JP2002076891A - Pre-processor, oversampling analog/digital conversion method and receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pre-processor that can flexibly cope with a requirement of different accuracies from a propagation environment and a system. SOLUTION: In the pre-processor 100 of this invention, a dynamic rage detection section 101 detects a maximum dynamic range of an input signal. A sampling frequency decision section 102 decides a sampling frequency required for the maximum dynamic range of the input signal and controls a sampling frequency of an over-sampling frequency analog/digital converter 103. The over-sampling frequency analog/digital converter 103 uses the sampling frequency under the control of the sampling frequency decision section 102 to apply analog/ digital conversion to the input signal and outputs a digital signal obtained after the analog/digital conversion to an output terminal 112.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a preprocessor for performing oversampling A / D conversion on an analog signal received wirelessly, an oversampling A / D conversion method, and a receiving apparatus for performing reception processing using the same.

[0002]

2. Description of the Related Art First, as a technical background, an oversampling A / D converter will be described.

[0003] Oversampling A / D (or D
The / A) converter has features such as (1) quadrature modulation and non-adjustment (digitization) of detection, and (2) reduction of input / output pins of a chip. , Recently attracted attention.

Quantization noise power (quantization noise power spectrum
Range f where the ram and quantization noise are present _s/ 2; f_sIs
Sampling frequency) is constant and f_s/ 2
It has the property of being uniformly distributed up to. Therefore, sump
The quantization noise power spectrum increases as the ring frequency increases.
The ram spreads over a wide area and falls uniformly. For example, FIG.
As shown in the figure, quantization noise with large sampling frequency
N1 is equal to quantization noise N2 having a small sampling frequency.
Therefore, the quantization noise power spectrum becomes smaller.

[0005] The oversampling A / D conversion method is as follows.
By utilizing the property of the quantization noise power, LPF (Low Pa
By limiting the signal bandwidth by inserting an ss filter, the effect of quantization noise is suppressed and the ratio between the desired wave S and the noise N (hereinafter, referred to as “S / N ratio”) is improved.

A ΔΣ modulator, which is a kind of oversampling A / D converter, integrates the difference between the current analog input and the analog input one clock before as shown in FIG. To minimize it.

[0007] The quantization noise in the ΔΣ modulation method is the difference between the current analog input and the analog input one clock before. That is, the ΔΣ modulation method has a characteristic in which quantization noise passes through a high pass. Therefore, by the ΔΣ modulation method,
Since the quantization noise N3 has a high-pass characteristic while the input signal remains in the all-pass characteristic, the S / N ratio is improved as compared with the oversampling A / D conversion method as shown in FIG.

The method of determining the oversampling frequency when the ΔΣ modulation method is applied is disclosed in (“Oversampling A / D Conversion Technology”, Nikkei BP).

The oversampling A / D conversion technology is
Because a high oversampling frequency is required,
To date, GSM (Global Systems for Mobil
e communication) is only partially applied.

Next, the dynamic range and reception accuracy required for high-speed transmission will be described. In recent years, with the increasing demand for multimedia mobile communications,
There is a demand for realization of broadband transmission, and research is being advanced.

The higher the transmission rate is, the shorter one symbol time is, and more delay waves are observed. For example, the delay time in an urban area is generally said to be 5 μs at the maximum, and in GSM, the transmission rate is about 270 ksps, so that the delay wave exists in the delay wave with a maximum of about 1.4 symbol delay. On the other hand, the transmission rate studied in recent years is tens of Msps, so if it is assumed to be 20 Msps,
The delayed wave will be present in a delayed wave with a delay of up to 100 symbols. In other words, it is considered that as the transmission speed increases, more delayed waves appear to be multiplexed, and the dynamic range becomes larger.

As a technique for suppressing such a long delay wave, an adaptive array technique for controlling directivity is regarded as effective. However, even if the directivity is slightly deviated, the characteristics are greatly deteriorated. Therefore, the adaptive array technology requires a high receiving signal capturing accuracy. For example, in FIG. 10, when directivity is controlled by estimating that a delayed wave arrives from the angle indicated by the solid arrow A, if the delay wave actually arrives from the angle indicated by the solid arrow A, it can be suppressed by about 70 dB. However, if the delayed wave arrives from the angle indicated by the dashed arrow B due to lack of accuracy,
Only about B can be suppressed.

In consideration of the dynamic range of the adaptive array and the accuracy of receiving a received signal during high-speed transmission, a plurality of high-resolution A / D converters are provided so as to cover a very wide dynamic range. It is only realized while controlling with.

Next, the software defined radio will be described. Software defined radio means various systems (PDC, GSM, IS-9) depending on software download.
5)).

[0015] As described in the 1999 IEICE Communications Society Conference (B-5-96), software defined radio has been targeted only at low-rate systems so far, and has an IF (intermediate frequency). AGC (Auto G
It is merely considered that the signal is passed through an A / D converter with a predetermined accuracy by performing an Ain Control, or a plurality of wireless lines are provided according to the system.

From the above, it is anticipated that there will be a demand for a receiver that can have a wide dynamic range, is highly accurate, and can flexibly cope with a plurality of systems. However, at present, there is no study on software defined radio for a configuration to which the adaptive array is applied in response to high-speed transmission.

If the conventional example is adapted to high-speed transmission, the receiving performance also depends on the accuracy (resolution) of the A / D converter. Prepare it so that it can cope with a certain dynamic range, or use A /
It is conceivable that a plurality of D converters are prepared and switched by AGC.

[0018]

However, in a communication device used in a conventional mobile communication system,
Since a single type of A / D converter is used, the calculation is performed with the highest accuracy even in a situation where a very low accuracy (dynamic range) is required, such as under one-wave static characteristics, so that the amount of calculation increases. Also, if a wireless circuit is provided according to the system, the circuit scale becomes enormous.

The present invention has been made in view of the above points, and a preprocessor and an oversampling A / D converter capable of flexibly coping with a required accuracy different depending on a propagation environment and a system with one circuit. An object of the present invention is to provide a method and a receiving device capable of performing a receiving process using the method.

[0020]

SUMMARY OF THE INVENTION A preprocessor according to the present invention detects a dynamic range detecting means for detecting a maximum value of a dynamic range of an input signal, and determines a required sampling frequency according to the maximum value of a dynamic range of the input signal. A configuration including first sampling frequency determining means and oversampling A / D converting means for performing A / D conversion on the input signal at the sampling frequency determined by the first sampling frequency determining means is adopted.

According to this configuration, the sampling frequency of the oversampling A / D converter can be controlled in accordance with the dynamic range of the input signal. This makes it possible to flexibly perform A / D conversion processing with accuracy according to the propagation environment. In addition, the processing amount in the oversampling A / D converter can be reduced as compared with the case where the input signal is always taken in with the precision in consideration of the maximum dynamic range.

The preprocessor according to the present invention includes maximum precision extracting means for extracting the maximum precision which is the maximum value among the maximum values of the dynamic range of a plurality of input signals, and the dynamic range detecting means comprises The first sampling frequency determination means determines a required sampling frequency according to the maximum accuracy, and the oversampling A / D conversion means determines the input value at the determined sampling frequency. A configuration for performing A / D conversion on a signal is employed.

With this configuration, oversampling A is performed according to the maximum value of the dynamic range of a plurality of input signals.
Since the sampling frequency of the A / D converter can be controlled, even when a plurality of input signal sources such as an adaptive array are provided, the input signal is optimally adjusted for each oversampling A / D converter. And the A / D conversion process can be flexibly performed with an accuracy corresponding to the propagation environment. In addition, the processing amount in the oversampling A / D converter can be reduced as compared with the case where the input signal is always taken in with the precision in consideration of the maximum dynamic range.

A receiving apparatus according to the present invention includes any one of the above preprocessors, a first digital filter for shaping an A / D-converted received signal, and demodulating means for demodulating an output signal of the digital filter and extracting received data. Is adopted.

According to this configuration, the reception processing can be performed using the preprocessor that can perform the A / D conversion processing with an accuracy corresponding to the propagation environment, so that high-quality wireless communication can be performed.

In the receiving apparatus according to the present invention, the preprocessor comprises:
The first digital filter is provided with operation accuracy determination means for determining operation accuracy based on the maximum value of the dynamic range of the input signal, and the first digital filter is configured to form a signal with the operation accuracy determined by the operation accuracy determination means. .

According to this configuration, the operation accuracy of the digital filter can be controlled in accordance with the dynamic range of the input signal. Therefore, the input signal can be taken in the digital filter with the optimum accuracy, and the accuracy can be adjusted according to the propagation environment. Filtering can be performed flexibly.

In the receiving apparatus according to the present invention, the demodulating means extracts the received data and the control signal indicating the type of the system, and the sampling frequency determining means of the preprocessor determines the maximum value of the dynamic range of the input signal and the type of the system. In this case, the required sampling frequency is determined.

With this configuration, the sampling frequency of the oversampling A / D converter can be controlled according to the dynamic range of the input signal and the type of system. Even when dealing with a system, an input signal can be taken in with optimal accuracy in the oversampling A / D converter, and A / D conversion processing with accuracy according to the propagation environment can be flexibly performed.

The postprocessor of the present invention determines the required sampling frequency according to the type of the system.
A configuration comprising sampling frequency determination means and oversampling D / A conversion means for performing D / A conversion on the output signal of the second digital filter at the sampling frequency determined by the second sampling frequency determination means. take.

[0031] The communication apparatus of the present invention comprises a receiving apparatus, a modulating means for modulating transmission data, a second digital filter for shaping an output signal of the modulating means, and a D signal for the output signal of the second digital filter. And a post-processor for performing the A / A conversion, wherein the second sampling frequency determining means of the post-processor includes a sampling frequency required according to the type of system indicated by the control signal demodulated by the demodulating means of the receiving device. Is adopted.

With these configurations, the sampling frequency of the oversampling D / A converter can be controlled according to the type of the system, so that even when a plurality of systems are handled, it is optimal for the oversampling D / A converter. An input signal can be taken in with accuracy, and D / A conversion processing with accuracy according to the propagation environment can be flexibly performed.

[0033] A base station apparatus according to the present invention employs a configuration in which any one of the above-described receiving apparatuses or communication apparatuses is mounted.
Further, the communication terminal device adopts a configuration in which any one of the receiving devices or the communication devices described above is mounted.

With these configurations, a wide dynamic range can be obtained, and high-precision wireless communication that can flexibly cope with a plurality of systems can be performed.

According to the oversampling A / D conversion method of the present invention, a maximum value of a dynamic range of an input signal is detected, and a necessary sampling frequency is determined according to the maximum value of the dynamic range. A method of performing A / D conversion at the determined sampling frequency is employed.

According to this method, the sampling frequency of the oversampling A / D converter can be controlled in accordance with the dynamic range of the input signal. This makes it possible to flexibly perform A / D conversion processing with accuracy according to the propagation environment.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention is to detect a maximum value of a dynamic range of an input signal, determine a required sampling frequency, and control a sampling frequency of an oversampling A / D converter.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1) In Embodiment 1, a preprocessor that controls the sampling frequency of an oversampling A / D converter according to the dynamic range of an input signal will be described.

FIG. 1 is a block diagram showing a configuration of a preprocessor according to the present embodiment. The preprocessor 100 shown in FIG. 1 includes a dynamic range detection unit 101,
It mainly includes a sampling frequency determination unit 102 and an oversampling A / D converter 103.

The input terminal 111 is connected to a dynamic range detector 101 and an oversampling A / D converter 103.
Output terminal 112 is connected to the oversampling A /
Connect to D converter 103.

The dynamic range detector 101 detects the maximum value of the dynamic range of the input signal, and outputs a signal indicating the detection result to the sampling frequency determiner 102.

The sampling frequency determination unit 102 determines a necessary sampling frequency according to the maximum value of the dynamic range of the input signal, and sets an oversampling A / D
The sampling frequency of the converter 103 is controlled.

Oversampling A / D converter 103
Performs A / D conversion on an input signal at a sampling frequency based on the control of the sampling frequency determination unit 102, and outputs a digital signal after the A / D conversion to an output terminal 112.

As described above, by controlling the sampling frequency of the oversampling A / D converter in accordance with the dynamic range of the input signal, the input signal can be fetched with optimum accuracy, and the accuracy can be adjusted according to the propagation environment. A
/ D conversion processing can be performed flexibly.

The amount of processing in the oversampling A / D converter can be reduced as compared with the case where the input signal is always taken in with the precision in consideration of the maximum dynamic range. For example, consider the case of always capturing with 16-bit precision and performing multiplication in the subsequent processing.
At 16, the output requires 31 bits to ensure full accuracy. On the other hand, when the propagation environment is good and it is sufficient to capture the data with 8-bit precision, the present invention uses 8 × 8,
The output is sufficient for 15 bits even if full precision is secured.

(Embodiment 2) In Embodiment 2, when a plurality of input signal sources such as an adaptive array are provided, oversampling A is performed according to the maximum dynamic range of each input signal. A preprocessor for controlling the sampling frequency of the / D converter will be described.

FIG. 2 is a block diagram showing a configuration of the preprocessor according to the present embodiment. In the preprocessor shown in FIG. 2, components common to those in the preprocessor shown in FIG. 1 are denoted by the same reference numerals as those in FIG.

The preprocessor 200 shown in FIG.
Is different from the preprocessor 100 in that the number of dynamic range detectors 101-1 to 101-N and the number of oversampling A / D converters 103-1 to 103-N are N (N is a natural number of 2 or more). With this, the input terminal 111
−1 to N and N output terminals 112-1 to 112 -N are also prepared. Further, the preprocessor shown in FIG. 2 has a configuration in which a maximum precision extraction unit 201 is added, as compared with the preprocessor shown in FIG.

The input terminals 111-1 to 111-N are connected to the corresponding dynamic range detectors 101-1 to 10-N and the corresponding oversampling A / D converters 103-1 to 103-1N,
Output terminals 112-1 to 112-N are connected to corresponding oversampling A / D converters 103-1 to 103-N.

Dynamic range detectors 101-1 to 101-N
Detects the maximum value of the dynamic range of the input signal, and outputs a signal indicating the detection result to the maximum precision extraction unit 201.
Output to

The maximum precision extraction unit 201 is the largest one of the maximum values of the dynamic range of each input signal (hereinafter referred to as the maximum value).
"Maximum accuracy").

The sampling frequency determination unit 102 determines a required sampling frequency according to the maximum precision, and controls the sampling frequency of each of the oversampling A / D converters 103-1 to 103-N.

Oversampling A / D converter 103
−1 to N are sampling frequency determination units 10
A / D conversion is performed on the input signal at a sampling frequency based on the control of 2, and the digital signal after the A / D conversion is output to the output terminal 112.

As described above, oversampling A / D is performed according to the maximum value of the dynamic range of a plurality of input signals.
By controlling the sampling frequency of the converter, it is possible to capture the input signal with optimal accuracy even when there are multiple input signal sources such as an adaptive array. A / D conversion processing can be performed flexibly. In addition, the processing amount in the oversampling A / D converter can be reduced as compared with the case where the input signal is always taken in with the precision in consideration of the maximum dynamic range.

(Embodiment 3) Embodiment 3 describes a receiving apparatus equipped with the preprocessor described in the above embodiment.

FIG. 3 is a block diagram showing a configuration of the receiving apparatus according to the present embodiment. Receiver 300 shown in FIG.
Is mainly composed of an antenna 301, a reception RF unit 302, a preprocessor 100, a digital filter 303, and a demodulation unit 304.

The signal received by antenna 301 is orthogonally detected by reception RF section 302 and output to preprocessor 100 as a baseband signal. The preprocessor 100 has the configuration shown in FIG. 1 and converts an input analog signal into a digital signal.

The digital signal output from preprocessor 100 is shaped by passing through digital filter 303, demodulated by demodulator 304, and the received data is extracted.

As described above, the accuracy of A /
By performing reception processing using a preprocessor that can perform D conversion processing, high-quality wireless communication can be performed with an increase in the amount of computation suppressed.

The preprocessor shown in FIG. 2 can cope with a case where there are a plurality of input signal sources such as an adaptive array.

(Fourth Embodiment) In the fourth embodiment, the sampling frequency of the oversampling A / D converter and the calculation accuracy of the digital filter are controlled according to the maximum dynamic range of each input signal. The preprocessor will be described.

FIG. 4 is a block diagram showing a configuration of a preprocessor according to the present embodiment and a configuration of a receiving apparatus equipped with the preprocessor. In FIG. 4, the same components as those in FIG. 1 or FIG. 3 are denoted by the same reference numerals as those in FIG. 1 or FIG.

The receiving device 400 shown in FIG. 4 differs from the receiving device 300 shown in FIG. 3 in the internal configuration of the preprocessor 401 and the digital filter 402 in the operation of the digital filter 402.

Further, the preprocessor 401 is different from the preprocessor 100 shown in FIG.
1 is added.

The dynamic range detector 101 detects the maximum value of the dynamic range of the input signal, and outputs a signal indicating the detection result to the sampling frequency determiner 102 and the arithmetic precision determiner 411.

The calculation accuracy determining section 411 controls the calculation accuracy of the digital filter 402 based on the maximum value of the dynamic range of the input signal.

The digital filter 402 performs shaping (filtering) on the output signal of the preprocessor 401 with the calculation accuracy based on the control of the calculation accuracy determination unit 411, and outputs the signal to the demodulation unit 304.

As described above, by controlling the calculation accuracy of the digital filter in accordance with the dynamic range of the input signal, the input signal can be taken in with the optimum accuracy for the digital filter, and the filtering with the accuracy corresponding to the propagation environment can be performed. It can be done flexibly.

(Embodiment 5) In Embodiment 5, when dealing with a plurality of systems such as software defined radio, the sampling frequency of the oversampling A / D converter is changed according to the dynamic range of the input signal and the type of system. The preprocessor to be controlled will be described.

FIG. 5 is a block diagram showing a configuration of a preprocessor according to the present embodiment and a configuration of a receiving apparatus equipped with the preprocessor. In FIG. 5, the same components as those in FIG. 1 or FIG. 3 are denoted by the same reference numerals as those in FIG. 1 or FIG.

The receiving apparatus 500 shown in FIG. 5 differs from the receiving apparatus 300 shown in FIG.
2 is different from that of the demodulation unit 304.

Further, the preprocessor 501 is different from the preprocessor 100 shown in FIG.
Different from 02.

The demodulation section 502 includes a digital filter 30
The digital signal that has passed through 3 is demodulated to extract received data, and a control signal indicating the type of system is output to the sampling frequency determination unit 511 of the preprocessor 501.

Sampling frequency determination section 511 determines a required sampling frequency in accordance with the maximum value of the dynamic range of the input signal and the content of the demodulated control signal, and sets the sampling frequency of oversampling A / D converter 103. Control.

For example, the control signal indicating the type of the system is 2-bit information, and “00” indicates PDC and “01” indicates
Is PHS, “10” is GSM, “11” is IS-9
5 shall be represented.

If the oversampling converter is of the second order ΔΣ type, the dynamic range is 60 dB, and the control signal indicating the type of system is “10”, the necessary minimum sampling is performed based on the dynamic range and the bandwidth of GSM. The frequency can be calculated as 24 MHz.

Further, it is also possible to determine a more optimized sampling frequency in consideration of other GSM-specific specifications and a fundamental frequency of 13 MHz.

As described above, according to the dynamic range of the input signal and the type of the system, the oversampling A /
By controlling the sampling frequency of the D converter,
In addition to the effects of the first embodiment, even when a plurality of systems such as software defined radios are handled, an input signal can be taken into the oversampling A / D converter with optimal accuracy, and A with an accuracy corresponding to the propagation environment can be obtained. / D conversion processing can be performed flexibly.

This embodiment can be combined with Embodiment 4. That is, the preprocessor 5
By adding the calculation accuracy determining unit 411 to the digital filter 01, the calculation accuracy of the digital filter can be controlled based on the maximum value of the dynamic range of the input signal.

(Embodiment 6) In Embodiment 6, when dealing with a plurality of systems such as software defined radio, the sampling frequency of the oversampling D / A converter is changed according to the dynamic range of the input signal and the type of system. The post processor to be controlled will be described.

FIG. 6 is a block diagram showing the configuration of a post-processor according to the present embodiment and the configuration of a communication device equipped with this post-processor. In FIG. 6, the same components as those in FIG. 5 are denoted by the same reference numerals as those in FIG.

Communication apparatus 600 shown in FIG. 6 differs from receiving apparatus 500 shown in FIG. 5 in that modulation section 601, digital filter 602, post processor 603, and transmission RF section 604 are added. take.

The post processor 603 includes a sampling frequency determination unit 611 and an oversampling D
It mainly comprises an / A converter 612.

The demodulation section 502 includes a digital filter 30
The demodulator 3 demodulates the digital signal that has passed through No. 3 to extract received data, and outputs a control signal indicating the type of system to the sampling frequency determination unit 511 of the preprocessor 501 and the sampling frequency determination unit 611 of the post processor 603.

The transmission signal modulated by modulation section 601 passes through digital filter 602 and is output to oversampling D / A converter 612 of post processor 603.

The sampling frequency determination section 611 determines a required sampling frequency according to the maximum value of the dynamic range of the input signal and the content of the demodulated control signal, and determines the sampling frequency of the oversampling D / A converter 612. Control. Oversampling D / A
The converter 612 converts an input digital signal into an analog signal at a sampling frequency based on the control of the sampling frequency determination unit 611.

The analog signal output from the post processor 603 is converted to a radio frequency by the transmission RF section 604 and transmitted from the antenna 301.

As described above, by controlling the sampling frequency of the oversampling D / A converter according to the type of the system, the input to the oversampling D / A converter can be performed with optimum accuracy even when a plurality of systems are handled. A signal can be taken in, and D / A conversion processing with an accuracy corresponding to the propagation environment can be flexibly performed.

[0090]

As described above, according to the present invention,
By controlling the sampling frequency of the oversampling A / D converter according to the dynamic range of the input signal, the input signal can be fetched with the optimum accuracy for the oversampling A / D converter, and the accuracy according to the propagation environment A / D conversion processing can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a preprocessor according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a preprocessor according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 3 of the present invention.

FIG. 4 is a block diagram showing a configuration of a preprocessor according to a fourth embodiment of the present invention and a configuration of a receiving device equipped with the preprocessor.

FIG. 5 is a block diagram showing a configuration of a preprocessor according to a fifth embodiment of the present invention and a configuration of a receiving device equipped with the preprocessor.

FIG. 6 is a block diagram showing a configuration of a postprocessor according to a sixth embodiment of the present invention and a configuration of a communication device equipped with the postprocessor.

FIG. 7 is a diagram illustrating oversampling conversion.

FIG. 8 is a circuit diagram of a first-order ΔΣ modulation method

FIG. 9 is a diagram illustrating a first-order ΔΣ modulation method.

FIG. 10 is a diagram illustrating directivity of an adaptive array.

[Explanation of symbols]

 100, 200, 401, 501 Preprocessor 101 Dynamic range detecting unit 102, 511, 611 Sampling frequency determining unit 103 Oversampling A / D converter 201 Maximum precision extracting unit 300, 400, 500 Receiving device 301 Antenna 302 Receiving RF unit 303, 402 Digital filter 304, 502 Demodulation unit 411 Operation accuracy determination unit 600 Communication device 601 Modulation unit 602 Digital filter 603 Post processor 604 Transmission RF unit 612 Oversampling D / A converter

Claims (12)

[Claims] 1. A dynamic range detecting means for detecting a maximum value of a dynamic range of an input signal, a first sampling frequency determining means for determining a required sampling frequency according to the maximum value of a dynamic range of the input signal, And an oversampling A / D converter for performing A / D conversion at the sampling frequency determined by the first sampling frequency determiner. 2. The apparatus according to claim 1, further comprising a maximum accuracy extracting unit for extracting a maximum accuracy which is a maximum value among the maximum values of the dynamic ranges of the plurality of input signals, wherein the dynamic range detecting unit includes a dynamic range detecting unit for detecting a dynamic range of each of the input signals. Each of the maximum values is detected, the first sampling frequency determination means determines a necessary sampling frequency according to the maximum precision, and the oversampling A / D conversion means determines the sampling frequency for each of the input signals at the determined sampling frequency. 2. The preprocessor according to claim 1, wherein the preprocessor performs A / D conversion. 3. A preprocessor according to claim 1 or 2, a first digital filter for shaping an A / D-converted received signal, and a demodulating means for demodulating an output signal of the digital filter and extracting received data. A receiving device comprising: 4. The apparatus according to claim 1, wherein the preprocessor includes an operation accuracy determination unit that determines operation accuracy based on a maximum value of a dynamic range of the input signal, and wherein the first digital filter includes an operation accuracy determined by the operation accuracy determination unit. The receiving device according to claim 3, wherein the signal is shaped by: 5. A demodulation means for extracting received data and a control signal indicating a type of a system, and a sampling frequency determination means of a preprocessor determines a sampling frequency required according to a maximum value of a dynamic range of an input signal and a type of the system. 4. The method according to claim 3, wherein
Or the receiving device according to claim 4. 6. A second sampling frequency determining means for determining a required sampling frequency according to a type of a system, and an output signal of the second digital filter at a sampling frequency determined by the second sampling frequency determining means. Oversampling D that performs D / A conversion
/ A conversion means. 7. A receiving apparatus according to claim 5, a modulating means for modulating transmission data, a second digital filter for shaping an output signal of the modulating means, and a D / D converter for outputting an output signal of the second digital filter. 7. The post-processor according to claim 6, which performs A-conversion, wherein the second sampling frequency determining means of the post-processor is required according to the type of system indicated by the control signal demodulated by the demodulating means of the receiving device. A communication device for determining a proper sampling frequency. 8. A base station device comprising the receiving device according to claim 3. 9. A communication terminal device comprising the receiving device according to claim 3 mounted thereon. 10. A base station device comprising the communication device according to claim 7. 11. A communication terminal device comprising the communication device according to claim 7. 12. A maximum value of a dynamic range of an input signal is detected, a necessary sampling frequency is determined according to the maximum value of the dynamic range, and A / D conversion is performed on the input signal at the determined sampling frequency. Oversampling A / D conversion method.