JPH09214452A - Signal transmission method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the transmission of a carrier signal with high quality by a small sized device. SOLUTION: A distribution section 11 for an information signal distributes input information into, e.g. four in time division. A modulation section 12 consisting of a Band 1 modulator 121 , a Band 2 modulator 122 , a Band 3 modulator 123 , and a Band 4 modulator 124 modulates 4 divided carrier signals obtained by dividing a band of a multi-carrier signal into four blocks. A power amplifier 13 consisting of a power amplifier 133 , a power amplifier 132 a power amplifier 133 , and a power amplifier 134 amplifies the four modulation outputs from the modulation section 12. Multicouplers 15, 16, 17 combines amplified outputs from the power amplifier section 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission method and device for transmitting a multi-carrier signal in which a plurality of carriers having different frequencies are collected.

[0002]

2. Description of the Related Art Conventionally, when a wide band signal as shown in FIG. 4 (A) is power-amplified, the band widens as shown in FIG. 4 (B) due to the non-linear distortion of the power amplifier, and interference with adjacent bands occurs. Was causing.

Therefore, in order to reduce the interference to the adjacent band, first, it is possible to use only the linear portion of the power amplifier without using the nonlinear portion. For example, even if the amplifier can output 10 W at the maximum output, only 1 W of the linear amplification portion is used. That is, the output level is made sufficiently low and used only in a range where the characteristics are considered to be sufficiently linear. This is quantified in the form of maximum output power / actual output power = backoff. It is also possible to have a wide guard band on both sides of the original signal.

It is also conceivable to disperse the power among a plurality of power amplifiers, amplify them, and then add them. Generally, output 2W
Power amplifier is more expensive than two power amplifiers with an output of 1W. Therefore, in order to obtain the output of 2 W, it is cheaper to prepare two power amplifiers of the output of 1 W.

[0005]

By the way, the method of taking a large backoff as described above increases the cost. Further, the method of providing a wide guard band on both sides of the original signal wastes frequency.

Furthermore, the method of distributing power to a plurality of power amplifiers requires that the phases of the amplified signals be accurately matched. For example, as shown in FIG. 5, the power of the input RF signal is divided into four by the power distributor 31, and the four power amplifiers 32 ₁ , 32 ₂ , and 32 _{3 of the} power amplification unit 32 are distributed.
And 32 ₄ to output 1 W respectively and finally combine them into 4 W output, the power amplifiers 32 ₁ , 32 ₂ ,
The phase of each signal after amplification at 32 ₃ and 32 ₄ is determined by the four phase correctors 33 ₁ , 33 ₂ , 33 ₃ and 33 ₄ of the phase correction unit 33.
You have to match it exactly. The outputs of which the phases are corrected by the phase correctors 33 ₁ and 33 ₂ are combined by the duplexer 34. Further, the outputs of which the phases have been corrected by the phase correctors 33 ₃ and 33 ₄ are combined by the duplexer 35. The outputs of the duplexers 34 and 35 are again phase-corrected by the phase correction circuits 36 and 37, and then power-combined by the duplexer 38 to obtain a 4 W output. However, in order to match the phases, a total of 6 phase correctors are required, and the device becomes large.

The present invention has been made in view of the above-mentioned circumstances, and when transmitting a carrier signal of a wide band, an expensive high output power amplifier is not necessary, wasteful use of frequency is prevented, and phase correction is further performed. It is an object of the present invention to provide a signal transmission method and device that can realize high-quality transmission of the above-mentioned carrier signal while suppressing interference with an adjacent band while reducing the size of the device without using a device.

[0008]

In order to solve the above-mentioned problems, a signal transmission method according to the present invention divides a multi-carrier signal in which a plurality of carriers having different frequencies are grouped into blocks and modulates each block. Then, power amplification is performed, and the power amplified outputs are combined and transmitted.

Further, in order to solve the above-mentioned problems, the signal transmission device according to the present invention, when transmitting a multi-carrier signal in which a plurality of carriers having different frequencies are bundled, transmits the band of the multi-carrier signal to the modulation means. Is divided into n blocks, the n divided outputs are modulated, the power amplifying means amplifies the n block divided modulated outputs from the modulating means, and the synthesizing means divides the n output from the power amplifying means.
The amplified output of each is made into one.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a signal transmission method and apparatus according to the present invention will be described below with reference to the drawings. This embodiment is a multicarrier signal transmission apparatus 10 as shown in FIG. 1 for transmitting a multicarrier signal in which a plurality of carriers (carriers) having different frequencies are collected.

When transmitting a wideband multicarrier signal, amplification by a power amplifier is required in consideration of loss in a wireless or wired transmission path. This multi-carrier signal transmission device 10 does not use only one high-output power amplifier, but obtains 1 W output from each of the four power amplifiers and combines these four 1 W outputs to obtain a 4 W output. , This output 4W is transmitted.

The multicarrier signal transmission device 10 is
For example, input information, which is time-series data, is time-divided into 4
The information signal distribution unit 11 that divides the multi-carrier signal band into four blocks and four Band1 modulations that modulate the four divided carrier signals by dividing the band of the multi-carrier signal into four blocks. Unit 12 ₁ and Band 2 modulator 1
2 ₂ , Band3 modulator 12 ₃ , Band 4 modulator 12 _4, and four power amplifiers 13 ₁ for amplifying the four modulated outputs from the above modulator 12, power amplifier 13 ₂ , power amplifier 13 _3. , A power amplifier 13 comprising a power amplifier 13 _4.
And a shared unit including shared units 15, 16 and 17 that combine the amplified outputs from the power amplification unit 13 into one unit.

The Band1 modulator 12 ₁ of the modulator 12 converts the Band1 signal as shown in FIG. 2B obtained by dividing the band of the multicarrier signal as shown in FIG. It is modulated by the first distribution information signal from the signal distribution unit 11. In addition, the Band2 modulator 12 ₂ uses the second distribution information signal from the information signal distribution unit 11 as a Band2 signal as shown in FIG. 2C obtained by dividing the band of the multicarrier signal into blocks. Modulate. Also, Band
The 3 modulator 12 3 modulates the Band ₃ signal as shown in FIG. 2D obtained by dividing the band of the multi-carrier signal with the third distribution information signal from the information signal distributing unit 11. . Further, Band4 modulator 12 _4, the fourth a Band4 signal as shown in the (E) 2 obtained by dividing the band of the multicarrier signal from the distribution unit 11 of the information signal
Modulation with the distribution information signal.

Here, the above four Band ₁ modulators 12 ₁ and Ba
nd2 modulator 12 ₂ , Band3 modulator 12 ₃ , Band4 modulator 12 ₄
Bands multiple pre-allocated carriers
Since it is divided and then modulated, band division multiple access (BDMA: Band Division Mult) is performed.
iple Access) method can be used.

The four Band ₁ modulators 12 ₁ and Band of the modulator 12
Each of the four modulation outputs from the 2 modulator 12 ₂ , the Band ₃ modulator 12 ₃ , and the Band 4 modulator 12 ₄ has four power amplifiers 13 ₁ , a power amplifier 13 ₂ , a power amplifier 13 ₃ , and a power amplifier 13 of the power amplifier 13. Each is amplified by 13 ₄ .

[0016] Here, four power amplifiers 13 _1, the power amplifier 13 _2, the power amplifier 13 _3, each amplified output of the power amplifier 13 _4, band splitting original signal a multicarrier signal, as shown in FIG. 2 Since it is a modulated signal,
A duplexer 1 that does not need to be aligned in phase and constitutes a shared part
5, 16 and 17 can be input. This is because, generally, in a multi-carrier signal, no information is contained in the carrier phase relationship between each carrier. And finally 4W
Is obtained.

Further, suppose that the four power amplifiers 13 ₁ ,
Power amplifier 13 ₂ , power amplifier 13 ₃ , power amplifier 13 ₄
Even if there is non-linear distortion, the band handled by power amplification of the individual band signals is a narrow band as shown in FIG. 3A, and therefore the spread of each spectrum is shown in FIG. 3B.
Small as shown in. Therefore, the output 4W obtained by synthesizing the individual spectra by using the duplexers 15, 16 and 17 has a spread to the adjacent band as compared with the spread of the spectrum in the conventional case as shown by the broken line. The spread can be made small enough. In addition, in FIG.
Power amplifier 13 ₁ , power amplifier 13 ₂ , power amplifier 1
3 ₃ and the combined output when there is no nonlinear distortion in the power amplifier 13 ₄ are shown.

As described above, the multicarrier signal transmission apparatus 10 according to the present embodiment has four Bas forming the modulator 12.
nd1 modulator 12 ₁ , Band2 modulator 12 ₂ , Band3 modulator 1
2 _3, Band4 modulator 12 ₄ modulates the four divided carrier signals, said four divided modulated output four power amplifiers 1
3 ₁ , the power amplifier 13 ₂ , the power amplifier 13 ₃ , and the power amplifier 13 ₄ are amplified, and the amplified outputs are combined in the common part, so that an expensive high-output power amplifier is unnecessary and the frequency is wasted. It is possible to realize high-quality transmission of the carrier signal while suppressing interference with adjacent bands while preventing the above, and further miniaturizing the device by eliminating the need for a phase corrector.

The signal transmission method and device according to the present invention are not limited to the above-mentioned embodiments, and are also effective when a higher output is obtained. For example, it is effective for obtaining a high-power amplified output for digital television broadcasting.

[0020]

According to the signal transmission method of the present invention, the band of a multicarrier signal in which a plurality of carriers having different frequencies are grouped is divided into blocks, each block is modulated, and then the power is amplified. Since the outputs are combined and then transmitted, an expensive high output power amplifier is not required when transmitting a wideband carrier signal, wasteful use of frequency is prevented, and a phase corrector is not required, thus reducing the size of the device. It is possible to realize high-quality transmission of the above-mentioned carrier signal while suppressing interference to the adjacent band, while achieving the above.

Further, in the signal transmission apparatus according to the present invention, when transmitting a multicarrier signal in which a plurality of carriers having different frequencies are collected, the modulation means divides the band of the multicarrier signal into n blocks. To modulate the n-divided output from the modulator,
Since the block-division-modulated outputs are respectively amplified and the synthesis means collects the n amplified outputs from the power amplification means, an expensive high-output power amplifier is unnecessary, and wasteful use of frequency is prevented. It is possible to realize the high-quality transmission of the carrier signal while suppressing the interference to the adjacent band while achieving the downsizing of the device without the need for the phase corrector.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a signal transmission method and apparatus according to the present invention.

FIG. 2 is a spectrum diagram showing band division of a multicarrier signal performed in the above embodiment.

FIG. 3 is a spectrum diagram showing the operation of the above embodiment.

FIG. 4 is an enlarged view of a spectrum due to nonlinear distortion in a conventional device.

FIG. 5 is a block diagram showing a configuration of a conventional signal transmission device.

[Explanation of symbols]

 10 multi-carrier signal transmission device 11 information signal distribution unit 12 division modulation unit 13 power amplification unit 15, 16, 17 duplexer

Claims (2)

[Claims] 1. A signal transmission method for transmitting a multi-carrier signal in which a plurality of carriers having different frequencies are grouped, wherein a band of the multi-carrier signal is divided into blocks, each block is modulated, and then power is amplified. A signal transmission method, characterized in that the power amplification outputs are combined and then transmitted. 2. A signal transmission device for transmitting a multi-carrier signal in which a plurality of carriers having different frequencies are grouped together, and a modulation means for dividing the band of the multi-carrier signal into n blocks and modulating the n-divided output. And a power amplifying means for amplifying each of the n-block division modulated outputs from the modulating means, and a synthesizing means for collecting n amplified outputs from the power amplifying means. Transmission equipment.