KR100715205B1 - System and method for digital multi-band transceiver of the wireless communication system - Google Patents

Abstract

The present invention relates to a multi-band digital transceiver and method thereof in a wireless communication system.

In a wireless communication system, a plurality of frequency band signals are transmitted or received through one transmitter and a receiver. The transmitting apparatus converts a multi-band basic band digital modulated signal into a signal of an intermediate frequency band having different frequencies by using a digital filter, combines them, and generates and transmits a single signal as a whole. The receiving device receives an analog radio signal which is mixed with multiple bands and separates the received analog radio signal into signals of each band by using a digital filter.

Therefore, by implementing a digital multi-band transceiver using a digital filter and a digital oscillator, it is possible to process signals for each band through a single digital circuit without having to individually configure a circuit for processing signals for each band. have.

Multiband, Transceiver, Intermediate Frequency, Digital Filter, Digital Oscillator

Description

Multiband digital transceiver for wireless communication system and method thereof {System and method for digital multi-band transceiver of the wireless communication system}

1A and 1B are structural diagrams of a general heterodyne transmitter and receiver.

2A and 2B are structural diagrams of a general single band digital IF transmitter and receiver.

3 is a structural diagram for a multi-band transmission apparatus according to an embodiment of the present invention.

4 is a structural diagram for a multi-band receiving apparatus according to an embodiment of the present invention.

5A and 5B are diagrams illustrating a relationship between a spectrum between a baseband signal and an IF band signal in transmission and reception according to an embodiment of the present invention.

The present invention relates to a multi-band digital transmission and reception apparatus and method thereof of a wireless communication system, and more particularly, to an apparatus capable of transmitting and receiving a multi-band frequency band signal in one system.

The transmitting device and the receiving device for a communication system are designed to transmit and receive a signal of a plurality of bands or signals of several bands at the same time within a band and bandwidth given to the system. The transceiver for a communication system includes a heterodyne transceiver and a digital intermediate frequency (IF) transceiver.

The heterodyne receiver converts the frequency of the input signal into an IF signal. This conversion is realized in a mixer where the input signal is combined with the signal generated by the local oscillator, where the combined result is the IF signal.

The IF signal is in turn combined with the signal generated by the IF local oscillator and converted into a baseband signal. The baseband signal is sampled in an analog-to-digital converter (ADC), converted into a digital signal, and transmitted to a demodulation circuit. In the case of transmission, the same configuration is handled. A heterodyne transceiver for processing a signal in this manner will be described in detail with reference to FIGS. 1A and 1B.

1A and 1B are structural diagrams of a general heterodyne transmitter and receiver.

A typical heterodyne transceiver includes a digital-to-analog converter (DAC) (10) or an ADC (110), a low-pass filter (LPF) 20, an amplifier 30, and a frequency. Mixer 40, Local Oscillator (LO) (50), Phase Shifter (60), Band-Pass Filter (70), High Power Amplifier And a high power amplifier (80) or a low noise amplifier (LNA) 90 and an auto gain control (AGC) 100.

First, referring to FIG. 1A, a transmission apparatus converts an analog signal from a DAC 10 into an in-phase signal / quad phase signal (hereinafter referred to as an I / Q signal), which is a baseband digital complex signal. Afterwards, only the signal in the frequency region lower than the reference frequency is passed using the LPF 20, and the analog signal in the low frequency region is amplified by the AMP 30. The amplified signal is mixed with the analog signal amplified by the AMP 30 in the frequency mixer 40 and the local oscillator signal output through the local oscillator 50 and converted into an IF signal which is an IF band signal.

At this time, one signal converts the phase by 90 degrees in the phase shifter 60. Combine these two signals into a single signal, pass only the signals that exist in a specific range of frequencies through the BPF (70), mix them with the RF local oscillator (50) signal, convert them to RF signals, and then HPA (80) Amplify the signal from the antenna and radiate it to the antenna.

Next, in the antenna of the receiving device shown in FIG. 1B, the received signal is mixed with the local oscillator 50 signal via the LNA 90 to convert the RF signal into an IF signal. The IF signal is again mixed with the second local oscillator 50 signal to become the baseband signal. At this time, the local oscillator 50 signal is mixed with the signal phase shifted by 90 degrees by the phase shifter 60 to separate the I / Q signal. This baseband I / Q signal is sampled by the ADC 110 to become a digital signal.

However, in the heterodyne transceiver, all processing is performed using analog elements, and local oscillators, mixers, and the like are used. Errors occur depending on their characteristics, resulting in a problem in that performance is degraded. In addition, in the process of processing a multi-band signal, there is a problem that the cost is added because the corresponding analog device is used for all bands.

In addition, when system parameters such as frequency and bandwidth are changed due to the development process or a change in transmission method, there is a problem that all devices must be changed to other ones. Therefore, the heterodyne receiver mainly uses only a single band and has a limitation that is used in a terminal requiring low power.

A structure of a digital IF transceiver, which is a transceiver for another communication system, will be described with reference to the structural diagrams of a general single band digital IF transmitter and receiver of FIGS. 2A and 2B.

2A illustrates a structure of a single band digital IF transmitter, and FIG. 2B illustrates a structure of a single band digital IF receiver. An LPF 20, a digital square wave generator 120, a multiplier 130, a DAC 10, or an ADC ( 110, amplifier 30 or AGC 100, BPF 70, frequency mixer 40, local oscillator 50, and HPA 80 or LNA 90.

As shown in FIG. 2A, the single band digital IF receiver generates a digital signal through an analog-to-digital conversion of the IF band signal through the ADC 110 as in a procedure performed in a heterodyne transceiver. The digital square wave generator 120 separates the digital I / Q signal. Similarly, the transmitter shown in FIG. 2B generates a digital I / Q signal as a digital IF signal, and then generates an analog signal through the DAC 10. The generated analog signal is mixed with the signal output through the local oscillator 50 in the frequency mixer 40 and converted into an RF signal, and then radiated through the antenna via the HPA 80.

However, such a digital IF transceiver has a problem in that it requires a high speed, high performance ADC or DAC and a digital circuit.

In addition to the above problems, the above-described communication system transceiver may transmit and receive signals in multiple bands, but should be configured to use a separate independent transceiver for signals of different bands and bandwidths, This configuration is complicated by the increase in the number of bands, there is a problem that the cost is added by the addition of a transceiver. In addition, when a common transmission / reception device can be used, since a band is selected using a switch, there is a problem that cannot be used when a plurality of signals must be transmitted and received at the same time.

Accordingly, the present invention is to solve the problems of the prior art as described above, and provides a digital IF multi-band digital transceiver apparatus and method capable of processing the transmission and reception signals of several frequency bands using a single digital circuit. do.

According to an aspect of the present invention, there is provided a transmission / reception apparatus including a plurality of signals of different bands in a communication system, the signal including a pair of in-phase signals and quadrature signals. A transmitting device for transmitting-

A first adder configured to output in-phase signals included in each of the plurality of signals as one digital in-phase signal; A second adder configured to output quadrature signals included in the plurality of signals as one digital quadrature signal; A first intermediate frequency generator converting the one digital in-phase signal output from the first adder into an intermediate frequency signal and outputting the intermediate frequency signal; A second intermediate frequency generator for converting the one digital quadrature signal output from the second adder into an intermediate frequency signal and outputting the intermediate frequency signal; And an analog signal which combines the one digital in-phase signal output from the first intermediate frequency generator and the one digital quadrature signal output from the second intermediate frequency generator to output one analog intermediate frequency signal. It includes a generation unit.

One signal transmitted from a transmitting device in a communication system which is another feature of the present invention for achieving the technical problem of the present invention--the signal is composed of a plurality of signals of different bands, the plurality of signals In a receiving device for receiving a pair of in-phase signals and quadrature signals, respectively,

A digital intermediate frequency signal generator which performs digital conversion and frequency downconversion on the received one signal, and outputs one in-phase signal and one quadrature signal of intermediate frequency, respectively; A first band signal generator for down-converting one in-phase signal output from the digital intermediate frequency signal generator to output one band in-phase signal; A second band signal generator for down-converting one quadrature signal output from the digital intermediate frequency signal generator to output one band quadrature signal; A first baseband signal generator for outputting a plurality of baseband in-phase signals by removing signals of adjacent bands so that one band in-phase signal output from the first band signal generator corresponds to a plurality of bands; And a second baseband signal generator for outputting a plurality of baseband quadrature signals by removing adjacent band signals so that one band quadrature signal output from the second band signal generator corresponds to a plurality of bands. do.

In the method for transmitting and receiving a plurality of band signals in a communication system which is another feature of the present invention for achieving the technical problem of the present invention,

(a) performing filtering to remove interference of adjacent bands in the plurality of digital signals to be transmitted in the plurality of bands; (b) outputting a plurality of digital intermediate frequency signals by up-converting the plurality of digital signals on which the filtering is performed to an intermediate frequency; (c) generating an in-phase signal / quad phase signal pair using the plurality of digital intermediate frequency signals; (d) combining the generated in-phase signal / quadrature signal pair into one signal, and then converting the analog in-phase signal into one analog intermediate frequency signal; and (e) converting the analog intermediate frequency signal into a radio frequency signal to receive the signal. Transmitting to the device.

At this time, after step (e), (i) converting the radio frequency signal received in one band by combining a plurality of bands into one analog intermediate frequency signal and then into one digital intermediate frequency signal; (Ii) down-converting the one digital intermediate frequency signal for each of a plurality of bands to generate a plurality of base band in-phase signals / quad phase signals; and (iii) the plurality of base band in-phase signals / quad phase signals. And removing the signals of the plurality of adjacent bands, and generating a signal in which the center frequency of the band is zero.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

3 is a structural diagram for a multi-band transmission apparatus according to an embodiment of the present invention.

Referring to FIG. 3, the multi-band transmitter includes a baseband digital filter 300, an LPF 310, a frequency mixer 320 and 325, a digitally controlled oscillator (NCO) 330 and 335, and an adder 340. 345, the BPFs 350 and 355, the DAC 360, and the RF up converter 370.

At this time, the baseband digital filter 300, LPF 310, the frequency mixer 320, the digital oscillator 330 is configured as the number of bands, the adder 340, BPF (350, 355), frequency mixer 325 ) And two digital oscillators 355 for I and Q signal processing. However, in the drawings, reference numerals should be given to only one representative component.

The baseband digital filter 300 performs a function of extracting only a digital signal which is a necessary component from a digital signal in which noise is mixed, and can obtain a shaping characteristic by digital signal processing. Since digital filters are obtained by numerical calculations compared with analog filters, signals with high precision can be obtained, and filter coefficient values can be easily modified to easily modify filter characteristics. In addition, when implemented in hardware, LSI (large scale integrated) is easy. The digital filter may be configured using various filters such as a finite impulse response (FIR) filter and an infinite impulse response (IIR) filter.

LPF 310 is a filter having a stopband frequency and passes only below a specific frequency, and is used for high frequency noise cancellation. The BPFs 350 and 355 are filters for passing only a specific band having a pass start frequency and a stop band frequency. The BPFs 350 and 355 are used for channel discrimination and image removal in wireless communication.

The frequency mixers 320 and 325 add the frequencies output from the digital oscillators 330 and 335 and the frequencies output through the LPF 310 to arrange signals of multiple bands adjacently, or the frequencies output through the LPF 310. Performs the function of upconverting to the intermediate frequency. In other words, it is a circuit that extracts the intermodulated signals of two frequencies using nonlinearity. When two frequencies F1 and F2 are mixed, secondary intermodulation components such as F1 + F2 or F1-F2 are generated to output the frequency. Do it.

The adders 340 and 345 bind a signal input in a plurality of bands into one signal.

The operation of the transmitting device having such a structure will be described.

For convenience of explanation of the operation, a description will be made of a first adder, a second adder, a first intermediate frequency generator, a second intermediate frequency generator, and an analog signal generator. The baseband digital filter 300, the LPF 310, the frequency mixer 320, and the adder 340 are blocked in order to perform the functions of the first adder and the second adder, and the BPFs 350 and 355 are digital oscillators. 335 and the frequency mixer 325 block with the first intermediate frequency generator and the second intermediate frequency generator.

In addition, the adder 345, the DAC 360 and the radio frequency up-converter 370 block with an analog signal generator. Here, the reason why the two adders and the intermediate frequency generator block each is because the signal is composed of a pair of in-phase signals and quadrature signals, and indicates that signal processing is performed separately in each block.

The baseband digital filter 300 performs a function of filtering to remove interference on adjacent channels. In the embodiment of the present invention, since the multiple bands are combined into one IF signal, it is important to eliminate interference between adjacent channels. Filtering may be omitted if the spectrum of the original signal itself is below a specified value for interference on adjacent channels.

The transmission signals filtered through the baseband digital filter 300 of the first and second adders are input to the frequency mixer 320 while the high frequency noise is removed through the LPF 310. At this time, the frequency output from the digital oscillator 330 (referred to as "cosω _k t" and "-sinω _k t" in the drawing (k = 1 ... n, k is the number of bands)) and the output through the LPF 310 In addition to the frequency, each of the transmission signals is arranged adjacent to each other to have a different center frequency by the difference in the center frequency in the final band.

Adjacently arranged multi-band signals are combined into I or Q signals through the adder 340 to generate one I or Q signal and are input to the first frequency generator and the second intermediate frequency generator. Signals generated as one I or Q signal are passed through the BPF 350 and the bands are combined. The signal passing through the frequency mixer 320 generates a desired frequency and an unwanted image frequency. The BPF 350 performs a function of removing an unwanted image frequency.

One I or Q signal passing only through the BPF 350 and only the desired frequency in the band is passed through the frequency mixer 325 to be upconverted to the intermediate frequency. At this time, the frequency is combined with the frequency output from the digital oscillator 335 is up-converted to the IF, passes through the BPF 335 is removed from the band unwanted frequency band is subjected to the band combining process.

One I or Q signal is then generated in the adder 345 as one I / Q signal pair. At this time, since the center frequencies between the I and Q signals are different, these spectra do not overlap each other. Finally, the I / Q signal combined into one signal is input to the analog signal generator and converted into an analog IF signal by the DAC 360. This process can be generated as an IF signal where the final digital-to-analog conversion takes place through several IF generation steps in several stages. In this case, the I / Q combining, up-converting, and band combining processes are ordered by implementation. It may be changed.

That is, I / Q may be combined by I / Q separately after I / Q, and may be combined by I / Q. After I / Q combining is performed, up-conversion or band combining may be performed later. In this process, if necessary, the filter may be passed to remove unnecessary portions of the spectrum, leaving only desired signal components, and interpolation may be performed in an interpolation filter required as the frequency rises.

The analog IF signal digitally-analog-converted through the DAC 360 is a signal in which multiple bands are combined into one with each band separated from each other, and the signal is a signal having a bandwidth in which the bandwidths of the bands are combined. The signal is converted into an RF signal through a mixture of an analog signal filtering and a local oscillator in the RF up-converter 370 performing the function of shifting the IF to a radio frequency, and then amplified by the high-power amplifier and transmitted through the antenna.

4 is a structural diagram for a multi-band receiving apparatus according to an embodiment of the present invention.

Referring to FIG. 4, the multi-band receiver includes an RF down converter 400, a baseband digital filter 300, an LPF 310, a frequency mixer 320 and 325, and a digital oscillator 330 and 335. , BPFs 350, 355, and ADC 410.

At this time, the baseband digital filter 300, LPF 310, frequency mixer 320, digital oscillator 330 is configured as the number of bands, BPF (350, 355), frequency mixer 325 and digital oscillator 355 is configured by two for I signal and Q signal processing. However, in the drawings, reference numerals should be given to only one representative component.

For convenience in describing the operation of the reception device configured as described above, the reception device is moved to an intermediate frequency signal generator, a first band signal generator, a second band signal generator, a first baseband signal generator, and a second baseband signal generator. Explain separately. At this time, in order to perform the function of the digital intermediate frequency signal generator, the RF down converter 400, the ADC 410 and the BPF 355 are blocked, and the frequency mixer 325 and the BPF 350 generate the first band signal. Blocking is performed by the second and second band signal generators.

In addition, the frequency mixer 320, the digital oscillator 330, the LPF 310, and the baseband digital filter 300 block the first baseband signal generator and the second baseband signal generator. The reason why two band signal generators and two baseband signal generators are blocked is because a signal is composed of a pair of in-phase signals and quadrature signals, and indicates that the signals are processed separately in each block.

The RF down converter 400 lowers the received RF signal to IF or baseband frequency. In general, the circuit portion of the frequency mixer 320 and 325 for frequency downconversion is referred to as the RF down converter 400, and the signals of the digital oscillators 330 and 335 ("cosω _k t" and " the IF or baseband frequency signal corresponding to the difference between two signal frequencies is generated, combined -sinω the _k t "refers to (k = 1 ... n, k is the band) in).

A plurality of digital oscillators 330 and 335 are configured for each band and perform a function of generating local oscillation signals of different frequencies. In this case, the frequency of the local oscillation signal generated by one digital oscillator is different from the frequency of the local oscillation signal generated by another digital oscillator. That is, the frequency of the local oscillation signal oscillated in the plurality of digital oscillators is provided by the number of digital oscillators.

The multi-band signal receiving apparatus including such a function receives the RF signal radiated from FIG. 3 using an antenna. The RF signal received by the digital intermediate frequency signal generator is amplified by a low power amplifier in the RF down converter 400 and then converted into an analog IF signal through a filtering process and a digital oscillator and output.

The output signal is converted into a digital signal through sampling in the ADC 410. At this time, sampling is performed by over-sampling in which a signal is sampled at a frequency more than twice as high as the frequency of a signal to be sampled or under-sampling by sampling at a frequency lower than a carrier frequency carrying information. ) May be one digital IF signal having a spectrum of bandwidths of the bandwidths of the respective bands in a specific frequency band after the sampling process.

One digital IF signal passes through the BPF 355 and passes only signals in the frequency band between two specific frequencies. The I-band in the baseband and the Q-band in the baseband are separated by downconversion and I / Q signals. Is generated. In this process, the digital oscillator 335 is configured for each band so that a desired signal in each band for each band becomes a signal of a basic band.

The generated base band signal is input to the first band signal part and the second band signal part, respectively, and mixed with the signal passing through the BPF 355 in the frequency mixer 325 to perform downconversion. At this time, the I and Q signals of the baseband signal are generated as many as the number of bands, and the signals of the corresponding bands have a center frequency of 0 in the baseband, and the signals of the remaining bands have a frequency separated from the band. In this regard, the spectral relationship between the baseband signal and the IF band signal is described in detail with reference to three bands, for example, in FIGS. 5A and 5B.

5A and 5B are diagrams illustrating a relationship between a spectrum between a baseband signal and an IF band signal in transmission and reception according to an embodiment of the present invention.

As shown in FIG. 5A, in the base band, there are signals of the base band having a center frequency of 0 for each band, and in the IF band, these three signals are spaced apart at a certain frequency interval so that IF is converted into the center frequency. The sum of the bandwidths of the three bands results in a signal having a spectrum of the total bandwidth.

For example, if each bandwidth is k and the center frequency of the signal in the first band is f1, the center frequency of the signal in the second band is f2, and the center frequency of the signal in the third band is f3. Assuming that the signals are followed by n bandwidth intervals, in the transmitting device, the center frequencies after the three bands have been combined are f1 + f0, f2 + f0, f3 + f0 (where f0 is the sum of the IFs generated by the three signals). Center frequency), and the bandwidth of this signal is 3k + 2n.

In addition, when a signal of three bands connected to one signal is to be separated for each band as shown in FIG. 5B, in the receiving apparatus, three band signals are combined, and the frequency of each band in the IF band is f1, f2, and f3. Assume that the frequency of the digital oscillator is also f1, f2, f3. After going through the digital oscillator, the center frequencies of the three signals in the first path are 0, f2-f1, f3-f2, and the three signal center frequencies in the second path are f1-f2, 0, f3-f2, The three signal center frequencies in the third path are f1-f3, f2-f3, and 0. After the center frequencies of the three signals are determined, the signals in the adjacent bands are removed, leaving only the signals having a center frequency of zero.

Such a process may perform several IF generation steps in multiple stages. 5A and 5B, after the IF is determined for each signal, decimation such as filtering and frequency drop required in the IF decision process is performed in the decimation filter 420. When analog-to-digital conversion of the analog intermediate frequency signal received by the RF down converter 400 is required, the conversion is required at a high sampling frequency because the I and Q signals are combined, but the low sampling is performed through I / Q separation or down conversion. Even if sampled and coded at a rate, decimation is performed because there is no loss in signal quality.

After the decimation is performed, the first baseband signal generator and the second baseband signal generator pass through the frequency mixer 320 to arrange the plurality of band signals adjacently. In the frequency mixer 320, the plurality of band signals are combined with the signals output from the digital oscillator 330 and arranged to be separated from the adjacent band by some frequency.

Finally, when each signal passes through the LPF 310 and then passes through the baseband digital filter 300 so that only the baseband signal of each band is passed, the signals of the adjacent bands are eliminated and the center frequency is zero. Only the desired signal in the band is passed through to generate a baseband signal. After that, each base band is demodulated.

Here, a program for realizing a function corresponding to the configuration of the above-described embodiment of the present invention or a recording medium on which the program is recorded is also included in the scope of the present invention.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the above-described embodiment, by implementing a multi-band transceiver device using a digital filter and a digital oscillator in a digital manner, it can be implemented as a single digital circuit without configuring a separate circuit for each band.

In addition, the digital implementation of the filter and oscillator ensures accurate implementation without compromising performance.

In addition, the digital circuit implemented as described above can be implemented as an ASIC, thereby reducing cost and complexity.

In addition, because the frequency and bandwidth can be changed according to the program change, the system configuration is flexible, and the additional cost of the change can be reduced.

Claims (13)

A transmitting apparatus for transmitting a plurality of signals of different bands in a communication system, each of the plurality of signals comprising a pair of in-phase and quadrature signals, A first adder configured to output in-phase signals included in each of the plurality of signals as one digital in-phase signal; A second adder configured to output quadrature signals included in the plurality of signals as one digital quadrature signal; A first intermediate frequency generator converting the one digital in-phase signal output from the first adder into an intermediate frequency signal and outputting the intermediate frequency signal; A second intermediate frequency generator for converting the one digital quadrature signal output from the second adder into an intermediate frequency signal and outputting the intermediate frequency signal; And Generating an analog signal which combines the one digital in-phase signal output from the first intermediate frequency generator and the one digital quadrature signal output from the second intermediate frequency generator and outputs it as one analog intermediate frequency signal part Multi-band digital transmission device comprising a. The method of claim 1, The first adding unit and the second adding unit, A plurality of baseband digital filters for filtering the plurality of in-phase signals and the plurality of quadrature signals to remove adjacent band interference, and then outputting only the plurality of digital in-phase signals and the plurality of digital quadrature signals; A plurality of low pass filters for removing specific high frequency noise from the plurality of digital in-phase signals and the plurality of digital quadrature signals; A first frequency mixer for placing the plurality of digital in-phase signals and the plurality of digital quadrature signals adjacently; And A first adder for outputting a plurality of digital in-phase signals and digital quadrature signals output through the first frequency mixer as one digital in-phase signal and one digital quadrature signal; Multi-band digital transmission device comprising a. The method of claim 1, The first intermediate frequency generator and the second intermediate frequency generator, A first band pass filter combining a plurality of bands of one digital in-phase signal and one digital quadrature signal output from the first and second adders; A digital oscillator for generating a required signal when frequency upconverting the one digital in-phase signal and one digital quadrature signal into a signal having an intermediate frequency; A second frequency mixer which up-converts the one digital in-phase signal and one quadrature signal into an in-phase intermediate frequency signal by using the signal output from the first band pass filter and the signal output from the digital oscillator; And A second band pass filter which removes a predetermined image frequency from the first band pass filter and outputs one digital in-phase signal and one digital quadrature signal from the in-phase intermediate frequency signal; Multi-band digital transmission device comprising a. The method of claim 1, The analog signal generator, A second adder for outputting one digital in-phase signal output from the first intermediate frequency generator and one digital quadrature signal output from the second intermediate frequency generator as one digital signal; A digital analog converter for converting the one digital signal into an analog signal; And Radio frequency up converter for converting the analog signal into a radio frequency signal for transmission to the receiving device Multi-band digital transmission device comprising a. The method of claim 4, wherein And an interpolation filter for increasing the frequency by reducing the frequency distortion of the high frequency region when the digital signal is converted into the analog signal in the digital analog converter. Receive one signal transmitted from a transmitting device in a communication system, the signal consisting of a plurality of signals of different bands, each of which comprises a pair of in-phase and quadrature signals In the receiving device, A digital intermediate frequency signal generator which performs digital conversion and frequency downconversion on the received one signal, and outputs one in-phase signal and one quadrature signal of intermediate frequency, respectively; A first band signal generator for down-converting one in-phase signal output from the digital intermediate frequency signal generator to output one band in-phase signal; A second band signal generator for down-converting one quadrature signal output from the digital intermediate frequency signal generator to output one band quadrature signal; A first baseband signal generator for outputting a plurality of baseband in-phase signals by removing signals of adjacent bands so that one band in-phase signal output from the first band signal generator corresponds to a plurality of bands; And A second baseband signal generation unit for removing one band quadrature signal output from the second band signal generation unit to output a plurality of baseband quadrature signals by removing adjacent band signals so as to correspond to a plurality of bands; Multi-band digital receiving device comprising a. The method of claim 6, The first and second band signal generator, A first digital oscillator for outputting a down-converted signal used for frequency down-converting the in-phase signal and the quadrature signal in a plurality of bands such that a desired signal becomes a signal of a base band; And A first frequency mixer for mixing the down-converted signal, the in-phase signal, and the quadrature acid signal to output a plurality of baseband signals Multi-band digital receiving device comprising a. The method of claim 6, The first and second baseband signal generator, A plurality of second digital oscillators for outputting contiguous constellation signals for use in contiguous arrangement of the plurality of baseband signals for each band; A plurality of second frequency mixers arranged to adjacently arrange the plurality of base band signals for each band by using the adjacent arrangement signal; And A plurality of baseband digital filters for generating only the signal having a center frequency of 0 for each of the plurality of baseband signals Multi-band digital receiving device comprising a. The method of claim 8, And a decimation filter for decimating an unnecessary signal from the down-converted signal. In the communication system for transmitting and receiving a plurality of band signals, (a) performing filtering to remove interference of adjacent bands in the plurality of digital signals to be transmitted in the plurality of bands; (b) outputting a plurality of digital intermediate frequency signals by up-converting the plurality of digital signals on which the filtering is performed to an intermediate frequency; (c) generating an in-phase signal / quad phase signal pair using the plurality of digital intermediate frequency signals; (d) combining the generated in-phase signal / quad phase signal pairs into one signal and converting the same into an analog intermediate frequency signal; And (e) converting the analog intermediate frequency signal into a radio frequency signal and transmitting the same; Method of transmitting and receiving a multi-band signal using a multi-band digital device comprising a. The method of claim 10, After step (e), (Iii) receiving the radio frequency signal and converting the signal into one analog intermediate frequency signal and then into one digital intermediate frequency signal; (Ii) down-converting the one digital intermediate frequency signal for each of a plurality of bands to generate a plurality of baseband in-phase signals and quadrature signals; And (Iv) removing signals of a plurality of adjacent bands from the plurality of baseband in-phase signals / quad phase signals, and then generating a signal having a center frequency of zero in each band; Method of transmitting and receiving a multi-band signal using a multi-band digital device comprising a. The method of claim 10, The method of transmitting and receiving a multi-band signal using a multi-band digital device comprising performing interpolation according to the frequency rise in the step (c). The method of claim 11, A method of transmitting and receiving a multi-band signal using a multi-band digital device comprising the decimation according to the frequency down-conversion in step (ii).

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