330, and a MUX 340.

Output ports 301 to 304 formed in the main unit 300 are connected to the signal combiner 540 of the existing mobile communication system 500 and the MIMO path of the base station 510 of the existing mobile communication system 500, And to connect the main unit 300 to the service unit 400. [

The input / output port 301 and the input / output port 302 are ports for connecting the main unit 300 to the external signal combiner 540, respectively.

The signal combiner 540 combines and transmits one or more multiband signals of different communication systems of the existing mobile communication system 500. In the forward path, the signal combiner 540 combines the signals of the existing mobile communication system 500, such as LTE, WCDMA, CDMA1X, A downlink main signal from the different base station apparatuses 510, 520 and 530 and a downlink main signal from the base station apparatus 310 of the main unit 300 output through the input / output port 301 are combined and output, Output port 302 from the unit 300 to the corresponding base station apparatus 510 or 520 or 530 or to the base station apparatus 310 through the input / output port 301 of the main unit 300. [

That is, the input / output port 301 is for connecting the base station device 310 of the main unit 300 and the external signal combiner 540, and in the forward path, The downward main signal is output to the outside through the input / output port 301 and input to the signal combiner 540. In the reverse path, the up main signal output from the signal combiner 540 is input to the inside through the input / output port 301 And is input to the base station apparatus 310 of the main unit 300.

The input / output port 302 is for connecting the mux 340 of the main unit 300 and the external signal combiner 540. In the forward path, the downward main signal coupled by the external signal combiner 540 Output port 302 to the mux 340 of the main unit 300 and the uplink main signal output from the mux of the main unit 300 is input to the external signal combiner 540).

The base station apparatus 310 is built in the main unit 300 and includes a main signal processing unit 311 for processing a main signal up or down, a MIMO signal processing unit 312 for down processing the MIMO signal, And a signal separator 314 connected between the main signal processor 311 and the input / output port 301 for separating the main signal into an up main signal and a down main signal.

The base station apparatus 310 may be a base station apparatus of the LTE system or a relay apparatus of the base station apparatus of the LTE system. The base station apparatus 310 may be a micro cell, a pico cell, a femto cell, Cell) service area.

The base station apparatuses 510, 520 and 530 of the existing mobile communication system 500 represent surrounding base station apparatuses using different communication systems or different frequency bands from the base station apparatus 310. As shown in the drawing, LTE, WCDMA, CDMA < RTI ID = 0.0 > 1X < / RTI >

The signal combiner 320 receives the MIMO signal from the MIMO signal processing unit 310 of the base station apparatus 310 and the MIMO signal from the LTE base station apparatus 510 according to the MIMO scheme among the base station apparatuses 510, 520, and 530 of the existing mobile communication system 500, And the MIMO signals input through the input / output port 303 are combined and output in a downward direction.

The downlink signal amplifying unit 330 is for frequency down-amplifying the downlink MIMO signal output from the signal combining unit. As shown in FIG. 4, the downlink signal amplifying unit 330 includes an amplifier a, a local oscillator b, and a mixer c And may include frequency downconverter b, c, amplifier d, filter e, and amplifier f.

For example, as shown in FIG. 6, frequency downconverters b and c including amplifier a, local oscillator b and mixer c, amplifier d, filter e, The frequency up-converter h, i, the amplifier j, the filter k, the amplifier 1, the variable attenuator m, and the amplifier (i), which include the local oscillator h and the mixer i, (n) are serially serially connected, the configuration of a to f is divided into a first part and the configuration of g to n is divided into a second part for the sake of convenience of explanation. In the amplifier of the conventional superheterodyne type, The amplification unit 330 may be configured with a first portion (a to f in FIG. 6) of the conventional superheterodyne type amplifier of FIG.

The MUX multiplexes the downlink MIMO signal output from the downlink signal amplifying unit 330 and the downlink (combined) main signal input through the input / output port 302 and outputs the combined downlink signal to the input / output port 304 Output port 302 or an upward main signal inputted from the single cable 304 through the input / output port 304 through the input / output port 302.

Next, the service unit 400 of FIG. 3 will be described.

The service unit 400 may include a plurality of input and output ports 401 to 403, a signal separation unit 410, a bypass line 420, and a downlink signal amplification unit 430.

The input / output port 401 is for connecting the main unit 300 and the service unit 400 via a single cable 10. The input / output port 401 is connected to the input / output port 304 of the main unit 300 and the input / Both ends of the single cable 10 are connected to the cable 401.

The input / output port 402 is for connecting the service antenna of the main signal, and the input / output port 403 is for connecting the service antenna of the MIMO signal.

The signal separation unit 410 is connected to the input / output terminal 401 to separate the main signal and the MIMO signal.

The bypass line 420 connects the signal separator 410 and the input / output port 402 to bypass the up / down main signal.

The downlink signal amplifying unit 430 is connected between the signal separating unit 410 and the input / output port 403 to amplify and amplify the downlink MIMO signal. As shown in FIG. 5, (k), an amplifier (l), a variable attenuator (m), and an amplifier (n), including a local oscillator (h) and a mixer ).

For example, as shown in FIG. 6, frequency downconverters b and c including amplifier a, local oscillator b and mixer c, amplifier d, filter e, The frequency up-converter h, i, the amplifier j, the filter k, the amplifier 1, the variable attenuator m, and the amplifier (i), which include the local oscillator h and the mixer i, (n) are serially serially connected, the configuration of a to f is divided into a first part and the configuration of g to n is divided into a second part for the sake of convenience of explanation. In the amplifier of the conventional superheterodyne type, The amplifying part 430 may be constituted by a second part (g to n in FIG. 6) of the conventional superheterodyne type amplifier of FIG.

The operation of the MIMO signal expander according to the embodiment of FIG. 3 will be described by dividing it into a forward path and a reverse path.

First, the forward path will be described.

The downlink main signal output from the main signal processing unit 311 of the base station apparatus 310 of the main unit 300 passes through the amplifier 313 and the signal separation unit 314 and is transmitted to the external signal combiner 540).

The external signal combiner 540 combines the downlink main signal from the different one or more base station apparatuses 510, 520 and 530 of the existing mobile communication system 500 and the downlink main signal transmitted from the base station apparatus 310 of the main unit 300 Output terminal 302 of the rear main unit 300 to the mux 340.

The downlink MIMO signal output from the MIMO signal processing unit 312 of the base station apparatus 310 of the main unit 300 and the downlink MIMO signal output from the LTE base station apparatus 510 of the existing mobile communication system 500 and input through the input / The downlink MIMO signal is combined in the signal combiner 320, down-converted in the downlink signal amplifier 330, amplified, and transmitted to the MUX 340.

The multiplexer 340 multiplexes and outputs a downlink main signal received through the input / output terminal 302 of the main unit 300 and a downlink MIMO signal received from the downlink signal amplifier 330, MIMO) signal is extended and transmitted to the service unit 400 through a single cable 10 connected to the input / output port 304.

The downlink (main + MIMO) signal input through the input / output port 401 of the service unit 400 is input to the signal separation unit 410 and the signal separation unit 410 outputs the downlink (main + MIMO) Demultiplexed into a downlink main signal and a downlink MIMO signal, and outputs the downlink main signal and the downlink MIMO signal to the bypass line 420 and the downlink signal amplification unit 430, respectively. The downlink signal amplifying unit 430 frequency-ups the downlink MIMO signal, and outputs the downlink MIMO signal.

The downlink main signal through the bypass line 420 and the downlink MIMO signal output from the downlink signal amplifier 430 are transmitted to two service antennas (not shown) connected to the two input / output ports 402 and 403 of the service unit 400 Respectively.

The following reverse path is described.

The uplink signal in the reverse direction from the user terminal (not shown) input through one of the two input / output ports 402 and 403 of the service unit 400 is transmitted to the signal separation unit 410 through the bypass line 420 The upstream signal output from the signal separator 410 is output through the input / output port 401 and extended and transmitted through the single cable 10 to the main unit 300.

The upstream signal input through the input / output port 304 of the main unit 300 is input to the multiplexer 340 and the multiplexer 340 transmits the upstream signal to the signal combiner 540 through the input / output port 302 The signal combiner 540 separates the uplink signals for the respective base stations and transmits the uplink signals to the base station apparatuses 510, 520 and 530 of the mobile communication system, and the uplink signals corresponding to the base station apparatuses 310 of the main unit 300, (301) to the main unit (300).

The upstream signal input through the input / output port 301 of the main unit 300 is input to the main signal processing unit 311 of the base station apparatus 310 via the signal separation unit 314 and the amplifier 313 and processed upward.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

10: Single (coaxial) cable
300: Main Unit (MU)
301 to 304: signal input / output port of the main unit
310: base station device
320: Signal combiner
330: Downstream signal amplification unit
340: MUX
400: Service Unit (SU)
401 to 403: Signal input / output port of the service unit
410:
420: Bypass line
430: Downstream signal amplification unit

Claims (9)

A first input / output port for inputting / outputting up / down main signals of the first base station device;
A second input / output port for inputting / outputting a main signal to which an uplink / downlink main signal of one or more communication system base stations (hereinafter, referred to as a second base station apparatus) is combined with an uplink / downlink main signal of the first base station apparatus;
A signal combiner for combining and outputting a MIMO signal from the first base station apparatus and a MIMO signal input from at least one of the second base station apparatus through a third input /
A first downlink signal amplifying unit for down-frequency-amplifying the downlink MIMO signal output from the signal combining unit; And
A downlink MIMO signal output from the first downlink signal amplifying unit and a downlink (combined) main signal input through the second input / output port are combined and output through a fourth input / output port connected to one end of a single cable, And a main unit (MU) for outputting an uplink main signal inputted through the fourth input / output port through the second input / output port from the MUX signal expander . The method according to claim 1,
The first base station device includes a main signal processing unit for processing a main signal up or down, a signal separation unit connected between the main signal processing unit and the first input / output port, for separating the main signal into an up main signal and a down main signal, And a MIMO signal processing unit for down-processing the MIMO signal. The method according to claim 1,
A fifth input / output port to which the other end of the single cable is connected;
A sixth input / output port for connecting the main antenna;
A seventh input / output port for connecting the MIMO antenna;
A second signal separator connected to the fifth input / output terminal for separating the main signal and the MIMO signal;
A bypass line connecting between the second signal separator and the sixth input / output port; And
And a second downlink signal amplifying unit connected between the second signal separating unit and the seventh input / output port to amplify and amplify a downlink MIMO signal by amplifying the downlink MIMO signal, and a service unit (SU) Wherein the MIMO signal extension device comprises: The method of claim 3,
A frequency downconverter and an amplifier sequentially connected in series; Wherein the first down-signal amplifier comprises a second portion connected in series with the frequency up-converter and the amplifier, and the first portion and the second portion are connected in series, wherein the first down-signal amplifier amplifies the super- And the second downlink signal amplifying unit is composed of the second portion of the superheterodyne type amplifier. The method according to claim 1,
Wherein the first base station device is a base station device of an LTE system. 6. The method of claim 5,
Wherein the first base station apparatus is a relay apparatus of a base station apparatus of an LTE system. 6. The method of claim 5,
Wherein the first base station device has a service area of a micro cell, a pico cell, a femto cell, or a macro cell. The method according to claim 1,
Wherein the second base station apparatus uses a different communication scheme or a different frequency band from the first base station apparatus. 9. The method of claim 8,
Wherein the second base station device comprises one or more of LTE, WCDMA, and CDMA 1X based base stations.

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