JP6414850B2 - TRANSMISSION DEVICE, RECEPTION DEVICE, TRANSMISSION METHOD, AND RECEPTION METHOD - Google Patents

Description

The present invention is a modulated signal having a phase and a plurality of amplitude levels of 0 and [pi, the frequency band to generate a digital SSB (Single Side Band) signals to 1/2, the transmission apparatus in a radio communication apparatus for performing transmission and reception The present invention also relates to a transmission method and a reception method in a receiving apparatus and a wireless communication method.

  SSB modulation is known as means for halving the frequency band of a signal obtained by analog AM modulation, and recently, digital SSB modulation has been studied as means for further narrowing the band of a digital modulation signal. (Non-Patent Documents 1 and 2).

  As a method for generating an SSB signal, a method using a band pass filter having a steep characteristic and a method using a Hilbert transform are known.

  In the method using the band pass filter, it is necessary to extract the upper side band (USB: Upper Side Band) or the lower side band (LSB: Lower Side Band) from the modulated signal generated by the digital modulator using the band pass filter. is there. However, it is extremely difficult to realize a bandpass ideal filter having a wide passband usable for high-speed digital communication and having a steep skirt characteristic by an analog circuit. Further, even when this is realized by digital signal processing, an FIR filter having an extremely large number of taps is required, and the hardware scale becomes a problem.

  On the other hand, in the method using the Hilbert transform, which is also used for analog SSB modulation, a Hilbert transformer and a quadrature modulator are used.

FIG. 16 shows a configuration example of a conventional transmission device using a Hilbert transformer. In FIG. 16, 101 is a modulator that performs amplitude modulation on input data in two phases of 0 and π, 102 is a Hilbert transformer, 103 is a quadrature modulator, and the output of the modulator 101 is expressed as s (t), If the output of the Hilbert transformer 102 is s (t), the output u (t) of the quadrature modulator 103 is given by the following equation.

ただし、f_cはキャリア周波数であり、ｓ(t) は実数である必要があるため、位相は０かπの２相のディジタル変調となるが、振幅は多値としてもよい。

However, f _c is the carrier frequency, since s (t) have a need to be real, the phase becomes a digital modulation of two phase 0 or [pi, the amplitude may be a multi-valued.

FIG. 17 shows the relationship between the power spectra of the DSB signal s (f) and the SSB signal u (f).
In FIG. 17, the frequency band of the power spectrum of the SSB signal u (f) can be ½ of the frequency band of the power spectrum of the DSB signal s (f). This is the same principle as that of analog SSB modulation, and the Hilbert transformer 102 is required to realize a digital SSB modulation wireless transmission apparatus having the configuration shown in FIG. It has been reported that an FIR filter having an extremely large number of taps is required to realize a nearly ideal Hilbert transformer with little deterioration in transmission characteristics even in a digital SSB signal of a multilevel modulation signal (non-patent document). 2).

  On the other hand, in recent mobile radio communication systems, good characteristics can be obtained even in severe frequency-selective fading when performing high-speed transmission, and PAPR (Peak to Average Power Ratio) is achieved by performing DFT spreading. A DFT spreading OFDM (Orthogonal Frequency Division Multiplexing) system that can reduce the ratio is used for transmission of portable terminals (Non-patent Document 3). This is a kind of single carrier modulation method, and a baseband signal is converted into a frequency domain signal by performing a discrete Fourier transform (DFT), and input to an inverse discrete Fourier transform (IDFT) having a large number of points in the frequency domain. After mapping and converting to a single carrier modulation signal in the time domain by inverse discrete Fourier transform, a cyclic prefix is added to obtain a modulation signal.

  Based on this DFT spreading OFDM, the baseband signal is subjected to discrete Fourier transform (DFT) to be converted into a frequency domain signal. In the frequency domain, an upper sideband (USB) or lower sideband (LSB) signal is converted. After taking out and performing SSB conversion, and then performing frequency conversion, it is input to an inverse discrete Fourier transform (IDFT) with a sufficiently large number of points, converted into a time domain signal by inverse discrete Fourier transform, and then a cyclic prefix. Has been proposed, and after that, D / A conversion is performed to obtain a digital SSB signal (Non-patent Document 4).

FIG. 18 shows a configuration example of a conventional transmission apparatus based on DFT spreading OFDM.
In FIG. 18, 111 is a digital modulator that performs multi-level amplitude modulation with two phases of 0 and π on input data, 112 is a DFT means that performs discrete Fourier transform (DFT) of an M-point modulated signal, and 113 is Mapping means for selecting M / 2 + 1 points from the DFT output, 114 is an IDFT means for performing N-point inverse discrete Fourier transform (IDFT), 115 is a cyclic prefix adding means, and 116 is a D / A converter. Since the M point DFT output of the DFT means 112 is a DSB (double sideband) signal in the frequency domain, the mapping means 113 generates an SSB signal from the upper sideband (USB) or lower sideband ( LSB) M / 2 + 1 point signal is taken out and input to N point IDFT means 114 sufficiently larger than M / 2 + 1. Here, when M and N are powers of 2, FFT and IFFT algorithms can be used, and the amount of calculation can be greatly reduced.

  When the M / 2 + 1 point signal is input to the NFT IDFT means 114, the M / 2 + 1 point signal in the upper side band is input above the position of the carrier frequency, and the amplitude at other frequencies is set to zero. Obtains the upper sideband digital SSB signal. On the other hand, when the M / 2 + 1 point signal in the lower sideband is input below the position of the carrier frequency and the amplitude at other frequencies is set to 0, the digital SSB signal in the lower sideband is obtained. The output signal of the IDFT means 114 is an SSB signal of a digital modulation signal corresponding to a single carrier modulation signal in the time domain band-limited by a roll-off filter having a roll-off rate of 0. A cyclic prefix is added by the adding means 115. This cyclic prefix is added on the receiving side in order to reduce the influence of intersymbol interference which becomes a problem when communication is performed in a multipath fading environment.

  Here, in the case of a modulation signal that performs multi-level amplitude modulation with two phases of 0 and π, since the output of the IDFT means 304 is a real number, only the signal of the real part of the output is used, and the D / A converter A digital SSB signal is obtained by D / A conversion at 306.

Gen-ichiro Ohta, Mitsuru Uesugi, Takuro Sato, Hideyuki Tominaga, “Study of Orthogonal SSB Modulation Method,” IEICE Transactions on Fundamentals, Vol.E87-A, No.10 Oct. 2004. S.A. Mujtaba, “A novel scheme for transmitting QPSK as a single sideband signal,” Proc. IEEE Globecom, 1988, vol.1, pp.592-597, Nov. 1998. H. G. Myung, J. Lim, and D. J. Goodman, “Single Carrier FDMA for Uplink Wireless Transmission,” IEEE Vehicular Technology Mag., Vol.1, no.3, pp.30-38, Sep. 2006. Kohei Abo, Votanhai, Amnat Bunkajai, Fumiyuki Adachi, “A study on digital SSB transmission using ASK modulation in frequency selective channel,” IEICE Technical Report, vol.114, no.295, RCS2014-200, pp.19-24, November 2014.

  In the configuration shown in FIG. 18, since it is necessary to sufficiently increase N in order to convert the frequency to be used for communication, the hardware scale of the IDFT means 304 increases and the IDFT means 304 is required to operate at high speed. In particular, there is a problem that the mounting becomes difficult particularly when high-speed transmission is performed. In order to solve this problem, there is a method using a Hilbert transformer and a quadrature modulator, which are also used for analog SSB modulation. However, as described above, a method for realizing the Hilbert transformer becomes a problem.

The present invention solves the problem in mounting a wireless communication apparatus that transmits and receives digital SSB signals as described above, and generates wireless SBS signals without using narrowband filters and Hilbert transforms, and can perform wireless communication It is an object of the present invention to provide a transmission method and a reception method in a wireless communication method with a transmission device and a reception device in an apparatus .

  In the present invention, when digital SSB signals are transmitted / received, transmission characteristics are caused by a DC offset error between a D / A converter and a quadrature modulator, a DC offset error between an A / D converter and a quadrature demodulator, and a frequency error between transmission / reception devices. It is an object to provide means for preventing degradation of transmission characteristics due to these causes.

The first invention is a transmission apparatus for generating a de-Ijitaru SSB signal, a digital modulator for generating a modulated signal or a modulated signal comprising a combination thereof having a phase state or amplitude level of 0 and [pi, digital modulation DFT means for performing discrete Fourier transform on the modulation signal of M (M is an even number) point which is the output of the detector, and M / 2 + 1 point output of the upper or lower side of the M point modulation signal which is the output of the DFT means Mapping means for taking out the signal arrangement, IDFT means for performing N-point inverse discrete Fourier transform with N ≧ M / 2 + 1 by inputting the output of the mapping means, and cyclic prefix added to the output of the IDFT means Cyclic prefix adding means and IDFT means with cyclic prefix added And two D / A converter for converting the signal of the real part and the imaginary part of the output respectively analog signals, quadrature modulation processing to quadrature modulation for outputting a digital SSB signal respective outputs of the two D / A converters The mapping means takes the M / 2 + 1 point output of the upper or lower side from the M point modulation signal, divides the M / 2 + 1 point signal into two, and arranges the DC component at the upper and lower sides, The DC component is configured to insert 0, and the IDFT unit is configured to perform an N-point inverse discrete Fourier transform with N ≧ M / 2 + 2 using the output of the mapping unit as an input.

According to a second aspect of the present invention, in a transmitter for generating a digital SSB signal, a digital modulator for generating a modulation signal having a phase state of 0 and π, a modulation signal having a plurality of amplitude levels, or a combination thereof, and a digital modulator DFT means for performing a discrete Fourier transform on the modulation signal of M (M is an even number) point that is the output of MFT, and the output of M / 2 + 1 point on the upper or lower side of the M point modulation signal that is the output of the DFT means A mapping means for performing signal arrangement, an IDFT means for performing an N-point inverse discrete Fourier transform with N ≧ M / 2 + 1 by inputting an output of the mapping means, and a cyclic prefix for adding a cyclic prefix to the output of the IDFT means Click prefix adding means and IDFT means with cyclic prefix added Two D / A converters that convert the real part and imaginary part of the output into analog signals, respectively, and quadrature modulation that outputs the digital SSB signal by performing quadrature modulation on the outputs of the two D / A converters And a pilot subcarrier generating means for generating a pilot signal for frequency synchronization on the receiving side, and the mapping means takes the M / 2 + 1 point output from the upper or lower side from the M-point modulated signal, The M / 2 + 1 point signal is divided into two parts, arranged above and below the DC component as the center, 0 is inserted into the DC component, and one or more pilot signals generated by the pilot subcarrier generating means are arranged The IDFT means is configured to perform N-point inverse discrete Fourier transform with N ≧ M / 2 + 2 by using the output of the mapping means as an input.
A third invention is a digital modulator that generates a modulation signal composed of a modulation signal having a phase state of 0 and π, a plurality of amplitude levels, or a combination thereof, and M (M is an even number) that is an output of the digital modulator. DFT means for performing discrete Fourier transform on the modulation signal at the point, mapping means for taking out the output of the upper or lower M / 2 + 1 point from the M-point modulation signal that is the output of the DFT means, and mapping means IDFT means for performing N-point inverse discrete Fourier transform with N ≧ M / 2 + 1, a cyclic prefix adding means for adding a cyclic prefix to the output of the IDFT means, and a cyclic prefix The real part and imaginary part signals of the added IDFT means are converted into analog signals. An SSB signal generated by a transmission device including two D / A converters for conversion and a quadrature modulator for outputting a digital SSB signal by performing orthogonal modulation processing on the outputs of the two D / A converters. In a receiving apparatus for receiving a signal, a quadrature demodulator that extracts an in-phase component and a quadrature component from the received signal, two A / D converters that respectively convert two outputs of the quadrature demodulator into digital signals, and two A / D A cyclic prefix removing unit that removes a cyclic prefix portion from each output of the D converter, a DFT transform unit that performs N-point discrete Fourier transform on the output of the cyclic prefix removing unit, and an output of the DFT transform unit Equalization means for equalization in the frequency domain, and M / 2 + 1 point by removing the DC component with null inserted from the output of the equalization means Is converted to a signal of M / 2 + 1, and the sign of the imaginary part of the signal of M / 2 + 1 point is inverted to generate a complex conjugate signal of M / 2−1 point, and the signal of M / 2 + 1 point and M / 2− Signal conversion means for reproducing an M-point DSB signal from a 1-point complex conjugate signal, and IDFT means for performing inverse discrete Fourier transform on the M-point DSB signal .

The fourth invention is a transmission apparatus for generating a de-Ijitaru SSB signal, a digital modulator for generating a modulated signal or a modulated signal comprising a combination thereof having a phase state or amplitude level of 0 and [pi, digital modulation DFT means for performing discrete Fourier transform on the modulation signal of M (M is an even number) point that is the output of the detector, and at least one of the M point modulation signals that are the output of the DFT means on the LSB side and the USB side, respectively The frequency where the point is selected and the frequency offset position from the center frequency of the point extracted on the LSB side and the USB side is different, and the frequency surrounded by the lower end frequency of the LSB side extracted spectrum and the upper end frequency of the USB side extracted spectrum M / 2 + 1 point output excluding the point corresponding to the frequency at the center of the band to extract the signal Mapping means to perform, IDFT means for performing N-point inverse discrete Fourier transform with N ≧ M / 2 + 1 by inputting the output of the mapping means, and cyclic prefix addition for adding a cyclic prefix to the output of the IDFT means Means, two D / A converters for converting the signals of the real part and imaginary part of the output of the IDFT means with a cyclic prefix into analog signals, respectively, and the outputs of the two D / A converters And a quadrature modulator that performs quadrature modulation processing and outputs a digital SSB signal.

In the transmission device of the fourth invention, the mapping means is configured to perform mapping in which a transmission signal of another user is frequency-multiplexed in a null frequency band formed in the transmission signal of one user.

The transmitter of the fourth invention further comprises pilot subcarrier generating means for generating a pilot signal for frequency synchronization on the receiving side, and the mapping means is a system band generated at the time of frequency multiplexing of transmission signals of a plurality of users One or more pilot signals generated by the pilot subcarrier generating means are arranged on the null point in the IDFT means, and the IDFT means is configured to perform N-point inverse discrete Fourier transform with the output of the mapping means as an input. is there.

In the transmitter of the fourth invention, the mapping means includes a DC component of the inverse discrete Fourier transform in which one of the null points in the system band generated during frequency multiplexing of the transmission signals of a plurality of users is N points. It is the structure which performs this mapping.

A fifth aspect of the invention is a receiving apparatus that uses the SSB signal generated by the transmitting apparatus of the fourth aspect of the invention as a received signal, and a quadrature demodulator that extracts an in-phase component and a quadrature component from the received signal, and two outputs of the quadrature demodulator two a / D converter for converting the digital signals, respectively, and cyclic prefix removal unit removes the cyclic prefix portion from the respective outputs of the two a / D converter, the output of the cyclic prefix removal unit a DFT transform means you discrete Fourier transform of N points, and equalizing means for equalizing a frequency domain the output of the DFT transform unit, by removing a DC component null is inserted from the output of the equalizing means M / 2 + 1 after conversion to the point of signal, M / 2 + 1 points of the signal of the imaginary part codes inverted M / 2-1 points complex conjugate of the signal of the And a signal converting means for reproducing an M-point DSB signal from the M / 2 + 1 point signal and an M / 2-1 point complex conjugate signal, and an IDFT means for performing an inverse discrete Fourier transform on the M-point DSB signal. Is provided.

A sixth aspect of the transmission method of generating a de-Ijitaru SSB signal, to generate a modulated signal or a modulated signal comprising a combination thereof having a phase state or amplitude level of 0 and π in a digital modulator, the digital modulation The MFT (M is an even number) point modulation signal is input to the DFT means, and the DFT means output is input to the mapping means. M / 2 + 1 point output is taken out, signal arrangement is performed, the output of the mapping means is input to the IDFT means, N-point inverse discrete Fourier transform of N ≧ M / 2 + 1 is performed, and the output of the IDFT means is cyclic Add the prefix and output the real part and imaginary part of the output of the IDFT means with the cyclic prefix. / A conversion, and outputs a digital SSB signal orthogonal modulation processing by the orthogonal modulator respective signals converted D / A, the mapping means, the modulated signals M points of the upper or lower M / 2 + 1 point , The M / 2 + 1 point signal is divided into two parts and placed above and below the DC component as the center, 0 is inserted into the DC component, and the IDFT means uses the output of the mapping means as input N ≧ M / Perform an N-point inverse discrete Fourier transform of 2 + 2.
According to a seventh aspect of the present invention, in a transmission method for generating a digital SSB signal, the digital modulator generates a modulation signal having a phase state of 0 and π, a modulation signal having a plurality of amplitude levels, or a combination thereof, and the digital modulator Is input to the DFT means, M (M is an even number) point of the modulation signal is subjected to discrete Fourier transform, and the output of the DFT means is input to the mapping means to select the upper or lower M of the M point modulation signals. / 2 + 1 point output is taken out and signal arrangement is performed, the output of the mapping means is input to the IDFT means, N point inverse discrete Fourier transform of N ≧ M / 2 + 1 is performed, and the cyclic prefix is applied to the output of the IDFT means And the real part and imaginary part of the output of the IDFT means with the cyclic prefix added. The A / D conversion and the D / A converted signal are each subjected to quadrature modulation processing by a quadrature modulator to output a digital SSB signal, and the mapping means outputs M / 2 + 1 points from the M-point modulated signal to the upper or lower side. The M / 2 + 1 point signal is divided into two and placed above and below the DC component as the center, 0 is inserted into the DC component, and one or more pilot signals for frequency synchronization on the receiving side The IDFT means performs an inverse discrete Fourier transform of N points where N ≧ M / 2 + 2 by using the output of the mapping means as an input.
According to an eighth aspect of the present invention, a digital modulator generates a modulation signal having a phase state of 0 and π, a modulation signal having a plurality of amplitude levels, or a combination thereof, and inputs the output of the digital modulator to the DFT means. (M is an even number) The point modulation signal is subjected to discrete Fourier transform, the output of the DFT means is input to the mapping means, and the M / 2 + 1 point output of the upper or lower side of the M point modulation signal is extracted and the signal arrangement is made. The output of the mapping means is input to the IDFT means, and N-point inverse discrete Fourier transform with N ≧ M / 2 + 1 is performed, and a cyclic prefix is added to the output of the IDFT means, and the cyclic prefix is added. The real and imaginary signals of the output of the IDFT means are D / A converted, and the D / A converted signals are directly converted. In a reception method in which an SSB signal generated by a transmission method that outputs a digital SSB signal by performing quadrature modulation processing with a modulator is used as a reception signal, quadrature demodulation processing for extracting an in-phase component and a quadrature component from the reception signal is performed. Each output is converted into a digital signal to remove the cyclic prefix portion, and the signal from which the cyclic prefix portion has been removed is input to the DFT means to perform N-point discrete Fourier transform, and the output of the DFT means is used as the equalization means. Input and equalize in the frequency domain, input the output of the equalization means to the signal conversion means, remove the DC component with the null inserted and convert it to an M / 2 + 1 point signal, then M / 2 + 1 point signal The M / 2-1 point complex conjugate signal is generated by inverting the sign of the imaginary part, and the M / 2 + 1 point signal and the M / 2-1 point signal are generated. An M-point DSB signal is reproduced from the complex conjugate signal of the input, the M-point DSB signal is input to the IDFT means, and an inverse discrete Fourier transform is performed to output a demodulated signal.

A ninth aspect of the invention, in the transmission method of generating a de-Ijitaru SSB signal, to generate a modulated signal or a modulated signal comprising a combination thereof having a phase state or amplitude level of 0 and π in a digital modulator, the digital modulation The MFT (M is an even number) point modulation signal is input to the DFT means, and the DFT means output is input to the mapping means. Among the M point modulation signals, the LSB side and the USB side And at least one point is selected, the frequency offset position from the center frequency of the point extracted on the LSB side and the USB side is different, and the lower end frequency of the LSB side extraction spectrum and the USB side extraction spectrum The output of M / 2 + 1 points excluding the point corresponding to the center frequency of the frequency band surrounded by the upper end frequency. Is extracted, signal arrangement is performed, the output of the mapping means is input to the IDFT means, N-point inverse discrete Fourier transform with N ≧ M / 2 + 1 is performed, and a cyclic prefix is added to the output of the IDFT means the signal of the real part and the imaginary part of the output of the IDFT means cyclic prefix is added to the D / a conversion, respectively, a digital SSB signal orthogonal modulation processing by the orthogonal modulator respective signals converted D / a Is output.

A tenth aspect of the invention is a reception method in which the SSB signal generated by the transmission method of the ninth aspect is used as a reception signal, performs quadrature demodulation processing for extracting an in-phase component and a quadrature component from the reception signal, and outputs the two outputs respectively. removes the cyclic prefix portion is converted into a digital signal, performs a discrete Fourier transform of N points by inputting a signal obtained by removing the cyclic prefix portion DFT unit inputs an output of the DFT means equalizing means equalized in the frequency domain, and an output of the equalizing means to the signal converting means, converts the M / 2 + 1 points of the signal by removing the DC component null is inserted, the imaginary of M / 2 + 1 points of the signal The M / 2-1 point complex conjugate signal is generated by inverting the sign of the part, and the M / 2 + 1 point complex conjugate signal and the M / 2-1 point complex conjugate signal are generated. The M-point DSB signal is reproduced, the M-point DSB signal is input to the IDFT means, and an inverse discrete Fourier transform is performed to output a demodulated signal.

The transmission method and the reception method in the wireless communication device according to the present invention can reduce the hardware scale in the implementation of the wireless communication device that transmits and receives digital SSB signals. There is no characteristic deterioration due to an offset error, and automatic frequency control which is a problem in demodulation of a digital SSB signal can be easily performed. As a result, it is possible to provide an economical portable terminal with a small hardware scale and easy to implement.

It is a figure which shows the structural example of the transmitter of Example 1 in the radio | wireless communication apparatus of this invention. It is a figure which shows the example of a mapping of the mapping means 13 of Example 1. FIG. 6 is a diagram illustrating an example of a spectrum arrangement of a digital SSB signal in Embodiment 1. FIG. It is a figure which shows the example of a mapping of the mapping means 13 of Example 2. FIG. 6 is a diagram illustrating an example of a spectrum arrangement of a digital SSB signal in Embodiment 2. FIG. It is a figure which shows the structural example of the transmitter of Example 3 in the radio | wireless communication apparatus of this invention. 10 is a diagram illustrating an example of a spectrum arrangement of a digital SSB signal in Embodiment 3. FIG. It is a figure which shows the example of a mapping of the mapping means 13 of Example 4. FIG. It is a figure which shows the example of spectrum arrangement | positioning of the digital SSB signal in Example 4. FIG. It is a figure which shows a PAPR characteristic. It is a figure which shows the example of spectrum arrangement | positioning of the digital SSB signal in Example 5. FIG. It is a figure which shows the example of spectrum arrangement | positioning of the digital SSB signal in Example 6. FIG. It is a figure which shows the example of spectrum arrangement | positioning of the digital SSB signal in Example 7. FIG. It is a figure which shows the structural example of the receiver of Example 8 in the radio | wireless communication apparatus of this invention. It is a figure which shows the signal conversion example of the signal conversion means 26 of Example 8. FIG. It is a figure which shows the structural example of the conventional transmitter using a Hilbert converter. It is a figure which shows the relationship of the power spectrum of DSB signal s (f) and SSB signal u (f). It is a figure which shows the structural example of the conventional transmitter based on DFT spreading OFDM.

Example 1
FIG. 1 shows a configuration example of a transmission apparatus according to a first embodiment of the wireless communication apparatus of the present invention.
In FIG. 1, the transmission apparatus according to the first embodiment generates a modulated signal having phases of 0 and π and a plurality of amplitude levels based on input data, and a modulated signal output from the digital modulator 11. The M / 2 + 1 point signal is selected from the M point signals in the frequency domain output from the DFT means 12 and the DFT means 12 for M (M is an even number) point for performing discrete Fourier transform (DFT). The mapping means 13 and the MFT + 1 output from the mapping means 13 are used as inputs, and the IDFT means 14 and IDFT means 14 for performing an NFT (N ≧ M / 2 + 1) point inverse discrete Fourier transform (IDFT). Add cyclic prefix to digital signal 15, D / A converters 16-1 and 16-2 for converting the real part and imaginary part signals of the digital signal output from the cyclic prefix adding means 15 into analog signals, respectively, and the D / A converter 16-1 , 16-2, a quadrature modulator 17 for generating a digital SSB signal.

  Here, the output of the digital modulator 11 is a DSB (double sideband) signal. In order to restore the DSB signal on the receiving side from the SSB signal transmitted from the transmitting apparatus, the DFT output is positive and negative in frequency. It must be a complex conjugate. For this reason, since the modulation signal must be a real number, the digital modulator 11 must be a modulator that generates a modulation signal having a phase state of 0 and π, a modulation signal having a plurality of amplitude levels, or a combination thereof. Must not.

Hereinafter, the operation of the transmission apparatus according to the first embodiment in the wireless communication apparatus of the present invention will be described in detail. If the output of the M point of the digital modulator 11 is s _m (m = 0 to M−1), the output t _n (n = 0 to N−1) of the M point of the DFT means 12 is given by the following equation. .

Here, t _n is a frequency domain signal, n = 0 is the frequency 0, that is, a direct current component, n = 1 to M / 2-1 is the positive frequency, and n = M / 2 to M−1 is If the frequency is a negative component and s _m is a modulated signal having a phase state of 0 and π, a modulated signal having a plurality of amplitude levels, or a combination thereof, that is, a real number, t _n and t _Mn are 1 ≦ n ≦ It becomes complex conjugate in the range of M / 2-1. Note that t ₀ and t _{M / 2} are real numbers. The mapping means 13 takes out the M / 2 + 1 point signal from the M point signal that is the output of the DFT means 12, and the M / 2 + 1 point signal is input to the N point IDFT means 14 to be converted into a time domain signal. Is done.

  FIG. 2 shows a mapping example of the mapping means 13 of the first embodiment. Here, as an example of mapping for generating a USB (upper sideband) digital SSB signal, an example of the output of the M-point DFT means 12 and the input of the N-point IDFT means 14 is shown.

In FIG. 2, the mapping unit 13 selects an M / 2 + 1 point signal from the M point signal t _n which is the output of the DFT unit 12 and inputs it to the N point IDFT unit 14, where n = 0 to M / When 2 is selected, it becomes USB (upper sideband), and when n = M / 2 to (M−1) and n = 0 are selected, the SSB signal is LSB (lower sideband). As shown in FIG. 2, the M / 2 + 1 point signal is divided into two and input to the IDFT means 14, but 0 (Null) is input to the other inputs. Therefore, it is necessary that N ≧ M / 2 + 1. If M and N are powers of 2, a fast Fourier transform algorithm can be applied, and the amount of calculation can be greatly reduced.

The selection above signal, the input signal of the N points in IDFT section _{14 u n (n = 0~N-} 1) becomes the following equation.

By inputting to the IDFT means 14 in this way, a digital SSB signal in the base band can be generated. The output u (kT) (k = 0 to N−1) of the IDFT means 14 is given by the following equation. However, T is a sampling period.

u (kT) is a digital SSB signal in which the band in the base band is about half (M / 2 + 1) / M. As shown in the configuration example of FIG. 1, a cyclic prefix is added to the output u (kT) (k = 0 to N−1) of the IDFT means 14 by the cyclic prefix adding means 15, and the digital signal that is the output of the cyclic prefix is added. The signals of the real part Re [u (kT)] and the imaginary part Im [u (kT)] are converted into analog signals u _I (t) and u _Q (t) by the D / A converters 16-1 and 16-2, respectively. And is input to the quadrature modulator 17 to obtain a digital SSB signal u (t) given by the following equation.

  FIG. 3 shows a spectrum arrangement example of the digital SSB signal in the first embodiment. Here, the relationship between the spectrum U (f) of the digital SSB signal u (t) generated by the transmitter and the spectrum S (f) of the original DSB signal is shown.

In the mapping unit 13 retrieves the M / 2 + 1 point signal a is from M points of the signal output of the DFT unit 12, an input signal of N points in the IDFT unit _{14 u n (n = 0~N-} 1) Equation (3 ), A digital SSB signal as shown in FIG. 3 is obtained. As a result, the frequency band of the power spectrum U (f) of the digital SSB signal can be reduced to about ½ of the frequency band of the power spectrum S (f) of the DSB signal. Carrier frequency in this case is f _c, diagram for explaining a relationship between the power spectrum of a conventional SSB signal generated by the SSB modulator using the Hilbert transformer of U (f) and the DSB signal S (f) 17 and a positional relationship of the SSB signal and a carrier frequency f _c is different. However, it is possible to obtain a digital SSB signal only by arithmetic processing by DFT and IDFT without using a Hilbert transformer using an FIR filter having a large number of taps as in a conventional digital SSB modulator.

  In the description of the transmitting apparatus of the first embodiment, the M / 2 + 1 point signal is extracted by the mapping unit 13 from the M point signal output from the DFT unit 12, and the M / 4 + 1 point and the M are obtained as shown in FIG. An example of dividing into / 4 points was shown. However, as a method of dividing the M / 2 + 1 point signal, M / 4 + 2 point and M / 4- 1 point, or M / 4 point and M / 4 + 1 point may be used. SSB signals having different upper and lower spectrum widths are generated.

(Example 2)
The transmission apparatus according to the second embodiment of the wireless communication apparatus of the present invention differs from the configuration shown in FIG. 1 only in the mapping process in the mapping unit 13.

  FIG. 4 shows a mapping example of the mapping means 13 of the second embodiment. Here, as an example of mapping for generating a USB (upper sideband) digital SSB signal, an example of the output of the M-point DFT means 12 and the input of the N-point IDFT means 14 is shown.

In FIG. 4, the mapping unit 13 selects the M / 2 + 1 point signal from the M point signal t _n which is the output of the DFT unit 12 and inputs the selected signal to the N point IDFT unit 14. Similarly, when n = 0 to M / 2 is selected, USB (upper sideband), when n = M / 2 to (M-1) and n = 0 are selected, LSB (lower sideband) is selected. SSB signal. Here, the M / 2 + 1 point signal is divided into two as shown in FIG. 4 and inputted to the IDFT means 14, but 0 (Null) is inputted to the other inputs. Input signal u _n of N point to IDFT unit 14 (n = 0~N-1), in the second embodiment, the u ₀ corresponding to the carrier frequency f _c in the baseband null, i.e. by the following equation as 0 Given.

In the second embodiment, as can be seen from the equation (6), it is necessary that N ≧ M / 2 + 2 in order to set u ₀ = 0. If M and N are powers of 2, the fast Fourier transform algorithm is applied. Therefore, the amount of calculation can be reduced. From the M-point modulation signal output from the DFT means 12, the mapping means 13 extracts the upper or lower M / 2 + 1 point output, and converts the M / 2 + 1 point signal to M / 4 + 1 and M / 4 point outputs. Divide into two, and input to the IDFT means 14 for performing N-point inverse discrete Fourier transform (IDFT) where N ≧ M / 2 + 2 by placing the DC component at the top and bottom, and inserting 0 into the DC component Thus, the output of the IDFT means 14 is an SSB signal that does not contain a DC component.

  As described above, according to this embodiment, since an SSB signal that does not include a direct current component can be generated, a DC offset between the outputs of the D / A converters 16-1 and 16-2 and the input of the quadrature modulator 17. However, the amplitude of the component having a frequency of 0, that is, the direct current component is always 0. That is, since an SSB signal that does not include a DC component can be generated, the error rate characteristic does not deteriorate in demodulation on the reception side, and the deterioration of the transmission characteristic can be prevented.

  FIG. 5 shows a spectrum arrangement example of the digital SSB signal in the second embodiment. Here, the relationship between the spectrum U (f) of the digital SSB signal u (t) generated by the transmitter and the spectrum S (f) of the original DSB signal is shown.

In the mapping unit 13 retrieves the M / 2 + 1 point signals from M points of the signal output from the DFT unit 12, the input signal _{u n (n = 0~N-1} ) the equation of N points in the IDFT unit 14 (6 ), A digital SSB signal as shown in FIG. 5 is obtained. As a result, the frequency band of the power spectrum U (f) of the digital SSB signal can be reduced to about ½ of the frequency band of the power spectrum S (f) of the DSB signal. Carrier frequency is f _c, the carrier frequency f _c of the U of a conventional SSB signal generated by the SSB modulator using the Hilbert converter shown (f) and the DSB signal power spectrum S (f) in FIG. 17 The positional relationship is different. However, since the transmission apparatus according to the second embodiment can generate an SSB signal that does not include a DC component, even if a DC offset occurs between the D / A converter and the quadrature modulator, the error rate characteristics in the demodulation on the reception side are reduced. Degradation does not occur, it is possible to prevent degradation of transmission characteristics, and without using a Hilbert transformer with an FIR filter having a large number of taps as in the conventional digital SSB modulator, only digital processing is performed by DFT and IDFT. An SSB signal can be obtained.

(Example 3)
FIG. 6 shows a configuration example of the transmission apparatus according to the third embodiment in the wireless communication apparatus of the present invention.
In FIG. 6, the transmission apparatus according to the third embodiment has a configuration in which pilot subcarrier generation means 18 is added to the transmission apparatus according to the first embodiment shown in FIG. 1.

  The mapping means 13 selects the M / 2 + 1 point signal from the M point output of the DFT means 12 and the pilot signal from the pilot subcarrier generation means 18 and maps them to N (N ≧ M / 2 + 2) points. Input to the IDFT means 14. At this time, since one or more pilot subcarriers can be inserted in the frequency domain, the receiving side can easily perform frequency synchronization using the pilot subcarriers, and transmission characteristics caused by frequency errors can be achieved. Transmission with little deterioration is possible.

  FIG. 7 shows a spectrum arrangement example of the digital SSB signal in the third embodiment. Here, the relationship between the spectrum U (f) of the digital SSB signal u (t) generated by the transmitter and the spectrum S (f) of the original DSB signal is shown.

In the mapping means 13, the M / 2 + 1 point signal and the pilot signal from the pilot subcarrier generation means 18 are selected from the M point output of the DFT means 12, and are mapped to obtain an IDFT of N (N ≧ M / 2 + 2) points. By inputting to the means 14, a digital SSB signal as shown in FIG. 7 is obtained. As a result, the frequency band of the power spectrum U (f) of the digital SSB signal can be reduced to about ½ of the frequency band of the power spectrum S (f) of the DSB signal. Carrier frequency is f _c, the carrier frequency f _c of the U of a conventional SSB signal generated by the SSB modulator using the Hilbert converter shown (f) and the DSB signal power spectrum S (f) in FIG. 17 The positional relationship is different. Further, in the transmission apparatus according to the third embodiment, pilot subcarriers can be multiplexed in the frequency domain, so that frequency synchronization can be easily performed on the reception side using this pilot signal, and transmission characteristics are hardly deteriorated due to frequency errors. Transmission is possible, and it is possible to obtain a digital SSB signal only by an arithmetic processing by DFT and IDFT and mapping processing without using a Hilbert transformer by an FIR filter having a large tap number like a conventional digital SSB modulator. Become.

Example 4
The transmission apparatus according to the fourth embodiment of the wireless communication apparatus of the present invention differs from the configuration illustrated in FIG. 1 only in the mapping process in the mapping unit 13.

  FIG. 8 shows a mapping example of the mapping means 13 of the fourth embodiment. Here, as an example of mapping for generating a USB (upper sideband) digital SSB signal, an example of the output of the M-point DFT means 12 and the input of the N-point IDFT means 14 is shown.

  FIG. 9 shows an example of the spectrum arrangement of the digital SSB signal in the fourth embodiment. Here, the relationship between the spectrum U (f) of the digital SSB signal u (t) generated by the transmitter and the spectrum S (f) of the original DSB signal is shown. However, FIG. 9 (4) corresponds to the input of the IDFT means 14 of N points in FIG.

8 and 9, the mapping unit 13 selects the M / 2 + 1 point signal from the M point signal t _n which is the output of the DFT unit 12, and inputs it to the N point IDFT unit 14. In this case, the frequency elements are selected so as to straddle the LSB side and the USB side, and the frequency offset positions extracted on the LSB side and the USB side are different with the center frequency Fc (zero in the case of the baseband) as the center. Is a feature. However, in the extracted frequency components, care is taken not to extract a frequency element for the center frequency Fc ′ in the frequency band surrounded by the lower end frequency of the LSB side spectrum and the upper end frequency of the USB side spectrum.

Here, if the frequency interval between DFT points is Δf, the frequency spectrum S (f) of the DSB signal is expressed as follows.

Further, the signal spectrum U ′ (f) transmitted in the fourth embodiment is expressed as follows.

  The extracted spectrum of M / 2 + 1 points is as shown in FIG. However, K is a positive integer smaller than M. When the modulation signal is a real signal, the frequency component on the LSB side and the frequency component on the USB side of the DSB signal have a conjugate complex relationship with the center frequency Fc (zero in the baseband) as a center. It can be seen that the signal extracted as shown in 8) has the same transmission information as the SSB signal transmitted in the first embodiment. Therefore, when the sign of the imaginary part of the M / 2 + 1 point signal actually transmitted in the fourth embodiment is inverted and copied to the paired LSB side or USB side band and received, it is equivalent to the SSB transmission method. It is self-evident.

  Further, since the frequency band surrounded by the lower end frequency of the LSB side spectrum and the upper end frequency of the USB side spectrum is transmitted as a transmission signal among the extracted frequency components, the center frequency Fc ′ of the transmission signal is shown in FIG. It becomes the position. As in the first embodiment, the frequency component U ′ (Fc ′) of the center frequency Fc ′ matches the DC component of the N-point IFFT block of the transmitter as shown in FIG. 9 (4). As described above, by extracting so that U ′ (Fc ′) = 0, the DC component is null, that is, information transmission is not performed, and thus the receiving apparatus is not affected by the above-described DC offset.

  Compared with the first and second embodiments, the total occupied bandwidth of the transmission signal is the same, but since the null frequency element is sandwiched near the DC component, the system bandwidth is expanded, so the frequency fading environment Below, a higher frequency diversity effect can be expected than the SSB signals of the first and second embodiments. Further, the fourth embodiment can avoid the influence of the DC offset as in the method of the second embodiment. However, the second embodiment partially destroys the relative positional relationship of the frequency elements of the original single carrier signal. Maintains the relative positional relationship of the frequency elements of the original single carrier signal, and has the advantage of keeping the PAPR low. FIG. 10 shows the PAPR characteristics. By avoiding the influence of the DC offset, the PAPR deteriorates more than the SSB signal, but the PAPR is lower in the fourth embodiment than in the second embodiment. I understand that.

  In FIG. 9 and Expression (8), an example is described in which there is one continuous spectrum on the LSB side and one continuous spectrum on the USB side. There may be a plurality of discrete spectra on the LSB side and the USB side, respectively, or one continuous spectrum on the LSB side and two discrete spectra on the USB side.

(Example 5)
FIG. 11 shows an example of the spectrum arrangement of the digital SSB signal in the fifth embodiment.
The fifth embodiment is based on the mapping example of the mapping unit 13 of the fourth embodiment. By frequency-multiplexing the transmission signal of another user's transmission signal in the null frequency band formed in the transmission signal of a certain user, the frequency utilization efficiency in the system band can be improved as compared with the fourth embodiment. In the example of FIG. 11, when the fourth embodiment is realized by two users having an M point DFT, the transmission device of the user 1 shown in FIG. 11 (1) has M / 4 points on the LSB side and M / M on the USB side. The transmission device of user 2 shown in FIG. 11 (2) has 4 + 1 point frequency elements (consecutive spectrum), and the frequency element (consecutive) of M / 4-1 points on the LSB side and M / 4 + 2 points on the USB side. (Spectrum).

  Here, the transmission device of the user 1 has an M / 4 point null point between the LSB side spectrum and the USB side spectrum, and the transmission device of the user 2 has an M / M between the LSB side spectrum and the USB side spectrum. It has 4 + 1 points of null points. As a result, the user 1 or the user 2 or the user 1 and the user 2 have a point corresponding to the upper end frequency of the LSB side spectrum of the user 2 adjacent to the point corresponding to the lower end frequency of the user 1 USB side spectrum. By appropriately setting the center frequency, as shown in FIG. 11 (3), the transmission signals can be frequency-multiplexed without interfering with each other. At this time, the system band is equivalent to M + 3 DFT points, and considering that the users 1 and 2 transmit M + 1 point signals, the occupied bandwidth is M + 2 points. Thus, this is a significant improvement over the fourth embodiment.

The receiving devices of the user 1 and the user 2 perform N-point IFFT processing centering on the center frequency of each desired transmission signal, so that the features of the fourth embodiment, which is the premise of the fifth embodiment, are confident. Since the center frequency of the signal is null, even if another user signal is frequency-multiplexed with the center frequency of the own signal, it can be ignored at the time of reception, so as in the second and fourth embodiments, The influence of the DC offset can be avoided.
In the fifth embodiment, an example of frequency multiplexing of two users having M DFT points has been shown. Similarly, frequency multiplexing of three or more users is performed so that the own signal and other user signals do not interfere with each other. Multiple users having different DFT points may be frequency multiplexed.

(Example 6)
FIG. 12 shows a spectrum arrangement example of the digital SSB signal in the sixth embodiment.
The sixth embodiment is based on the mapping example of the mapping unit 13 of the fifth embodiment. In the fifth embodiment, when a plurality of users are frequency-multiplexed, the frequency component equivalent to the SSB signal is composed of odd points of M / 2 + 1 including the DC component of the DSB signal, as already shown in FIG. In this case, at least one null point is generated in the system band. Since this point does not contribute to data transmission, in the sixth embodiment, as in the third embodiment, frequency synchronization is facilitated by mapping a common pilot signal or a user-specific pilot signal on the null point. The difference from the third embodiment is that, as described in the fourth embodiment, since the frequency positional relationship of the frequency components of the original single carrier signal can be maintained, PAPR can be suppressed.

(Example 7)
FIG. 13 shows a spectrum arrangement example of the digital SSB signal in the seventh embodiment.
The seventh embodiment is based on the mapping example of the mapping unit 13 of the fifth embodiment. In the seventh embodiment, a case where a plurality of users are frequency-multiplexed as in the fifth embodiment is considered. That is, when realizing Example 5 of two users having an M-point DFT, the transmission device of user 1 shown in FIG. 13 (1) has a frequency of M / 4 points on the LSB side and M / 4 + 1 points on the USB side. The transmission device of user 2 shown in FIG. 13 (2) having an element (continuous spectrum) has a frequency element (continuous spectrum) of M / 4-1 point on the LSB side and M / 4 + 2 point on the USB side. Design as follows.

  The frequency component equivalent to the SSB signal is composed of an odd number of M / 2 + 1 points including the DC component of the DSB signal, as shown in FIG. Null points will occur. In the seventh embodiment, as shown in FIG. 13 (4), mapping is performed so that the null point becomes the DC component of the N-point IFFT. The difference from the fifth embodiment is that, in order to avoid the influence of the DC offset in the fifth embodiment, the N-point FFT corresponding to the center frequency of each user transmission signal is equal to the number of users in order to receive the desired signal of each user. On the other hand, since the DC component can be shared by all users in the seventh embodiment, one N-point FFT is sufficient, that is, it is suitable for collective reception at the base station in the cellular uplink.

  In addition, Example 7 can also be used together with Example 6 when the null point in the system band produced at the time of the frequency multiplexing is 2 points or more.

(Example 8)
FIG. 14 shows a configuration example of a receiving apparatus according to the eighth embodiment in the wireless communication apparatus of the present invention.
Referring to FIG. 14, the receiving apparatus includes a quadrature demodulator 21, A / D converters 22-1, 22-2, cyclic prefix removing means 23, N-point DFT means 24, equalizing means 25, and digital SSB signals. The signal conversion means 26 for converting to a DSB signal and the M-point IDFT means 27 are configured.

  The SSB signal generated by the transmission apparatus according to the first to seventh embodiments is used as a reception signal, and the quadrature demodulator 21 extracts the in-phase component and the quadrature component of the baseband signal from the reception signal. , 22-2 converts the signal of the in-phase component and the quadrature component into a digital signal, and the cyclic prefix removing means 23 removes the cyclic prefix from the outputs of the A / D converters 22-1, 22-2, An N-point received SSB signal is obtained. The N-point received SSB signal is subjected to N-point discrete Fourier transform (DFT) by the DFT transform means 24, and the output of the DFT transform means 24 is subjected to frequency domain equalization by the equalization means 25. The signal converting means 26 removes nulls and pilot signals inserted in the DC component on the transmission side from the output of the equalizing means 25, and performs a signal of M / 2 + 1 points in the reverse procedure to the mapping means 13 in FIG. Then, the sign of the imaginary part of the M / 2 + 1 point signal is inverted to generate a M / 2−1 point complex conjugate signal, and the M / 2 + 1 point signal and the M / 2−1 point complex signal are generated. An M-point DSB signal is reproduced from the conjugate signal. The IDFT means 27 demodulates the signal by performing inverse discrete Fourier transform on the M-point DSB signal.

  Here, since the null inserted in the DC component on the transmission side is removed, the reception side is not affected by the DC offset between the quadrature demodulator 21 and the A / D converters 22-1, 22-2. Thus, transmission with little deterioration in error rate characteristics due to DC offset becomes possible. Further, since the signal conversion means 26 can extract the pilot signal inserted on the transmission side, the reception side can easily perform frequency synchronization using the pilot signal, and transmission characteristics due to frequency errors. Transmission with less deterioration of the signal becomes possible.

  FIG. 15 shows a signal conversion example of the signal conversion means 26 of the eighth embodiment. Here, in the receiving apparatus of the eighth embodiment corresponding to the transmitting apparatus of the second embodiment, when receiving a USB (upper sideband) digital SSB signal, the output of the N-point DFT means 24 and the M-point IDFT means An example of the relationship of 27 inputs is shown.

  In this example, no pilot signal is inserted, and a null is inserted only in the DC component. The N-point signal that is the output of the DFT means 24 is equalized by the equalizing means 25, and then the null and pilot signal inserted in the DC component on the transmission side are removed by the signal converting means 26 to remove M. / 2 + 1 point signal. Further, the sign of the imaginary part of the M / 2 + 1 point signal is inverted to generate an M / 2-1 point complex conjugate signal, and the M / 2 + 1 point signal and the M / 2-1 point complex conjugate signal are generated. To M-point double sideband signals.

Hereinafter, a specific example will be described. The N-point signal u _n (n = 0 to N−1), which is the output of the DFT means 24, corresponds to the carrier frequency f _c in the baseband in the receiving device of the eighth embodiment corresponding to the transmitting device of the second embodiment. U ₀ is null, that is, 0, is given by equation (10). Expression (10) is the same as Expression (6).

In equation (10), M / 2 + 1 point signals u _n (n = 1 to M / 4, n = N−M / 4 to N) are extracted.

This is an SSB signal, t ₀ and t _{M / 2} are real numbers, and t _n (n = 1 to M / 2-1) is a complex number. When this complex conjugate is t _n ^* (n = 1 to M / 2-1), the reproduced DSB signal is given by the following equation.

When this M-point DSB signal is subjected to inverse discrete Fourier transform, s _m and t _n are Fourier transform pairs as shown in the equation (2), so that s _m (m = 0 to M−1) which is a transmission signal. ) Can be obtained.

DESCRIPTION OF SYMBOLS 11 Digital modulator 12 M point DFT means 13 Mapping means 14 N point IDFT means 15 Cyclic prefix addition means 16 D / A converter 17 Quadrature modulator 18 Pilot subcarrier generation means 21 Orthogonal demodulator 22 A / D conversion 23 Cyclic prefix removal means 24 N-point DFT means 25 Equalization means 26 Signal conversion means 27 M-point IDFT means 101 Modulator 102 Hilbert transformer 103 Orthogonal modulator 111 Digital modulator 112 M-point DFT means 113 Mapping Means 114 N-point IDFT means 115 Cyclic prefix addition means 116 D / A converter

Claims (13)

In the transmitting apparatus for generating a de-Ijitaru SSB signal,
A digital modulator that generates a modulation signal comprising a modulation signal having a phase state of 0 and π or a plurality of amplitude levels, or a combination thereof;
DFT means for performing a discrete Fourier transform on a modulation signal of M (M is an even number) point that is an output of the digital modulator;
Mapping means for taking out the output of M / 2 + 1 points on the upper side or the lower side of the M-point modulated signal that is the output of the DFT means and performing signal arrangement;
IDFT means for inputting the output of the mapping means and performing N-point inverse discrete Fourier transform where N ≧ M / 2 + 1;
A cyclic prefix adding means for adding a cyclic prefix to the output of the IDFT means;
Two D / A converters for converting the real part and the imaginary part of the output of the IDFT means to which the cyclic prefix is added, into analog signals, respectively;
And a quadrature modulator for outputting the digital SSB signal by quadrature modulation process a respective output of the two D / A converters,
The mapping means takes the M / 2 + 1 point output from the M point modulation signal from the M point modulation signal, divides the M / 2 + 1 point signal into two, arranges the DC component at the top and bottom, Is a configuration for inserting 0,
The transmission apparatus according to claim 1, wherein the IDFT means is configured to perform N-point inverse discrete Fourier transform with N ≧ M / 2 + 2 by using the output of the mapping means as an input . In the transmitting apparatus for generating a de-Ijitaru SSB signal,
A digital modulator that generates a modulation signal comprising a modulation signal having a phase state of 0 and π or a plurality of amplitude levels, or a combination thereof;
DFT means for performing a discrete Fourier transform on a modulation signal of M (M is an even number) point that is an output of the digital modulator;
Mapping means for taking out the output of M / 2 + 1 points on the upper side or the lower side of the M-point modulated signal that is the output of the DFT means and performing signal arrangement;
IDFT means for inputting the output of the mapping means and performing N-point inverse discrete Fourier transform where N ≧ M / 2 + 1;
A cyclic prefix adding means for adding a cyclic prefix to the output of the IDFT means;
Two D / A converters for converting the real part and the imaginary part of the output of the IDFT means to which the cyclic prefix is added, into analog signals, respectively;
A quadrature modulator that performs quadrature modulation processing on the outputs of the two D / A converters and outputs the digital SSB signal ;
Pilot subcarrier generating means for generating a pilot signal for frequency synchronization on the receiving side ,
The mapping means takes the M / 2 + 1 point output from the M point modulation signal from the M point modulation signal, divides the M / 2 + 1 point signal into two, arranges the DC component at the top and bottom, Is a configuration in which one or more pilot signals generated by the pilot subcarrier generating means are arranged by inserting 0.
The transmission apparatus according to claim 1, wherein the IDFT means is configured to perform N-point inverse discrete Fourier transform with N ≧ M / 2 + 2 by using the output of the mapping means as an input . A digital modulator that generates a modulation signal composed of a modulation signal having a phase state of 0 and π, a plurality of amplitude levels, or a combination thereof, and a modulation signal of M (M is an even number) point that is an output of the digital modulator; DFT means for performing a discrete Fourier transform, mapping means for taking out the output of M / 2 + 1 points on the upper side or the lower side of the M-point modulated signal that is the output of the DFT means, and the output of the mapping means IDFT means for performing N-point inverse discrete Fourier transform, N ≧ M / 2 + 1, cyclic prefix adding means for adding a cyclic prefix to the output of the IDFT means, and the cyclic prefix added The real and imaginary signals of the output of the IDFT means Generated by the transmission device equipped with two D / A converters for converting the grayed signal, and a quadrature modulator for outputting a de-Ijitaru SSB signal respective outputs orthogonal modulation processing of the two D / A converters In the receiving device using the received SSB signal as a reception signal,
A quadrature demodulator that extracts in-phase and quadrature components from the received signal;
Two A / D converters that respectively convert the two outputs of the quadrature demodulator into digital signals;
Cyclic prefix removing means for removing a cyclic prefix portion from the respective outputs of the two A / D converters;
DFT transform means for performing N-point discrete Fourier transform on the output of the cyclic prefix removing means;
Equalization means for equalizing the output of the DFT conversion means in the frequency domain;
After removing the DC component in which nulls are inserted from the output of the equalizing means and converting it to a signal of M / 2 + 1 point, the sign of the imaginary part of the signal of M / 2 + 1 point is inverted and M / 2-1 Signal converting means for generating a complex conjugate signal of points and reproducing an M-point DSB signal from the M / 2 + 1 point signal and the M / 2- 1 point complex conjugate signal;
IDFT means for performing an inverse discrete Fourier transform on the M-point DSB signal;
Receiving apparatus characterized by comprising a. In the transmitting apparatus for generating a de-Ijitaru SSB signal,
A digital modulator that generates a modulation signal comprising a modulation signal having a phase state of 0 and π or a plurality of amplitude levels, or a combination thereof;
DFT means for performing a discrete Fourier transform on a modulation signal of M (M is an even number) point that is an output of the digital modulator;
The frequency from the center frequency of the points extracted on the LSB side and the USB side, and at least one point is selected on the LSB side and the USB side from among the M point modulation signals that are the output of the DFT means The signal position is extracted by extracting the output of M / 2 + 1 points excluding the point corresponding to the center frequency of the frequency band that is different in offset position and surrounded by the lower end frequency of the LSB side extracted spectrum and the upper end frequency of the USB side extracted spectrum. Mapping means for performing
IDFT means for inputting the output of the mapping means and performing N-point inverse discrete Fourier transform where N ≧ M / 2 + 1;
A cyclic prefix adding means for adding a cyclic prefix to the output of the IDFT means;
Two D / A converters for converting the real part and the imaginary part of the output of the IDFT means to which the cyclic prefix is added, into analog signals, respectively;
Transmitting apparatus characterized by comprising a quadrature modulator for outputting the digital SSB signal by quadrature modulation process a respective output of the two D / A converters. The transmission device according to claim 4, wherein
The transmission device is configured to perform mapping in which a transmission signal of another user is frequency-multiplexed in a null frequency band formed in a transmission signal of one user. The transmission device according to claim 5, wherein
Further comprising a pilot subcarrier generating means for generating a pilot signal for frequency synchronization on the receiving side,
The mapping means is a configuration in which one or more pilot signals generated by the pilot subcarrier generation means are arranged on a null point in a system band generated at the time of frequency multiplexing of transmission signals of a plurality of users.
The IDFT unit, transmission, wherein the is configured to perform an inverse discrete Fourier transform of N points outputted as the input of the mapping means device. In the transmission device according to claim 5 or 6,
The mapping means is configured to perform mapping in which any one of the null points in the system band generated at the time of frequency multiplexing of transmission signals of a plurality of users is a DC component of an N-point inverse discrete Fourier transform. A transmitter characterized by the above. In the receiving apparatus to receive signals SSB signals generated by the transmission device according to any one of claims 4-7,
A quadrature demodulator that extracts in-phase and quadrature components from the received signal;
Two A / D converters for converting the two outputs of the quadrature demodulator into digital signals,
Cyclic prefix removing means for removing a cyclic prefix portion from the respective outputs of the two A / D converters ;
And DFT conversion means you discrete Fourier transform of N points to the output of the previous Symbol cyclic prefix removal means,
And equalizing means for equalizing a frequency domain to the output of the DFT transform means,
After removing the DC component in which nulls are inserted from the output of the equalizing means and converting it to a signal of M / 2 + 1 point, the sign of the imaginary part of the signal of M / 2 + 1 point is inverted and M / 2-1 Signal converting means for generating a complex conjugate signal of points and reproducing an M-point DSB signal from the M / 2 + 1 point signal and the M / 2- 1 point complex conjugate signal;
Receiving apparatus characterized by comprising a IDFT means for inverse discrete Fourier transform of the DSB signal of the M points. In the transmission method of generating a de-Ijitaru SSB signal,
Generate a modulation signal consisting of a modulation signal having a phase state of 0 and π or a plurality of amplitude levels, or a combination thereof, with a digital modulator,
The output of the digital modulator is input to the DFT means, and the modulated signal of M (M is an even number) point is subjected to discrete Fourier transform,
The output of the DFT means is input to the mapping means, and the M / 2 + 1 point output of the upper or lower side of the M-point modulated signal is taken out and signal placement is performed.
The output of the mapping means is input to the IDFT means to perform an N-point inverse discrete Fourier transform where N ≧ M / 2 + 1.
Add a cyclic prefix to the output of the IDFT means,
D / A conversion of the real part and imaginary part of the output of the IDFT means to which the cyclic prefix is added,
Each D / A converted signal is subjected to quadrature modulation processing by a quadrature modulator to output the digital SSB signal ,
The mapping means extracts the M / 2 + 1 point output from the M point modulation signal from the M point modulation signal, divides the M / 2 + 1 point signal into two, arranges the DC component at the top and bottom, Inserts 0,
Wherein the IDFT means, transmission method and performing an inverse discrete Fourier transform of N points is N ≧ M / 2 + 2 output as the input of the mapping means. In the transmission method of generating a de-Ijitaru SSB signal,
Generate a modulation signal consisting of a modulation signal having a phase state of 0 and π or a plurality of amplitude levels, or a combination thereof, with a digital modulator,
The output of the digital modulator is input to the DFT means, and the modulated signal of M (M is an even number) point is subjected to discrete Fourier transform,
The output of the DFT means is input to the mapping means, and the M / 2 + 1 point output of the upper or lower side of the M-point modulated signal is taken out and signal placement is performed.
The output of the mapping means is input to the IDFT means to perform an N-point inverse discrete Fourier transform where N ≧ M / 2 + 1.
Add a cyclic prefix to the output of the IDFT means,
D / A conversion of the real part and imaginary part of the output of the IDFT means to which the cyclic prefix is added,
Each D / A converted signal is subjected to quadrature modulation processing by a quadrature modulator to output the digital SSB signal ,
The mapping means extracts the M / 2 + 1 point output from the M point modulation signal from the M point modulation signal, divides the M / 2 + 1 point signal into two, arranges the DC component at the top and bottom, Inserts 0 and places one or more pilot signals for frequency synchronization on the receiving side,
Wherein the IDFT means, transmission method and performing an inverse discrete Fourier transform of N points is N ≧ M / 2 + 2 output as the input of the mapping means. Modulated signal by de Ijitaru modulator having the phase states or more amplitude levels of 0 and π or to generate a modulated signal comprising a combination thereof, and an output of said digital modulator to the DFT unit M (M is an even number ) Perform discrete Fourier transform on the modulation signal at the point, input the output of the DFT means to the mapping means, extract the M / 2 + 1 point output from the upper or lower side of the M point modulation signal, perform signal arrangement, The output of the mapping means is input to the IDFT means to perform N-point inverse discrete Fourier transform with N ≧ M / 2 + 1, and a cyclic prefix is added to the output of the IDFT means, and the cyclic prefix is added. Further, D / A conversion is performed on the real part and imaginary part of the output of the IDFT means, and the D / A converted signal In the reception method for a reception signal SSB signal generated by the transmission method for outputting a de-Ijitaru SSB signals by quadrature modulation processing Les signal in the quadrature modulator,
Perform quadrature demodulation processing to extract the in-phase component and the quadrature component from the received signal, convert the two outputs into digital signals, respectively, and remove the cyclic prefix portion.
The signal from which the cyclic prefix portion has been removed is input to DFT means to perform N-point discrete Fourier transform,
The output of the DFT means is input to the equalization means and equalized in the frequency domain,
The output of the equalization means is input to the signal conversion means, the direct current component with the null inserted is removed and converted to an M / 2 + 1 point signal, and then the sign of the imaginary part of the M / 2 + 1 point signal is inverted. Then, an M / 2-1 point complex conjugate signal is generated, and an M point DSB signal is reproduced from the M / 2 + 1 point signal and the M / 2-1 point complex conjugate signal,
A receiving method, wherein the M-point DSB signal is input to IDFT means, and an inverse discrete Fourier transform is performed to output a demodulated signal . In the transmission method of generating a de-Ijitaru SSB signal,
Generate a modulation signal consisting of a modulation signal having a phase state of 0 and π or a plurality of amplitude levels, or a combination thereof, with a digital modulator,
The output of the digital modulator is input to the DFT means, and the modulated signal of M (M is an even number) point is subjected to discrete Fourier transform,
The output of the DFT means is input to the mapping means to select at least one point on the LSB side and the USB side from among the M point modulated signals, and the points extracted on the LSB side and the USB side Output M / 2 + 1 points excluding the point corresponding to the center frequency of the frequency band that is different in frequency offset position from the center frequency and is surrounded by the lower end frequency of the LSB side extracted spectrum and the upper end frequency of the USB side extracted spectrum. Extract and place the signal,
The output of the mapping means is input to the IDFT means to perform an N-point inverse discrete Fourier transform where N ≧ M / 2 + 1.
Add a cyclic prefix to the output of the IDFT means,
D / A conversion of the real part and imaginary part of the output of the IDFT means to which the cyclic prefix is added,
A transmission method, wherein each of the D / A converted signals is subjected to orthogonal modulation processing by an orthogonal modulator, and the digital SSB signal is output. In the receiving method which uses the SSB signal generated by the transmitting method according to claim 12 as a received signal ,
It performs quadrature demodulation processing to take out the in-phase component and a quadrature component from the received signal, removes the cyclic prefix portion by converting the two output into digital signals,
The signal from which the cyclic prefix portion has been removed is input to DFT means to perform N-point discrete Fourier transform,
Type equalized in the frequency domain to the equalization means an output of the DFT means,
The output of the equalization means is input to the signal conversion means, the direct current component with the null inserted is removed and converted to an M / 2 + 1 point signal, and then the sign of the imaginary part of the M / 2 + 1 point signal is inverted. Then, an M / 2-1 point complex conjugate signal is generated, and an M point DSB signal is reproduced from the M / 2 + 1 point signal and the M / 2-1 point complex conjugate signal,
A receiving method comprising: inputting the M-point DSB signal to an IDFT means, performing inverse discrete Fourier transform, and outputting a demodulated signal.

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