JP2003332920A - Radio transmission apparatus and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve SN ratio in a transmission signal, and to reduce the number of required bits of a transmission digital signal. <P>SOLUTION: A diffusion section 101 diffuses and processes transmission data. A delay section 108 absorbs delay time generated at a section power calculation section 102. A gain section 109 multiplies gain (Gn) outputted from a delay control section 107 by transmission digital data. A transmission RRC filter 110 restricts the bandwidth of the transmission digital data. A DAC 111 converts the transmission digital data to transmission analog data. An orthogonal modulator 112 allows the transmission analog data to be subjected to orthogonal modulation. An inverse gain section 113 multiplies gain (1/Gn) outputted from the delay control section 107 by the transmission analog data. A radio transmission section 114 performs specific radio processing to the transmission analog data for transmitting from an antennal 115. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wireless transmission device and a wireless transmission method in a mobile communication system.

[0002]

2. Description of the Related Art A conventional radio transmitting apparatus includes a spreading section and a transmitting R.
RC (Root Raised Cosine) filter, DAC (Digital
Some have analog converters), modulators, and wireless transmitters. The transmission digital data is D / A converted in the DAC through the spreading unit and the transmission RRC filter. The output transmission analog data is transmitted from the antenna via the modulator and the wireless transmission unit (see "Keiji Tachikawa: W-CDMA communication system, page 29, Maruzen Co., Ltd.").

When the radio transmitting apparatus having the above configuration is installed in a base station, the transmission power is controlled according to the number of mobile stations so that the reception quality can be maintained when the mobile station receives data. There is. In addition, since the propagation path environment changes even during daytime and nighttime, the base station similarly controls the transmission power according to the propagation path environment.

[0004]

However, in the conventional radio transmitter, for example, when the number of mobile stations is small or when the propagation state is good such as at night, the dynamic range of the transmission signal is Since the situation is wide and the transmission power is small, there is a problem that the power level of the original digital data becomes very small. That is, since the DAC and the modulator process an analog signal, noise may be mixed in, and when noise is mixed in, the SN ratio deteriorates.

Although it is possible to increase the number of bits of the transmission signal in order to maintain the SN ratio at a certain level or higher, it is necessary to increase the number of bits of the dynamic range of the DAC, so the number of required bits increases. The problem arises.

The present invention has been made in view of the above points, and provides a radio transmission apparatus and a radio transmission method capable of maximally utilizing the dynamic range of a transmission signal and improving the SN ratio. The purpose is to It is another object of the present invention to provide a wireless transmission device and a wireless transmission method capable of keeping the power of a transmission signal within a certain range and reducing the required number of bits of a transmission digital signal.

[0007]

According to the present invention, there is provided a radio transmitting apparatus which comprises: an amplifying means for amplifying the power of a transmission digital signal to a maximum allowable level or a vicinity of the maximum allowable level; and a digital signal amplified by the amplifying means. To an analog signal, and an attenuator that attenuates the power of the analog signal converted by the converter to the power level of the transmission digital signal before being amplified by the amplifier. take.

According to this structure, the transmission digital data is amplified to a predetermined level once before being converted into analog data, and after being converted into analog data, the data is attenuated, so that the dynamic range of the transmission signal is maximally utilized. It is possible to improve the SN ratio.

In the radio transmitting apparatus of the present invention, the amplifying means for amplifying the power of the transmitting digital signal so that the required number of bits of the transmitting digital signal becomes the minimum or a bit number close to the minimum, and the amplifying means amplifies A configuration including: a conversion unit that converts the subsequent digital signal into an analog signal; and an attenuation unit that attenuates the power of the analog signal converted by the conversion unit to the power of the transmission digital signal before being amplified by the amplification unit. Take.

According to this structure, the power of the transmission signal is kept within a certain range because the transmission digital data is once amplified to a predetermined level before being converted into analog data and is attenuated after being converted into analog data. It is possible,
It is possible to reduce the required number of bits of the transmission digital signal.

In the above-mentioned structure, the radio transmitting apparatus of the present invention further comprises a power value acquiring means for acquiring the power value of the transmission digital signal before being amplified by the amplifying means, and the amplifying means includes the power value. It has an acquisition part which acquires the amplification gain according to the electric power value acquired by the value acquisition means, and employs a configuration for amplifying the power of the transmission digital signal using the amplification gain acquired by the acquisition part.

According to this configuration, since the power of the transmission digital signal is amplified by the amplification gain (gain) according to the power of the transmission digital signal before being amplified, it is possible to use the existing amplification circuit. It is possible to immediately provide a wireless transmission device having the same operation and effect.

In the above structure, the radio transmitting apparatus of the present invention further comprises a power value acquisition means for acquiring the power value of the transmission digital signal before being amplified by the amplification means, and the amplification means comprises the power When the power value acquired by the value acquisition means is within the predetermined power range,
The configuration has an acquisition unit that acquires a constant amplification gain, and that amplifies the power of the transmission digital signal using the amplification gain acquired by the acquisition unit.

According to this structure, when the power of the transmission digital signal is within the predetermined power range (power range), the power of the transmission digital signal is amplified by using the corresponding constant gain. Even when the power of the digital signal fluctuates or oscillates in a short cycle in a burst manner, it is possible to prevent the gain from being frequently changed, and to stabilize the wireless transmission device.

The radio transmitting apparatus of the present invention has the above-mentioned configuration in which there are a plurality of power ranges, and adjacent power ranges have a hysteresis characteristic by having overlapping portions.

According to this structure, since there are a plurality of power ranges and the adjacent power ranges have overlapping portions (crossover portions), hysteresis characteristics can be exerted when determining the power range. It is possible to prevent the power range from being changed frequently, and to stabilize the wireless transmission device.

In the above-mentioned configuration, the radio transmitting apparatus of the present invention adopts a configuration in which the size of the overlapping portions of the adjacent power ranges changes according to the fluctuation range of the power of the transmission digital signal.

According to this structure, when the fluctuation range of the power of the transmission digital signal is large, the crossover section is widened, so that it is possible to perform processing according to the fluctuation status of the power of the transmission digital signal. The wireless transmitter can be stabilized.

In the radio transmitting apparatus of the present invention having the above-mentioned configuration, the power value acquiring means, if the transmission digital signals before being amplified by the amplifying means have a plurality of channels, the power of the transmission digital signals of all the channels. A configuration is adopted in which the sum of the set values is acquired as the power value of the transmission digital signal.

According to this configuration, when there are a plurality of channels of transmission digital signals before being amplified, the gain is determined based on the sum of the power set values of the transmission digital signals of all channels. Therefore, the timing of multiplying the transmission digital data by the gain can be advanced and the control delay can be prevented. Further, since it is not necessary to provide the power calculation unit, the circuit scale can be reduced.

The radio transmitting apparatus according to the present invention has the above-mentioned configuration, and has a configuration including a delay unit that delays the transmission digital signal by at least the time during which the power value obtaining unit obtains the power value.

According to this configuration, the transmission digital data can be delayed by the amount of time while the power of the transmission digital data is being acquired (measurement or the like), and the control delay can be prevented.

In the radio transmitting apparatus according to the present invention, in the above configuration, when the current amplification amount in the amplification means is larger than the previous amplification amount, the amplification means delays the timing of amplifying the transmission digital signal by a predetermined time. As described above, a configuration having a control unit that controls the amplification unit is adopted.

According to this configuration, when the amplification amount of the current transmission digital signal is larger than the previous amplification amount (the gain by which the transmission digital signal is multiplied is larger than the previous time), the timing of amplification (multiplication by the gain) is delayed. Therefore, it is possible to prevent an excessive transmission power output caused by a slight shift in the timing of the amplification operation.

In the radio transmitting apparatus according to the present invention, in the above structure, when the current attenuation amount of the attenuating means is smaller than the previous attenuation amount, the attenuating means attenuates the analog signal converted by the converting means. Is provided with a control means for controlling the attenuating means so as to delay by a predetermined time.

According to this structure, when the attenuation amount of the analog signal transmitted this time is smaller than the attenuation amount of the previous time, the timing of attenuating the analog signal is delayed, so that an excessive transmission caused by a slight deviation of the timing of the attenuation operation. Power output can be prevented.

In the radio transmitting apparatus of the present invention, in the above configuration, when the power value currently acquired by the power value acquiring means is larger than the power value previously acquired by the power value acquiring means, the attenuating means is The control unit controls the attenuating unit so that the timing at which the analog signal converted by the converting unit is attenuated is delayed by a predetermined time from the timing at which the amplifying unit amplifies the transmission digital signal.

According to this structure, when the power value of the current transmission digital signal is larger than the previous value, the attenuation timing is delayed from the amplification timing by a predetermined time, which causes a slight deviation in the timing of the attenuation operation. It is possible to prevent excessive transmission power output.

In the wireless transmitter of the present invention, in the above configuration, when the power value currently acquired by the power value acquisition means is smaller than the power value previously acquired by the power value acquisition means, the attenuation means is The control unit controls the attenuating unit so that the timing at which the analog signal converted by the converting unit is attenuated is earlier than the timing at which the amplifying unit amplifies the transmission digital signal by a predetermined time.

According to this configuration, when the power value of the current transmission digital signal is smaller than the previous value, the attenuation timing is advanced by a predetermined time from the amplification timing. It is possible to prevent the transmission power output from being excessive.

The communication terminal apparatus of the present invention has a configuration including any one of the above-described wireless transmission apparatuses.

According to this structure, it is possible to provide a communication terminal device having the same effects as the above.

The base station apparatus of the present invention has a configuration having any one of the above-described wireless transmission apparatuses.

With this configuration, it is possible to provide a base station device having the same effects as the above.

In the wireless transmission method of the present invention, an amplification step of amplifying the power of the transmission digital signal to a maximum allowable level or a vicinity of the maximum allowable level, and the digital signal amplified by the amplifying step is converted into an analog signal. The method further includes a converting step and an attenuating step of attenuating the power of the analog signal converted by the converting step to the level of the power of the transmission digital signal before being amplified by the amplifying step.

According to this method, the transmission digital data is amplified to a predetermined level once before it is converted into analog data, and after being converted into analog data, it is attenuated, so that the dynamic range of the transmission signal is maximally utilized. It is possible to improve the SN ratio.

In the wireless transmission method of the present invention, an amplification step of amplifying the power of the transmission digital signal so that the required number of bits of the transmission digital signal becomes the minimum or the number of bits close to the minimum, and the amplification step is performed. A conversion step of converting the subsequent digital signal into an analog signal, and an attenuation step of attenuating the power of the analog signal converted by the conversion step to the power of the transmission digital signal before being amplified by the amplification step. I chose

According to this method, the power of the transmission signal is kept within a certain range because the transmission digital data is once amplified to a predetermined level before it is converted into analog data and is attenuated after being converted into analog data. It is possible,
It is possible to reduce the required number of bits of the transmission digital signal.

The radio transmission program of the present invention comprises an amplification step of amplifying the power of the transmission digital signal to a maximum allowable level or a vicinity of the maximum allowable level, and converting the digital signal amplified by the amplification step into an analog signal. The computer is made to execute the converting step and the attenuating step of attenuating the power of the analog signal converted by the converting step to the level of the power of the transmission digital signal before being amplified by the amplifying step.

According to this program, the transmission digital data is amplified to a predetermined level once before being converted into analog data, and is attenuated after being converted into analog data, so that the dynamic range of the transmission signal is utilized to the maximum extent. It is possible to improve the SN ratio.

The radio transmission program of the present invention is amplified by the amplification step of amplifying the power of the transmission digital signal so that the required number of bits of the transmission digital signal becomes the minimum or the number of bits close to the minimum, and the amplification step. A computer includes a conversion step of converting the subsequent digital signal into an analog signal, and an attenuation step of attenuating the power of the analog signal converted by the conversion step to the power of the transmission digital signal before being amplified by the amplification step. I tried to run it.

According to this program, since the transmission digital data is once amplified to a predetermined level before being converted into analog data, and after being converted into analog data, it is attenuated, the power of the transmission signal is kept within a certain range. Therefore, the required number of bits of the transmission digital signal can be reduced.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION The essence of the present invention is that a transmission digital data is once amplified to a predetermined level before being converted into analog data, and is then attenuated after being converted into analog data. Is to determine the gain to be used for and the reverse gain to be used for attenuation based on a power table having a hysteresis characteristic.

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

(Embodiment 1) FIG.1 is a block diagram showing an example of the configuration of a radio transmitting apparatus according to Embodiment 1 of the present invention. Here, CDMA (Code Division Multip
An example will be described in which a wireless access device of the le access type is installed in a base station device.

The radio transmitting apparatus shown in FIG.
1, section power calculation unit 102, upper limit comparison unit 103, lower limit comparison unit 104, storage unit 105, range determination unit 106, delay control unit 107, delay unit 108, gain unit 109, transmission R
RC filter 110, DAC 111, quadrature modulator 11
2, the inverse gain unit 113, the wireless transmission unit 114, and the antenna 115.

First, the configuration of the spreading section 101 to the antenna 115 for processing the main signal flow will be described. The section power calculation unit 102, the upper limit comparison unit 103, the lower limit comparison unit 104, the storage unit 105, the range determination unit 106, and the delay control unit 107 will be described later.

In FIG. 1, spreading section 101 performs spread modulation processing on information data to be transmitted. The delay unit 108 delays the signal by the total amount of processing time required in each component configuration from the section power calculation unit 102 to the delay control unit 107 (in particular, the processing time required in the section power calculation unit 102 is long). The gain unit 109 multiplies the transmission digital data by the gain (Gn) output from the delay control unit 107, and amplifies the dynamic range of the transmission signal to the maximum level. The transmission RRC filter 110 limits the band of transmission digital data. DAC111
Converts the transmission digital data into transmission analog data. The quadrature modulator 112 quadrature modulates transmission analog data. The inverse gain unit 113 multiplies the transmission analog data by the gain (1 / Gn) output from the delay control 107. The wireless transmission unit 114 performs predetermined wireless processing on the transmission analog data and transmits it from the antenna 115.

With the above configuration, the transmission digital signal before being converted into analog data is multiplied by the gain (Gn),
The original power is obtained by multiplying the dynamic range of the transmission signal to a level at which it can be used to the maximum extent, and multiplying the transmission analog signal after conversion into analog data by the gain that is the reciprocal of Gn (hereinafter, this gain is referred to as the inverse gain). You can return to the level. The effect of this process will be described below.

For example, when a base station apparatus equipped with the radio transmitting apparatus according to this embodiment transmits data to mobile stations owned by the user, the transmission is performed according to the number of mobile stations and the radio signal propagation state. The power is changing. That is, when the number of mobile stations is large, the transmission power is increased in order to maintain the reception performance on the mobile station side. Further, since the propagation path environment also changes during the day and night, the base station similarly changes the transmission power according to the propagation situation in order to maintain the reception performance on the mobile station side.

Assuming that the dynamic range of the transmission signal is wide and the transmission power is small,
Since the power level of the original digital data is smaller,
The conventional device has a problem that noise may be mixed due to processing of an analog signal in the DAC and the modulator, and the SN ratio is deteriorated when the noise is mixed. Incidentally, since the transmission RRC filter processes a digital signal, basically no noise is mixed.

However, in the present embodiment, with the above configuration, the gain is multiplied at the stage of the digital signal before noise is mixed, and the power is amplified to a level at which the dynamic range of the transmission signal can be maximally used, and then the analog signal is obtained. Since it is converted into a signal, even if noise is mixed in at the stage of analog signal, the influence of noise can be relatively reduced,
It is possible to suppress deterioration of the SN ratio. Further, since the digital data having the maximum power level is converted into the analog data, a high resolution can be obtained as the data itself.

It can be said that this method has both the high resolution inherent in analog data and the ease and reliability of data processing possessed by digital data.

Further, in the present embodiment, the input range of the transmission RRC filter 110 is set within a certain range.
Since the gain multiplied by the gain unit 109 is adjusted, the number of bits required in the transmission RRC filter 110 can be reduced.

For example, when the data has a very small value such as 0.0001 and a large number of bits are required to express it, multiply this by 10000 to obtain 1 so that the expression is required. The number of bits can be reduced.

The derivation of the gain that can maximize the dynamic range of the transmission signal or the gain that can reduce the number of bits required by the transmission RRC filter 110 will be described later. Is based on.

Next, the operations of the section power calculation unit 102, the upper limit comparison unit 103, the lower limit comparison unit 104, the storage unit 105, the range determination unit 106, and the delay control unit 107 will be described in detail.

The characteristic of these configurations is that the power value of the transmission digital data is calculated in order to obtain the gain and the inverse gain according to the power of the transmission digital data, and this power value and the power table stored in advance are referred to. Then, the power range n corresponding to the power value is obtained, and the gain and the inverse gain are determined.

Section power calculation section 102 calculates the section power value (P _TX ) of the transmission digital signal. Upper limit comparison unit 10
3 compares this P _TX with a preset upper limit value (ULn) of the power range n. Lower limit comparing section 104 compares P _TX with a preset lower limit value (LLn) of power range n. Range determination unit 106 determines which power range n _PTX is in, based on the comparison result output from upper limit comparison unit 103 and lower limit comparison unit 104. The storage unit 105 stores in advance a power table having a hysteresis characteristic. The delay control unit 107 includes the range determination unit 10
The previous power range n from 6 and the current power range n are compared to control the output timing of the power range to the gain unit 109 and the inverse gain unit 113.

FIG. 2 is a flow chart showing the processing procedure of the section power calculation unit 102, the upper limit comparison unit 103, the lower limit comparison unit 104, the storage unit 105, the range determination unit 106, and the delay control unit 107.

First, section power calculation section 102 calculates power (P _TX ) in a predetermined section of transmission digital data (ST1100).

Lower limit comparison section 104 compares P _TX with the lower limit value (LLn) of power range n output from storage section 105 (ST1200). Here, n of the power range n
Uses a preset initial value when the device is activated, and thereafter uses a value updated by the range determination unit 106.

When P _TX is smaller than LLn, range determining section 106 outputs a control signal to storage section 105 to decrement n in power range n by 1 (ST1250).
The storage unit 105 stores the L updated based on this control signal.
The value of Ln is fed back to the lower limit comparison unit 104. The above operation is repeated until P _TX becomes LLn or more.

Next, upper limit comparison section 103 compares P _TX with the upper limit value (ULn) of power range n (ST130).
0). As this n, the n obtained by the above lower limit comparison is used as it is.

When P _TX is larger than ULn, range determining section 106 outputs a control signal to storage section 105 and sets n to 1
It is incremented (ST1350). Storage unit 105
Feeds back the value of ULn updated based on this control signal to the upper limit comparison unit 103. This operation is also P
_It is repeated until _TX becomes less than ULn.

Then, the range determination section 106 determines the power range n finally obtained by the above procedure as the delay control section 1
It is output to 07 (ST1400).

The delay control unit 107 obtains the gain and the inverse gain based on this power range n, and outputs these values while considering the delay time. The output timing will be described later.

FIG. 3A and FIG. 3B show the storage unit 105.
FIG. 6 is a diagram for explaining the characteristics of the power table stored in FIG.

In FIG. 3A, for example, P _TX is LL1.
To UL1, the power range is determined to be 1. That is, the power range 1 has the lower limit value LL1.
From the range of the upper limit UL1 P _TX, power range 2, P _TX range upper limit value UL2 from the lower limit value LL2, power range 3
Is P _TX in the range of the lower limit LL3 to the upper limit UL3, and the power range 4 is P _{TX in} the range of the lower limit LL4 to the upper limit UL4.
_TX and power range 5 cover P _TX in the range of lower limit value LL5 to upper limit value UL5.

According to this power table, the power range n to be judged becomes large, although it is non-linear, depending on the size of P _TX . On the other hand, the gain corresponding to the power range n is
The power range n is set to decrease as it increases (not shown). Therefore, the gain and the inverse gain according to the power of the transmission digital signal can be obtained.

In addition, P _TX included in the same power range
Then, since the corresponding gain and inverse gain are constant, it is possible to prevent the gain from being frequently changed even when the P _TX fluctuates or oscillates in a burst in a short cycle. The operation of the wireless transmission device according to the present embodiment can be stabilized. When the gain is changed frequently, a slight time lag occurs between the original multiplication timing of the inverse gain in the inverse gain unit 113 and the actual multiplication timing, which causes distortion in the transmission signal and movement. It may cause deterioration of the reception performance of the station,
This can be prevented.

Further, by setting the gain corresponding to the power range n to an appropriate value, the transmission RRC filter 1
It is also possible to keep the 10 input ranges within a certain range.

As can be seen from FIG. 3 (A), the two adjacent power ranges overlap (crossover part).
have. The effect (hysteresis characteristic) of this will be described below.

In FIG. 3A, when P _TX = V1, there are the following two power ranges finally obtained by the judgment of the range judgment unit 106. For example, when the initial value of the power range is 1, the power range is determined to be 1 through the above procedure. However, the initial value of the power range is 2
If larger, the power range is determined to be 2. That is, this power table has a hysteresis characteristic that the obtained power range is different when the power range determination proceeds from the bottom to the top and when the power range determination proceeds from the top to the bottom.

As a result, if the power table does not have the hysteresis characteristic, the power range changes frequently if the P _TX is oscillating near the power range switching point. However, this situation can be avoided by having a hysteresis characteristic in the power table. Therefore, it is possible to prevent frequent switching of the gain and the reverse gain due to the change of the power range, and it is possible to stabilize the radio transmitting apparatus according to the present embodiment and improve the reception quality of the mobile station.

The storage section 105 can change the size of the crossover section of the electric power table according to the situation by a control signal input from another section. At this time, the power table has hysteresis characteristics that differ depending on the situation, as shown in FIGS. 3 (A) and 3 (B).

The delay control section 107 also performs the control described below, in addition to the derivation of the above-described gain and inverse gain.

FIG. 4 is a diagram showing operation timings of the gain unit 109 and the inverse gain unit 113 when the power range n is updated. In this figure, the total gain is the sum of effects obtained by multiplying the gain and the inverse gain.

At time t1, the power range is higher than the previous power range n. In this case, the gain unit 109 multiplies the transmission signal by the gain at time t2 delayed by a certain time. On the other hand, the inverse gain unit 113 multiplies the transmission signal by the inverse gain at time t3, which is a little later. The delay time from time t2 to time t3 is the transmission RRC.
The processing time from the filter 110 to the quadrature modulator 112 is taken into consideration.

At time t4, the power range is
It is lower than the previous power range n. Also in this case,
The gain unit 109 multiplies the transmission signal by a gain at time t6 delayed by a certain time. However, the inverse gain unit 113
Is different from the case where the above power range is raised, at time t
At time t5 before 6, the transmission signal is multiplied by the inverse gain. This is to prevent the power from being excessively amplified when the multiplication timing of the gain in the gain unit 109 is originally too fast as compared with the timing to be multiplied. The delay time from time t5 to time t6 takes into consideration the delay time between the transmission RRC filter 110 and the quadrature modulator 112, and the safety margin for preventing the above-mentioned excessive amplification of power. Therefore, the time between times t5 and t6 is set longer than the time between times t2 and t3.

With the above configuration, when the power range is changed and the gain and the inverse gain are changed, it is possible to prevent an excessive transmission power output caused by a slight shift in the timing of the amplification operation and the attenuation operation.

Here, a case has been described as an example where, after the power range n is changed, the gain is multiplied by the gain unit 109 with a certain delay, but this delay time may not be constant.

As described above, according to the present embodiment, the transmission digital data is amplified to a predetermined level once before being converted into analog data, and is attenuated after being converted into analog data. The range can be used to the maximum extent and the SN ratio can be improved. Moreover, the power of the transmission signal can be kept within a certain range, and the required number of bits of the transmission digital signal can be reduced.

Further, since the gain used for amplifying the transmission signal and the inverse gain used for attenuation are determined based on the power table having the hysteresis characteristic, the power of the transmission digital signal fluctuates or oscillates in a short cycle in bursts. Even in such a case, the power range and the gain can be prevented from being frequently changed, and the wireless transmission device can be stabilized.

(Embodiment 2) FIG.5 is a block diagram showing an example of the configuration of a radio transmitting apparatus according to Embodiment 2 of the present invention. Note that this wireless transmission device has the same basic configuration as the wireless transmission device shown in FIG. 1, and the same components are assigned the same reference numerals and explanations thereof are omitted.

The feature of this embodiment is that it has a designated power unit 201 instead of the section power calculation unit 102 shown in FIG.

The designated power unit 201 designates the power for each user or channel to the spreading unit 101, obtains the total of the designated powers, and outputs it to the upper limit comparison unit 103 and the lower limit comparison unit 104 as section power (P _TX ). Output. Other operations are similar to those of the first embodiment.

With this, the time for calculating the section power can be eliminated, so that the timing of multiplying the transmission digital data by the gain can be advanced and the control delay can be prevented. Further, the section power calculation unit 10 shown in FIG.
2 and the delay unit 108 are not necessary, the circuit scale can be reduced.

The radio transmitting apparatus according to the present invention can be installed in a communication terminal apparatus, and by doing so, it is possible to provide a communication terminal apparatus having the same operation as described above.

Here, the CDMA radio transmission apparatus has been described as an example, but the radio transmission apparatus according to the present invention is not limited to the CDMA system.

[0091]

As described above, according to the present invention,
Before the transmission digital data is converted to analog data, it is amplified to a predetermined level once, and after being converted to analog data, it is attenuated, so that the dynamic range of the transmission signal can be utilized to the maximum and the SN ratio is improved. be able to. Moreover, the power of the transmission signal can be kept within a certain range, and the required number of bits of the transmission digital signal can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of a wireless transmission device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of a section power calculation unit, an upper limit comparison unit, a lower limit comparison unit, a storage unit, a range determination unit, and a delay control unit.

FIG. 3A is a diagram for explaining features of a power table stored in a storage unit; FIG. 3B is a diagram for explaining features of a power table stored in a storage unit;

FIG. 4 is a diagram showing operation timings of a gain unit and an inverse gain unit when a power range is updated.

FIG. 5 is a block diagram showing an example of a configuration of a wireless transmission device according to a second embodiment of the present invention.

[Explanation of symbols]

102 section power calculation unit 103 Upper limit comparison section 104 Lower limit comparison section 105 storage 106 Range determination unit 107 Delay control unit 109 gain section 113 Inverse gain section 201 Designated power department

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Claims (18)

[Claims] 1. An amplifying means for amplifying the power of a transmission digital signal up to a maximum allowable level or a vicinity of the maximum allowable level, a converting means for converting a digital signal amplified by the amplifying means into an analog signal, and the converting means. And attenuating means for attenuating the power of the analog signal converted by the means to the level of the power of the transmitting digital signal before being amplified by the amplifying means. 2. An amplifying unit for amplifying the power of the transmission digital signal so that the required number of bits of the transmission digital signal becomes the minimum or the number of bits close to the minimum, and an analog digital signal amplified by the amplification unit. Radio transmission, comprising: a conversion unit that converts the signal into a signal; apparatus. 3. A power value acquisition unit for acquiring a power value of the transmission digital signal before being amplified by the amplification unit, wherein the amplification unit is responsive to the power value acquired by the power value acquisition unit. The wireless transmission according to claim 1 or 2, further comprising: an acquisition unit configured to acquire the amplified gain, and amplifying the power of the transmission digital signal by using the amplification gain acquired by the acquisition unit. apparatus. 4. A power value acquisition unit for acquiring the power value of the transmission digital signal before being amplified by the amplification unit, wherein the amplification unit has a predetermined power value acquired by the power value acquisition unit. When it is within the power range of, the power supply device has an acquisition unit that acquires a constant amplification gain, and amplifies the power of the transmission digital signal using the amplification gain acquired by the acquisition unit. The wireless transmission device according to claim 1 or 2. 5. The wireless transmission device according to claim 4, wherein there are a plurality of power ranges, and adjacent power ranges have a hysteresis characteristic by having overlapping portions. 6. The wireless transmission device according to claim 5, wherein the sizes of the overlapping portions of the adjacent power ranges change according to the fluctuation range of the power of the transmission digital signal. 7. The power value acquisition means, when the transmission digital signal before being amplified by the amplification means has a plurality of channels, sums the power set values of the transmission digital signals of all channels to obtain the power value of the transmission digital signal. The wireless transmission device according to claim 3 or 4, characterized in that 8. The wireless transmission device according to claim 3, further comprising a delay unit that delays the transmission digital signal by at least the time during which the power value acquisition unit acquires the power value. 9. A control means for controlling the amplifying means so as to delay a timing for amplifying the transmission digital signal by the amplifying means by a predetermined time when the current amplifying amount in the amplifying means is larger than the previous amplifying amount. The wireless transmission device according to claim 1 or 2, further comprising: 10. If the current attenuation amount of the attenuating means is smaller than the previous attenuation amount, the attenuating means delays the timing at which the attenuating means attenuates the analog signal converted by the converting means by a predetermined time. The wireless transmission device according to claim 1 or 2, further comprising control means for controlling. 11. The attenuating unit attenuates the analog signal converted by the converting unit when the electric power value acquired by the electric power value acquiring unit this time is larger than the electric power value previously acquired by the electric power value acquiring unit. 5. The radio according to claim 3, further comprising control means for controlling the attenuating means such that the timing is delayed by a predetermined time from the timing at which the amplifying means amplifies the transmission digital signal. Transmitter. 12. The attenuating means attenuates the analog signal converted by the converting means when the power value acquired by the power value acquiring means this time is smaller than the power value previously acquired by the power value acquiring means. 5. The radio transmitting apparatus according to claim 3, further comprising control means for controlling the attenuating means so that the timing is earlier by a predetermined time than the timing at which the amplifying means amplifies the transmission digital signal. . 13. A communication terminal device, comprising the wireless transmission device according to claim 1. Description: 14. A base station device comprising the wireless transmission device according to claim 1. Description: 15. An amplification step for amplifying the power of a transmission digital signal to a maximum allowable level or a vicinity of the maximum allowable level; a conversion step for converting the digital signal amplified by the amplification step into an analog signal; Attenuating step for attenuating the power of the analog signal converted by the step to the level of the power of the transmission digital signal before being amplified by the amplifying step, and a radio transmitting method. 16. An amplification step of amplifying the power of the transmission digital signal so that the required number of bits of the transmission digital signal becomes the minimum or the number of bits close to the minimum, and the digital signal amplified by the amplification step is converted into an analog signal. A wireless transmission comprising: a conversion step of converting into a signal; and an attenuation step of attenuating the power of the analog signal converted by the conversion step to the power of the transmission digital signal before being amplified by the amplification step. Method. 17. An amplification step of amplifying the power of a transmission digital signal to a maximum allowable level or to a vicinity of the maximum allowable level, a conversion step of converting the digital signal amplified by the amplification step into an analog signal, and the conversion. A radio transmitting program characterized by causing a computer to execute an attenuating step of attenuating the power of the analog signal converted by the step to the level of the power of the transmitting digital signal before being amplified by the amplifying step. 18. An amplification step of amplifying the power of the transmission digital signal so that the required number of bits of the transmission digital signal becomes a minimum or a number of bits close to the minimum, and the digital signal after being amplified by the amplification step is an analog signal. A conversion step of converting the signal into a signal; and an attenuating step of attenuating the power of the analog signal converted by the converting step to the power of the transmission digital signal before being amplified by the amplifying step. A wireless transmission program.