JP2002064411A - Digital transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required until a distortion compensating factor is updated at the time of adjusting a reference table. SOLUTION: A digital transmitter is provided with the reference table 11 prestoring distortion compensating factors, a table adjusting signal generating section 12 which generates a table adjusting signal, and a signal selecting section 13 which selects and outputs the table adjusting signal instead of a quadrature base-band signal when the table 11 is adjusted. The transmitter is also provided with a predistortion section 15 which compensates the distortion of the output signal of the signal selecting section 13 based on one of the distortion compensating factors stored on the table 11, a quadrature modulation section 17 which performs quadrature modulation on the output signal of the section 13, and an amplifying section 18 which amplifies the quadrature modulated signals. In addition, the transmitter is also provided with a quadrature demodulation section 19 which performs quadrature demodulation on part of the quadrature modulated signals by feeding back the part and a factor updating section 21 which updates the distortion compensating factor corresponding to the power value related to the output signal of the signal selecting section 13 and stored on the table 11 based on the comparative error of the quadrature demodulated signals and the output signal of the section 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital transmission apparatus for compensating for distortion characteristics of an amplifying unit generated in a transmission system in a wireless communication system.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing a schematic configuration inside a conventional digital transmitting apparatus.

[0003] The digital transmission apparatus 100 shown in FIG.
It has a feedback system distortion compensation function for compensating for distortion characteristics of an amplifying unit generated in a transmission system in a wireless communication system, and a reference table 101 in which distortion compensation coefficients are stored in advance, and a power for calculating a power value of a quadrature baseband signal. A calculating unit 102 for reading out a distortion compensation coefficient corresponding to the power value from the look-up table 101 and, based on the read out distortion compensation coefficient, a predistortion unit 10 for performing distortion compensation on the orthogonal baseband signal;
3, a D / A converter 104 that converts the output signal of the predistortion unit 103 into an analog signal, a quadrature modulation unit 105 that generates a quadrature modulation signal by quadrature modulating the analog output signal, and amplification that amplifies the quadrature modulation signal. Part 10
6 and a quadrature demodulation unit 107 for generating a quadrature demodulation signal by feeding back a part of the amplified quadrature modulation signal and performing quadrature demodulation.
And an A / D converter 108 for digitally converting the quadrature demodulated signal, a digitally converted quadrature demodulated signal and a quadrature baseband signal which is an input signal of the pre-distortion unit 103, and based on the comparison error, Coefficient updating unit 10 for updating the distortion compensation coefficient in the lookup table 101 corresponding to the power value related to the band signal
9.

[0004] The operation of compensating for the distortion characteristics of amplifying section 106 inside conventional digital transmitting apparatus 100 will be described.

[0005] Power calculation section 102 calculates the power value of the orthogonal baseband signal input to predistortion section 103.

The pre-distortion section 103 reads a distortion compensation coefficient corresponding to the power value calculated by the power calculation section 102 from the look-up table 101, and performs a complex product operation of the distortion compensation coefficient and the orthogonal baseband signal. The distortion compensation of the amplification unit 106 is performed by reflecting the characteristic opposite to the distortion characteristic of the amplification unit 106 to the orthogonal baseband signal.

Further, the quadrature demodulation unit 105 includes
A part of the quadrature modulated signal amplified in step 6 is fed back, and the fed back quadrature modulated signal is quadrature demodulated to generate a quadrature demodulated signal. The orthogonal demodulated signal is input to coefficient updating section 109.

[0008] The coefficient updating section 109 combines the digitally converted quadrature demodulated signal with the pre-distortion section 103.
And updates the distortion compensation coefficient in the lookup table 101 corresponding to the power value of the orthogonal baseband signal based on the comparison error.

As described above, the conventional digital transmission apparatus 10
According to 0, the distortion compensation coefficient for compensating the distortion characteristic of the amplification unit 106 is stored in the reference table 101 in advance, and the reference table
By updating the distortion compensation coefficient within 1, distortion characteristics of the amplifier 106 can be accurately compensated.

If the distortion compensation coefficient is not stored in the reference table 101 in advance, the above operation is repeated to adjust (converge) the distortion compensation coefficient in the reference table 101, and the adjusted reference table 101 Is used, the distortion characteristic of the amplification unit 106 can be accurately compensated.

[0011]

However, according to the conventional digital transmitting apparatus 100, when adjusting the distortion compensation coefficient in the reference table 101, the reference table 101 corresponding to the power value of the orthogonal baseband signal is adjusted. Is updated, but when the levels of the orthogonal baseband signals are not equal, the distortion corresponding to each power value of the orthogonal baseband signal is adjusted so that all the distortion compensation coefficients in the lookup table 101 are equal. The compensation coefficient has to be updated, and there is a problem that it takes a considerable time until the adjustment for all the distortion compensation coefficients in the lookup table 101 is completed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a digital transmission apparatus capable of instantly adjusting a distortion compensation coefficient in a lookup table.

[0013]

In order to achieve the above object, a digital transmission apparatus according to the present invention comprises a reference table storing distortion compensation coefficients in advance, and a table adjustment signal for adjusting the distortion compensation coefficients in the reference table. A signal generator for generating a table adjustment signal, a signal selector for selecting and outputting a signal for table adjustment or a quadrature baseband signal, a power calculator for calculating a power value of an output signal of the signal selector, and a power value corresponding to the power value. A pre-distortion section for reading out the distortion compensation coefficient from the reference table, based on the read-out distortion compensation coefficient, and a D / A converter for converting the output signal of the pre-distortion section into an analog signal; A quadrature modulation section that quadrature modulates an analog-converted output signal to generate a quadrature modulation signal; and an amplification section that amplifies the quadrature modulation signal. A quadrature demodulation unit that generates a quadrature demodulation signal by feeding back part of the amplified quadrature modulation signal and quadrature demodulates it; an A / D converter that converts the quadrature demodulation signal into a digital signal; Compare the output signals of the selection unit, and based on this comparison error,
A coefficient updating unit for updating the distortion compensation coefficient in the reference table corresponding to the power value related to the output signal of the signal selecting unit, and the signal selecting unit adjusts the distortion compensation coefficient in the reference table. The table adjustment signal from the table adjustment signal generator is selectively output as an output signal.

Therefore, according to the digital transmitting apparatus of the present invention, when a table adjustment signal is generated separately so that all the distortion compensation coefficients in the reference table are equal, and the distortion compensation coefficient in the reference table is adjusted, Since the distortion compensation coefficient in the reference table is updated by selectively outputting the table adjustment signal instead of the orthogonal baseband signal, the distortion compensation coefficient in the reference table can be adjusted instantaneously.

The digital transmitting apparatus of the present invention has a memory in which a plurality of signal patterns are stored, and the table adjusting signal generator selects an arbitrary signal pattern from the memory.
A table adjustment signal corresponding to an arbitrary signal pattern is generated.

Therefore, according to the digital transmission apparatus of the present invention, since a plurality of signal patterns for generating different table adjustment signals are stored, even if amplification sections having different distortion characteristics are used, the amplification sections have the same characteristics. By selecting a table adjustment signal that matches the distortion characteristic of, the distortion compensation coefficient of the reference table can be instantaneously adjusted.

The digital transmitting apparatus of the present invention has a timing section for outputting a predetermined timing allocated for distortion compensation adjustment, and the signal selection section detects a predetermined timing from the timing section and generates a table adjustment signal generation signal. The table adjustment signal from the section is selectively output as an output signal.

Therefore, according to the digital transmission apparatus of the present invention, not only the case where the distortion compensation coefficient in the look-up table is adjusted in advance, but also the predetermined value assigned for distortion compensation adjustment in a system such as TDMA or FDMA. By using the timing, for example, the preamble section for the linearizer, the distortion compensation coefficient in the reference table can be adjusted even during the operation.

The digital transmitting apparatus according to the present invention has a memory storing a plurality of signal patterns, and a timing section for outputting a predetermined timing allocated for distortion compensation adjustment. The signal selecting unit selects a signal pattern from the table, generates a table adjustment signal corresponding to the arbitrary signal pattern, and detects a predetermined timing from the timing unit. A signal is selectively output as an output signal.

Therefore, according to the digital transmission apparatus of the present invention, since a plurality of signal patterns for generating different table adjustment signals are stored, even if amplification sections having different distortion characteristics are used, the amplification sections have the same characteristics. By selecting a table adjustment signal that matches the distortion characteristic of, the distortion compensation coefficient in the reference table can be instantaneously adjusted, and not only when the distortion compensation coefficient in the reference table is adjusted in advance, but also For example, by using a predetermined timing assigned for distortion compensation adjustment in a system such as TDMA or FDMA, for example, a preamble section for a linearizer,
Even during the operation, the distortion compensation coefficient in the reference table can be adjusted.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital transmission apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a schematic configuration inside a digital transmitting apparatus according to a first embodiment.

The digital transmission apparatus 10 shown in FIG. 1 has a reference table 11 in which distortion compensation coefficients are stored in advance, and a table adjustment signal generator 12 for generating a table adjustment signal for adjusting the distortion compensation coefficients in the reference table 11. And a signal selection unit 13 for selecting and outputting a table adjustment signal or an orthogonal baseband signal, a power calculation unit 14 for calculating a power value of an output signal of the signal selection unit 13, and a distortion compensation coefficient corresponding to the power value. The pre-distortion unit 15 reads out from the table 11 and performs distortion compensation on the output signal of the signal selection unit 13 based on the read-out distortion compensation coefficient.
A / A converter 16, a quadrature modulator 17 that quadrature-modulates an analog-converted output signal to generate a quadrature-modulated signal,
An amplifying unit 18 for amplifying the quadrature modulated signal; a quadrature demodulating unit 19 for generating a quadrature demodulated signal by feeding back a part of the amplified quadrature modulated signal to perform quadrature demodulation; The converter 20 compares the digitally-converted quadrature demodulated signal with the output signal of the signal selection unit 13, and based on the comparison error, stores the reference value in the reference table 11 corresponding to the power value related to the output signal of the signal selection unit 13. And a coefficient updating unit 21 for updating the distortion compensation coefficient.

When adjusting the distortion compensation coefficient in the reference table 11, the signal selector 13 selects and outputs the table adjustment signal from the table adjustment signal generator 12 as an output signal.

FIG. 2 is an explanatory diagram showing an example of the input / output characteristics of the amplifier 18, and FIG. 3 is an explanatory diagram showing the contents of the reference table 11.

Although the input / output characteristics of the amplifying section 18 are almost linear up to a certain input, the input signal is distorted when the input signal exceeds a certain level.

The look-up table 11 shown in FIG. 3 holds the inverse characteristic of the input / output characteristic of FIG. 2, and relates to the power value of the input signal shown in FIG. 2 as the power value of the input signal increases. Since the range (section) becomes narrow, for example, the distortion compensation coefficient 1 in FIG. 3A is a distortion compensation coefficient corresponding to the power value in the section in FIG. 2A, and the distortion compensation coefficient in FIG. The coefficient 2 is a distortion compensation coefficient corresponding to the power value in the section (2) in FIG. 2, and the distortion compensation coefficient n in (n) in FIG. 3 is a distortion compensation coefficient corresponding to the power value in the section (n) in FIG. A distortion compensation coefficient corresponding to the power value of each section, such as a compensation coefficient, is stored in the reference table 11.

Considering the input / output characteristics of the amplifying unit 18 as described above, the distortion increases as the power value of the input signal increases, and as the distortion increases, the distortion characteristics are finely compensated. is there.

Next, the operation of the digital transmitting apparatus 10 according to the first embodiment will be described. FIG. 4 is an explanatory diagram showing an example of the table adjustment signal.

When adjusting the distortion compensation coefficient in the look-up table 11, the table adjustment signal generator 12 is configured as shown in FIG.
, And outputs the table adjustment signal to the signal selector 13.

The signal selection unit 13 selects a table adjustment signal instead of the orthogonal baseband signal, and transmits the table adjustment signal to the pre-distortion unit 15 and the power calculation unit 14. The power calculation unit 14 calculates the power value of the table adjustment signal, reads out the distortion compensation coefficient corresponding to the power value from the reference table 11, and transmits the distortion compensation coefficient to the predistortion unit 15.

The pre-distortion section 15 performs a complex product operation on the input table adjustment signal and the compensation coefficient, and transmits the calculated output signal to the D / A converter 16.

The quadrature modulator 17 includes a D / A converter 16
A quadrature modulation is performed on the output signal that has been converted into an analog signal to generate a quadrature modulation signal, and this quadrature modulation signal is transmitted to the amplifier 18. The amplifier 18 amplifies this quadrature modulated signal and outputs it as a transmission signal.

The quadrature demodulation section 19 feeds back a part of the quadrature modulation signal amplified by the amplification section 18 and quadrature demodulates the fed back quadrature modulation signal to generate a quadrature demodulation signal. / D converter 20.

The coefficient updating unit 21 is provided with the A / D converter 20
The quadrature demodulated signal digitally converted in step (b) is compared with the table adjustment signal selected by the signal selection unit 13, and based on the comparison error, the reference table 11 in the reference table 11 corresponding to the power value already obtained. The distortion compensation coefficient is adjusted, that is, updated.

It should be noted that the table adjustment signal has a higher data density than a low level in accordance with the input / output characteristics of the amplifying section 18 and the sectioning characteristics in the reference table 11. 4 (a) is output,
The reference table 11 can be uniformly updated. Reference table 1
If the section 1 is uniform, it is desirable to output the table adjustment signal shown in FIG.

As described above, according to the first embodiment, according to the input / output characteristics of the amplifying section 18 and the division of the section of the reference table 11, the table adjustment is performed such that the total distortion compensation coefficients in the reference table 11 are equal. When separately generating a signal for use and adjusting the distortion compensation coefficient in the reference table 11, the distortion compensation coefficient in the reference table 11 is updated by selectively outputting a table adjustment signal instead of the orthogonal baseband signal. As a result, the distortion compensation coefficient in the lookup table 11 can be adjusted instantaneously.

(Embodiment 2) Next, a digital transmission apparatus according to a second embodiment will be described. FIG. 5 shows the second
FIG. 2 is a block diagram illustrating a schematic configuration inside a digital transmission device according to the embodiment. The same components as those of the digital transmission device 10 according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description of the overlapping configuration and operation will be omitted.

The digital transmission apparatus 10A shown in FIG. 5 differs from the digital transmission apparatus 10 shown in FIG. 1 in that the digital transmission apparatus 10 shown in FIG. 1 can generate only one pattern of table adjustment signal. , FIG.
In the digital transmission device 10A shown in FIG. 7, a plurality of signal patterns corresponding to the characteristics of each amplifying unit 18 are stored in the memory 31, so that a table adjustment signal corresponding to the amplifying unit 18 can be generated.

That is, the digital transmission device 1 shown in FIG.
0A table adjustment signal generation unit 12
It is possible to select an arbitrary signal pattern from the plurality of signal patterns stored in 1 and selectively output a table adjustment signal corresponding to the arbitrary signal pattern.

Next, the operation of the digital transmitting apparatus 10A according to the second embodiment will be described.

When adjusting the distortion compensation coefficient of the reference table 11, the table adjustment signal generator 12 reads a signal pattern corresponding to the current characteristic of the amplifier 18 from a plurality of patterns stored in the memory 31, and A table adjustment signal is output based on the pattern.

According to the second embodiment, a signal pattern for generating a different table adjustment signal is stored in the memory 3.
When the distortion compensation coefficient of the reference table 11 is adjusted, even if the amplification unit 18 having different distortion characteristics is used, the current amplification unit is stored based on the plurality of signal patterns stored in the memory 31. By selecting the table adjustment signal having the distortion characteristic of 18, the total distortion compensation coefficient in the reference table 11 can be instantaneously adjusted.

(Embodiment 3) Next, a digital transmission apparatus according to a third embodiment will be described. FIG. 6 shows the third
FIG. 2 is a block diagram illustrating a schematic configuration inside a digital transmission device according to the embodiment. The same components as those of the digital transmission device 10 according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description of the overlapping configuration and operation will be omitted.

The digital transmitting apparatus 10B shown in FIG. 6 differs from the digital transmitting apparatus 10 shown in FIG. 1 in that the digital transmitting apparatus 10 shown in FIG. However, the digital transmitting apparatus 10B shown in FIG. 6 has a timing section 41 that outputs the timing of a linearizer preamble section assigned for distortion compensation adjustment in a system such as TDMA or FDMA. On the point.

That is, in the signal selecting section 13 of the digital transmitting apparatus 10B, even if the signal is being operated, when the timing section 41 detects the timing of the linearizer preamble section, the table adjusting signal from the table adjusting signal generating section 12 is used. The point is that the distortion compensation coefficient in the lookup table 11 is adjusted by selecting a signal.

Next, the operation of the digital transmitting apparatus 10B according to the third embodiment will be described.

The table adjustment signal generator 12 is provided as shown in FIG.
A table adjustment signal as shown in FIG. The timing section 41 outputs the timing of the linearizer preamble section.

The signal selector 13 normally selects and outputs a quadrature baseband signal. However, upon detecting the timing output from the timing section 41, the signal selector 13 determines that the timing of the linearizer preamble section is the timing of the table adjustment signal generator. 12 to select and output the table adjustment signal. In the linearizer preamble section, FIG.
By selectively outputting the table adjustment signal as shown in (c), the period of the signal can be shortened.

According to the third embodiment, not only the case where the distortion compensation coefficient in the lookup table 11 is adjusted in advance, but also
For example, by using a predetermined timing assigned for distortion compensation adjustment in a system such as TDMA or FDMA, for example, a preamble section for a linearizer, the distortion compensation coefficient in the lookup table 11 can be adjusted even during its operation. Can be.

(Embodiment 4) Next, a digital transmission apparatus according to a fourth embodiment will be described. FIG. 7 shows the fourth
FIG. 2 is a block diagram illustrating a schematic configuration inside a digital transmission device according to the embodiment. The same components as those of the digital transmission device 10 according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description of the overlapping configuration and operation will be omitted.

The digital transmitting apparatus 10C shown in FIG. 7 is different from the digital transmitting apparatus 10 shown in FIG. 1 in that the digital transmitting apparatus 10 shown in FIG. 1 can generate only one pattern of a table adjustment signal. Although it was necessary to adjust the distortion compensation coefficient in the reference table 11 in advance, the digital transmission device 10C shown in FIG. 7 stores a plurality of signal patterns corresponding to the characteristics of each amplifier 18 in the memory 51. , A table adjustment signal corresponding to each amplifying unit 18 can be generated, and for example, TDMA or F
The present invention has a timing section 52 for outputting the timing of a preamble section for a linearizer assigned for distortion compensation adjustment in a system such as a DMA.

Next, the operation of the digital transmission apparatus 10C according to the fourth embodiment will be described.

When adjusting the distortion compensation coefficient of the reference table 11, the table adjustment signal generator 12 selects an arbitrary signal pattern corresponding to the distortion characteristic of the amplifier 18 from the plurality of signal patterns stored in the memory 51. Then, a table adjustment signal corresponding to the arbitrary signal pattern is selectively output.

The timing section 52 outputs the timing of the linearizer preamble section.

The signal selection section 13 normally selects and outputs a quadrature baseband signal. When detecting the timing output from the timing section 52, the signal selection section 13 determines that it is the timing of the preamble section for the linearizer and generates the signal for the table adjustment. 12 to select and output the table adjustment signal.

In a section such as a preamble for a linearizer, a table adjustment signal is selected, and FIG.
Is output, and the cycle of the signal is shortened. Further, since the signal according to the characteristic of the amplifier 18 is output, the reference table 11 can be updated uniformly.

According to the fourth embodiment, even if the amplifiers 18 having different distortion characteristics are used, by selecting a table adjustment signal that matches the distortion characteristics of the amplifier 18, any distortion characteristics can be obtained. Even if the amplifying unit 18 is used, the distortion compensation coefficient of the reference table 11 can be instantaneously adjusted, and the distortion compensation coefficient in the reference table 11 is not only adjusted in advance, but also, for example, a preamble section for a linearizer. , The distortion compensation coefficient in the lookup table 11 can be adjusted even during the operation.

The digital transmission device 10 (10A, 10B, 10C) shown in the first to fourth embodiments.
Is desirably employed in a wireless communication system as described below. FIG. 8 is a block diagram showing a schematic configuration inside a wireless communication system employing the digital transmission device 10 (10A, 10B, 10C) according to the present embodiment.

The wireless communication system 60 shown in FIG. 8 includes a plurality of base station communication devices 70 connected to the public communication network 61 by wire.
And a plurality of mobile station communication devices 80 wirelessly connected to each base station communication device 70.

Further, each base station communication device 70 includes an antenna 71 for wirelessly connecting to the mobile station communication device 80, and a transmitting device 72 and a receiving device for wirelessly connecting to the mobile station communication device 80 through the antenna 71. A wireless device 74 includes a wireless communication device 73 and a control device 75 that controls the entire base station communication device 70.

Each mobile station communication device 80 includes an antenna 81 for wireless connection with the base station communication device 70, and a transmitting device 82 and a receiving device 83 for wireless connection with the base station communication device 70 via the antenna 81. Have.

The transmitting devices 72 and 82 of the base station communication device 70 and the mobile station communication device 80 are provided with the digital transmitting device 10 (10A, 10B, 10A, 10B, 10B) described in the first to fourth embodiments.
By adopting 10C), it is possible to construct a base station device, a mobile station communication device, and a wireless communication system including the same that can instantaneously adjust the distortion compensation coefficient in the lookup table 11 and adjust even during operation.

[0064]

According to the digital transmission apparatus of the present invention configured as described above, a table adjustment signal is generated separately such that all the distortion compensation coefficients in the lookup table are equal, and the distortion compensation in the lookup table is generated. When adjusting the coefficient,
Since the distortion compensation coefficient in the reference table is updated by selectively outputting the table adjustment signal instead of the orthogonal baseband signal, the distortion compensation coefficient in the reference table can be adjusted instantaneously.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration inside a digital transmitting apparatus according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram showing an example of input / output characteristics in an amplifying unit inside the digital transmitting apparatus according to the first embodiment;

FIG. 3 is an explanatory diagram showing memory contents of a reference table in the digital transmission device shown in the first embodiment;

FIG. 4A is an explanatory diagram illustrating an example of a table adjustment signal generated by a table adjustment signal generation unit in the digital transmission device according to the first embodiment; FIG. 4B is a diagram illustrating the first embodiment; Explanatory drawing showing an example of a table adjustment signal generated by a table adjustment signal generator inside a digital transmission device. (C) Table generated by a table adjustment signal generator inside the digital transmission device shown in the first embodiment. Explanatory diagram showing an example of an adjustment signal

FIG. 5 is a block diagram showing a schematic configuration inside a digital transmitting apparatus according to a second embodiment;

FIG. 6 is a block diagram showing a schematic configuration inside a digital transmission apparatus according to a third embodiment;

FIG. 7 is a block diagram illustrating a schematic configuration inside a digital transmission apparatus according to a fourth embodiment;

FIG. 8 is a block diagram showing a schematic configuration inside a wireless communication system employing the digital transmission apparatus according to the first to fourth embodiments;

FIG. 9 is a block diagram showing a schematic configuration inside a conventional digital transmission device.

[Explanation of symbols]

 10, 10A, 10B, 10C Digital transmitter 11 Reference table 12 Signal generator for table adjustment 13 Signal selector 14 Power calculator 15 Predistortion unit 16 D / A converter 17 Quadrature modulation unit 18 Amplification unit 19 Quadrature demodulation unit 20 A / D converter 21 Coefficient update unit 31,51 Memory 41,52 Timing unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kunihiko Sakaihara 3-1, Tsunashimahigashi 4-chome, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 5K004 AA05 BA02 BD01 FF05 FH03 5K046 AA01 EE32 EE51 EE59 EF05 EF23 5K060 BB07 CC04 DD04 EE01 FF06 FF09 FF10 HH01

Claims (16)

[Claims] A reference table storing distortion compensation coefficients in advance; a table adjustment signal generator for generating a table adjustment signal for adjusting the distortion compensation coefficients in the reference table;
A signal selector for selecting and outputting the table adjustment signal or the orthogonal baseband signal, a power calculator for calculating a power value of an output signal of the signal selector, and a distortion compensation coefficient corresponding to the power value in the reference table. A pre-distortion unit for compensating for the output signal of the signal selection unit based on the read distortion compensation coefficient; a D / A converter for converting the output signal of the pre-distortion unit into an analog signal; A quadrature modulation unit that performs quadrature modulation on the converted output signal to generate a quadrature modulation signal;
An amplifier for amplifying the quadrature modulated signal; a quadrature demodulator for generating a quadrature demodulated signal by feeding back a part of the amplified quadrature modulated signal to perform quadrature demodulation; The D-converter compares the digitally-converted quadrature demodulated signal and the output signal of the signal selection unit. Based on the comparison error, the reference table corresponding to the power value related to the output signal of the signal selection unit is stored. And a coefficient updating unit that updates the distortion compensation coefficient of: where the signal selecting unit adjusts the distortion compensation coefficient in the lookup table,
A digital transmission device, wherein the table adjustment signal from the table adjustment signal generator is selectively output as an output signal. 2. A memory for storing a plurality of signal patterns, wherein the table adjustment signal generator selects an arbitrary signal pattern from the memory, and the table adjustment signal corresponding to the arbitrary signal pattern. The digital transmission device according to claim 1, wherein 3. A timing section for outputting a predetermined timing allocated for distortion compensation adjustment, wherein the signal selection section detects the predetermined timing from the timing section and outputs the predetermined timing from the table adjustment signal generation section. 2. The digital transmitting apparatus according to claim 1, wherein said table adjusting signal is selectively output as an output signal. 4. A memory for storing a plurality of signal patterns, and a timing unit for outputting a predetermined timing allocated for distortion compensation adjustment, wherein the table adjustment signal generation unit is configured to output an arbitrary signal from the memory. Selecting a pattern, generating the table adjustment signal corresponding to the arbitrary signal pattern, the signal selection unit detects the predetermined timing from the timing unit, and outputs the table adjustment signal from the table adjustment signal generation unit. 2. The digital transmitting apparatus according to claim 1, wherein the table adjusting signal is selectively output as an output signal. 5. The digital transmitting apparatus according to claim 1, wherein the digital transmitting apparatus is provided in a mobile station wirelessly connected to a base station. 6. The digital transmitting apparatus according to claim 1, wherein the digital transmitting apparatus is provided in a base station wirelessly connected to the mobile station. 7. The digital transmitting apparatus according to claim 1, wherein the digital transmitting apparatus is provided in a base station and a mobile station of a wireless communication system. 8. The digital transmitting apparatus according to claim 2, wherein the digital transmitting apparatus is provided in a mobile station wirelessly connected to a base station. 9. The digital transmitting apparatus according to claim 2, wherein the digital transmitting apparatus is provided in a base station wirelessly connected to the mobile station. 10. The digital transmitting apparatus according to claim 2, wherein the digital transmitting apparatus is provided in a base station and a mobile station of a wireless communication system. 11. The digital transmitting apparatus according to claim 3, wherein the digital transmitting apparatus is provided in a mobile station wirelessly connected to a base station. 12. The digital transmitting apparatus according to claim 3, wherein the digital transmitting apparatus is provided in a base station wirelessly connected to the mobile station. 13. The digital transmitting apparatus according to claim 3, wherein the digital transmitting apparatus is provided in a base station and a mobile station of a wireless communication system. 14. The digital transmitting apparatus according to claim 4, wherein said digital transmitting apparatus is provided in a mobile station wirelessly connected to a base station. 15. The digital transmitting apparatus according to claim 4, wherein the digital transmitting apparatus is provided in a base station wirelessly connected to the mobile station. 16. The digital transmitting apparatus according to claim 4, wherein the digital transmitting apparatus is provided in a base station and a mobile station of the wireless communication system.