KR20110004018A - Method and apparatus for signal processing - Google Patents

Abstract

PURPOSE: A signal processing method for reducing the distortion of a signal outputted from a power amp and an apparatus thereof are provided to estimate the characteristic change of the power amp in case the frequency of MIMO(Multiple Input Multiple Output) data burst is low. CONSTITUTION: A digital up-converter(110) up-converts a first MIMO signal and a second MIMO signal of a first transmitter by using a first frequency. The digital up-converter up-converts a third MIMO signal and a fourth MIMO signal of a second transmitter by using a second frequency. A combiner(120) synthesizes the up-converted first MIMO signal and the up-converted fourth MIMO signal.

Description

Method and apparatus for signal processing

The present invention relates to a wireless communication system, and more particularly, to a signal processing method and apparatus for synthesizing a plurality of signals output using a multiple input multiple output (MIMO) scheme.

Due to the development of communication technology and the development of the contents industry, there is an increasing demand for high-speed data transmission over a wireless channel. In order to transmit data at high speed, large transmission power and wide bandwidth are required as compared with general data transmission. Therefore, in order to implement high-speed communication, a method for reducing interference signals and efficiently transmitting desired signals is required.

One such scheme is IEEE, which employs orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA). (Institute of Electrical and Electronics Engineers) 802.16e system, and Multiple Input Multiple Output (MIMO) technology has been proposed.

In a wireless communication system based on the IEEE 802.16e system, orthogonality between a plurality of transmission signals (carriers) is maintained through the OFDM / OFDMA scheme, and after combining the plurality of transmission signals, the MIMO scheme is applied. By applying the signal transmission and reception through a plurality of antennas can be obtained high-speed data transmission performance.

In a wireless communication system based on the IEEE 802.16e system, the digital up-converter has a frequency shift with respect to the first antenna signal and the second antenna signal of each signal so that the frequency bands do not overlap each other among a plurality of signals having the same frequency band. And output to the combiner.

The combiner synthesizes and outputs a plurality of signals input from the digital up-converter through an independent path. After generating the second synthesized signal, and outputs the synthesized signal through a separate path. The first composite signal and the second composite signal output from the combiner are processed through digital-to-analog conversion (DAC) and RF signal processing through separate paths, and then transmitted through a plurality of antennas.

In the IEEE 802.16 based WiMAX standard, data bursts are allocated by dividing the non-MIMO mode and the MIMO mode. In the non-MIMO mode, only the non-MIMO data burst is allocated to the downlink data interval. In the case of MIMO, non-MIMO data bursts and MIMO data bursts may be allocated to downlink data sections.

Referring to FIG. 1, the downlink subframe includes a preamble section, a map section, and a data section, and the preamble has various uses such as synchronization between the terminal and the base station, channel estimation, and automatic gain control (AGC). Used as The map section includes allocation information of data bursts included in the data section, and the actual data bursts transmitted to each terminal are allocated to the data section.

When the transmitter supports the MIMO scheme, each of the plurality of signals output from the plurality of transmitters includes a first antenna signal (signal of antenna # 0) and a second antenna signal (signal of antenna # 1). As shown in FIG. 1A, the antenna signal may include a preamble signal, a map signal, a non-MIMO data signal, and a MIMO data signal disposed in a downlink of the frame, and the second antenna signal. As shown in FIG. 1 (b), may not include a preamble signal and a map signal, and may include only a MIMO data signal.

2 is a diagram illustrating a 2-FA (Frequency Assignment) output signal according to whether or not MIMO data burst is included. 2 illustrates an example of 2-FA (Frequency Assignment) in which two signals are output from a transmitter and synthesized.

Referring to FIG. 2, when two signals including a MIMO data signal are output from a transmitter of a base station and synthesized in a combiner, a first signal including a preamble signal, a map signal, a non-MIMO data signal, and a MIMO data signal Antenna signals are synthesized as shown in FIG. Second antenna signals including only the MIMO data signal are synthesized as shown in FIG. That is, the frame for the first antenna signal may include a preamble section, a map section, and a data section, and the data section may include a MIMO data burst and a non-MIMO data burst.

On the other hand, the frame for the second antenna signal consists of a data section only, and the data section includes only the MIMO data burst. In this case, after the preamble and the map are transmitted as the first antenna signal, the data burst of the first antenna signal and the MIMO data burst of the second antenna signal are transmitted according to the data interval of the first antenna signal. At this time, the transmission power of the MIMO data burst is transmitted at a power of 1/2 (-3dB) to the transmission power of the non-MIMO data burst.

Even if the base station is operated in the MIMO mode, MIMO data does not always exist in every frame. Thus, when there is no MIMO data to transmit, the first synthesized signal synthesized with the first antenna signals is shown in FIG. It includes a preamble signal, a map signal, and a non-MIMO signal. On the other hand, the second synthesized signal to which the second antenna signals are synthesized has no signal to transmit, as shown in FIG.

Therefore, when the frequency of the MIMO data burst is low in a plurality of frames transmitted from the base station to the terminal, most downlink frames may be in the form of including only the non-MIMO data burst.

Digital pre-distortion (DPD) is performed by a signal processor in order to reduce distortion of a signal amplified by a power amplifier of a transmitter. In order to perform the DPD, a signal output from a power amplifier is used. Feedback should be made.

Since there is a preamble section, a map section, and a data section in the path of the first antenna signal regardless of the presence or absence of the MIMO data burst, it is possible to estimate the characteristic change of the power amplifier by feeding back the output signal of the power amplifier.

However, since the signal is output only when the MIMO data burst is transmitted in the path of the second antenna signal, it is difficult to estimate the characteristic change of the power amplifier when the frequency of the MIMO data burst is low, which is the second antenna output from the power amplifier. It can cause distortion of the signal. When distortion occurs in a signal output from the power amplifier, there is a problem that it is difficult to decode the received signal at the receiver.

As described above, when combining the first antenna signals of the plurality of signals together and combining the second antenna signals together to perform RF processing, the amplitude of the first antenna signal in proportion to the number of signals output from the transmitter and The power is increased. In this case, the peak signal-to-average power ratio (PAPR) of the output signal is high, making it difficult to operate the power amplifier for amplifying the signal in a linear section, and high output specifications are applied as the amplitude level and power of the output signal increase. As a result, there is a problem that the cost is increased when the system is implemented.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and in the wireless communication system using the OFDM scheme, it is possible to estimate the characteristic change of the power amplifier even when the frequency of MIMO data burst is low, thereby reducing the distortion of the signal output from the power amplifier. It is a technical object of the present invention to provide a signal processing method and apparatus for MIMO signal synthesis.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in the wireless communication system using the OFDM method, the cost of applying a high output power amplifier due to an increase in the amplitude level and power of the output signal synthesized with a plurality of signals It is a technical object of the present invention to provide a signal processing method and apparatus for MIMO signal synthesis that can reduce an increase.

A signal processing method according to an embodiment of the present invention is a signal processing method for synthesizing a multiple input multiple output (MIMO) signal, using a first frequency for a first MIMO signal and a second MIMO signal of a first transmitter. Upconverting and upconverting using the second frequency with respect to the third and fourth MIMO signals of the second transmitter; And synthesizing the up-converted first MIMO signal and the up-converted fourth MIMO signal, and synthesizing the up-converted second MIMO signal and the third MIMO signal. The signal and the third MIMO signal include a preamble signal, and the second MIMO signal and the fourth MIMO signal do not include a preamble.

According to an aspect of the present invention, there is provided a signal processing method for synthesizing multiple input multiple output (MIMO) signals, the method comprising: outputting MIMO signals from each of a plurality of transmitters; Synthesizing the MIMO signals such that at least one MIMO main signal is included for each radio frame transmitted through a plurality of transmit antennas, wherein the MIMO main signal includes a preamble.

The signal processing apparatus according to the embodiment of the present invention up-converts the first MIMO signal and the second MIMO signal of the first transmitter by using the first frequency, and applies the third MIMO signal and the fourth MIMO signal of the second transmitter. An upconverter upconverting using the second frequency with respect to the second frequency; And a synthesizer configured to synthesize the upconverted first MIMO signal and the upconverted fourth MIMO signal and to synthesize the upconverted second MIMO signal and the third MIMO signal. And the third MIMO signal includes a preamble signal, and the second MIMO signal and the fourth MIMO signal do not include a preamble.

In a signal processing method according to an embodiment of the present invention, in the signal processing method for synthesizing a multiple input multiple output (MIMO) signal, up-converting the MIMO signals output from the first transmitter using a first frequency, Upconverting the MIMO signals output from the second transmitter using the second frequency; And combining at least one of the MIMO signals output from the first transmitter and at least one of the MIMO signals output from the second transmitter, and outputting the MIMO signal output from the first transmitter. At least one of the signals or at least one of the MIMO signals output from the second transmitter is characterized in that it comprises a preamble (preamble) signal.

According to an embodiment of the present invention, in a wireless communication system using an OFDM scheme, even when the frequency of MIMO data bursts is low, it is possible to estimate the characteristic change of the power amplifier, thereby providing an effect of reducing the distortion of the signal output from the power amplifier. do.

According to an embodiment of the present invention, when a signal is synthesized in an OFDM communication wireless communication system, amplitude and power increase are prevented from being biased to one of a plurality of output signals, thereby reducing the cost of implementing the system. .

According to an exemplary embodiment of the present invention, the preamble signal is prevented from being biased to one output signal, thereby reducing signal-to-average power ratio (PAPR) compared to the prior art, thereby improving signal processing performance.

Hereinafter, a signal processing method and apparatus according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. Matters not described in detail in the present invention may refer to the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard document and the WiMAX Forum Network Working Group (NWG) standard document.

3 is a view showing a signal processing apparatus according to an embodiment of the present invention, Figure 4 is a view showing a signal processing method according to an embodiment of the present invention. 3 illustrates a transmitter of a base station including a signal processing apparatus 100 according to an exemplary embodiment of the present invention.

3 and 4, the signal processing apparatus 100 according to an exemplary embodiment of the present invention includes a digital up-converter 110 and a combiner 120. The transmitter of the base station includes a plurality of transmitters (Transmitter # 1, Transmitter # 2), a signal processor, a digital-to-analog converter (DAC), an RF processor, and the signal processor 100.

Each of the plurality of transmitters of the transmitter outputs an OFDM signal, and generates data and control signals to be transmitted to the digital up converter 110 of the signal processing apparatus 100.

When the transmitter supports the MIMO scheme, the signals output from each of the plurality of transmitters are composed of a first antenna signal (signal of antenna # 0) and a second antenna signal (signal of antenna # 1), and the first antenna signal. May include a preamble signal, a map signal, a non-MIMO data signal, and a MIMO data signal disposed in a downlink of the frame, and the second antenna signal may include only a MIMO data signal.

In the present invention, the first antenna signal may be defined as a main signal as an equivalent term, and the second antenna signal may be defined as a diversity signal as an equivalent term.

The digital up converter 110 controls the phase of each signal input from a plurality of transmitters and combines the frequency bands of the first antenna signal and the second antenna signal by using the input frequency. Will output

Here, as illustrated in FIG. 4, the digital up converter 110 combines a first antenna signal of a first signal and a second antenna signal of a second signal among a plurality of signals input from a plurality of transmitters. The signal is output to the first signal combiner 122 of 120. The second antenna signal of the first signal and the first antenna signal of the second signal among the plurality of signals are output to the second signal combiner 124 of the combiner 120.

The combiner 120 includes a plurality of signal synthesizing units, for example, a first signal synthesizing unit 122 and a second signal synthesizing unit 124, and a plurality of transmitters via the digital up converter 110. Synthesize a plurality of signals output from the first signal synthesizer 122 and the second signal synthesizer 124, and synthesized by the first signal synthesizer 122 and the second signal synthesizer 124 Outputs the signal to a signal processor through a separate path.

Referring to FIG. 5, when the signals synthesized and output from the combiner 120 are described in detail, the first antenna signal output from the transmitter # 1 and the second antenna signal output from the transmitter # 2 may be the first signal synthesizer. It is synthesized at 122 and output to the first path. The second antenna signal output from the transmitter # 1 and the first antenna signal output from the transmitter # 2 are synthesized by the second signal combiner 124 and output through the second path. That is, the signals output through the first path and the second path include a first antenna signal and a second antenna signal output from different transmitters (transmitter # 1 and transmitter # 2).

As described above, when the first antenna signal and the second antenna signal are synthesized in the combiner 120, as shown in FIG. 6, the first synthesized signal 2-FA output through the first path is illustrated. The second composite signal 2-FA output through the second path may include a preamble signal, a map signal, a non-MIMO data signal, and a MIMO data signal. That is, one non-MIMO data signal and two MIMO data signals are included together with the preamble signal and the map signal.

In FIG. 6, 'Non-MIMO Data Burst 1 and MIMO Data Burst 1' means a signal output from the first transmitter (transmitter # 1), and 'Non-MIMO Data Burst 2 and MIMO Data Burst 2' is a second transmitter. It means the signal output from (Transmitter # 2).

In detail, the first composite signal output through the first path may include a preamble signal, a map signal, a non-MIMO data signal, a MIMO data signal, and a plurality of signals included in the first antenna signal of the first signal among the plurality of signals. MIMO data signal included in the second antenna signal of the two signals. The second composite signal output through the second path may include a preamble signal, a map signal, a non-MIMO data signal, a MIMO data signal, and a first signal among the plurality of signals included in the first antenna signal of the second signal among the plurality of signals. MIMO data signal included in the second antenna signal of the signal.

As described above, since the power of the MIMO data signal has a value 1/2 of the power of the non-MIMO data signal, one non-MIMO data signal and two MIMO data signals of the first output signal and the second output signal. The signal power of is the same.

The signal processor is synthesized in the combiner 120 via the digital up-converter 110, and then performs a CFR (Crest Factor Reduction) on each of the signals output through different paths, the signal is a power amplifier Digital pre-distortion (DPD) is performed to reduce distortion when amplified by the digital-to-analog converter (DAC).

A digital-to-analog converter (DAC) converts a digital signal input from a signal processor into an analog signal and outputs it to an RF processor.

The RF mixer of the RF processor includes components such as a filter and a front end unit, and performs RF processing to transmit a signal output from the digital-to-analog converter (DAC) on an actual air. After that, the power amplifier outputs a power amplifier, and the power amplifier amplifies the input signal in a linear section to prevent distortion of the signal, and amplifies the amplified signal through air through a Tx antenna. Send on).

7 is a diagram illustrating another signal processing device according to another embodiment of the present invention, and FIG. 8 is a diagram illustrating another signal processing method according to another embodiment of the present invention. Since the signal processing apparatus 200 illustrated in FIG. 7 is the same as the embodiment described with reference to FIGS. 3 and 4 except for the configuration and operation of the digital up converter 210 and the switch 230, the digital up converter A description of matters not related to 210 and the switch unit 230 will be omitted.

7 and 8, when the transmitter supports the MIMO scheme, the signals output from each of the plurality of transmitters are composed of a first antenna signal and a second antenna signal, and the first antenna signal is a downlink of a frame. And a preamble signal, a map signal, a non-MIMO data signal, and a MIMO data signal, wherein the second antenna signal includes only a MIMO data signal.

The digital up converter 210 controls the phase of each signal input from the plurality of transmitters and moves the frequency bands of the first antenna signal and the second antenna signal to the switch unit 230 by using the input frequency. Output Here, when two signals are input from the transmitter, the digital up converter 210 outputs a first signal to the first switch 232 of the switch unit 230 and a second signal to the first signal of the switch unit 230. 2 is output to the switch 234.

The switch unit 230 includes a plurality of switches 232 and 234 corresponding to the plurality of transmitters. As illustrated in FIG. 9, the first switch 232 and the second switch include a first antenna signal and a first antenna signal of each of the first and second signals input from the digital up-converter 210 according to a select signal. The output path of the two-antenna signal is controlled and output to the combiner 220.

Specifically, as illustrated in FIG. 8, the first switch 232 outputs the first antenna signal of the first signal among the plurality of signals to the first signal combiner 222 of the combiner 220, The second antenna signal of the first signal is output to the second signal combiner 224 of the combiner 220.

The second switch 234 outputs the second antenna signal of the second signal among the plurality of signals to the first signal combiner 222 of the combiner 220 and combines the first antenna signal of the second signal. Output to the second signal synthesizing unit 224 of you (220).

The combiner 220 includes a plurality of signal synthesizing units, for example, a first signal synthesizing unit 222 and a second signal synthesizing unit 224, and the digital up converter 210 and the switch unit 230. Through the first signal synthesizing unit 222 and the second signal synthesizing unit 224 are synthesized as shown in FIG. 5, the first signal synthesizing unit 222 and the second signal are combined. The synthesizer 224 outputs the synthesized signal to the signal processor through a separate path.

Looking at the signals synthesized and output from the combiner 220 in detail, the first antenna signal output from the transmitter # 1 and the second antenna signal output from the transmitter # 2 are synthesized by the first signal synthesizer 222. It is output to the first path. The second antenna signal output from the transmitter # 1 and the first antenna signal output from the transmitter # 2 are synthesized by the second signal combiner 224 and output through the second path. That is, the signals output through the first path and the second path include a first antenna signal and a second antenna signal output from different transmitters (transmitter # 1 and transmitter # 2).

In the signal processing apparatus and the signal processing method according to the embodiments of the present invention described above, even when there is no MIMO data burst, a composite signal including a preamble signal, a map signal, and non-MIMO data is outputted every frame in the power amplifier. The feedback of the signal output from the amplifier allows the estimation of the characteristic change of the power amplifier to be performed every frame. This reduces the distortion of the signal output from the power amplifier, improving the efficiency of data transfer.

In addition, the present invention described above can prevent the phenomenon that the non-MIMO data signal is biased to one of the plurality of output signals in the plurality of output signals synthesized and output. This prevents the amplitude level and power of the output signal from increasing, thereby reducing the cost of applying a high output power amplifier.

In addition, the present invention can prevent the preamble signal from being biased to one output signal, thereby lowering the peak-to-average power ratio (PAPR) compared to the prior art, and the CFR (signal processor) in the signal processor. Crest Factor Reduction) Improves signal processing performance.

FIG. 10 is a diagram illustrating a signal processing method according to another embodiment of the present invention, and FIG. 11 is a diagram illustrating a signal arrangement method having a 3-FA structure.

In another embodiment of the present invention, as shown in FIG. 10, when three signals are output from the transmitter, the output path of each signal is controlled through a switch unit 230 including three switches, The binner may synthesize and output the first antenna signal and the second antenna signal of the signals.

10 and 11, when synthesizing three signals, the digital up-converter 220 operates in the same manner as the embodiment of FIG. 7, and the first antenna signal and the second antenna signal of each of the three signals The frequency band of the shift is output to the switch unit 230.

The switch unit 230 includes first to third switches 232, 234, and 236, and controls a path of the first to third signals inputted through the first to third switches, thereby combining the combiner ( 220).

As an example, the first switch 232 outputs the first antenna signal of the first signal to the first signal combiner 222 of the combiner 220 and outputs the second antenna signal of the first signal. The signal is output to the second signal synthesizing unit 224 of the combiner 220.

The second switch 234 outputs the first antenna signal of the second signal to the first signal combiner 222 of the combiner 220 and the second antenna signal of the second signal of the combiner 220. Is output to the second signal synthesizing unit 224.

The third switch 236 outputs the first antenna signal of the third signal to the second signal combiner 224 of the combiner 220 and the second antenna signal of the third signal to the combiner 220. The first signal combiner 220 outputs the signal.

The combiner 220 synthesizes and outputs the first to third signals input as described above. In the combiner 220, when the first to third signals are synthesized into two synthesized signals having separate output paths, as shown in FIG. 12, the first synthesized signal output to the first path (3- FA) and the second composite signal 3-FA output through the second path may include at least one non-MIMO data signal with each of the preamble signal and the map signal regardless of whether MIMO data is included or not. Can be. In addition, when the MIMO data is included, the preamble signal, the map signal, the non-MIMO data signal, and the MIMO data signal may be included.

In the case of 3-FA, a total of six signals are transmitted in the case of 3-FA. Since each signal output from each transmitter is composed of a first antenna signal and a second antenna signal, two MIMO data are transmitted to each transmitter. Bursts may be present. Therefore, when two transmitting antennas are applied in the transmitter, a total of six MIMO data signals may correspond to three of each of the two transmitting antennas.

For example, as shown in FIG. 12A, the first antenna signal MIMO Data Burst 1 of the first transmitter and the first antenna signal MIMO of the second transmitter are used as the first output signal. The data burst 2 and the first antenna and the second antenna signal (MIMO data burst 3 and the second antenna) of the third transmitter may be synthesized in the combiner 220.

As shown in FIG. 12B, the second antenna signal MIMO Data Burst 1 of the first transmitter and the second antenna signal MIMO Data Burst 2 of the second transmitter are used as the second output signal. The second antenna) and the first antenna signal (MIMO Data Burst 3, first antenna) of the third transmitter may be synthesized in the combiner 220.

In this way, it is possible to estimate the characteristic change of the power amplifier every frame, thereby reducing the distortion of the signal output from the power amplifier. In addition, the preamble signal is prevented from being biased to one output signal, thereby lowering the peak-to-average power ratio (PAPR) compared to the prior art, and the non-MIMO data signal is one output signal among a plurality of output signals. The phenomenon which is biased in can be prevented. This prevents the amplitude level and power of the output signal from increasing, thereby reducing the cost of applying a high output power amplifier.

In the above description, the switch unit 220 is illustrated and described as being implemented in a separate configuration in the transmitting unit of the base station, the switch unit 230 is another component of the transmitting unit (for example, transmitter, combiner It may be included in the implementation.

The signal processing method according to the embodiment of the present invention described above may be performed through various computer means. In addition, the signal processing apparatus according to the embodiment of the present invention may be composed of one or more software modules or hardware.

On the other hand, those skilled in the art will understand that the present invention described above may be implemented in other specific forms without changing the technical spirit or essential features. Therefore, it is to be understood that the embodiments described above are exemplary in all respects and not restrictive.

The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

1 is a diagram illustrating a 1-FA (Frequency Assignment) output signal.

22-FA (Frequency Assignment) output signal.

3 is a diagram illustrating a signal processing apparatus according to an embodiment of the present invention.

4 is a diagram illustrating a signal processing method according to an embodiment of the present invention.

5 is a diagram illustrating a signal arrangement method of a 2-FA structure.

6 illustrates a 2-FA output signal according to embodiments of the present invention.

7 is a diagram illustrating a signal processing device according to another embodiment of the present invention.

8 is a diagram illustrating a signal processing method according to another embodiment of the present invention.

9 is a view showing a switch unit of a signal processing device according to another embodiment of the present invention.

10 is a diagram illustrating a signal processing method according to another embodiment of the present invention.

11 is a view showing a signal arrangement method of a 3-FA structure.

12 illustrates a 3-FA output signal according to embodiments of the present invention.

<Description of the symbols for the main parts of the drawings>

100: signal processing device 110: digital up-converter

120: combiner 130: switch unit

Claims (8)

In the signal processing method for synthesizing a multiple input multiple output (MIMO) signal, Upconverting the first MIMO signal and the second MIMO signal of the first transmitter using the first frequency and upconverting the second MIMO signal and the fourth MIMO signal of the second transmitter using the second frequency; ; And Synthesizing the upconverted first MIMO signal and the upconverted fourth MIMO signal and synthesizing the upconverted second MIMO signal and the third MIMO signal, The first MIMO signal and the third MIMO signal include a preamble signal, and the second MIMO signal and the fourth MIMO signal do not include a preamble. The method of claim 1, The first MIMO signal and the fourth MIMO signal are signals for a first transmit antenna. The method of claim 1, And the second MIMO signal and the third MIMO signal are signals for a second transmit antenna. Up-converting the first MIMO signal and the second MIMO signal of the first transmitter using the first frequency, and up-converting the second MIMO signal and the fourth MIMO signal of the second transmitter by using the second frequency. converter; And a synthesizer configured to synthesize the upconverted first MIMO signal and the upconverted fourth MIMO signal, and to synthesize the upconverted second MIMO signal and the third MIMO signal. Wherein the first MIMO signal and the third MIMO signal include a preamble signal, and the second MIMO signal and the fourth MIMO signal do not include a preamble. The method of claim 4, wherein And a path controller configured to control an output path of the first MIMO signal and the second MIMO signal of the first transmitter, and to control the output path of the third MIMO signal and the fourth MIMO signal of the second transmitter. The path control unit may control the output path to synthesize the first MIMO signal and the fourth MIMO signal, and control the output path to synthesize the second MIMO signal and the third MIMO signal. Signal processing device. In the signal processing method for synthesis of multiple input multiple output (MIMO) signals, Outputting MIMO signals from each of the plurality of transmitters; And Synthesizing the MIMO signals such that at least one MIMO main signal is included for each radio frame transmitted through a plurality of transmit antennas; The MIMO main signal comprises a preamble (Preamble). The method of claim 6, And upconverting the MIMO signals to a frequency determined according to each transmitter. The method of claim 6, The MIMO signals include the MIMO main signal and a diversity signal.

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