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Distortion compensation apparatus and method

A technology of distortion compensation and constraining information, applied in the parts of amplifying devices, adaptive predistortion of look-up tables, improving amplifiers to reduce nonlinear distortion, etc. deterioration, etc.

Inactive Publication Date: 2010-12-01
FUJITSU LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Therefore, in such a state, the distortion compensation characteristic added to the transmission signal becomes far from the optimum characteristic, thereby causing high distortion power to be generated in the output of the power amplifier 1109, which results in the out-of-band radiation power characteristic Deterioration will occur
[0033] Therefore, when a low-power transmission signal suddenly becomes a high-power transmission signal due to a power change, the prior art cannot optimally remove distortion by using the series operation coefficients that have been generated up to that time

Method used

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  • Distortion compensation apparatus and method
  • Distortion compensation apparatus and method
  • Distortion compensation apparatus and method

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Experimental program
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Embodiment Construction

[0050] figure 1 is a configuration diagram of a distortion compensation device using a predistortion method using a power series according to the first embodiment.

[0051] The distortion compensation unit 101 includes predistortion signal generation units 102 and 103, an error calculation unit 104, a coefficient update unit 105, a data switching control unit 106, a power conversion unit 107, selectors 108 and 109, memories 110 and 111, and a data storage control unit. Unit 112.

[0052] The predistortion signal generation unit 102 in the distortion compensation unit 101 adds the transmission signal and the compensation signal having the inverse characteristic of the transmission amplifier, and outputs a distortion compensation signal (predistortion signal).

[0053] The predistortion signal output from the predistortion signal generating unit 102 is up-converted by the quadrature modulator 113 using the signal output from the local oscillator 114 after being converted into ...

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Abstract

A distortion compensation apparatus includes a distortion compensation signal generation unit that performs, on a transmission signal, distortion compensation processing using a series operation; a coefficient updating unit that updates series operation coefficients used for the series operation based on a feedback signal of a power amplification output which is output through power amplificationprocessing of a distortion compensation signal output from the distortion compensation signal generation unit, and based on the distortion compensation signal; a memory that stores the distortion compensation signal corresponding to a transmission signal having a given power value and the feedback signal of the power amplification output as restraint information; and a control unit that performs control so that, in accordance with the power value of the transmission signal, restraint information corresponding to a power value different from the power value of the transmission signal is read and used for updating the series operation coefficients.

Description

technical field [0001] Embodiments of the present invention relate to a predistortion-based distortion compensation technique that digitally processes a signal input to a transmission amplifier in advance and suppresses nonlinear distortion output by the transmission amplifier in digital wireless communication. Background technique [0002] In general, high-efficiency transmission amplifiers used in wireless transmission devices such as mobile communication stations have very high nonlinear characteristics. Thus, when transmitting modulated signals for high-speed wireless communications, this nonlinear distortion in the transmission amplifier results in out-of-band radiated power that will affect adjacent transmission channels. [0003] In a typical transmission amplifier, the output becomes saturated as the input power increases, making it difficult to match the input signal (reference Figure 14 1401 and 1402 shown) are directly proportional to the signal. This non-linear...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L25/49H04B1/04H03F1/32
CPCH03F3/195H03F2201/3233H03F3/24H03F1/3258H04L27/366H04W28/04
Inventor 长谷和男宇都宫裕一滨田一石川广吉札场伸和石川颂平
Owner FUJITSU LTD