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Distortion compensation controller and distortion compensation control method

A distortion correction and control device technology, which is applied to the parts of the amplifying device, the adaptive predistortion of the look-up table, and the electrical components, etc., can solve the problems of the waveform deformation of the amplifier output signal and the slow rise of the signal.

Inactive Publication Date: 2013-03-20
FUJITSU LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this technology, it is necessary to prepare the signal rising period before the pulse segment is ON, or to slowly rise the signal after the pulse segment is ON, which causes the waveform of the output signal of the amplifier to be deformed.

Method used

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  • Distortion compensation controller and distortion compensation control method
  • Distortion compensation controller and distortion compensation control method
  • Distortion compensation controller and distortion compensation control method

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no. 1 Embodiment approach

[0033] Refer to the structure (basic structure) of the first embodiment of the present invention figure 2 , the burst distortion correction control device adopts the structure of multiplying (or adding) the correction coefficient to the input signal x(t) for the transmission amplifier (RF amplifier) ​​1, so as to correct the input signal x(t) due to the transmission target Amplifier distortion caused by bursts (burst distortion).

[0034] This correction coefficient (burst distortion correction coefficient) is based on the signal (in this case, the signal that notifies the timing of the ON of the burst (start)) that notifies the switching of the input signal (here, the signal that notifies the timing of the burst (start) ON), that is, the burst information. The burst correction coefficient storage unit 2 reads it out, and multiplies the input signal x(t) by the multiplier 3 as the inverse characteristic of the burst distortion.

[0035] The burst distortion correction coeffi...

no. 2 Embodiment approach

[0046] Figure 5 The configuration of the burst distortion correction control device according to the second embodiment of the present invention is shown. This second embodiment shows figure 2 The basic configuration in the first embodiment shown is an example of a specific configuration.

[0047] refer to Figure 5 The burst distortion correction control device has a burst correction coefficient storage unit 2 , a multiplier 3 and a burst correction coefficient update unit 4 . The burst correction coefficient update unit 4 is composed of an adder 41 , a comparator (subtractor) 42 , multipliers 43 , 44 , and 45 , and a complex conversion circuit (conj) 46 . In this configuration, the adaptive algorithm uses the least square method (LMS) in order to generate correction coefficients for the burst distortion in the transmit amplifier 1 .

[0048] In this pulse segment distortion correction control device, and from the pulse segment ON(t 0 ) The correction coefficient corres...

no. 3 Embodiment approach

[0061] Image 6 The configuration of a burst distortion correction control device according to a third embodiment of the present invention is shown. This third embodiment shows Figure 5 This is a modified example of the specific configuration in the second embodiment shown.

[0062] The burst distortion correction control device in the third embodiment is aimed at the burst distortion correction processed by the specific structure in the second embodiment above, and combines the known technology, that is, the digital predistortion that compensates the nonlinear distortion of the transmission amplifier ( DPD) example. In addition, the details of the DPD are described in the aforementioned Patent Document 4 (Japanese Patent No. 3560398).

[0063] First, refer to Figure 7 The DPD for correcting the nonlinear distortion of the transmission amplifier 1 will be described. In DPD, the distortion compensation coefficient is obtained from the power or amplitude of the input sign...

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Abstract

A distortion correction control apparatus is for compensating for burst distortion of a transmission amplifier caused by a burst of an input signal of a transmission target. The apparatus includes holding means for storing a distortion correction coefficient having reverse characteristics to the burst distortion; means for multiplying the distortion correction coefficient read out from the holding means by the input signal or adding the distortion correction coefficient read out from the holding means to the input signal, upon reception of burst information notifying of switching between presence and absence of the input signal; and update means for updating, based on the input signal, the distortion correction coefficient of the last time, and a signal fed back as an output signal of the transmission amplifier, the distortion correction coefficient by an adaptive algorithm, and inputting the updated distortion correction coefficient to the holding means.

Description

technical field [0001] The invention relates to a distortion correction control device and a distortion correction control method suitable for a wireless communication system. Background technique [0002] In wireless communication systems using wireless transmission methods such as Orthogonal Frequency Division Multiplexing (OFDM: Orthogonal Frequency Division Multiplexing), burst signals are mostly used. [0003] Generally, in order to improve the power efficiency of the amplifier, the operating point of the amplifier is set to AB to B class. Therefore, when there is no signal (when the pulse segment is OFF), the current flowing to the amplifier decreases. When a signal is suddenly input (burst ON) from the burst OFF period, the current flows rapidly to the amplifier power supply system. As a result, the power system cannot follow the sharp change in current value, and the current and voltage waveforms show a transient response (refer to figure 1 ), the amplifier charac...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H03F1/32
CPCH03F2201/3233H03F1/3247H03F1/32H03F3/24
Inventor 石川广吉长谷和男滨田一札场伸和宇都宫裕一大石泰之
Owner FUJITSU LTD