JP4634328B2 - Amplifying device, transmitting device, terminal device, and base station device - Google Patents

Description

  The present invention relates to an amplification device, a transmission device, a terminal device, and a base station device, and more particularly to a technique for suppressing the occurrence of distortion in an output signal.

  When performing amplification processing of an input signal having a predetermined power in the amplifier circuit, if the amplification factor becomes too large, the amplifier circuit does not operate linearly and the desired target power cannot be obtained. Such a characteristic of the amplifier circuit is called a non-linear characteristic. Due to this non-linear characteristic, when the amplification factor fluctuates, the waveform of the output signal may be distorted.

Patent Document 1 discloses a technique for suppressing distortion of an output signal by generating an inverse distortion signal and synthesizing it with an output signal. Patent Document 2 discloses a technique for suppressing distortion of an output signal by generating and acquiring a predistortion signal and multiplying it by an input signal.
JP 2005-203925 A JP-A-2005-151400

  However, the techniques described in Patent Document 1 and Patent Document 2 have a problem in that it is necessary to generate and synthesize and multiply inverse distortion signals and predistortion signals, resulting in a complicated circuit configuration.

  Accordingly, an object of the present invention is to provide an amplifying apparatus, a transmitting apparatus, a terminal apparatus, and a base station apparatus that can suppress the occurrence of distortion in an output signal with a simple circuit configuration. .

  An amplifying apparatus according to the present invention for solving the above-described problems is an amplifying apparatus including an amplifying unit that amplifies an input signal having a predetermined power at an amplification factor corresponding to input data, and the output signal power of the amplifying unit is It further comprises input data changing means for changing the input data so as to obtain a given target power.

  According to this, it is possible to suppress the occurrence of distortion in the output signal with a simple circuit configuration that only changes the input data.

  Further, in the amplifying device, the amplifying device further includes processing means for changing the input data changed by the input data changing means based on a set amplification factor, and the amplifying means converts the input signal to the input data. The amplification device amplifies at an amplification factor according to the input data changed by the processing means, and the amplification device stores the amplification factor and the gain associated with each other when the input signal is amplified. Storage means, and the input data changing means includes an amplification factor stored in the storage means in association with a gain determined based on the predetermined power and the target power, and the set amplification. The input data may be changed based on the rate.

  According to this, even if there is a processing means for changing the input data based on the set amplification factor, the input data input to the processing means is preliminarily set so that the power of the output signal of the amplification means becomes a given target power. Therefore, the output signal can be prevented from being distorted with a simple circuit configuration that only changes the input data.

  The transmission device according to the present invention is a transmission device including amplification means for amplifying an input signal having a predetermined power at an amplification factor corresponding to input data, and the input data for generating the input data based on the transmission data. And generating means; input data changing means for changing the input data so that the power of the output signal of the amplifying means becomes a given target power; and transmitting means for transmitting the output signal of the amplifying means. It is characterized by that.

  The terminal device according to the present invention is a terminal device including amplification means for amplifying an input signal having a predetermined power at an amplification factor corresponding to input data, and the input data is based on transmission data to a base station device. The input data generating means for generating the input data, the input data changing means for changing the input data so as to be the target power determined by the power of the output signal of the amplifying means and the transmission power control, and the output signal of the amplifying means And transmitting means for transmitting to the base station apparatus.

  The base station apparatus according to the present invention is a base station apparatus including an amplifying unit that amplifies an input signal having a predetermined power at an amplification factor according to input data, and the input signal is based on transmission data to a terminal apparatus. Input data generating means for generating data, input data changing means for changing the input data so that the power of the output signal of the amplifying means becomes a target power determined by transmission power control, and the output of the amplifying means Transmission means for transmitting a signal to the terminal device.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a system configuration and functional blocks of a base station apparatus 10 according to the present embodiment. As shown in the figure, the base station apparatus 10 includes, as hardware, a symbol point determination unit 20, a signal processing unit 21, a mixer 22Q, a mixer 22I, an oscillator 23, a phase converter 24, an amplifier 25, and a digital / analog converter 26. , Amplifier 27, amplifier 28, and antenna 29. The function unit includes a target power acquisition unit 30, a set amplification factor determination unit 31, a power acquisition unit 32, a target power calculation unit 33, an input data change unit 34, and a storage unit 35.

  The base station apparatus 10 is a computer that includes a CPU and a memory. The CPU is a processing unit for executing a program stored in the memory, and performs processing for controlling each unit of the base station apparatus 10 and realizes functions described later. The memory stores programs and data for carrying out the present embodiment. It also operates as a work memory for the CPU.

  The base station apparatus 10 is a component of the mobile communication system. The base station apparatus 10 performs wireless communication with a mobile station apparatus (not shown) and also performs wired communication with an exchange or network (not shown). In this Embodiment, the base station apparatus 10 determines the transmission power at the time of transmitting from the antenna 29 about the signal transmitted by radio | wireless with respect to a mobile station apparatus according to a radio | wireless state.

  Hereinafter, the processing of each hardware will be described with reference to FIG.

  First, the symbol point determination unit 20 receives input of data (transmission data) to be transmitted to the mobile station apparatus from a communication processing unit (not shown). This transmission data is a bit string. The symbol point determination unit 20 sequentially determines symbol points from the transmission data input in this manner by a predetermined modulation method, and sequentially generates input data to the signal processing unit 21 based on the determined symbol points.

  For example, when 16QAM is used as the modulation method, 16 symbol points are set on the IQ plane. Each symbol point is assigned any one of 4-bit bit strings 0000 to 1111. Note that the bit strings assigned to each symbol point are different from each other. The symbol point determination unit 20 determines the symbol point by acquiring the transmission data by 4 bits and acquiring the symbol point assigned to the bit string indicated by the 4 bits.

  FIG. 2 is a diagram showing an IQ plane. In the figure, 16QAM symbol points are described on the IQ plane. As shown in FIG. 2, the amplitude of each symbol point is indicated by the distance from the origin on the IQ plane. Further, the I-axis amplitude is indicated by the I-axis coordinates, and the Q-axis amplitude is indicated by the Q-axis coordinates.

  In the mixer 22 described later, a power signal determined according to the amplitude of each symbol point is generated. Hereinafter, the term “power” refers to the power determined according to the amplitude. The symbol point determination unit 20 inputs input data (I system input data) indicating the I-axis power of the determined symbol point and input data (Q system input data) indicating the Q-axis power to the signal processing unit 21. To do.

  The signal processing unit 21 changes the input data of each system according to the amplification factor set by the set amplification factor determination unit 31 described later. Specifically, for example, if the amplification factor is a, the input data of each system is multiplied by a. The signal processing unit 21 outputs the changed I system input data to the mixer 22I and the Q system input data to the mixer 22Q.

  The oscillator 23 oscillates an input signal (carrier wave) of a predetermined power (hereinafter referred to as input signal power) and outputs it to the mixer 22I and the phase converter 24. The phase converter 24 changes the phase of the input signal input from the oscillator 23 by 90 ° and outputs it to the mixer 22Q.

  The mixer 22I amplifies the input signal input from the oscillator 23 with an amplification factor corresponding to the I system input data, and generates an I system output signal. Specifically, by multiplying the input signal by I-system input data, the power of the input signal is raised in accordance with the power indicated by the I-system input data to obtain an I-system output signal. The mixer 22I outputs the generated I-system output signal to the amplifier 25.

  The mixer 22Q amplifies the input signal input from the phase converter 24 with an amplification factor corresponding to the Q system input data, and generates a Q system output signal. Specifically, by multiplying the input signal by the Q system input data, the power of the input signal is raised according to the power indicated by the Q system input data to obtain a Q system output signal. The mixer 22Q outputs the generated Q system output signal to the amplifier 25.

  The amplifier 25 amplifies the input I-system output signal and Q-system output signal with a predetermined amplification rate, and inputs the amplified signal to the digital-analog converter 26. The digital / analog converter 26 converts the signal input from the amplifier 25 into an analog signal and inputs the analog signal to the amplifier 27. The amplifier 27 and the amplifier 28 amplify the signal input from the digital-analog converter 26 with a predetermined amplification factor. The amplifier 27 and the amplifier 28 can operate in a non-linear manner. The signal output from the amplifier 28 is transmitted from the antenna 29 to the wireless section as a wireless signal.

  Next, each functional unit will be described.

  First, the target power acquisition unit 30 performs transmission power control such as closed loop control and open loop control, and acquires the target value (reference target power) of the power of the output signal of the amplifier 28. For example, in the closed loop control, the reference target power is acquired based on the received power when the mobile station apparatus receives the radio signal transmitted by the base station apparatus 10. Specifically, the reference target power is determined so that the received power of the mobile station apparatus becomes a predetermined value. The target power acquisition unit 30 outputs the acquired reference target power to the set amplification factor determination unit 31.

  The set amplification factor determination unit 31 determines an amplification factor (set amplification factor) to be set in the signal processing unit 21 based on the reference target power acquired by the target power acquisition unit 30. Hereinafter, the set amplification factor will be specifically described.

  The storage unit 35 stores an output power / set amplification factor correspondence table. This output power-set amplification factor correspondence table stores a set amplification factor for each output signal power (output power) output from the amplifier 28 when an input signal of input signal power is input to the mixer 22. It is. Table 1 is an example of an output power-set amplification factor correspondence table. Since the value actually input to the signal processing unit 21 is not the set amplification factor itself but a set value indicating the set amplification factor, the storage unit 35 stores the output power and the set value in association with each other. In Table 1, the output power is proportional to the set value up to an output power of 20 dBm, and is not proportional when the output power exceeds 20 dBm. This indicates that the linear operation range of the amplifier 27 and the amplifier 28 is an output power of 20 dBm or less.

  The set amplification factor determination unit 31 acquires a set value (set amplification factor) stored in association with the reference target power acquired by the target power acquisition unit 30 in the output power-set amplification factor correspondence table, and the signal processing unit 21. Is determined as the amplification factor to be set in For example, if the reference target power is 21 dBm (126 mW), the set value 846 is acquired. The signal processing unit 21 changes the input data according to the amplification factor thus determined.

  The power acquisition unit 32 acquires the symbol point power of the symbol points sequentially determined by the symbol point determination unit 20 and outputs the symbol point power to the target power calculation unit 33.

The target power calculation unit 33 calculates the target power of each symbol point based on the symbol point power of each symbol point input from the power acquisition unit 32. Specifically, the target power of each symbol point is calculated based on the set amplification factor and the symbol point power of each symbol point. More specifically, the target power of each symbol point is calculated by the following equation (1).
Target power = symbol point power × set amplification factor (1)

  If the amplifier 27 and the amplifier 28 perform a linear operation, the signal processing unit 21 changes the input data according to the set amplification factor, thereby obtaining an output signal of the target power. However, when the amplifier 27 and the amplifier 28 perform non-linear operation, an output signal having the target power cannot be obtained. Therefore, the input data changing unit 34 changes the input data input to the signal processing unit 21 so that the power of the output signal of the amplifier 28 becomes the target power.

  Specifically, the storage unit 35 stores an amplification factor and a gain in association with each other in a section from the mixer 22 to the amplifier 28 when the input signal power is amplified. The input data changing unit 34 correlates the input data based on the amplification factor stored in the storage unit 35 in association with the gain determined based on the input signal power and the target power, and the set amplification factor. change. Hereinafter, the input data change by the input data change unit 34 will be described in detail.

  FIG. 3 is an explanatory diagram for explaining the input data change by the input data change unit 34. In the figure, the vertical axis indicates power.

  FIG. 3A shows an example in which the symbol point power of the symbol point is the input signal power X. In this example, the input data output from the symbol point determination unit 20 is 1. The signal processing unit 21 changes the input data 1 based on the set amplification factor a. That is, the input data is set to a value a obtained by multiplying these. When this input data is input, the amplifier 28 outputs an output signal of power Xa. This indicates that a gain according to the set amplification factor is obtained.

  On the other hand, (A) in FIG. 3B shows an example in which the symbol point power of the symbol point is Xd (d> 1). In this example, the input data output from the symbol point determination unit 20 is d. The signal processing unit 21 changes the input data d based on the set amplification factor a. That is, the input data is set to a value da obtained by multiplying these. In the section from the mixer 22 to the amplifier 28, when this input data is input, an output signal of power Xdb (b <a) is output. This indicates that a gain as set gain is not obtained.

  Therefore, the input data changing unit 34 changes the input data input to the signal processing unit 21 so that the output power of the amplifier 28 becomes Xda. Hereinafter, this point will be described.

  As shown in FIG. 3B, if the gain da is obtained in the section from the mixer 22 to the amplifier 28 from the input signal power and the target power, the output power of the amplifier 28 is the above-mentioned Xda. Become. The input data changing unit 34 acquires an amplification factor c for obtaining this gain.

  Specifically, the input data changing unit 34 acquires the amplification factor stored in association with the target power (Xda) in the output power-set amplification factor correspondence table. Here, it is assumed that the amplification factor c is acquired ((B) in FIG. 3B). The input data changing unit 34 changes the input data d output from the symbol point determining unit 20 based on the gain c thus obtained and the set gain a. Specifically, the input data change amount c / a is calculated based on the amplification factor c and the set amplification factor a. This is multiplied by the input data to obtain dc / a.

  The input data dc / a thus changed by the input data changing unit 34 is further changed in the signal processing unit 21. Specifically, the set amplification factor a is multiplied to become input data dc. When the input data dc is input, the amplifier 28 outputs an output signal of power Xda. This indicates that a gain according to the set amplification factor is obtained.

  A specific example will be described. For example, assume that X is 50 mW and Xa is 100 mW. In this case, the set amplification factor a (= Xa / X) is 2. For example, if Xd is 63 mW, Xda is 63 × 2 = 126 mW.

  Due to the non-linear operation of the amplifier 27 and the amplifier 28, there is a possibility that an output power of 126 mW cannot be obtained even if the radio carrier wave is amplified with an amplification factor d × 2. Therefore, the input data changing unit 34 obtains the amplification factor c for amplifying the input signal of the input signal power to obtain 126 mW from the output power-set amplification factor correspondence table. Then, the input data is changed based on the amplification factor c and the set amplification factor a. By doing so, the output power of the amplifier 28 can be set as the target power.

  FIG. 4 is a diagram illustrating a specific example of input data change by the input data change unit 34. This figure is a diagram showing an IQ plane as in FIG. 2, and 16QAM symbol points are described. For example, the input data changing unit 34 changes the input data indicating the point A based on the change amount calculated as described above. As a result of this change, the symbol point indicated by the input data moves in a direction away from the origin.

  Note that, among the 16QAM symbol points, when comparing the A point with the B point, the C point, and the D point, the power at the A point is relatively large. As a result, the input data changing unit 34 often changes only the input data indicating point A.

  The input data changing unit 34 changes the input data input to the signal processing unit 21 as described above.

  The process relating to the change of the input data described above will be described again in detail with reference to the process flow diagram of the base station apparatus 10.

  FIG. 5 is a diagram illustrating a processing flow of the base station apparatus 10. As shown in the figure, the base station apparatus 10 first determines a set value (set gain a) from the reference target power (S1). Next, the base station apparatus 10 calculates the target power of each symbol point using equation (1) (S2).

  Then, the processes of S4 to S6 are performed for all the symbol points constituting the transmission data (S3 and S7).

  In S4, the base station apparatus 10 acquires the amplification factor c when the output power becomes the target power. This amplification factor is stored in association with the target power in the output power-set amplification factor correspondence table.

  Next, the base station apparatus 10 calculates the amount of power change based on the amplification factor c / the set amplification factor a (S5). If the change amount calculated in this way is 1, no special processing is performed. On the other hand, if the change amount is not 1, the input data is changed based on the change amount (S6).

  As described above, according to the base station apparatus 10, it is possible to suppress the occurrence of distortion in the output signal with a simple circuit configuration that only changes the input data.

  Further, even if there is the signal processing unit 21 that changes the input data based on the set amplification factor, the input data input to the signal processing unit 21 is preliminarily set so that the power of the output signal of the amplifier 28 becomes a given target power. Therefore, the output signal can be prevented from being distorted with a simple circuit configuration that only changes the input data.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the case where the signal processing unit 21 sets the amplification factor according to the transmission power control has been described as an example. For example, an amplifier circuit is provided at the subsequent stage of the digital-analog converter 26, and the amplifier circuit includes: It is good also as setting the gain according to transmission power control. Also in this case, it is possible to suppress the occurrence of distortion in the output signal by the input data changing process similar to that in the above embodiment.

  Moreover, although the case where the present invention is applied to the base station apparatus of the mobile communication system has been described as an example in the above embodiment, the present invention is, for example, as long as it uses amplitude modulation and includes an amplifier circuit. The present invention can be applied to any transmission device such as a terminal device such as a mobile station device.

It is a figure which shows the system configuration | structure and functional block of the base station apparatus which concern on embodiment of this invention. It is a figure which shows IQ plane which concerns on embodiment of this invention. In the figure, 16QAM symbol points are described. It is explanatory drawing for demonstrating the input data change which concerns on embodiment of this invention. It is a figure which shows IQ plane which concerns on embodiment of this invention. In the figure, 16QAM symbol points are described. It is a figure which shows the processing flow of the base station apparatus which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Base station apparatus, 20 Symbol point determination part, 21 Signal processing part, 22I, 22Q Mixer, 23 Oscillator, 24 Phase converter, 25, 27, 28 Amplifier, 26 Digital analog converter, 29 Antenna, 30 Target power acquisition part , 31 setting amplification factor determination unit, 32 power acquisition unit, 33 target power calculation unit, 34 input data change unit, 35 storage unit.

Claims (4)

An amplifying apparatus including amplifying means for amplifying an input signal of a predetermined power at an amplification factor according to input data,
Symbol point determination means for determining a symbol point from data input to the amplification device, and generating the input data based on the symbol point;
Storage means for associating and storing the amplification factor, gain, and output power when the input signal is amplified for the amplification means;
A set amplification factor determining means for determining a set amplification factor of the input data as an amplification factor stored in the storage means in association with a given output signal target power;
Input data changing means for changing the input data so that the power of the output signal of the amplifying means becomes the output signal target power;
Processing means for changing the input data changed by the input data changing means based on the set gain;
Means for multiplying the power of the symbol point and the set amplification factor to calculate a data signal target power;
Including
The input data changing means is based on the amplification factor stored in the storage means in association with the gain determined based on the predetermined power and the data signal target power, and the set amplification factor, Change the input data,
The amplification means amplifies the input signal at an amplification factor according to the input data changed by the processing means;
An amplifying device characterized by that. A transmission device including amplification means for amplifying an input signal of a predetermined power at an amplification factor according to input data,
Symbol point determination means for determining a symbol point from transmission data and generating the input data based on the symbol point;
Storage means for associating and storing an amplification factor and gain when the input signal is amplified for the amplification means ;
Setting the amplification factor of the entering force data, and set the amplification factor determining means for determining the amplification factor stored in the storage means in association with a given output signal target power,
Input data changing means for changing the input data so that the power of the output signal of the amplifying means becomes the output signal target power;
Processing means for changing the input data changed by the input data changing means based on the set gain;
Means for multiplying the power of the symbol point and the set amplification factor to calculate a data signal target power;
Transmitting means for transmitting an output signal of the amplifying means;
Including
The input data changing means is based on the amplification factor stored in the storage means in association with the gain determined based on the predetermined power and the data signal target power, and the set amplification factor, Change the input data,
The amplification means amplifies the input signal at an amplification factor according to the input data changed by the processing means;
A transmission apparatus characterized by the above. A terminal device including amplification means for amplifying an input signal of a predetermined power with an amplification factor according to input data,
Symbol point determining means for determining a symbol point from transmission data to a base station apparatus and generating the input data based on the symbol point;
Storage means for associating and storing the amplification factor, gain, and output power when the input signal is amplified for the amplification means ;
Setting the amplification factor of the entering force data, and set the amplification factor determining means for determining the amplification factor stored in the storage means in association with the output signal target power determined by the transmit power control,
Input data changing means for changing the input data so that the power of the output signal of the amplifying means becomes the output signal target power;
Processing means for changing the input data changed by the input data changing means based on the set gain;
Means for multiplying the power of the symbol point and the set amplification factor to calculate a data signal target power;
Transmitting means for transmitting the output signal of the amplifying means to the base station apparatus;
Including
The input data changing means is based on the amplification factor stored in the storage means in association with the gain determined based on the predetermined power and the data signal target power, and the set amplification factor, Change the input data,
The amplification means amplifies the input signal at an amplification factor according to the input data changed by the processing means;
A terminal device characterized by that. A base station apparatus including amplification means for amplifying an input signal of a predetermined power at an amplification factor according to input data,
Symbol point determination means for determining a symbol point from transmission data to the terminal device and generating the input data based on the symbol point;
Storage means for associating and storing an amplification factor and gain when the input signal is amplified for the amplification means ;
Setting the amplification factor of the entering force data, and set the amplification factor determining means for determining the amplification factor stored in the storage means in association with the output signal target power determined by the transmit power control,
Input data changing means for changing the input data so that the power of the output signal of the amplifying means becomes the output signal target power;
Processing means for changing the input data changed by the input data changing means based on the set gain;
Means for multiplying the power of the symbol point and the set amplification factor to calculate a data signal target power;
Transmitting means for transmitting the output signal of the amplifying means to the terminal device;
Including
The input data changing means is based on the amplification factor stored in the storage means in association with the gain determined based on the predetermined power and the data signal target power, and the set amplification factor, Change the input data,
The amplification means amplifies the input signal at an amplification factor according to the input data changed by the processing means;
A base station apparatus.

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