JP4803379B2 - Wireless transmission device with quadrature modulator - Google Patents

Description

  The present invention relates to a radio communication apparatus including a quadrature modulator, and more particularly to a radio transmission apparatus capable of compensating for an image component of a quadrature modulator.

  In next-generation radio communication systems, widening the radio frequency bandwidth is being studied. As a technology for stable transmission of wideband signals, a baseband signal, which is a modulation signal (baseband signal) created from transmission data, is once converted to an intermediate frequency (IF) signal Then, a method is known in which the signal is converted into a radio frequency (RF) band signal and transmitted.

  In addition to the technique using such an IF band signal, a direct conversion method for directly converting a baseband signal into an RF band signal is also known. According to this direct conversion method, the circuit configuration is simple, no IF filter is required, the radio device can be miniaturized, and the cost can be reduced.

  However, in the analog quadrature modulator used for the direct conversion method, image component leakage occurs due to an amplitude or phase shift between the in-phase component and the quadrature component of the input baseband signal. This image component leak (hereinafter referred to as “image leak”) is not required at a frequency (+ f) symmetrical to the frequency (−f) of the transmission signal with the carrier frequency as the center as shown in FIG. This is a phenomenon where waves are generated. There is a problem that the transmission signal is deteriorated by such an image component which is an unnecessary wave.

  Japanese Patent Application Laid-Open No. 2004-228561 describes a conventional technique that compensates for image components generated by the analog quadrature modulator described above by baseband signal processing. The configuration of this conventional wireless transmission apparatus will be described with reference to FIG.

  In the conventional radio transmission apparatus shown in FIG. 23, an input transmission signal is converted from a digital signal to an analog signal by a digital / analog (D / A) conversion unit 62 via an amplitude / timing correction unit 61, Input to the quadrature modulator 64.

  The analog quadrature modulator 64 performs quadrature modulation and frequency conversion into an RF band signal using the carrier frequency signal supplied from the oscillator 63 with respect to the input baseband analog signal. The RF signal is distributed and outputted to the multiplier 72 of the feedback system.

  The multiplier 72 multiplies the quadrature-modulated RF signal supplied from the quadrature modulator 64 and the carrier frequency signal supplied from the oscillator 71 to convert it to a baseband signal, and converts the converted baseband signal to analog / Output to the digital (A / D) converter 73.

  The A / D conversion unit 73 performs analog / digital conversion on the signal supplied from the multiplier 72 and outputs the converted signal to the digital quadrature demodulator 74.

  The digital quadrature demodulator 74 performs quadrature demodulation on the signal supplied from the A / D conversion unit 73 and outputs the quadrature demodulated signal to the amplitude / timing check unit 75.

  The amplitude / timing investigation unit 75 varies the amplitude balance and timing of the in-phase component and the quadrature component of the signal supplied from the digital quadrature demodulator 74 according to the correction value supplied from the correction value calculation unit 78 described later, The data is output to the fast Fourier transform unit (FFT) 76.

  The fast Fourier transform unit 76 performs fast Fourier transform on the signal supplied from the amplitude / timing investigation unit 75 and outputs the signal to the image power analysis unit 77.

  The image power analysis unit 77 measures the image component of the signal supplied from the fast Fourier transform unit 76 and outputs it to the correction value calculation unit 78.

  The correction value calculation unit 78 monitors the image power supplied from the image power analysis unit 77 and outputs a correction value related to the amplitude balance and timing to the amplitude / timing investigation unit 75 or the amplitude / timing correction unit 61.

  The conventional wireless transmission apparatus having such a configuration operates as follows.

  The correction value calculation unit 78 varies the correction values of amplitude and timing (amplitude balance and timing difference between in-phase component and quadrature component) while monitoring the image power notified from the image power analysis unit 77. The changed correction value is output to the amplitude / timing investigation unit 75 of the feedback system, and correction processing is performed on a trial basis.

  The correction value calculation unit 78 repeats the operation of changing the amplitude / timing correction value until the correction value that minimizes the image power is found, and when the correction value that minimizes the image power is found, The signal is output to the amplitude / timing correction unit 61 of the signal system, and the amplitude and timing of the in-phase component and the quadrature component of the main signal are corrected in the previous stage of the quadrature modulator 64.

Further, in the prior art, since a digital quadrature demodulator is used as the feedback quadrature demodulator 74, no image leak occurs in the quadrature demodulator 74, and only image leak generated in the analog quadrature modulator 64 is detected. Image correction can be performed.
JP 2005-311710 A (FIG. 36, FIG. 37, [0181], etc.)

  However, the above-described conventional wireless transmission device has the following problems.

  The first problem is that it cannot be applied to orthogonal frequency division multiplexing (OFDM). The reason is that, since OFDM arranges subcarriers on both sides of a carrier frequency (center frequency), only image components cannot be measured in a state where subcarriers having a symmetrical relationship are transmitted.

  The second problem is that image leaks depending on frequency characteristics cannot be corrected sufficiently during wideband transmission using OFDM or the like. This is because the image component is not corrected for each subcarrier.

  A third problem is that a processing time for obtaining a correction value for correcting an image component is long. The reason is that, when obtaining the correction value, the amplitude and timing of the image power is minimized by trially changing the amplitude and timing of the in-phase component and the quadrature component of the feedback system. For this reason, it takes time to determine the correction value that minimizes the image power.

  An object of the present invention is to compensate for an image component generated in an analog quadrature modulator without interrupting a signal to be transmitted in a transmission method such as OFDM in which subcarriers are arranged on both sides of a carrier frequency and transmitted simultaneously. It is to provide a wireless transmission device.

  Another object of the present invention is to provide a radio transmission apparatus capable of reducing the transmission of unnecessary components depending on the frequency and outputting a highly accurate modulated signal during wideband transmission using OFDM or the like.

  Still another object of the present invention is to provide a wireless transmission device that shortens the processing time when determining a correction value of an image component and has good followability to fluctuations in the image component due to temperature changes and power supply voltage changes. There is.

  To achieve the above object, a wireless transmission device according to the present invention corrects an image component generated by a quadrature modulator, and delays a signal supplied to the wireless transmission device by a predetermined time. A delay adjusting unit for adding, a correction unit for adding the signal output from the delay adjusting unit and a correction value for canceling the image component, and an inverse Fourier transform of the corrected signal of the image component output from the correcting unit An inverse Fourier transform unit, a radio transmission unit for performing orthogonal modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform unit, and a baseband for the signal output from the radio transmission unit A radio receiving unit that performs frequency conversion and quadrature demodulation to a band signal, a Fourier transform unit that Fourier-transforms a signal output from the radio receiving unit, and the Fourier transform unit A signal et output, said input transmission signal and, from the signal outputted from the correcting unit, and a correction value calculation unit for calculating a correction value of the image component. With this configuration, the correction value calculated by the correction value calculation unit is output to the correction unit, and the image component generated by the quadrature modulator is corrected.

  The radio transmission apparatus according to the present invention is a radio transmission apparatus that corrects an image component generated by a quadrature modulator, and delay adjustment that delays an OFDM transmission signal supplied to the radio transmission apparatus by a predetermined time , A correction unit that adds the signal output from the delay adjustment unit and the correction value of the image component, and an inverse Fourier transform unit that performs inverse Fourier transform on the corrected signal of the image component output from the correction unit A radio transmission unit that performs orthogonal modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform unit, and a frequency to a baseband signal for the signal output from the radio transmission unit A radio receiving unit that performs transformation and orthogonal demodulation, a Fourier transform unit that Fourier-transforms a signal output from the radio receiving unit, and an output from the Fourier transform unit No. and includes the input transmission signal and, from the signal outputted from the correcting unit, and a correction value calculation unit for calculating a correction value of the image component for each subcarrier. With this configuration, the correction value calculated by the correction value calculation unit is output to the correction unit, and the image component generated by the quadrature modulator is corrected for each subcarrier.

  In the present invention, the correction value calculation unit uses the input transmission signal, a signal output from the correction unit, and a signal output from the Fourier transform unit to calculate a leak coefficient indicating a leak amount of the image component. It is preferable that a leak coefficient calculation unit to be calculated, a multiplier that multiplies the input transmission signal by the leak coefficient that is always output from the leak coefficient calculation unit and outputs the product to the correction unit.

  In the configuration as described above, the correction value calculation unit calculates the correction value from the input transmission signal, the feedback signal of the transmission signal supplied from the Fourier transform unit, and the corrected signal supplied from the correction unit. Even in OFDM in which subcarriers are arranged on both sides of a carrier frequency without using a special test signal, image components can be corrected while transmitting all subcarriers.

  Further, since the correction value of the image component is calculated for each subcarrier, and correction is performed using the correction value for each signal corresponding to the subcarrier in the previous stage of the inverse Fourier transform unit, the image depends on the frequency even during wideband transmission. Leakage can be corrected and a highly accurate modulation signal can be output.

  Furthermore, when calculating the correction value, it is not necessary to repeat the process or to change the correction value on a trial basis, and the correction value calculation unit calculates the optimal correction value by numerical calculation. Even if the image leak characteristics fluctuate, the image leak can be corrected in a short time, and the follow-up of the correction can be improved.

  The first effect is that an image component generated by an orthogonal modulator can be corrected while transmitting a signal to be transmitted in a transmission scheme such as OFDM in which subcarriers are arranged on both sides of a carrier frequency. The reason is that the correction value is calculated by numerical calculation while transmitting the signal to be transmitted from the input transmission signal, the feedback signal of the transmission signal supplied from the Fourier transform unit, and the corrected signal supplied from the correction unit. It is to do.

  The second effect is that an unnecessary component can be reduced for each subcarrier and a highly accurate modulated signal can be output by correcting the image component for each subcarrier during broadband transmission using OFDM or the like. The reason is that a correction value is calculated for each subcarrier and correction is performed for each subcarrier.

  The third effect is that by calculating the correction value of the image component by numerical calculation, it is possible to improve the follow-up of the correction with respect to the fluctuation of the image component accompanying the change of the temperature and the power supply voltage. The reason is that, when calculating the correction value, it is not necessary to perform an iterative process or an operation of changing the correction value on a trial basis.

Next, an embodiment of a wireless transmission device according to the present invention will be described with reference to the drawings.
(First embodiment)
First, the configuration of the first embodiment of the present invention will be described with reference to FIG.

  The present embodiment is a wireless transmission apparatus that performs inverse Fourier transform on a signal that has been subjected to modulation processing or weight multiplication, then orthogonally modulates the signal, converts the signal into an RF band signal, and outputs the signal. This radio transmission apparatus includes a delay adjustment unit 11, a correction unit 12, an inverse Fourier transform unit 13, a radio transmission unit 14 having a quadrature modulator, a radio reception unit 21 having a quadrature demodulator, and a Fourier transform unit 22. And a correction value calculation unit 23. Among these, the radio | wireless receiving part 21, the Fourier-transform part 22, and the correction value calculation part 23 comprise the feedback system.

The delay adjustment unit 11 delays the input transmission signal composed of the in-phase component and the quadrature component modulated and weight-multiplied by the processing unit (not shown) in the previous stage by a predetermined time, and then outputs the delayed signal to the correction unit 12. The delay time in the delay adjustment unit 11 is the correction value B2 _{s, k} (s = 0, 1,..., N−1: N is the number of subcarriers after the input transmission signal is supplied in the correction value calculation unit 23. k = 0, 1,..., K−1: K is preferably the same as the time for calculating the number of transmission signals in the time direction.

The correction unit 12 adds the transmission signal X _{s, k} supplied from the delay adjustment unit 11 and the correction value B2 _{s, k} supplied from the correction value calculation unit 23 for each subcarrier, and adds the result XC _{s, k} is output to the inverse Fourier transform unit 13 and the correction value calculation unit 23, respectively.

  The inverse Fourier transform unit 13 performs inverse Fourier transform on the corrected signal supplied from the correction unit 12 and outputs the result to the wireless transmission unit 14. The inverse Fourier transform unit 13 preferably performs inverse fast Fourier transform from the viewpoint of reducing the amount of calculation.

  The wireless transmission unit 14 includes an analog quadrature modulator, performs digital / analog conversion on the signal supplied from the inverse Fourier transform unit 13, and performs quadrature modulation and frequency conversion from a baseband signal to an RF band signal. The configuration to perform is optimal. The signal frequency-converted to the RF band signal by the wireless transmitter 14 is distributed and output to the feedback wireless receiver 21.

  The radio reception unit 21 includes a digital quadrature demodulator, frequency-converts the RF band signal supplied from the radio transmission unit 14 into a baseband signal, performs analog / digital conversion, digital quadrature demodulation, and Fourier transform The configuration for outputting to the unit 22 is optimal. This is because by performing quadrature demodulation by digital processing, occurrence of image leak in the quadrature demodulator can be reduced, and only image leak in the quadrature modulator can be observed.

The Fourier transform unit 22 performs Fourier transform on the signal supplied from the wireless reception unit 21, and outputs the signal F _{s, k} obtained by Fourier transform to the correction value calculation unit 23. The Fourier transform unit 22 preferably performs fast Fourier transform from the viewpoint of reducing the amount of calculation.

The correction value calculation unit 23 calculates the correction value B2 _s, from the signal F _{s, k} supplied from the Fourier transform unit 22, the input transmission signal X _{s, k,} and the signal XC _{s, k} supplied from the correction unit 12 _{. k} is calculated and output to the correction unit 12.

  Next, the configuration of the correction value calculation unit 23 in FIG. 1 will be described with reference to FIG.

2 corrects from the input transmission signal X _{s, k} , the signal F _{s, k} supplied from the Fourier transform unit 22 _, and the signal XC _{s, k} supplied from the correction unit 12. The value B2 _{s, k} is calculated and includes a leak coefficient calculation unit 231 and a multiplier 232.

The leak coefficient calculation unit 231 calculates the leak coefficient B _{s, j} (j = 0, 1,...) From the signal XC _{s, k} supplied from the correction unit 12 and F _{s, k} supplied from the Fourier transform unit 22. , J−1: J is the number of leak coefficients), and the leak coefficient B _{s, j} is always output to the multiplier 232.

The multiplier 232 multiplies the input transmission signal X _{s, k} by the leak coefficient B _{s, j} supplied from the leak coefficient calculation unit 231 to obtain a correction value B2 _{s, k} , and the correction value B2 _{s, k.} Is output to the correction unit 12.

  Next, the configuration of the leak coefficient calculation unit 231 in FIG. 2 will be described with reference to FIG.

The leak coefficient calculation unit 231 illustrated in FIG. 3 leaks from the input transmission signal X _{s, k} , the signal F _{s, k} supplied from the Fourier transform unit 22 _, and the signal XC _{s, k} supplied from the correction unit 12. The coefficient B _{s, j} is calculated, and includes a delay adjustment unit 2311, a control unit 2312, storage units 2313-1 and 213, and a calculation unit 2314.

The delay adjustment unit 2311 delays the input transmission signal X _{s, k} for a predetermined time and outputs the delayed signal to the control unit 2312. The delay time in the delay adjustment unit 2311 is preferably the total value of the delay time in the delay adjustment unit 11 and the processing time in the correction unit 12.

The control unit 2312 refers to the input transmission signal X _{s, k} supplied from the delay adjustment unit 2311 and, for example, a timer provided in the control unit 2312, and sends timing control signals to the storage unit 2313-1 and the calculation unit 2314, respectively. Is output.

The storage unit 2313-1 holds the signal XC _{s, k} supplied from the correction unit 12 according to the timing control signal notified from the control unit 2312 _, and outputs the signal XC _{s, k} to the calculation unit 2314.

The computing unit 2314 follows the timing control signal notified from the control unit 2312 _, and leaks the coefficient B _s from XC _{s, k} supplied from the storage unit 2313-1 and F _{s, k} supplied from the Fourier transform unit 22. _{, J} (j = 0, 1,..., J-1: J is the number of leak coefficients) is obtained by numerical calculation, and the leak coefficient B _{s, j} is output to the storage unit 2313-2.

The storage unit 2313-2 holds the leak coefficient B _{s, j} supplied from the calculation unit 2314 _, and always outputs the stored leak coefficient B _{s, j} to the multiplier 232.

  Next, the configuration of multiplier 232 in FIG. 2 will be described with reference to FIG.

The multiplier 232 shown in FIG. 4 includes N multipliers 2321-1,. . . , N, and the input transmission signal X _{s, k} (X _{0, k} , X _{1, k} , X _{2, k} ,..., X _{N−1, k} ) and the storage unit 2313-2. The leakage coefficient B _{s, j} (B _{0, j} , B _{1, j} , B _{2, j} ,..., B _{N−1, j} ) is multiplied for each subcarrier, and the multiplication result B2 _{s, k} (B2 _{0, k} , B2 _{1, k} , B2 _{2, k} ,..., B2 _{N−1, k} ) are output to the correction unit 12.

  Next, a configuration example of the wireless transmission unit 14 in FIG. 1 will be described with reference to FIG.

  5 is preferably composed of a digital / analog (D / A) converter 141, an oscillator 142, and an analog quadrature modulator 143.

  The D / A conversion unit 141 performs digital / analog conversion on the signal supplied from the inverse Fourier transform unit 13 and outputs the converted analog signal XC (t) to the analog quadrature modulator 143.

  The oscillator 142 generates an RF band carrier frequency signal and outputs the carrier frequency signal to the analog quadrature modulator 143.

  The analog quadrature modulator 143 receives the analog signal XC (t) supplied from the D / A converter 141 and the carrier frequency signal supplied from the oscillator 142, and performs quadrature modulation and quadrature modulation frequency-converted to the RF band. A post-RF signal S (t) is generated. The RF signal S (t) is distributed and output to the feedback radio receiver 21 and the power amplifier (not shown) in the subsequent stage.

  Next, the configuration of the analog quadrature modulator 143 in FIG. 5 will be described with reference to FIG.

The analog quadrature modulator 143 shown in FIG. 6 is supplied from the oscillator 142 with the in-phase component XC _i (t) and the quadrature component XC _q (t) of the analog signal XC (t) supplied from the D / A converter 141. A carrier frequency sine wave cosω _c t is input, quadrature modulation is performed to perform frequency conversion from the baseband to the RF band, and an RF signal S (t) after quadrature modulation is generated. 1, 1431-2, a phase converter 1432, and an adder 1433. In FIG. 6, an analog signal XC (t) supplied from the D / A converter 141 includes an in-phase component XC _i (t) and a quadrature component XC _q (t), and is represented by the following equation (1). .

XC (t) = XC _i (t) + jXC _q (t) (1)
The multiplier 1431-1 multiplies the in-phase component XC _i (t) of the analog signal XC (t) supplied from the D / A converter 141 and the carrier frequency signal (cos ω _c t) supplied from the oscillator 142. The signal (XC _i (t) · cos ω _c t) is output to the adder 1433.

The phase converter 1432 generates a signal (−sin ω _c t) obtained by phase-converting the carrier frequency signal (cos ω _c t) supplied from the oscillator 142 by π / 2. The generated signal is output to the multiplier 1431-2.

The multiplier 1431-2 receives the quadrature component XC _q (t) of the analog signal XC (t) supplied from the D / A converter 141 and the signal (−sinω _c t) supplied from the phase converter 1432. Multiplication is performed, and the signal (−XC _q (t) · sin ω _c t) is output to the adder 1433.

The adder 1433, a signal supplied from the multiplier _{1431-1 (XC i (t) ·} cosω c t) and the signal supplied from the multiplier _{1431-2 (-XC q (t) ·} sinω c t) Are added to generate an RF signal S (t) after quadrature modulation. The RF signal S (t) after quadrature modulation is expressed by the following equation (2).

S (t) = XC _i (t) · cos ω _c t−XC _q (t) · sin ω _c t (2)
Next, a configuration example of the wireless reception unit 21 in FIG. 1 will be described with reference to FIG.

  7 is preferably composed of an oscillator 211, a multiplier 212, an analog / digital (A / D) converter 213, and a digital quadrature demodulator 214.

  The oscillator 211 generates a carrier frequency signal and outputs it to the multiplier 212.

  The multiplier 212 multiplies the quadrature-modulated RF signal S (t) supplied from the wireless transmission unit 14 and the carrier frequency signal supplied from the oscillator 211 to thereby convert the RF band signal into a baseband signal. And the converted baseband signal is output to the A / D converter 213.

  The A / D converter 213 converts the baseband analog signal supplied from the multiplier 212 into a digital signal, and outputs the converted digital signal to the digital quadrature demodulator 214.

  The digital quadrature demodulator 214 performs quadrature demodulation on the digital signal supplied from the A / D conversion unit 213 and outputs the digital signal to the Fourier transform unit 22.

  Next, the overall operation of this embodiment will be described with reference to the flowchart of FIG. The flowchart of FIG. 8 is an operation example showing the flow of (a) main signal generation and (b) leak coefficient calculation.

  First, (a) the flow of main signal generation will be described.

First, the delay adjustment unit 11 delays the input transmission signal X _{s, k} by a predetermined time, and then outputs it to the correction unit 12 (step A1).

Next, the correction unit 12 adds the input transmission signal X _{s, k} supplied from the delay adjustment unit 11 and the correction value B2 _{s, k} supplied from the correction value calculation unit 23 for each subcarrier, and the addition result XC _{s, k} is output to the inverse Fourier transform unit 13 and the correction value calculation unit 23 (step A2).

  Next, the inverse Fourier transform unit 13 performs inverse Fourier transform on the corrected signal supplied from the correction unit 12 and outputs the signal to the wireless transmission unit 14 (step A3).

  Then, the wireless transmission unit 14 performs digital / analog conversion on the signal supplied from the inverse Fourier transform unit 13, and performs frequency conversion from the quadrature modulation and baseband signal to the RF band signal (step A4).

  Next, the flow of (b) leak coefficient calculation will be described.

First, the leak coefficient calculation unit 231 refers to the input transmission signal X _{s, k} to determine whether a predetermined determination formula is satisfied. If the determination formula is satisfied, the corrected signal output from the correction unit 12 is determined. XC _{s, k} is held and the process proceeds to step B2. If the determination formula is not satisfied, the process waits until a signal that satisfies the determination formula is input (step B1).

  Next, the inverse Fourier transform unit 13 performs inverse Fourier transform on the corrected signal supplied from the correction unit 12 and outputs the signal to the wireless transmission unit 14 (step B2).

  Next, the wireless transmission unit 14 performs digital / analog conversion on the signal supplied from the inverse Fourier transform unit 13, performs orthogonal modulation, and converts the frequency from a baseband signal to an RF band signal (step B3).

  Next, the radio reception unit 21 frequency-converts the RF band signal supplied from the radio transmission unit 14 into a baseband signal, performs analog / digital conversion, performs digital quadrature demodulation, and outputs the result to the Fourier transform unit 22 ( Step B4).

  Next, the Fourier transform unit 22 performs a Fourier transform on the signal supplied from the wireless reception unit 21 and outputs it to the correction value calculation unit 23 (step B5).

Next, the leak coefficient calculation unit 231 calculates the leak coefficient B _{s, k} from the signal F _{s, k} supplied from the Fourier transform unit 22 and the signal XC _{s, k} supplied from the correction unit 12 and held in step B1 _{. j} is calculated (step B6).

  Next, regarding the operation of the present embodiment, the operation of the correction value calculation unit 23 will be described with reference to the flowchart of FIG. The flowchart of FIG. 10 is an operation example in which a leak coefficient for one time is calculated (updated) for a certain subcarrier and correction is performed.

  As a precondition, FIG. 9 shows the relationship between the variable s indicating the subcarrier number of the signal and the subcarrier position when the horizontal axis in the output of the quadrature modulator is the frequency. Hereinafter, the subcarrier number s is defined and described so that the value increases in the direction from the low frequency to the high frequency. In addition, the signal of subcarrier number s and the signal of subcarrier number N-1-s are described as having a symmetrical relationship with respect to the carrier frequency, that is, a relationship in which the image components influence each other.

First, the control unit 2312 in the leak coefficient calculation unit 231 determines whether the input transmission signal X _{s, k} supplied from the delay adjustment unit 2311 satisfies the following determination formula (3) (step C1).

Xs _{, k0} * _{XN -1-s, k1} ≠ Xs _{, k1} * _{XN-1-s, k0}
Xs _{, k1} * _{XN-1-s, k0} ≠ Xs _{, k0} * _{XN -1-s, k1} (3)
Here, k0 and k1 are arbitrary k values (transmission signals in different time directions). In addition, as a signal used in the determination formula, XC _{s, k} supplied from the correction unit 12 can be used instead of X _{s, k} , but the input transmission signal X _{s, k} is preferably used. The reason is that when the input transmission signal Xs, k is used in the determination formula, when the correction value is obtained, the amount of change in signal between transmission signals in different time directions becomes large, and a highly accurate correction value is obtained. It is.

As a result of the determination, if the input transmission signal Xs _{, k} does not satisfy the determination formula (3) (NO), step C1 is repeated again, and the process waits until a signal that satisfies the determination formula (3) is input. On the other hand, when the input transmission signal X _{s, k} satisfies the determination formula (3) (YES), the control unit 2312 outputs a timing control signal to the storage unit 2313-1 and is supplied from the correction unit 12. XC _{s, k0} , XC _{s, k1} , XC _{N-1-s, k0} , XC _{N-1-s, k1} are held in the storage unit 2313-1 (step C2).

  Next, the control unit 2312 waits for a time during which the transmission signal is fed back via the inverse Fourier transform unit 13, the wireless transmission unit 14, the wireless reception unit 21, and the Fourier transform unit 22 (step C3).

Next, after waiting in Step C3, the control unit 2312 outputs a timing control signal to the calculation unit 2314, and the calculation unit 2314 calculates the leak coefficient B _{s, j according} to the following equation (4) (Step C4). Here, α _{s, j} is a transmission coefficient of a desired subcarrier signal, and β _{s, j} is a transmission coefficient of a subcarrier signal serving as an image component.

B _{s, j} = β _{s, j} / α _{s, j} (4)
α _{s, j} = (F _{s, k0} · XCN _{-1−s, k1−} F _{s, k1} · XCN _{−1−s, k0} ) / (XC _{s, k0} · _{XCN −1−s, k1} − XC _{s, k1} · XC _{N-1-s, k0} )
_{β s, j = (F s} , k0 · XC s, k1 -F s, k1 · XC s, k0) / (XC s, k1 · XC N-1-s, k0 -XC s, k0 · XC N- _{1-s, k1} )
α _{s, j} and β _{s, j} can be derived from the following simultaneous equations.

_{F s, k0 = α s,} j · XC s, k0 + β s, j · XC N-1-s, k0
F _{s, k1} = α _{s, j} · XC _{s, k1} + β _{s, j} · XC _{N-1-s, k1
Further, F s, k, XC s} , k, XC N-1-s, k, α s, j, β s, j, B s, the relationship of _j is defined as shown in Figure 11, beta _s, The relationship between _j , α _{s, j} and B _{s, j} is as shown in the following equation.

β _{s, j} = α _{s, j} · B _{s, j}
The leak coefficient B _{s, j} calculated by the above equation (4) is stored in the storage unit 2313-2.

Then, the multiplier 232 uses the signal B _{s, j} that is always supplied from the storage unit 2313-2 and the transmission signal X _{N-1-s, k,} and the correction value B2 _{s, k} is calculated.

B2 _{s, k} = −B _{s, j ×} X _{N-1-s, k} (5)
The correction value B2 _{s, k} calculated by the multiplier 232 is output to the correction unit 12. The correction unit 12 adds the correction value B2 _{s, k} supplied from the multiplier 232 and the signal X _{s, k} supplied from the delay adjustment unit 11 according to the following equation (6), and the corrected signal XC _{s, Find k} . In this way, correction processing is performed.

XC _{s, k} = X _{s, k} + B2 _{s, k} (6)
Next, with respect to the operation of this embodiment, an operation example in which the operation example of the flowchart of FIG. 10 is applied to all subcarriers to calculate the leak coefficients B _{s, j} of all subcarriers will be described with reference to FIG. explain.

  First, the control unit 2312 in the leak coefficient calculation unit 231 assigns 0 to a variable s indicating a subcarrier number, and initializes the variable s (step D1).

Next, the control unit 2312 calculates the leak coefficient B _{s, j} for the subcarrier of subcarrier number s according to the operation example of FIG. 10 (step D2).

Next, the control unit 2312 determines whether the variable s is smaller than N−1 (step D3). As a result, when the variable s is smaller than N−1 (YES), 1 is added to the variable s, the process proceeds to Step D2, and Step D2 to Step D3 are repeated (Step D4). On the other hand, when the variable s is not smaller than N−1 (NO), the operation of calculating the leak coefficient B _{s, j} is terminated.

FIG. 13 shows the transition of the variable s in the operation example of the flowchart of FIG. This figure shows an operation example in which the variable s is increased from 0 to N−1 by one step and the leak coefficient B _{s, j} with N subcarriers is calculated.

FIG. 14 shows an input transmission signal X _{s, k} (X _{s, 0} , X _{s, 1} , X _{s, 2} ,..., X _{s, K-1} ) and an output signal X _{s, k (X s, 0, X} s, 1, X s, 2, ..., X s, K-1) , the output signal _B2 s of the correction value calculation unit _{23, k (B2 s, 0} , B2 s _{, 1} , B2 _{s, 2} ,..., B2 _{s, K−1} ). As shown in the figure, it is preferable that the delay processing unit 11 absorbs the processing time in the multiplier 232 by delaying the transmission signal X _{s, k} by the processing time of the multiplier 232.

15 illustrates an output signal B _{s, j} (j = 0, 1, 2,..., J−1) of the arithmetic unit 2314 and an output signal B _{s, j} (j = 0, 1, 2,..., J-1), the output signal B2 _{s, k} (k = 0, 1, 2,..., K-1) of the multiplier 232, and the output signal XC of the correction unit 12. The timing with _{s, k} (k = 0, 1, 2,..., K−1) is illustrated. As shown in the figure, the storage unit 2313-2 holds the leak coefficient B _{s, j} supplied from the calculation unit 2314 and always outputs it to the multiplier 232.

  16 and 17 illustrate the effect of the present invention by computer simulation results. FIG. 16 is a constellation showing a symbol arrangement of a quadrature phase shift keying (QPSK) signal simulating a state where an image leak of 10% is generated at the amplitude level in the quadrature modulator. FIG. 17 is a constellation showing a symbol arrangement of a QPSK signal when the image leak in the quadrature modulator is corrected by the method of the present invention. According to this, in FIG. 16 when correction is not performed, the modulation accuracy is deteriorated due to the influence of the image leak, whereas in FIG. 17 when correction is performed, symbol variation is reduced, and the effect of correcting image leak is confirmed. it can.

As described above, according to the present embodiment, the correction value calculation unit 23 corrects the input transmission signal X _{s, k} , the feedback signal F _{s, k of the} transmission signal supplied from the Fourier transform unit 22 _, and the correction. Since the correction value B2 _{s, k} is calculated from the corrected signal XC _{s, k} supplied from the unit 12, it is not necessary to use a special test signal, and even in OFDM in which subcarriers are arranged on both sides of the carrier frequency The image component can be corrected while transmitting all subcarriers.

  In addition, according to the present embodiment, the correction value of the image component is calculated for each subcarrier, and correction is performed using the correction value for each signal corresponding to the subcarrier in the previous stage of the inverse Fourier transform unit 13, so that during broadband transmission Also, the image leak depending on the frequency can be corrected and a highly accurate modulation signal can be output.

In addition, according to the present embodiment, when calculating the correction value, it is not necessary to perform an iterative process or an operation of changing the correction value on a trial basis, and the correction value calculation unit 23 performs an optimal correction value B2s _{, Since k} is calculated, the image leak can be corrected in a short time even if the characteristics of the image leak fluctuate due to changes in the temperature and the power supply voltage, and the followability of the correction can be improved.

  Furthermore, in this embodiment, the following effects can also be obtained.

That is, in this embodiment, as shown in FIG. 1, the correction value B2 _{s, k} is calculated from the output signal XC _{s, k} of the correction unit 12 and the output signal F _{s, k of the} Fourier transform unit 22, As an example of a specific correction value calculation method, the output signal XC _{s, k} of the correction unit 12 and the output signal F _{s, k of the} Fourier transform unit 22 have different OFDM symbols on the time axis and symmetrical relations on the frequency axis. The correction value is calculated from six subcarrier signals in

That is, in the present embodiment, as illustrated in the above-described equation (4) and the like, the output signal XC _{s, k} of the correction unit 12 and the output signal F _{s, k} of the Fourier transform unit 22 are different on the time axis. A correction value B2 _{s, k} is calculated based on the fluctuation amount of the transmission signal from the symbol and the subcarrier signal that is symmetric about the frequency axis. Therefore, the correction value can be calculated correctly even if the output signal XC _{s, k of} the correction unit 12 and the output signal F _{s, k of the} Fourier transform unit 22 are not normalized. Thus, there is an advantage that an accurate correction value of the distortion component in the quadrature modulator can be calculated without depending on the distortion-free transfer characteristic from the wireless transmission unit 14 to the wireless reception unit 21.
(Second Embodiment)
Next, the configuration of the second exemplary embodiment of the present invention will be described with reference to FIG.

The present embodiment is a wireless transmission device that performs inverse Fourier transform on a signal that has been modulated and weight-multiplied, then orthogonally modulates the signal, converts it into an RF band signal, and outputs the signal. The configuration of the first embodiment is modified. is there. The difference from the first embodiment is that when the leak coefficient B _{s, j} is _obtained , instead of using the corrected signal XC _{s, k} which is the output signal of the correction unit 42, input transmission is performed in the correction value calculation unit 53. The leak coefficient is calculated by adding the signal X _{s, k} and the correction value B2 _{s, k} to obtain the corrected signal XC _{s, k} .

  18 includes a delay adjustment unit 41, a correction unit 42, an inverse Fourier transform unit 43, a radio transmission unit 44, a radio reception unit 51, a Fourier transform unit 52, and a correction value calculation unit 53. It is the structure provided with.

The delay adjustment unit 41 delays the input transmission signal by a predetermined time, and then outputs it to the correction unit 42. The delay time in the delay adjustment unit 41 is preferably the same as the time for calculating the correction value B2 _{s, k} in the correction value calculation unit 53.

The correction unit 42 adds the transmission signal X _{s, k} supplied from the delay adjustment unit 41 and the correction value B2 _{s, k} supplied from the correction value calculation unit 53 for each subcarrier, and adds the result XC _{s, k} is output to the inverse Fourier transform unit 43.

  The inverse Fourier transform unit 43 performs inverse Fourier transform on the corrected signal supplied from the correction unit 42 and outputs the result to the wireless transmission unit 44.

  The wireless transmission unit 44 is optimally configured to perform digital / analog conversion on the signal supplied from the inverse Fourier transform unit 43, and to perform orthogonal modulation and frequency conversion from a baseband signal to an RF band signal. The signal frequency-converted to the RF band signal is output to the feedback wireless receiver 51.

  The radio receiving unit 51 is optimally configured to frequency-convert the RF band signal supplied from the radio transmitting unit 44 into a baseband signal, perform analog / digital conversion, perform digital quadrature demodulation, and output to the Fourier transform unit 52 It is.

The Fourier transform unit 52 performs a Fourier transform on the signal supplied from the wireless reception unit 51 and outputs a signal F _{s, k} obtained by the Fourier transform to the correction value calculation unit 53.

The correction value calculation unit 53 calculates a correction value from the signal F _{s, k} supplied from the Fourier transform unit 52 and the input transmission signal X _{s, k} and outputs the correction value to the correction unit 42.

  Next, the configuration of the correction value calculation unit 53 in FIG. 18 will be described with reference to FIG.

The correction value calculation unit 53 shown in FIG. 19 calculates the correction value B2 _{s, k} from the input transmission signal X _{s, k} and the signal F _{s, k} supplied from the Fourier transform unit 52. The leak coefficient calculation unit 531 and a multiplier 532.

The leak coefficient calculation unit 531 calculates the leak coefficient B _{s, j} from the input transmission signal X _{s, k} , the signal B2 _{s, k} supplied from the multiplier 532 _, and F _{s, k} supplied from the Fourier transform unit 52. Is obtained by numerical calculation, and the leak coefficient B _{s, j} is always output to the multiplier 532.

The multiplier 532 multiplies the input transmission signal X _{s, k} by the leak coefficient B _{s, j} supplied from the leak coefficient calculation unit 531, and the signal B 2 _{s, k} is corrected by the correction unit 42, the leak coefficient calculation unit 531, and the like. To each output.

  Next, the configuration of the leak coefficient calculation unit 531 in FIG. 19 will be described with reference to FIG.

The leak coefficient calculation unit 531 shown in FIG. 20 leaks from the input transmission signal X _{s, k} , the signal F _{s, k} supplied from the Fourier transform unit 52 _, and the signal B 2 _{s, k} supplied from the multiplier 532. The coefficient B _{s, j} is calculated, and includes a delay adjustment unit 5311, a control unit 5312, an addition unit 5313, storage units 5314-1 and 531, and a calculation unit 5315.

The delay adjustment unit 5311 delays the input transmission signal X _{s, k} by a predetermined time, and outputs the signal X _{s, k} to the addition unit 5313 and the control unit 5312, respectively. The delay time in the delay adjustment unit 5311 is preferably equal to that of the delay adjustment unit 41.

The adding unit 5313 adds the signal X _{s, k} supplied from the delay adjusting unit 5311 and the signal B2 _{s, k} supplied from the multiplying unit 532 _, and sends the signal XC _{s, k} to the storage unit 5314-1. Output.

The control unit 5312 refers to the signal X _{s, k} supplied from the delay adjustment unit 5311 and, for example, a timer provided in the control unit 5312, and outputs timing control signals to the storage unit 5314-1 and the calculation unit 5315, respectively. To do.

The storage unit 5314-1 holds the signal XC _{s, k} supplied from the addition unit 5313 in accordance with the timing control signal notified from the control unit 5312, and outputs the signal XC _{s, k} to the calculation unit 5315.

The arithmetic unit 5315 calculates a leak coefficient from the signal XC _{s, k} supplied from the storage unit 5314-1 and the signal F _{s, k} supplied from the Fourier transform unit 52 according to the timing control signal notified from the control unit 5312. B _{s, j} is generated by numerical calculation, and the leak coefficient B _{s, j} is output to the storage unit 5314-2.

The storage unit 5314-2 holds the leak coefficient B _{s, j} supplied from the calculation unit 5315 and always outputs the stored leak coefficient B _{s, j} to the multiplier 532.

  Next, regarding the operation of the present embodiment, the operation of the correction value calculation unit 53 will be described with reference to the flowchart of FIG. The flowchart of FIG. 21 is an operation example in which one leak coefficient is calculated (updated) for a certain subcarrier and correction is performed.

  First, the control unit 5312 in the leak coefficient calculation unit 531 determines whether the input transmission signal Xs, k supplied from the delay adjustment unit 5311 satisfies the determination formula (3) (step E1).

As a result, when the determination formula is not satisfied (NO), the control unit 5312 repeats Step E1 again and waits until a signal satisfying the determination formula is input. On the other hand, when the input transmission signal X _{s, k} supplied from the delay adjustment unit 5311 satisfies the determination formula (YES), the control unit 5312 outputs a timing control signal to the storage unit 5314-1 and adds the unit 5313. The signals XC _{s, k0} , XC _{s, k1} , XC _{N-1-s, k0} , XC _{N-1-s, k1} supplied from are stored in the storage unit 5314-1 (step E2). Note that the output timing of the timing control signal output to the storage unit 5314-1 may be adjusted in consideration of the processing time in the addition unit 5313.

  Next, the control unit 5312 waits for a time during which the transmission signal is fed back via the inverse Fourier transform unit 43, the wireless transmission unit 44, the wireless reception unit 51, and the Fourier transform unit 52 (step E3).

Next, after waiting in step E3, the control unit 5312 outputs a timing control signal to the calculation unit 5315, and the calculation unit 5315 calculates the leak coefficient B _{s, j} according to the calculation formula (4). The calculated leak coefficient B _{s, j} is stored in the storage unit 5314-2 and is always output to the multiplier 532 (step E 4). The correction value B2 _{s, k} calculated by the multiplier 532 is output to the correction unit 42. The correction unit 42 adds the correction value B2 _{s, k} supplied from the multiplier 532 and the signal supplied from the delay adjustment unit 41 to obtain a corrected signal XC _{s, k} . In this way, correction processing is performed.

  Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained.

  In the first and second embodiments, the correction units 12 and 42 are provided with N adders corresponding to N subcarriers. However, for example, N subcarrier data is time-divisionally divided. When multiplexing, only one adder is required. That is, the wireless transmission devices of the first and second embodiments may have any number of adders provided in the correction units 12 and 42.

  In the first and second embodiments, the operation of obtaining and correcting the leak coefficient for one time has been exemplified. However, since the leak coefficient varies depending on the temperature and the power supply voltage, the leak coefficient is periodically calculated (updated). ) Is preferable. That is, the number of times of obtaining the leak coefficient may be any number.

  Further, in the first embodiment, an example is shown in which the leak coefficients are obtained in order of subcarriers from subcarrier numbers 0 to N-1, but there is no restriction on the order of subcarriers for obtaining the leak coefficients.

  As mentioned above, although each embodiment of the present invention was described in detail, the present invention is not limited to each of the above-described exemplary embodiments, and those skilled in the art will understand the contents of the claims. Based on the above, various modifications and changes can be made without departing from the scope of the present invention, and these modifications and changes also belong to the scope of the present invention.

  For example, the wireless transmission device according to the present invention can be implemented using a wireless transmission method or a wireless transmission control program. In this case, each unit (delay adjustment unit, correction unit, inverse Fourier transform unit, radio transmission unit, radio reception unit, Fourier transform unit, and correction value calculation unit) that configures the wireless transmission device includes each component that configures the wireless transmission method. Steps (delay adjustment step, correction step, inverse Fourier transform step, wireless transmission step, wireless reception step, Fourier transform step, and correction value calculation step) or each function of the computer realized by the wireless transmission control program (delay adjustment) (Function, correction function, inverse Fourier transform function, wireless transmission function, wireless reception function, Fourier transform function, and correction value calculation function).

  Further, at least a part of functions of each unit (delay adjustment unit, correction unit, inverse Fourier transform unit, radio transmission unit, radio reception unit, Fourier transform unit, and correction value calculation unit) constituting the wireless transmission device according to the present invention. Can be realized by a processor (CPU: Central Processing Unit) operating under program control. In this case, the processor executes the instructions of the program code stored in a memory such as a ROM (Read Only Memory), so that at least a part of the functions are realized. Such a program code and a recording medium for recording the program code are included in the category of the present invention.

  The present invention can be applied to a radio transmission apparatus having a quadrature modulator.

It is a block diagram which shows the structure of the radio | wireless transmitter which concerns on the 1st Embodiment of this invention. It is a block diagram which shows one structural example of the correction value calculation part shown in FIG. FIG. 3 is a block diagram illustrating a configuration example of a leak coefficient calculation unit illustrated in FIG. 2. FIG. 3 is a block diagram illustrating a configuration example of a multiplier illustrated in FIG. 2. FIG. 2 is a block diagram illustrating a configuration example of a wireless transmission unit illustrated in FIG. 1. FIG. 6 is a block diagram illustrating a configuration example of a quadrature modulator illustrated in FIG. 5. FIG. 2 is a block diagram illustrating a configuration example of a wireless reception unit illustrated in FIG. 1. FIG. 4 is a diagram for explaining the operation of the first embodiment of the present invention, where (a) is a diagram for explaining the flow of main signal processing, and (b) is a diagram for explaining the flow of leak coefficient calculation processing. In the 1st Embodiment of this invention, it is a schematic diagram which shows the relationship between a subcarrier position and a subcarrier number. It is a figure explaining operation | movement of the 1st Embodiment of this invention, and is a flowchart which shows the process of a correction value calculation part. It is a block diagram which shows the model used for calculation of the leak coefficient shown in FIG. It is a figure explaining the operation | movement of the 1st Embodiment of this invention, and is a flowchart which shows the process in the case of calculating the leak coefficient of all the subcarriers. It is a schematic diagram which shows the transition of the subcarrier number s in the operation example shown in FIG. In the 1st Embodiment of this invention, it is a schematic diagram which shows the timing of an input transmission signal, a delay process part output signal, and a correction value calculation part output signal. In the 1st Embodiment of this invention, it is a schematic diagram which shows the timing of a leak coefficient calculation part output signal, a memory | storage part output signal, a multiplier output signal, and a correction | amendment part output signal. It is a figure which shows the computer simulation result which shows the effect of this invention, and is a constellation which shows the symbol arrangement | positioning of the QPSK signal which simulated the state which the image leak has generate | occur | produced in the quadrature modulator. It is a figure which shows the figure of the computer simulation result which shows the effect of this invention, and is a constellation which shows the symbol arrangement | positioning of the QPSK signal at the time of correct | amending the image leak which generate | occur | produces in a quadrature modulator with the method of this invention. It is a block diagram which shows the structure of the radio | wireless transmitter which concerns on the 2nd Embodiment of this invention. FIG. 19 is a block diagram illustrating a configuration example of a correction value calculation unit illustrated in FIG. 18. FIG. 20 is a block diagram illustrating a configuration example of a leak coefficient calculation unit illustrated in FIG. 19. It is a figure explaining operation | movement of the 2nd Embodiment of this invention, and is a flowchart which shows the process of a correction value calculation part. It is a schematic diagram explaining the mode of generation | occurrence | production of an image component in the orthogonal modulator of the wireless transmitter of a prior art example. It is a block diagram which shows the structure of the radio | wireless transmitter of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Delay adjustment part 12 Correction | amendment part 13 Inverse Fourier transform part 14 Wireless transmission part 21 Wireless reception part 22 Fourier transform part 23 Correction value calculation part 231 Leak coefficient calculation part 232 Multiplier 2311 Delay adjustment part 2312 Control part 2313-1, 2313- 2 Storage Unit 2314 Operation Units 2321-1 to 2321 -N Multiplier 141 Digital / Analog Conversion Unit 142 Oscillator 143 Analog Quadrature Modulators 1431-1 and 1431-2 Multiplier 1432 Phase Converter 1433 Adder 211 Oscillator 212 Multiplier 213 Analog / digital conversion unit 214 Digital quadrature demodulator 31-1, 31-2 Multiplier 32 Adder 41 Delay adjustment unit 42 Correction unit 43 Inverse Fourier transform unit 44 Wireless transmission unit 51 Wireless reception unit 52 Fourier transform unit 53 Calculation of correction value Unit 531 Leak Coefficient Calculation Unit 532 Multiplier 53 1 Delay adjustment unit 5312 Control unit 5313 Addition unit 5314-1, 5314-2 Storage unit 5315 Operation unit 61 Amplitude / timing correction unit 62 Digital / analog conversion unit 63, 71 Oscillator 64 Analog quadrature modulator 72 Multiplier 73 Analog / digital Conversion unit 74 Digital quadrature demodulator 75 Amplitude / timing investigation unit 76 Fast Fourier transform unit 77 Image power analysis unit 78 Correction value calculation unit

Claims (16)

A wireless transmission device that corrects an image component generated by a quadrature modulator,
A delay adjusting unit that delays a transmission signal supplied to the wireless transmission device by a predetermined time;
A correction unit that adds the signal output from the delay adjustment unit and a correction value that cancels the image component;
An inverse Fourier transform unit for performing an inverse Fourier transform on the corrected signal of the image component output from the correction unit;
A radio transmission unit that performs orthogonal modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform unit;
A radio reception unit that performs frequency conversion and orthogonal demodulation to a baseband signal for the signal output from the radio transmission unit;
A Fourier transform unit for Fourier transforming a signal output from the wireless reception unit;
A correction value calculation unit that calculates a correction value of the image component from a signal output from the Fourier transform unit, the input transmission signal, and a signal output from the correction unit. Wireless transmission device. A wireless transmission device that corrects an image component generated by a quadrature modulator,
A delay adjusting unit that delays the OFDM transmission signal supplied to the wireless transmission device by a predetermined time;
A correction unit that adds the signal output from the delay adjustment unit and the correction value of the image component;
An inverse Fourier transform unit for performing an inverse Fourier transform on the corrected signal of the image component output from the correction unit;
A radio transmission unit that performs orthogonal modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform unit;
A radio reception unit that performs frequency conversion and orthogonal demodulation to a baseband signal for the signal output from the radio transmission unit;
A Fourier transform unit for Fourier transforming a signal output from the wireless reception unit;
A correction value calculation unit that calculates a correction value of the image component for each subcarrier from a signal output from the Fourier transform unit, the input transmission signal, and a signal output from the correction unit; A wireless transmitter characterized by the above. The correction value calculation unit
A leak coefficient calculation unit that calculates a leak coefficient indicating a leak amount of the image component using the input transmission signal, a signal output from the correction unit, and a signal output from the Fourier transform unit;
3. The radio according to claim 1, further comprising: a multiplier that multiplies the input transmission signal by the leak coefficient that is constantly output from the leak coefficient calculation unit and outputs the product to the correction unit. Transmitter device. The leak coefficient calculation unit
S (s = 0, 1,..., N−1: N is the number of subcarriers), and the element number in the time direction of the leak coefficient is j (j = 0, 1, , J-1: J is the number of leak coefficients in the time direction, and the element number in the time direction of the corrected signal of the image component is k (k = 0, 1,..., K-1: K is the number of corrected signals in the time direction), the leakage coefficient, the corrected signal of the image component, the signal after Fourier transform, the transmission coefficient of the desired subcarrier signal, and the transmission of the subcarrier signal as the image component The coefficients are B _{s, j} , XC _{s, k} , F _{s, k} , α _{s, j} , β _{s, j} , k0 and k1 are arbitrary k values, the signal of the subcarrier s and the subcarrier The N-1-s signal has a relationship in which the image components influence each other. The leak coefficient B _{s, j} is
B _{s, j} = β _{s, j} / α _{s, j}
α _{s, j} = (F _{s, k0} · XCN _{-1−s, k1−} F _{s, k1} · XCN _{−1−s, k0} ) / (XC _{s, k0} · _{XCN −1−s, k1} − XC _{s, k1} · XC _{N-1-s, k0} )
_{β s, j = (F s} , k0 · XC s, k1 -F s, k1 · XC s, k0) / (XC s, k1 · XC N-1-s, k0 -XC s, k0 · XC N- _{1-s, k1} )
The wireless transmission device according to claim 3, wherein the wireless transmission device is generated so as to satisfy the following formula. The leak coefficient calculation unit
S (s = 0, 1,..., N−1: N is the number of subcarriers), and the element number in the time direction of the input transmission signal is k (k = 0, 1). ,..., K-1: K is the number of transmission signals in the time direction), the input transmission signal is Xs _{, k} , k0 and k1 are arbitrary k values, the signal of the subcarrier s and the sub When the signal of the carrier N-1-s is in a relationship in which the image components influence each other, the input transmission signal X _{s, k} is
Xs _{, k0} * _{XN -1-s, k1} ≠ Xs _{, k1} * _{XN-1-s, k0}
Xs _{, k1} * _{XN-1-s, k0} ≠ Xs _{, k0} * _{XN -1-s, k1}
The radio transmission apparatus according to claim 3, wherein the leak coefficient is generated when the following equation is satisfied. The leak coefficient calculation unit
The subcarrier for calculating the leak coefficient is s (s = 0, 1,..., N−1: N is the number of subcarriers), and the element number in the time direction of the corrected signal of the image component is k (k = 0, 1, ..., K-1: K is the number of corrected signals in the time direction), the corrected signal of the image component is XC _{s, k} , k0 and k1 are arbitrary k values, When the signal of the carrier s and the signal of the subcarrier N-1-s are in a relationship in which the image components influence each other, the corrected signal XC _{s, k of the} image component is
XC _{s, k0} · XC _{N-1-s, k1} ≠ XC _{s, k1} · XC _{N-1-s, k0}
XC _{s, k1} · XC _{N-1-s, k0} ≠ XC _{s, k0} · XC _{N-1-s, k1}
The radio transmission apparatus according to claim 3, wherein the leak coefficient is generated when the following equation is satisfied. The multiplier is
The subcarrier for correcting the image component is s (s = 0, 1,..., N−1: N is the number of subcarriers), and the element number in the time direction of the leak coefficient is j (j = 0, 1 ,..., J-1: J is the number of leak coefficients in the time direction, and element numbers in the time direction of the input transmission signal are k (k = 0, 1,..., K-1: K is The number of transmission signals in the time direction), the correction value, the leak coefficient, and the input transmission signal are B2 _{s, k} , B _{s, j} , and X _{s, k, respectively,} and the signal of the subcarrier s and the subcarrier N When it is assumed that the image component affects the signal of -1-s, the correction value B2 _{s, k} is
B2 _{s, k} = −B _{s, j ×} X _{N-1-s, k}
The wireless transmission device according to claim 3, wherein multiplication is performed so as to satisfy the expression: The leak coefficient calculation unit
A delay adjusting unit that delays the input transmission signal by a predetermined time;
Referring to the delay adjustment signal output from the delay adjustment unit, generating a timing control signal that triggers holding the signal output from the correction unit, and a timing control signal triggering calculation of the leak coefficient A control unit for generating
In accordance with a timing control signal output from the control unit, a storage unit that holds a signal output from the correction unit;
In accordance with the timing control signal output from the control unit, the leak coefficient is calculated using the signal output from the storage unit that holds the signal output from the correction unit and the signal output from the Fourier transform unit. An arithmetic unit;
The wireless transmission device according to claim 3, further comprising: a storage unit that holds a leak coefficient output from the arithmetic unit and constantly outputs the leak coefficient to the multiplier. The controller is
It is determined whether the signal output from the delay adjustment unit satisfies a predetermined determination formula. If the determination formula is satisfied, the signal output from the correction unit is stored in the storage unit, and the transmission signal is fed back. The radio transmission apparatus according to claim 8, wherein the wireless transmission device waits for a time that is input to the calculation unit and controls the calculation of the leak coefficient at the calculation unit after the standby time has elapsed. The delay adjustment unit
The radio transmission apparatus according to claim 1, wherein the input transmission signal is delayed by a processing time required to calculate a correction value in the correction value calculation unit. A wireless transmission method for correcting image components generated by quadrature modulation,
A delay adjustment step of delaying the supplied transmission signal by a predetermined time;
A correction step of adding the signal output from the delay adjustment step and a correction value for canceling the image component;
An inverse Fourier transform step of performing an inverse Fourier transform on the corrected signal of the image component output from the correction step;
A radio transmission step of performing quadrature modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform step;
A radio reception step for performing frequency conversion and orthogonal demodulation to a baseband signal for the signal output from the radio transmission step;
A Fourier transform step of Fourier transforming the signal output from the wireless reception step;
And a correction value calculating step of calculating a correction value of the image component from the signal output from the Fourier transform step, the input transmission signal, and the signal output from the correction step. Wireless transmission method. A wireless transmission method for correcting image components generated by quadrature modulation,
A delay adjustment step of delaying the supplied OFDM transmission signal by a predetermined time;
A correction step of adding the signal output from the delay adjustment step and the correction value of the image component;
An inverse Fourier transform step of performing an inverse Fourier transform on the corrected signal of the image component output from the correction step;
A radio transmission step of performing quadrature modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform step;
A radio reception step for performing frequency conversion and orthogonal demodulation to a baseband signal for the signal output from the radio transmission step;
A Fourier transform step of Fourier transforming the signal output from the wireless reception step;
A correction value calculating step of calculating a correction value of the image component for each subcarrier from the signal output from the Fourier transform step, the input transmission signal, and the signal output from the correction step. A wireless transmission method characterized by the above. The correction value calculating step includes:
A leak coefficient calculating step of calculating a leak coefficient indicating a leak amount of the image component using the input transmission signal, a signal output from the correction step, and a signal output from the Fourier transform step;
The wireless transmission according to claim 11 or 12, further comprising a multiplication step of multiplying the input transmission signal by the leak coefficient output from the leak coefficient calculation step and outputting the multiplication result to the correction step. Method. A control program for a wireless transmission device that corrects an image component generated by quadrature modulation,
A delay adjustment function for delaying the supplied transmission signal by a predetermined time;
A correction function for adding the signal output from the delay adjustment function and a correction value for canceling the image component;
An inverse Fourier transform function for performing an inverse Fourier transform on the corrected signal of the image component output from the correction function;
A radio transmission function for performing quadrature modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform function;
A radio reception function for performing frequency conversion and orthogonal demodulation to a baseband signal for a signal output from the radio transmission function;
A Fourier transform function for Fourier transforming a signal output from the wireless reception function;
A computer realizes a correction value calculation function for calculating a correction value of the image component from a signal output from the Fourier transform function, the input transmission signal, and a signal output from the correction function. A program for wireless transmission control. A control program for a wireless transmission device that corrects an image component generated by quadrature modulation,
A delay adjustment function for delaying the supplied OFDM transmission signal by a predetermined time;
A correction function for adding the signal output from the delay adjustment function and the correction value of the image component;
An inverse Fourier transform function for performing an inverse Fourier transform on the corrected signal of the image component output from the correction function;
A radio transmission function for performing quadrature modulation and frequency conversion to a radio frequency band signal on the signal output from the inverse Fourier transform function;
A radio reception function for performing frequency conversion and orthogonal demodulation to a baseband signal for a signal output from the radio transmission function;
A Fourier transform function for Fourier transforming a signal output from the wireless reception function;
The computer realizes a correction value calculation function for calculating the correction value of the image component for each subcarrier from the signal output from the Fourier transform function, the input transmission signal, and the signal output from the correction function. A program for wireless transmission control, characterized in that The correction value calculation function is
A leak coefficient calculation function for calculating a leak coefficient indicating a leak amount of the image component using the input transmission signal, a signal output from the correction function, and a signal output from the Fourier transform function;
16. The radio transmission control according to claim 14, further comprising a multiplication function that multiplies the input transmission signal by the leak coefficient output from the leak coefficient calculation function and outputs the multiplication result to the correction function. Program.

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