JP2004159319A - Data converter, signal generator, transmitter and communication device using same, and data conversion method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem that it is difficult to linearly and highly efficiently amplify a signal having a fluctuating envelope. <P>SOLUTION: The data converter is provided with an arithmetic circuit connected to an input terminal 106, a vector quantizer 111 connected to the arithmetic circuit and an output terminal 114 of an output side thereof. The arithmetic circuit (n) ((n) is a natural number) units are respectively composed of a vector ubtractor 107 having a first input terminal 801 and a second input terminal 802 and a vector integrator 108 connected to an output side of the vector subtractor 107. An output of the output terminal 114 and/or an output of each vector integrator 108 is then inputted to the second input terminal 802 of the vector subtractor 107 in each of unit circuits. The vector subtractor 107 outputs data in which a vector inputted to the second input terminal 802 is subtracted from a vector inputted from the first input terminal 801, and the vector quantizer 111 outputs a predetermined value quantized at least with respect to size of the inputted vector. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a data converter, a signal generator, a transmitter using the same, a communication device, and a data conversion method used for wireless devices such as a mobile phone and a wireless LAN.

FIG. 27 shows an example of a conventional transmission circuit (for example, see Non-Patent Document 1). In FIG. 27, I data (in-phase data) and Q data (quadrature-phase data) are output from two output terminals of the data generator 5001, respectively. These data are input to the modulator 5002 and modulated. The output from modulator 5002 is amplified by amplifier 5003 and radiated from antenna 5004.
B. Razavi, "RF Microelectronics", Prentice-Hall PTR, 1998 (p.153, FIG. 5.39).

  However, in the transmission circuit of FIG. 27, since the signal to be radiated from the antenna 5004 has a fluctuating envelope, the amplifier 5003 is required to have linearity so as not to deteriorate such a signal. In order to ensure the linearity of the amplifier 5003, the amplifier 5003 must be operated in a linear region sufficiently smaller than the saturation output, and the power consumption increases.

This will be specifically described with reference to FIG. FIG. 28 is a graph showing the output power with respect to the input power of the amplifier 5003 and the efficiency. In order to increase the efficiency of the amplifier 5003, it is better that the input power and the output power are large. That is, when the input power is Pin2, the output power is Pout2, and the efficiency at this time is η2. However, at such an operating point, if a signal whose envelope fluctuates is input, the signal will be distorted and cannot be actually used. Therefore, in order to reduce distortion, it is necessary to reduce input power and output power. At this time, the efficiency becomes low. That is, when the input power is Pin1, the output power is Pout1 and the efficiency is η1.
An object of the present invention is to provide a data converter, a signal generator, a transmitter, a communication device, and a data conversion method that can suppress the influence of nonlinearity of an amplifier and have high efficiency.

In order to solve the above problem, a first aspect of the present invention provides a parallel data input terminal to which parallel data having I data and Q data is input,
An arithmetic circuit connected to the parallel data input terminal;
A first vector quantizer connected to an output side of the arithmetic circuit;
An output terminal connected to the output side of the first vector quantizer;
The I data and the Q data form a predetermined vector,
The arithmetic circuit includes a first vector subtracter having a first input terminal and a second input terminal, and a unit circuit including a vector integrator connected to an output side of the first vector subtractor, wherein n (n Is a natural number) connected,
An output of the output terminal and / or an output of each of the vector integrators is input to a second input terminal of a first vector subtracter of each of the unit circuits,
The parallel data input terminal is connected to a first input terminal of a first vector subtracter of a first unit circuit,
The unit circuits have an output terminal of a vector integrator connected to a first input terminal of a first vector subtracter,
The first vector subtractor outputs parallel data obtained by subtracting a vector formed by the parallel data input to the second input terminal from a vector formed by the parallel data input from the first input terminal,
The vector integrator integrates a vector composed of the input parallel data,
The first vector quantizer is a data converter that outputs a predetermined value quantized with respect to at least the magnitude of the input vector.

  The second invention is the data converter according to the first invention, wherein the first vector quantizer outputs a vector having the same phase as an input vector.

According to a third aspect of the present invention, when the magnitude of the vector input to the first vector quantizer is equal to or larger than a predetermined threshold, the first vector quantizer has a magnitude equal to the predetermined threshold. Output a vector whose phase is equal to the input vector,
When the magnitude of the vector input to the first vector quantizer is smaller than a predetermined threshold, the first vector quantizer is a data converter according to the first aspect of the present invention that outputs a zero vector. .

  A fourth invention is the data converter according to the first invention, wherein the first vector quantizer quantizes both the magnitude and the phase of a vector.

A fifth aspect of the present invention provides a parallel data input terminal to which parallel data having a predetermined vector is input,
A first vector subtractor having a first input terminal and a second input terminal, wherein the first input terminal is connected to the parallel data input terminal;
A second vector quantizer connected to the output of the first vector subtractor;
An output terminal connected to an output side of the second vector quantizer;
The second vector quantizer outputs a predetermined value quantized with respect to at least the magnitude of the input vector;
The quantized predetermined value is input to a second input terminal of the first vector subtractor,
A data converter that outputs parallel data obtained by subtracting a vector formed by the parallel data input to the second input terminal from a vector formed by the parallel data input to the first input terminal; It is.

  A sixth invention is the data converter according to the fifth invention, wherein the second vector quantizer outputs a vector having the same phase as the input vector.

  A seventh invention is the data converter according to the fifth invention, wherein the second vector quantizer quantizes both the magnitude and the phase of the vector.

An eighth aspect of the present invention further includes a second vector subtracter having a first input terminal and a second input terminal, wherein the second input terminal is connected to the output side of the second vector quantizer.
An output of the first vector subtractor is also connected to a second input terminal of the second vector subtractor;
The second vector subtracter converts a vector formed by the parallel data input to the second input terminal of the second vector subtracter from a vector formed by the parallel data input to the first input terminal of the second vector subtractor. Output the subtracted parallel data,
A fifth data converter according to the present invention, wherein an output of the second vector quantizer is input to a second input terminal of the first vector subtractor via the second vector subtractor.

In a ninth aspect of the present invention, the first vector subtracter is orthogonal to the first data, the first vector subtracter having a first input terminal and a second input terminal to which first data is input. A second scalar subtractor having a first input terminal to which the second data is input and a second input terminal;
The vector integrator has a first scalar integrator connected to the output of the first scalar subtractor, and a second scalar integrator connected to the output of the second scalar subtractor,
The first vector quantizer receives the output of the first scalar integrator and the output of the second scalar integrator as data of a rectangular coordinate system, and converts the input data of the rectangular coordinate system into a polar coordinate system. And a first scalar quantizer for quantizing at least the amplitude data output from the first coordinate converter, the first coordinate converter outputting the polar coordinate system data as amplitude data and phase data. Connected to the output side of the first scalar quantizer and / or the output side of the first coordinate converter, and as the data of the polar coordinate system, the first scalar quantizer and / or the first coordinate converter From the amplitude data and the phase data output from the third data corresponding to the first data and the second data as the data of the rectangular coordinate system. And a second coordinate converter for outputting a fourth data, and
The first scalar quantizer is connected to an output side of the first coordinate converter, and outputs at least amplitude data quantized as a predetermined value;
A first output terminal connected to the second coordinate converter and outputting the third data; a second output terminal connected to the second coordinate converter and outputting the fourth data; , And
At least one of the third data or the output of each of the first scalar integrators is input to at least a second input terminal of each of the first scalar subtractors, and the fourth data or each of the fourth scalar integrators is input. A data converter according to the first aspect of the present invention, wherein at least one of the outputs of the second scalar integrator is input to at least one of the second input terminals of the second scalar subtractor.

In a tenth aspect, the n is 1.
The third data is input to a second input terminal of the first scalar subtractor, and the first scalar subtracter subtracts the third data from the first data, and the subtracted data is the first data. Output to the scalar integrator,
The fourth data is input to a second input terminal of the second scalar subtractor, and the second scalar subtracter subtracts the fourth data from the second data, and the subtracted data is the second data. A ninth data converter according to the present invention, which is output to a scalar integrator.

  An eleventh invention is the data converter according to the tenth invention, wherein the first vector quantizer outputs a vector having the same phase as an input vector.

  A twelfth invention is the data converter according to the tenth invention, wherein the first vector quantizer quantizes the amplitude data and quantizes the phase data.

In a thirteenth aspect of the present invention, the first vector subtracter is orthogonal to the first data, the first scalar subtractor having a first input terminal and a second input terminal to which first data is input. A second scalar subtractor having a first input terminal to which the second data is input and a second input terminal;
The second vector quantizer receives the output of the first scalar subtractor and the output of the second scalar subtractor as data of a rectangular coordinate system, and converts the input data of the rectangular coordinate system into a polar coordinate system. A first coordinate converter for converting the data into polar data and outputting the data in the polar coordinate system as amplitude data and phase data; and a second scalar quantizer for quantizing at least the amplitude data output from the first coordinate converter. The amplitude data and the phase data output from the second scalar quantizer and / or the first coordinate converter are converted from the data in the polar coordinate system into the data in the rectangular coordinate system, and correspond to the first data. A second coordinate converter that outputs third data and fourth data corresponding to the second data,
The second scalar quantizer is connected to an output side of the first coordinate converter, and outputs at least amplitude data quantized as a predetermined value;
The output terminal is connected to the second coordinate converter, a first output terminal for outputting the third data, and a second output terminal connected to the second coordinate converter, for outputting the fourth data. And having
The third data is input to a second input terminal of the first scalar subtractor, and the first scalar subtracter subtracts the third data from the first data, and the subtracted data is the first data. Input to one input of the coordinate converter,
The fourth data is input to a second input terminal of the second scalar subtractor, and the second scalar subtracter subtracts the fourth data from the second data, and the subtracted data is the first data. A fifth data converter according to the present invention, which is input to the other input of the coordinate converter.

  The fourteenth invention is the data converter according to the thirteenth invention, wherein the second vector quantizer outputs a vector having the same phase as the input vector.

  A fifteenth aspect of the present invention is the data converter according to the thirteenth aspect, wherein the second vector quantizer quantizes the amplitude data with respect to the magnitude of the vector and quantizes the phase data with respect to the phase of the vector. It is.

In a sixteenth aspect of the present invention, the first vector subtracter has a first scalar subtracter having a first input terminal to which first data is input and a second input terminal, and a first scalar subtractor having a relationship orthogonal to the first data. A second scalar subtractor having a first input terminal and a second input terminal to which certain second data is input,
The second vector quantizer receives the output of the first scalar subtractor and the output of the second scalar subtractor as data of a rectangular coordinate system, and converts the input data of the rectangular coordinate system into a polar coordinate system. A first coordinate converter that converts the data into data and outputs the data of the polar coordinate system as amplitude data and phase data, and a second scalar quantizer that quantizes at least the amplitude data output from the first coordinate converter. The amplitude data and the phase data output from the second scalar quantizer and / or the first coordinate converter are converted from the data of the polar coordinate system to the data of the orthogonal coordinate system, and correspond to the first data. And a second coordinate converter that outputs fourth data corresponding to the second data.
The second scalar quantizer is connected to an output side of the first coordinate converter, and outputs at least amplitude data quantized as a predetermined value;
The second vector subtracter receives the third data at its first input terminal, receives output data from the first scalar subtractor at its second input terminal, and converts the third data into the first data. A third scalar subtractor for subtracting output data from the scalar subtractor and outputting as fifth data, the fourth data being input to a first input terminal thereof, and an output data from the second scalar subtractor being A fourth scalar subtractor that is input to a second input terminal and subtracts output data from the second scalar subtractor from the fourth data and outputs the result as sixth data;
The fifth data is input to a second input terminal of the first scalar subtractor, and the first scalar subtracter subtracts the fifth data from the first data, and the subtracted data is the first data. Input to one input of the coordinate converter,
The sixth data is input to a second input terminal of the second scalar subtractor, and the second scalar subtracter subtracts the sixth data from the second data, and the subtracted data is the first data. An eighth data converter according to the present invention, which is input to the other input of the coordinate converter.

  A seventeenth invention is the data converter according to the sixteenth invention, wherein the second vector quantizer outputs a vector having the same phase as an input vector.

  In an eighteenth aspect of the present invention, the second vector quantizer quantizes the amplitude data with respect to the magnitude of the vector and quantizes the phase data with respect to the phase of the vector. It is.

In a nineteenth aspect of the present invention, the first vector quantizer has n threshold values,
When the magnitude of the input vector to the first vector quantizer is larger than the largest threshold among the n thresholds, the magnitude is the magnitude of the largest threshold and the phase is Outputs a vector equal to the vector,
When the magnitude of the input vector to the first vector quantizer is smaller than the smallest threshold value among the n threshold values, a zero vector is output;
When the magnitude of the input vector to the first vector quantizer is between the smallest threshold and the largest threshold among the n thresholds, the largest of the thresholds smaller than the magnitude of the input vector is The first or tenth data converter of the present invention outputs a vector having a large threshold value as its amplitude and a phase equal to the input vector.

  The twentieth invention is the data converter according to the fifth or eighth invention, wherein the second vector quantizer outputs a vector having a predetermined amplitude and a phase equal to the input vector.

  In a twenty-first aspect of the present invention, the second vector quantizer outputs a when the input vector is smaller than an intermediate value between a and b (a and b are real numbers that are not negative and a <b). The fifth or eighth data converter according to the present invention, which outputs b when the value is equal to or larger than the intermediate value.

A twenty-second invention provides a data converter according to the first or fifth invention,
A quadrature modulator for quadrature modulating an output from the data converter.

  A twenty-third invention is the signal generator according to the twenty-second invention, wherein the data converter is realized by digital signal processing.

A twenty-fourth aspect of the present invention provides the signal generator of the twenty-second aspect,
An amplifier directly or indirectly connected to the quadrature modulator of the signal generator;
A bandpass filter connected to the amplifier;
An antenna directly or indirectly connected to the bandpass filter.

  A twenty-fifth aspect of the present invention is provided between the output side of the data converter and the input side of the quadrature modulation section, for low-pass filtering a signal output from the data converter and transmitting the signal to the quadrature modulation section. The transmitter according to the twenty-fourth aspect of the present invention, further comprising:

  A twenty-sixth aspect of the present invention is the transmitter according to the twenty-fourth aspect of the present invention, wherein the predetermined value is controlled according to a type of a modulated wave output from the transmitter.

  A twenty-seventh aspect of the present invention is the transmitter according to the twenty-fourth aspect, wherein a pass frequency of the band-pass filter is controlled according to a frequency of an output signal.

  A twenty-eighth invention is the transmitter according to the twenty-fourth invention, wherein the data converter generates data for compensating for the nonlinearity of the amplifier.

A twenty-ninth aspect of the present invention provides a data generation unit for generating parallel data,
A first or fifth data converter of the present invention connected to the data generator;
A first modulator connected to the data converter;
A first amplifier connected to the first modulator;
A third vector subtractor having one input connected to the data generator;
A second modulator connected to the output of the third vector subtractor;
A second amplifier connected to the second modulator;
The output side of the first amplifier and the output side of the second amplifier are connected as inputs, respectively, and the output of the first amplifier and the output of the second amplifier are combined to output the combined signal. Synthesizer,
An antenna connected to the output side of the synthesizer,
The output of the data converter is also connected to the other input of the third vector subtractor;
The third vector subtractor outputs quantization noise data by subtracting the parallel data generated by the data generator from the parallel data converted by the data converter.
The transmitter, wherein the combining is performed on the quantized noise data with substantially equal amplitude and opposite phase.

  A thirtieth invention is a communication device comprising the transmitter according to the twenty-fifth invention, a receiver for receiving a signal, and an antenna for transmitting and / or receiving a signal.

A thirty-first aspect of the present invention provides a step of inputting parallel data having I data and Q data to a parallel data input terminal,
A step of performing n (n is a natural number) arithmetic steps of a vector subtraction step and a vector integration step in an arithmetic circuit connected to the parallel data input terminal;
Outputting a predetermined value quantized with respect to at least the magnitude of the vector output from the arithmetic circuit,
The I data and the Q data form a predetermined vector,
The vector subtraction step includes a step of outputting parallel data obtained by subtracting an output vector of the arithmetic circuit and / or an output vector of each vector integration from a vector formed by the input parallel data,
The vector integration step is a data conversion method including a step of integrating a vector constituted by the input parallel data.

  ADVANTAGE OF THE INVENTION According to this invention, the data converter, the signal generator, the transmitter, the communication apparatus, and the data conversion method which can suppress the influence of the nonlinearity of an amplifier and have high efficiency can be provided.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIG. In FIG. 1, a first input terminal 801 of a vector subtracter 102 which is an example of a first vector subtracter of the present invention is connected to an input terminal 101 which is an example of a parallel data input terminal of the present invention. Is connected to a vector integrator 103 which is an example of a vector integrator of the present invention, and an output of the vector integrator 103 is connected to a vector quantizer 104 which is an example of a first vector quantizer of the present invention. The output is connected to the output terminal 105. The output of the vector quantizer 104 is input to a second input terminal 802 of the vector subtracter 102.

  Next, the operation will be described. Parallel data is input to the input terminal 101. Here, these are I data (in-phase data) and Q data (quadrature-phase data). The I data and Q data are input to the vector integrator 103 via the vector subtracter 102. The vector integrator 103 integrates a vector formed by the I data and the Q data by a vector operation. The result of this integration is input to the vector quantizer 104.

  First, the case where the vector quantizer 104 quantizes the magnitude of a vector will be described. When 0 <a (a is a real number), a vector having a magnitude of 0 or a is output depending on the magnitude of the input vector to the vector quantizer 104. As a quantization method, for example, when the size of the input vector is smaller than a which is the threshold value, the size of the output vector is set to 0 (see FIG. 2A). When the size is not smaller than a, the size of the output vector is set. Is defined as a (see FIG. 2B). Although there is no particular limitation on the phase of this output vector, it is typically considered that the phase is the same as the phase of the input vector to the vector quantizer 104. This output is output from an output terminal 105, and is simultaneously subjected to a subtraction process by a vector subtractor 102. Specifically, the vector subtractor performs an operation of subtracting a vector output from the vector quantizer 104 from a vector input from the input terminal 101 by a vector operation. The relationship between the parallel data I and Q input to the input terminal 101 when the modulated wave is subjected to a root raised cosine filter with π / 4 shift QPSK is shown. FIG. 3 shows that the parallel data output from the output terminal 105 is I ′ data and Q ′ data, and the relationship between them is illustrated when the horizontal axis is I ′ data and the vertical axis is Q ′ data. , As shown in FIG.

  An example of a circuit for implementing these data conversions will be described with reference to FIG. In FIG. 5, a first input terminal 811 of a scalar subtractor 403 which is an example of a first scalar subtractor of the present invention is connected to an input terminal 401, and an example of a second scalar subtractor of the present invention is connected to an input terminal 402. The first input terminal 813 of the scalar subtractor 404 is connected. The outputs of the scalar subtractors 403 and 404 are connected to a scalar integrator 405 as an example of a first scalar integrator of the present invention and a scalar integrator 406 as an example of a second scalar integrator of the present invention, respectively. . Outputs of the scalar integrators 405 and 406 are respectively input as data of a rectangular coordinate system to two inputs of a coordinate converter 407 which is an example of the first coordinate converter of the present invention. One output of the coordinate converter 407 is connected to a scalar quantizer 408 as an example of the first scalar quantizer of the present invention. The output of the scalar quantizer 408 and the other output of the coordinate converter 407 are connected to two inputs of a coordinate converter 409, which is an example of the second coordinate converter of the present invention. Two outputs of the coordinate converter 409 are connected to a second input terminal 812 of the scalar subtractor 403 and a second input terminal 814 of the scalar subtractor 404. Two outputs of the coordinate converter 409 are connected to an output terminal 410, which is an example of a first output terminal of the present invention, and an output terminal 411, which is an example of a second output terminal of the present invention. Here, the first vector quantizer of the present invention corresponds to the coordinate transformer 407, the scalar quantizer 408, and the coordinate transformer 409.

Next, the operation will be described. I data, which is an example of the first data of the present invention, and Q data, which is an example of the second data of the present invention, which are orthogonal to the I data, are input to input terminals 401 and 402, respectively. The I data input to the input terminal 401 is integrated by the scalar integrator 405 via the scalar subtractor 403 and input to the coordinate converter 407. The same processing is performed on the Q data input to the input terminal 402, and the Q data is input to the other input of the coordinate converter 407. The coordinate converter 407 performs conversion from a rectangular coordinate system to a polar coordinate system (amplitude, phase). That is, assuming that the outputs of the scalar integrators 405 and 406 are I2 and Q2, respectively, the data I2 and Q2 are converted into data M and θ based on (Equation 1) and (Equation 2). Here, M is the magnitude (amplitude) of I2 and Q2,
(Equation 1)
M = (I2 ² + Q2 ² ) ^1/2
θ is the angle between I2 and Q2,
(Equation 2)
θ = Arctan (Q2 / I2)
It is expressed as

  The amplitude data output from the coordinate converter 407 is input to the scalar quantizer 408. The scalar quantizer 408 quantizes an input signal. Specifically, for example, the scalar quantizer 408 outputs a, which is an example of the predetermined value of the present invention, when the input signal is equal to or more than a certain predetermined value a, and outputs 0 otherwise. The output from the scalar quantizer 408 is input to a coordinate converter 409. The phase data output from the coordinate converter 407 is input to the other input of the coordinate converter 409. The coordinate converter 409 converts polar coordinate system data into rectangular coordinate system data. That is, the input amplitude data and phase data are converted into rectangular coordinate system data such as I 'data, which is an example of the third data of the present invention, and Q' data, which is an example of the fourth data of the present invention. The output from the coordinate converter 409 is fed back to scalar subtractors 403 and 404. That is, I ′ data is input to the second input terminal 812 of the scalar subtractor 403, and Q ′ data is input to the second input terminal 814 of the scalar subtractor 403. The scalar subtractor 403 performs an operation of subtracting the I ′ data output from the coordinate converter 409 from the data I input from the input terminal 401. Similarly, the scalar subtractor 404 performs an operation of subtracting the data Q 'output from the coordinate converter 409 from the data Q input from the input terminal 402.

  Two data I 'and Q' output from the coordinate converter 409 are output from output terminals 410 and 411, respectively. Here, the two data I 'and Q' output from the output terminals 410 and 411 have a vector size of a or 0 and are signals suitable for realizing a highly efficient transmitter.

  Although the above description has been given of an example in which quantization is performed with binary values, quantization may be performed with any value. For example, quantization may be performed with three values of 0, a, and b (0 <a <b, a and b are real numbers). You can change it. In this case, when the input is greater than b, the scalar quantizer 408 outputs b, when the input is greater than a and less than b, the scalar quantizer 408 outputs a, and when the input is less than a, the scalar quantizer 408 outputs scalar. The quantizer 408 outputs 0.

  Also, quantization may be performed on the phase. For example, in the above description, an example in which the phase from the output vector from the vector quantizer 104 is the same as the phase from the input vector has been described, but the phase of the output vector is quantized to some point in accordance with the phase of the input vector. You may. For example, assume that the phase is quantized at four points of 45 °, 135 °, −45 °, and −135 °. As a criterion for quantization, for example, quantization may be performed at the phase point closest to the phase of the vector input to the vector quantizer. That is, when the phase of the input vector is 10 °, a phase of 45 ° is output, and when the phase of the input vector is 120 °, a phase of 135 ° is output. Assuming that the output of this operation is I ′ data and Q ′ data, the relationship between the I ′ data and Q ′ data in this case is as follows. Assuming that the horizontal axis is I ′ data and the vertical axis is Q ′ data, FIG. It becomes as shown in.

  Further, in the case where quantization relating to the phase is also performed, the phase output from the coordinate converter 407 in FIG. 5 is input to a scalar quantizer (not shown), and the phase is quantized. 409. In that case, the first vector quantizer of the present invention also includes a scalar quantizer that quantizes the phase. Alternatively, the phase output from the coordinate transformer 407 may also be input to the scalar quantizer 408, and the scalar quantizer 408 may quantize both the amplitude and the phase.

  Next, a case where a transmitter is configured using the high-efficiency transmission data converter will be described with reference to FIG. The data generator 701 generates I and Q data. The high-efficiency transmission data converter 702 converts the I and Q data into I 'and Q' data as described above. The I ′ and Q ′ data are input to the modulator 703 and modulated. The signal output from the modulator 703 is amplified by an amplifier 704 as an example of the amplifier of the present invention, and after removing quantization noise by a bandpass filter 705 as an example of the bandpass filter of the present invention, It is transmitted from an antenna 706 which is an example of an antenna. Here, since the I ′ and Q ′ data output from the high-efficiency transmission data converter 702 have the size of a or 0, the output from the modulator 703 turns on the constant envelope signal as shown in FIG. It will be switched off. Therefore, even if the amplifier 704 is non-linear, no intermodulation distortion occurs. Therefore, the amplifier 704 does not need to have linearity and can operate near the saturation point of the amplification characteristic, thereby enabling high-efficiency operation.

  Although the description has been given here assuming that the amplitude of the signal vector magnitude output from the high-efficiency transmission data converter is a binary value of a or 0, the linearity required for the amplifier is reduced as compared with the conventional one even if the amplitude is multi-valued. Therefore, high efficiency can be achieved. That is, in the related art, since the input power changes continuously, linearity has been required over a wide power range (FIG. 9A). According to the data converter of the present invention, when the amplitude of the signal vector of the data converter is binary, the linearity of the amplifier is not required. Furthermore, when the amplitude is multi-valued, the possible input power is discrete as shown in FIG. 9C, and these input power values are indicated by dotted lines in FIGS. 9B and 9C. As shown, continuous linearity of the amplifier is not required as long as linearity is maintained with respect to discrete values of the amplitude.

  To specifically explain the reason, consider a case where the amplitude of the original I data and Q data greatly fluctuates. For example, it is assumed that the value fluctuates in a range of 20 dB. In this case, the amplifier must ensure linearity in the range of 20 dB. On the other hand, if the amplitude is quantized by, for example, three values of 0, 1, and 2, the amplifier changes by 6 dB between 1 and 2 when the amplifier operates, so that the amplifier must compensate for the linearity at the point of 6 dB difference. It is sufficient (see FIG. 9B).

  It is also conceivable to compensate for the nonlinearity of the amplifier 1005. An example is shown in FIG. The difference from FIG. 7 is that a distortion compensation circuit 1004 is added before the amplifier 1005. The distortion compensation circuit 1004 is a circuit including an active element, and has a distortion characteristic opposite to that of the amplifier 1005. That is, the distortion compensation circuit 1004 generates data for compensating for the nonlinearity of the amplifier 1005. Therefore, by combining the distortion compensation circuit 1004 and the amplifier 1005, linear amplification can be performed.

  Another example is shown in FIG. A distortion compensator 1103 is connected after the high-efficiency transmission data converter 1102. The distortion compensating unit 1103 performs digital signal processing on the baseband signal to predistort the signal to the inverse characteristic of the distortion generated in the amplifier 1105 in order to compensate for the distortion of the amplifier 1105. Here, data is controlled by a compensation table corresponding to the magnitude of the envelope of the signal input to the amplifier 1105. Conventionally, the sizes of I and Q are finely discretely divided, and it is necessary to provide a table for them, so that a large table is required. On the other hand, when the high-efficiency data converter for transmission 1102 is used as shown in FIG. 11, for example, when the amplitude is quantized by three values of 0, a, and 2a, only the two values of a and 2a are converted into a table. , The size of the distortion compensation table can be significantly reduced.

  In addition, a higher-order configuration can be considered as the high-efficiency transmission data converter. FIG. 12 shows an n-th configuration as an example.

  That is, an input terminal 106 to which I and Q data are input as an example of parallel data having a predetermined vector, an arithmetic circuit connected to the input terminal 106, and a first vector quantum of the present invention connected to the arithmetic circuit. A first vector quantizer, which is an example of a quantizer, and an output terminal 114 connected to the vector quantizer 111. The arithmetic circuit has a first input terminal 801 and a second input terminal 802. The number of unit circuits of the vector subtracter 107 and the vector integrator 108 connected to the output side of the vector subtracter 107 are n. The output of the output terminal 114 is the vector subtraction of each of the unit circuits. Input to all the second input terminals 802 of the circuit 107, and the input terminal 106 is connected to the first input terminal of the vector subtracter 107 of the first unit circuit. The unit circuit each other has only to have a structure in which a first input terminal of the output terminal and a vector subtracter 107 vector integrator 108 is connected. FIG. 30 shows an example of such a high-order specific configuration. When such a high-order configuration is applied, an ordinary delta-sigma modulator (for example, “Delta-Sigma Data Converters Theory, Design, and Simulation” by SR Norsworthy, R. Schreitter, GC Temes) ( U.S.A., IEEE Press, 1997, p.14) can reduce noise near the desired wave.

  Typically, up to the data converter is realized by digital signal processing, and after DA conversion, modulation is performed by the modulator. Furthermore, if the output up to the modulator is realized by digital signal processing, the number of analog parts can be reduced.

  In the case of a multi-mode transmitter that transmits a plurality of modulated waves, the noise level can be minimized by changing the predetermined value a according to the type of modulation. That is, if the peak is large due to the modulation, the value of a is increased, and if the peak is small, the value of a is reduced.

  In the case of a transmitter that transmits signals of a plurality of frequencies, transmission of a plurality of frequencies can be handled by changing the band (pass frequency) of a band-pass filter connected to the output of the amplifier according to the transmission frequency. .

  Although the output of the vector quantizer 111 is input to each subtractor in the configuration shown in FIG. 12, the output of each integrator may be input to each subtractor. For example, as shown in FIG. 13, the output of the vector 110 may be amplified or attenuated by a scalar multiple by the amplifier 115 and input to the vector subtractor 109, or the output of the vector quantizer 111 may be used as the vector subtraction as feedback. May be input to one or both of the devices 107 and 109.

  Further, in the transmitter shown in FIG. 7, a configuration in which a low-pass filter 708 is inserted between the high-efficiency transmission data converter 702 and the modulator 703 as shown in FIG. 29 is also conceivable. Since the quantization noise covers a wide frequency range, if the unnecessary signal is suppressed by limiting the band before being input to the modulator 703, the specifications of the band-pass filter 705 after the amplifier 704 can be relaxed. In this case, since the data output from the high-efficiency transmission data converter 702 needs to secure from DC to half the clock frequency, the cutoff frequency of the low-pass filter 708 may be higher than this.

Further, although the delay element is not described in the present embodiment, a delay element may be inserted between each component. For example, in FIG. 1, a path from the vector subtractor 102 to the vector integrator 103, a path from the vector integrator 103 to the vector quantizer 104, and a path from the vector quantizer 104 to the vector subtractor 102. It may be inserted into any of the paths.
(Embodiment 2)
Embodiment 2 of the present invention will be described with reference to FIG. In FIG. 14, a first input terminal 801 of a vector subtracter 202 which is another example of the first vector subtracter of the present invention is connected to an input terminal 201 which is another example of the parallel data input terminal of the present invention. The output of the subtracter 202 is connected to a vector quantizer 203 which is an example of the second vector quantizer of the present invention. An output of the vector quantizer 203 is connected to a second input terminal 802 of the vector subtracter 202 via a delay unit 204. An output terminal 205 is connected to the output of the vector quantizer 203.

  Next, the operation will be described. First, consider the case where the vector quantizer 203 quantizes the magnitude of a vector. Parallel data is input to the input terminal 201. These are called I data and Q data. This data is input to the vector quantizer 203 via the vector subtractor 202. The vector quantizer 203 outputs a vector having a predetermined amplitude a. Although the phase of this vector is not particularly limited, for example, it is set to be equal to the phase of the input parallel data. The output from the vector quantizer 203 is delayed by one or several clocks by a delay unit 204 and then input to a second input terminal 802 of the vector subtractor 202. The delay amount is, for example, one clock. The vector subtracter 202 subtracts the data input from the input terminal 201 by the data input from the delay unit 204. An output terminal 205 is connected to an output of the vector quantizer 203, and parallel data is output.

  The relationship between the parallel data I and Q input to the input terminal 201 is shown in FIG. 15, where the horizontal axis is I data and the vertical axis is Q data, and the parallel data output from the output terminal 205 is as shown in FIG. Assuming that the relationship is I 'data and Q' data, the relationship is shown in FIG. 16 when the horizontal axis is I 'data and the vertical axis is Q' data.

  An example of a circuit for implementing these data conversions will be described with reference to FIG. In FIG. 17, a first input terminal 821 of a scalar subtractor 503 which is an example of a first scalar subtractor of the present invention, and a scalar subtractor which is an example of a second scalar subtractor of the present invention are provided at input terminals 501 and 502, respectively. A first input terminal 823 of the 504 is connected. Outputs of the scalar subtractors 503 and 504 are connected to two inputs of a coordinate converter 505, which is an example of a first coordinate converter of the present invention, as data of a rectangular coordinate system. An output of the scalar quantizer 506, which is an example of the second scalar quantizer of the present invention, and an output of the coordinate converter 505 are connected to two inputs of a coordinate converter 507, which is an example of the second coordinate converter of the present invention. It is connected. The two outputs of the coordinate transformer 507 are connected to the second input terminal 822 of the scalar subtractor 503 and the second input terminal 824 of the scalar subtractor 504 via the delay unit 508 and the delay unit 509. . Two outputs of the coordinate converter 507 are connected to an output terminal 510 which is an example of a first output terminal of the present invention, and an output terminal 511 which is an example of a second output terminal of the present invention. Here, the second vector quantizer of the present invention corresponds to the coordinate transformer 505, the scalar quantizer 506, and the coordinate transformer 507.

  Next, the operation will be described. I data and Q data are input to input terminals 501 and 502, respectively. The I data input to the input terminal 501 is input to the coordinate converter 505 via the scalar subtractor 503. The same processing is performed on the Q data input to the input terminal 502, and the Q data is input to the other input of the coordinate converter 505.

In the coordinate converter 505, conversion from a rectangular coordinate system to a polar coordinate system (amplitude, phase) is performed. That is, assuming that the outputs of the scalar subtractors 503 and 504 are I2 and Q2, respectively, the data I2 and Q2 are converted into data M and θ based on (Equation 3) and (Equation 4). Here, M is the magnitude (amplitude) of I2 and Q2,
(Equation 3)
M = (I2 ² + Q2 ² ) ^1/2
θ is the angle between I2 and Q2,
(Equation 4)
θ = Arctan (Q2 / I2)
It is expressed as

  The coordinate converter 505 outputs amplitude data M and phase data θ. The vector quantizer 506 outputs a constant value a. The output from the scalar quantizer 506 is input to a coordinate converter 507. The phase data output from the coordinate converter 505 is input to the other input of the coordinate converter 507. The coordinate converter 507 converts data in the polar coordinate system into data in the rectangular coordinate system. That is, the inputted constant value a and the phase data θ as the amplitude data are defined by the orthogonal coordinate system of I ′ data which is an example of the third data of the present invention and Q ′ data which is an example of the fourth data of the present invention. Convert to data.

  The output from the coordinate converter 507 is fed back to the scalar subtractors 503 and 504 via the delay units 508 and 509.

  The scalar subtractor 503 performs an operation of subtracting the I ′ data output from the coordinate converter 507 and delayed from the data input from the input terminal 501. Similarly, the scalar subtractor 504 performs an operation of subtracting the Q ′ data output from the coordinate converter 507 and delayed from the data input from the input terminal 502. Two data I 'and Q' output from the coordinate converter 507 are output from output terminals 510 and 511, respectively.

  Here, an example in which quantization is performed with one value has been described, but quantization may be performed with any value. For example, quantization may be performed with two values of a and b (a <b). In this case, for example, when the magnitude of the vector input to the vector quantizer 203 is smaller than the intermediate value between a and b, the magnitude of the output vector may be set to a, and when the magnitude is equal or greater, b may be set.

  Also, quantization may be performed on the phase. For example, in the above description, an example in which the phase of the output vector from the vector quantizer 203 is the same as the phase of the input vector has been described, but the phase of the output vector is quantized to some points in accordance with the phase of the input vector. Is also good. For example, assume that the phase is quantized at four points of 45 °, 135 °, −45 °, and −135 °. As a criterion for quantization, for example, quantization may be performed at the phase point closest to the phase of the vector input to the vector quantizer. That is, when the phase of the input vector is 10 °, a phase of 45 ° is output, and when the phase of the input vector is 120 °, a phase of 135 ° is output. Assuming that the output of this operation is I 'data and Q' data, the horizontal axis is I 'data, and the vertical axis is Q' data, the relationship is shown in FIG.

  Further, in the case where quantization relating to the phase is also performed, the phase output from the coordinate converter 505 in FIG. 17 is input to a scalar quantizer (not shown), and the phase is quantized. 507 may be input. In that case, the second vector quantizer of the present invention also includes a scalar quantizer for quantizing the phase. Alternatively, the phase output from the coordinate converter 505 may also be input to the scalar quantizer 506, and the scalar quantizer 506 may quantize both the amplitude and the phase.

A case where a transmitter is configured using such a data converter will be described. The configuration is the same as that of the first embodiment, as shown in FIG. However, the time waveform of the output is as shown in FIG. 19 when the amplitude is quantized by one value, and is an angle-modulated wave having a constant envelope. Therefore, even when the amplifier 704 is non-linear, no intermodulation distortion occurs. Therefore, the amplifier 704 does not need to have linearity and can operate near the saturation point of the amplification characteristic, thereby enabling high-efficiency operation.
(Embodiment 3)
Embodiment 3 of the present invention will be described with reference to FIG. In FIG. 20, a first input terminal 831 of a vector subtracter 302 which is another example of the first vector subtracter of the present invention is connected to an input terminal 301 which is another example of the parallel data input terminal of the present invention. , The output of the vector subtractor 302 is connected to a vector quantizer 303 which is another example of the second vector quantizer of the present invention. The output of the vector quantizer 303 is connected to a vector subtractor 304 which is an example of the second vector subtracter of the present invention. The output of the vector subtractor 302 is connected to a second input terminal 842 of the vector subtractor 304. An output of the vector subtractor 304 is connected to a second input terminal 832 of the vector subtractor 302 via a delay unit 305. An output terminal 306 is connected to the output of the vector quantizer 303.

  Next, the operation will be described. Parallel data is input to the input terminal 301. These are called I data and Q data. This data is input to the vector quantizer 303 via the vector subtractor 302. The vector quantizer 303 outputs a vector having a predetermined amplitude a. The phase of this vector is made equal to the phase formed by the input parallel data I and Q. An output from the vector quantizer 303 is input to a first input terminal 841 of the vector subtractor 304. The output of the vector subtractor 302 is input to a second input terminal 842, which is the other input of the vector subtractor 304.

  The vector subtractor 304 performs an operation of subtracting the output of the vector subtractor 302 from the output of the vector quantizer 303. The output of the vector subtractor 304 is input to a second input terminal 832 which is the other input of the vector subtracter 302 after being delayed by one clock in the delay unit 305. The vector subtractor 302 subtracts the data output from the delay unit 305 from the data input from the input terminal 301. An output terminal 306 is connected to the output of the vector quantizer 303, and parallel data is output.

  The relationship between the parallel data I and Q input to the input terminal 301 is shown in FIG. 21, where the horizontal axis is I data and the vertical axis is Q data, and the parallel data output from the output terminal 306 is as shown in FIG. Assuming that the relation is I 'data and Q' data, the relationship between them is shown in FIG. 22 when the horizontal axis is I 'data and the vertical axis is Q' data.

  An example of a circuit for implementing this data conversion will be described with reference to FIG. In FIG. 23, a scalar subtractor 603 as an example of a first scalar subtractor of the present invention and a scalar subtractor 604 as an example of a second scalar subtractor of the present invention are connected to input terminals 601 and 602, respectively. I have. Outputs of the scalar subtractors 603 and 604 are connected to two inputs of a coordinate converter 605 which is an example of the first coordinate converter of the present invention. The output of the scalar quantizer 606, which is another example of the second scalar quantizer of the present invention, and the output of the phase data of the coordinate converter 605 are the coordinate converter 607, which is an example of the second coordinate converter of the present invention. Are connected to two inputs. Here, the second vector quantizer of the present invention corresponds to the coordinate transformer 605, the scalar quantizer 606, and the coordinate transformer 607.

  Two outputs of the coordinate converter 607 are provided as third data and fourth data, respectively, as a first input terminal 855 of a scalar subtractor 608 which is an example of a third scalar subtracter of the present invention, and a fourth scalar subtractor of the present invention. Are connected to a first input terminal 857 of a scalar subtractor 609, which is an example of the scalar subtractor 609. Outputs of the scalar subtractors 603 and 604 are input to second inputs 856 and 858 which are the other inputs of the scalar subtractors 608 and 609, respectively. The outputs of the scalar subtractors 608 and 609 are connected to the other inputs of the scalar subtractors 603 and 604, the second input terminal 852 and the second input terminal 854, via the delay units 610 and 611. I have. The output of the coordinate converter 607 is connected to an output terminal 612 which is an example of a first output terminal of the present invention, and an output terminal 613 which is an example of a second output terminal of the present invention.

Next, the operation will be described. I data, which is an example of the first data of the present invention, and Q data, which is an example of the second data of the present invention, orthogonal to the I data are input to the input terminals 601 and 602, respectively. The I data input to the input terminal 601 is input to the coordinate converter 605 via the scalar subtractor 603. The same process is performed on the Q data input to the input terminal 602, and the Q data is input to the other input of the coordinate converter 605. The coordinate converter 605 performs conversion from a rectangular coordinate system to a polar coordinate system (amplitude, phase). That is, assuming that the outputs of the scalar subtracters 603 and 604 are I2 and Q2, respectively, the data I2 and Q2 are converted into the data M and θ based on (Equation 5) and (Equation 6). Here, M is the magnitude (amplitude) of I2 and Q2,
(Equation 5)
M = (I2 ² + Q2 ² ) ^1/2
θ is the angle between I2 and Q2,
(Equation 6)
θ = Arctan (Q2 / I2)
It is expressed as

  The coordinate converter 605 outputs amplitude data M and phase data θ. The scalar quantizer 606 outputs a constant value a. An output from the scalar quantizer 606 is input to one input of a coordinate converter 607. The phase data output from the coordinate converter 605 is input to the other input of the coordinate converter 607. The coordinate converter 607 converts polar coordinate system data into rectangular coordinate system data. That is, the inputted amplitude data and phase data as the constant value a are converted into I ′ data which is an example of the third data of the present invention and Q ′ which is an example of the fourth data of the present invention in the orthogonal coordinate system. I do. Here, the third and fourth data of the present invention are data converted corresponding to the first and second data of the present invention.

  The output from the coordinate converter 607 is output to the output terminals 612 and 613, and is also input to the first input terminal 855 of the scalar subtractor 608 and the first input terminal 857 of the scalar subtractor 609. The outputs of the scalar subtractors 603 and 604 are input to the other input of the scalar subtractors 608 and 609, that is, the second input terminal 856 and the second input terminal 858. The scalar subtracter 608 performs an operation of subtracting the output of the scalar subtractor 603 from the output I 'of the coordinate converter 607. Similarly, the scalar subtractor 609 subtracts the output of the scalar subtractor 604 from Q 'output from the coordinate converter 607. The fifth data and the sixth data output from the scalar subtractors 608 and 609 are delayed by one clock in the delay units 610 and 611, and then the second input terminals 852, which are the other inputs of the scalar subtractors 603 and 604, 854 respectively. The scalar subtractor 603 performs an operation of subtracting the output of the delay unit 610 from the signal input from the input terminal 601. Similarly, the scalar subtractor 604 performs an operation of subtracting the output of the delay unit 611 from the signal input from the input terminal 602.

  Here, an example in which quantization is performed with one value has been described, but quantization may be performed with any value. For example, quantization may be performed with two values a and b (a <b). In this case, for example, when the magnitude of the vector input to the vector quantizer 303 is smaller than an intermediate value between a and b, the magnitude of the output vector may be set to a, and when it is larger, the magnitude may be set to b.

  Also, quantization may be performed on the phase. For example, in the above description, an example in which the phase of the output vector from the vector quantizer 303 is the same as the phase of the input vector has been described, but the phase of the output vector is quantized to some points in accordance with the phase of the input vector. Is also good. For example, the phase is quantized at 45 °, 135 °, −45 °, and −135 °. As a criterion for quantization, quantization may be performed at the phase point closest to the phase of the vector input to the vector quantizer. That is, when the phase of the input vector is 10 °, a phase of 45 ° is output, and when the phase of the input vector is 120 °, a phase of 135 ° is output. If the output of this operation is I 'data and Q' data, the horizontal axis is I 'data, and the vertical axis is Q' data, the relationship is shown in FIG.

  In addition, in the case of performing the quantization relating to the phase, the phase output from the coordinate converter 605 in FIG. 23 is input to a scalar quantizer (not shown), and after the phase is quantized, the coordinate converter 607 may be input. In that case, the second vector quantizer of the present invention also includes a scalar quantizer for quantizing the phase. Alternatively, the phase output from the coordinate transformer 605 may also be input to the scalar quantizer 606, and the scalar quantizer 606 may quantize both the amplitude and the phase.

A case where a transmitter is configured using such a data converter will be described. The configuration is the same as that of the first embodiment, as shown in FIG. However, the time waveform of the output is as shown in FIG. 19, which is a constant envelope angle modulated wave. Therefore, even when the amplifier 704 is non-linear, no intermodulation distortion occurs. Therefore, the amplifier 704 does not need to have linearity and can operate near the saturation point of the amplification characteristic, thereby enabling high-efficiency operation.
(Embodiment 4)
Embodiment 4 will be described with reference to FIG. The transmitter shown in FIG. 25 is connected to a data generator 1201 for generating parallel data, a data converter 1202 of the first to third embodiments connected to the data generator 1201, and a data converter 1202. A first modulator 1204, a first amplifier 1206 connected to the first modulator 1204, and a vector subtraction which is an example of a third vector subtractor of the present invention in which one input side is connected to the data generator 1201. Modulator 1203, a second modulator 1205 connected to the output side of the vector subtractor 1203, a second amplifier 1207 connected to the second modulator 1205, an output side of the first amplifier 1206, and the second amplifier 1207. Are connected as inputs, the output of the first amplifier 1206 and the output of the second amplifier 1207 are combined, and the combined signal is It includes a synthesizer 1208 to force, and an antenna 1209 connected to the output side of the combiner 1208. The output of the data converter 1202 is also connected to the other input side of the vector subtractor 1203, and the vector subtractor 1203 generates the data generated by the data generator 1201 from the parallel data converted by the data converter 1202. By subtracting the parallel data, quantization noise data is output. Then, the synthesis is performed with substantially equal amplitude and opposite phase with respect to the quantization noise data.

  In FIG. 25, data (I and Q) generated by a data generator 1201 which is an example of a data generation unit of the present invention is converted into I ′ and Q ′ by a high-efficiency transmission data converter 1202. . These I 'and Q' contain a quantization noise component in the desired signal, and this quantization noise must be removed. Although there is a method of removing using a band-pass filter, it is difficult to remove because the frequency is near the desired wave, and the size increases.

  Therefore, only the noise component is extracted by subtracting (I, Q) from (I ', Q') by the vector subtractor 1203. The noise component is quadrature-modulated and amplified, and is combined with the output signal of the first amplifier 1206 by the combiner 1208. At this time, the synthesis is controlled so that the noise component has a substantially opposite phase, that is, a phase difference of substantially 180 degrees. That is, the noise component included in the signal output from the data converter 1202 is synthesized by the synthesizer 1208 such that the noise component output from the vector subtractor 1203 has substantially the same amplitude and substantially the opposite phase. Is done.

  With such a configuration and operation, quantization noise can be removed without using a bandpass filter. However, the quantization noise is spread over a wide band, and it is difficult to remove all the noise. Therefore, a configuration in which quantization noise in a certain band is removed by this configuration and quantization noise outside the band is removed by a band-pass filter is considered. In this configuration, since the frequency interval between the quantization noise and the desired wave becomes large, a small-sized and low-loss bandpass filter can be realized.

  As described above, according to the present invention, a signal obtained by performing a switching operation of a constant envelope signal is obtained by modulating data output from the high-efficiency transmission data converter. Therefore, a device connected at the subsequent stage does not need linearity, and a highly efficient transmitter can be realized.

  Although the configuration using the delay unit to delay each data by a predetermined clock has been described above, the data may be delayed without using the delay unit.

  Further, in the above description, each vector quantizer quantizes the amplitude data by multi-valued, which means that among the n (n is 2 or more) thresholds, the largest one of the thresholds smaller than the size of the input vector is Each quantizer outputs a vector whose amplitude is equal to the phase of the input vector, and when the magnitude of the input vector is larger than the largest threshold among the n thresholds, the magnitude is the magnitude of the largest threshold. By the way, a vector whose phase is equal to the input vector is output, and when the magnitude of the input vector is smaller than the smallest threshold value among the n threshold values, it means that a zero vector is output.

  In the above description, an example in which both the amplitude data and the phase data are quantized has been described. However, quantization of only the amplitude data reduces quantization noise.

  In the above description, the data converter of the present invention has been described as a transmission data converter. However, there may be a data converter other than transmission, such as a reception data converter. Even in such a case, a similar effect can be obtained in that the effect of nonlinearity of an active circuit such as an amplifier can be suppressed.

  The present invention also includes a signal generator including the data converters according to the first to third embodiments and a quadrature modulation unit that performs quadrature modulation on the output of each data converter.

  In addition, as shown in FIG. 26, the present invention provides a transmitter 2002 and / or a receiver 2003 having the data converter or the signal generator described above, for transmitting and / or receiving a signal. A communication device 2001 including the antenna 5004 is included.

  ADVANTAGE OF THE INVENTION According to the data converter and the data conversion method concerning this invention, the influence of the nonlinearity of an amplifier can be suppressed and it is useful as a transmitter, a communication apparatus, etc.

FIG. 2 is a diagram illustrating a configuration of a data converter according to the first embodiment of the present invention. (A) A diagram illustrating the operation of the data converter according to the first embodiment of the present invention. (B) A diagram illustrating the operation of the data converter according to the first embodiment of the present invention. FIG. 4 shows characteristics of the data converter according to the first embodiment of the present invention. FIG. 4 shows characteristics of the data converter according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of an embodiment of a data converter according to the first embodiment of the present invention; FIG. 4 shows characteristics of the data converter according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a transmitter using the data converter according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating an operation of a transmitter using the data converter according to the first embodiment of the present invention. (A) A diagram illustrating the operation of a transmitter using the data converter according to the first embodiment of the present invention (b) A diagram illustrating the operation of a transmitter using the data converter according to the first embodiment of the present invention (C) A diagram illustrating the operation of the transmitter using the data converter according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a transmitter using the data converter according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a transmitter using the data converter according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of a data converter according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of a data converter according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating a configuration of a data converter according to a second embodiment of the present invention. The figure which shows the characteristic of the data converter of Embodiment 2 of this invention. The figure which shows the characteristic of the data converter of Embodiment 2 of this invention. FIG. 4 is a block diagram showing a configuration of an embodiment of the data converter according to the second embodiment of the present invention; The figure which shows the characteristic of the data converter of Embodiment 2 of this invention. FIG. 4 is a diagram illustrating an operation of a transmitter that also uses a data converter according to Embodiment 2 of the present invention. FIG. 3 is a diagram illustrating a configuration of a data converter according to a third embodiment of the present invention. The figure which shows the characteristic of the data converter of Embodiment 3 of this invention. The figure which shows the characteristic of the data converter of Embodiment 3 of this invention. FIG. 9 is a block diagram showing a configuration of an embodiment of the data converter according to the third embodiment of the present invention; The figure which shows the characteristic of the data converter of Embodiment 3 of this invention. FIG. 2 is a block diagram showing a configuration of a transmitter using the quantization noise elimination circuit of the present invention. FIG. 2 is a diagram illustrating a configuration of a communication device according to the present invention. Block diagram showing the configuration of a conventional transmitter Diagram showing characteristics of conventional transmitter Configuration diagram of a transmitter using the data converter according to the first embodiment of the present invention FIG. 1 is a configuration diagram of a data converter according to a first embodiment of the present invention.

Explanation of reference numerals

101 input terminal 102 vector subtracter 103 vector integrator 104 vector quantizer 105 output terminal 106 input terminal 107, 109 vector subtracter 108, 110 vector integrator 111 vector quantizer 112, 113 amplifier 114 output terminal 201 input terminal 202 Vector subtracter 203 Vector quantizer 204 Delay unit 205 Output terminal 301 Input terminal 302, 304 Vector subtractor 303 Vector quantizer 305 Delay unit 306 Output terminal 401, 402 Input terminal 403, 404 Scalar subtractor 405, 406 Scalar integration Unit 407 coordinate converter (IQ → polar)
408 Scalar quantizer 409 Coordinate converter (polar → IQ)
410, 411 Output terminals 501, 502 Input terminals 503, 504 Scalar subtractor 505 Coordinate converter (IQ → polar)
506 Vector quantizer 507 Coordinate transformer (polar → IQ)
508, 509 Delay units 510, 511 Output terminals 601, 602 Input terminals 603, 604, 608, 609 Scalar subtracter 605 Coordinate converter (IQ → polar)
606 Vector quantizer 607 Data converter (polar → IQ)
610, 611 Delay unit 612, 613 Output terminal 701 Data generation unit 702 High-efficiency transmission data converter 703 Modulator 704 Amplifier 705 Bandpass filter 706 Antenna 1001 Data generation unit 1002 High-efficiency transmission data converter 1003 Modulator 1004 Distortion Compensation circuit 1005 Amplifier 1006 Bandpass filter 1007 Antenna 1101 Data generation unit 1102 High-efficiency transmission data converter 1103 Distortion compensation unit 1104 Modulator 1105 Amplifier 1106 Bandpass filter 1107 Antenna 1201 Data generation unit 1202 High-efficiency transmission data converter 1203 Vector subtractor 1204, 1205 Modulator 1206, 1207 Amplifier 1208 Combiner 1209 Output terminal 5001 Data generator 5003 Amplifier 5004 Antenna

Claims (31)

A parallel data input terminal to which parallel data having I data and Q data is input;
An arithmetic circuit connected to the parallel data input terminal;
A first vector quantizer connected to an output side of the arithmetic circuit;
An output terminal connected to the output side of the first vector quantizer;
The I data and the Q data form a predetermined vector,
The arithmetic circuit includes a first vector subtracter having a first input terminal and a second input terminal, and a unit circuit including a vector integrator connected to an output side of the first vector subtractor, wherein n (n Is a natural number) connected,
An output of the output terminal and / or an output of each of the vector integrators is input to a second input terminal of a first vector subtracter of each of the unit circuits,
The parallel data input terminal is connected to a first input terminal of a first vector subtracter of a first unit circuit,
The unit circuits have an output terminal of a vector integrator connected to a first input terminal of a first vector subtracter,
The first vector subtractor outputs parallel data obtained by subtracting a vector formed by the parallel data input to the second input terminal from a vector formed by the parallel data input from the first input terminal,
The vector integrator integrates a vector composed of the input parallel data,
The data converter, wherein the first vector quantizer outputs a predetermined value quantized with respect to at least a magnitude of an input vector.   The data converter according to claim 1, wherein the first vector quantizer outputs a vector having the same phase as an input vector. When the magnitude of the vector input to the first vector quantizer is greater than or equal to a predetermined threshold, the magnitude of the first vector quantizer is the predetermined threshold, and the phase of the input is Output a vector equal to the vector
The data converter according to claim 1, wherein the first vector quantizer outputs a zero vector when a magnitude of a vector input to the first vector quantizer is smaller than a predetermined threshold.   The data converter according to claim 1, wherein the first vector quantizer quantizes both the magnitude and the phase of the vector. A parallel data input terminal to which parallel data having a predetermined vector is input;
A first vector subtractor having a first input terminal and a second input terminal, wherein the first input terminal is connected to the parallel data input terminal;
A second vector quantizer connected to the output of the first vector subtractor;
An output terminal connected to an output side of the second vector quantizer;
The second vector quantizer outputs a predetermined value quantized with respect to at least the magnitude of the input vector;
The quantized predetermined value is input to a second input terminal of the first vector subtractor,
A data converter that outputs parallel data obtained by subtracting a vector formed by the parallel data input to the second input terminal from a vector formed by the parallel data input to the first input terminal; .   The data converter according to claim 5, wherein the second vector quantizer outputs a vector having the same phase as an input vector.   The data converter according to claim 5, wherein the second vector quantizer quantizes both the magnitude and the phase of the vector. A second vector subtractor having a first input terminal and a second input terminal, wherein the second input terminal is connected to the output side of the second vector quantizer;
An output of the first vector subtractor is also connected to a second input terminal of the second vector subtractor;
The second vector subtracter converts a vector formed by the parallel data input to the second input terminal of the second vector subtracter from a vector formed by the parallel data input to the first input terminal of the second vector subtractor. Output the subtracted parallel data,
The data converter according to claim 5, wherein an output of the second vector quantizer is input to a second input terminal of the first vector subtractor via the second vector subtractor. The first vector subtracter has a first scalar subtractor having a first input terminal and a second input terminal to which first data is input, and second data which is orthogonal to the first data. A second scalar subtractor having a first input terminal and a second input terminal;
The vector integrator has a first scalar integrator connected to the output of the first scalar subtractor, and a second scalar integrator connected to the output of the second scalar subtractor,
The first vector quantizer receives the output of the first scalar integrator and the output of the second scalar integrator as data of a rectangular coordinate system, and converts the input data of the rectangular coordinate system into a polar coordinate system. And a first scalar quantizer for quantizing at least the amplitude data output from the first coordinate converter, the first coordinate converter outputting the data of the polar coordinate system as amplitude data and phase data. Connected to the output side of the first scalar quantizer and / or the output side of the first coordinate converter, and as the data of the polar coordinate system, the first scalar quantizer and / or the first coordinate converter From the amplitude data and the phase data output from the third data corresponding to the first data and the second data as the data of the rectangular coordinate system. And a second coordinate converter for outputting a fourth data, and
The first scalar quantizer is connected to an output side of the first coordinate converter, and outputs at least amplitude data quantized as a predetermined value;
A first output terminal connected to the second coordinate converter and outputting the third data; a second output terminal connected to the second coordinate converter and outputting the fourth data; , And
At least one of the third data or the output of each of the first scalar integrators is input to at least a second input terminal of each of the first scalar subtractors, and the fourth data or each of the fourth scalar integrators is input. The data converter according to claim 1, wherein at least one of the outputs of the second scalar integrator is input to a second input terminal of at least one of the second scalar subtractors. N is 1;
The third data is input to a second input terminal of the first scalar subtractor, and the first scalar subtracter subtracts the third data from the first data, and the subtracted data is the first data. Output to the scalar integrator,
The fourth data is input to a second input terminal of the second scalar subtractor, and the second scalar subtracter subtracts the fourth data from the second data, and the subtracted data is the second data. The data converter according to claim 9, which is output to a scalar integrator.   The data converter according to claim 10, wherein the first vector quantizer outputs a vector having the same phase as an input vector.   The data converter according to claim 10, wherein the first vector quantizer quantizes the amplitude data and quantizes the phase data. The first vector subtracter has a first scalar subtractor having a first input terminal and a second input terminal to which first data is input, and second data which is orthogonal to the first data. A second scalar subtractor having a first input terminal and a second input terminal;
The second vector quantizer receives the output of the first scalar subtractor and the output of the second scalar subtractor as data of a rectangular coordinate system, and converts the input data of the rectangular coordinate system into a polar coordinate system. A first coordinate converter for converting the data into polar data and outputting the data in the polar coordinate system as amplitude data and phase data; and a second scalar quantizer for quantizing at least the amplitude data output from the first coordinate converter. The amplitude data and the phase data output from the second scalar quantizer and / or the first coordinate converter are converted from the data in the polar coordinate system into the data in the rectangular coordinate system, and correspond to the first data. A second coordinate converter that outputs third data and fourth data corresponding to the second data,
The second scalar quantizer is connected to an output side of the first coordinate converter, and outputs at least amplitude data quantized as a predetermined value;
The output terminal is connected to the second coordinate converter, a first output terminal for outputting the third data, and a second output terminal connected to the second coordinate converter, for outputting the fourth data. And having
The third data is input to a second input terminal of the first scalar subtractor, and the first scalar subtracter subtracts the third data from the first data, and the subtracted data is the first data. Input to one input of the coordinate converter,
The fourth data is input to a second input terminal of the second scalar subtractor, and the second scalar subtracter subtracts the fourth data from the second data, and the subtracted data is the first data. The data converter according to claim 5, which is input to the other input of the coordinate converter.   14. The data converter according to claim 13, wherein the second vector quantizer outputs a vector having the same phase as an input vector.   14. The data converter according to claim 13, wherein the second vector quantizer quantizes the amplitude data with respect to a magnitude of the vector and quantizes the phase data with respect to a phase of the vector. The first vector subtractor has a first scalar subtractor having a first input terminal to which first data is input and a second input terminal, and second data which is orthogonal to the first data. A second scalar subtractor having a first input terminal and a second input terminal.
The second vector quantizer receives the output of the first scalar subtractor and the output of the second scalar subtractor as data of a rectangular coordinate system, and converts the input data of the rectangular coordinate system into a polar coordinate system. A first coordinate converter for converting the data into polar data and outputting the data in the polar coordinate system as amplitude data and phase data; and a second scalar quantizer for quantizing at least the amplitude data output from the first coordinate converter. The amplitude data and the phase data output from the second scalar quantizer and / or the first coordinate converter are converted from the data of the polar coordinate system to the data of the orthogonal coordinate system, and correspond to the first data. And a second coordinate converter that outputs fourth data corresponding to the second data.
The second scalar quantizer is connected to an output side of the first coordinate converter, and outputs at least amplitude data quantized as a predetermined value;
The second vector subtractor receives the third data at a first input terminal thereof, receives output data from the first scalar subtractor at a second input terminal thereof, and outputs the first data from the third data. A third scalar subtractor for subtracting output data from the scalar subtractor and outputting as fifth data, the fourth data being input to a first input terminal thereof, and an output data from the second scalar subtractor being A fourth scalar subtractor that is input to a second input terminal and subtracts output data from the second scalar subtractor from the fourth data and outputs the result as sixth data;
The fifth data is input to a second input terminal of the first scalar subtractor, and the first scalar subtracter subtracts the fifth data from the first data, and the subtracted data is the first data. Input to one input of the coordinate converter,
The sixth data is input to a second input terminal of the second scalar subtractor, and the second scalar subtracter subtracts the sixth data from the second data, and the subtracted data is the first data. 9. The data converter according to claim 8, which is input to the other input of the coordinate converter.   17. The data converter according to claim 16, wherein the second vector quantizer outputs a vector having the same phase as an input vector.   17. The data converter of claim 16, wherein the second vector quantizer quantizes the amplitude data with respect to vector magnitude and quantizes the phase data with respect to vector phase. The first vector quantizer has n thresholds,
When the magnitude of the input vector to the first vector quantizer is larger than the largest threshold among the n thresholds, the magnitude is the magnitude of the largest threshold and the phase is Outputs a vector equal to the vector,
When the magnitude of the input vector to the first vector quantizer is smaller than the smallest threshold value among the n threshold values, a zero vector is output;
When the magnitude of the input vector to the first vector quantizer is between the smallest threshold and the largest threshold among the n thresholds, the largest of the thresholds smaller than the magnitude of the input vector is The data converter according to claim 1, wherein a large threshold value is set as the amplitude, and a vector whose phase is equal to the input vector is output.   9. The data converter according to claim 5, wherein the second vector quantizer outputs a vector having a predetermined amplitude and a phase equal to the input vector.   The second vector quantizer outputs a when the input vector is smaller than an intermediate value of a and b (a and b are non-negative real numbers and a <b). 9. The data converter according to claim 5, wherein b outputs b. A data converter according to claim 1 or 5,
A quadrature modulator for quadrature modulating an output from the data converter.   23. The signal generator according to claim 22, wherein said data converter is realized by digital signal processing. A signal generator according to claim 22,
An amplifier directly or indirectly connected to the quadrature modulator of the signal generator;
A bandpass filter connected to the amplifier;
A transmitter directly or indirectly connected to the bandpass filter.   A low-pass filter installed between an output side of the data converter and an input side of the quadrature modulation unit, for transmitting a signal output from the data converter to the quadrature modulation unit by performing low-pass filtering; A transmitter according to claim 24.   The transmitter according to claim 24, wherein the predetermined value is controlled according to a type of a modulated wave output from the transmitter.   The transmitter according to claim 24, wherein a pass frequency of the band-pass filter is controlled according to a frequency of the output signal.   The transmitter of claim 24, wherein the data converter generates data that compensates for the non-linearity of the amplifier. A data generator for creating parallel data,
The data converter according to claim 1 or 5, which is connected to the data generator.
A first modulator connected to the data converter;
A first amplifier connected to the first modulator;
A third vector subtractor having one input connected to the data generator;
A second modulator connected to the output of the third vector subtractor;
A second amplifier connected to the second modulator;
The output side of the first amplifier and the output side of the second amplifier are connected as inputs, respectively, and the output of the first amplifier and the output of the second amplifier are combined to output the combined signal. Synthesizer,
An antenna connected to the output side of the synthesizer,
The output of the data converter is also connected to the other input of the third vector subtractor;
The third vector subtractor outputs quantization noise data by subtracting the parallel data generated by the data generator from the parallel data converted by the data converter.
The transmitter, wherein the combining is performed on the quantized noise data with substantially equal amplitude and opposite phase.   A communication device comprising the transmitter according to claim 25, a receiver for receiving a signal, and an antenna for transmitting and / or receiving a signal. Inputting parallel data having I data and Q data to a parallel data input terminal;
A step of performing n (n is a natural number) arithmetic steps of a vector subtraction step and a vector integration step in an arithmetic circuit connected to the parallel data input terminal;
Outputting a predetermined value quantized with respect to at least the magnitude of the vector output from the arithmetic circuit,
The I data and the Q data form a predetermined vector,
The vector subtraction step includes a step of outputting parallel data obtained by subtracting an output vector of the arithmetic circuit and / or an output vector of each vector integration from a vector formed by the input parallel data,
The data conversion method, wherein the vector integration step includes a step of integrating a vector constituted by the input parallel data.

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