A peak clipping method for adaptive in-band processing

An adaptive and band-adapting technology, applied in multi-frequency code systems and other directions, can solve problems such as low efficiency of power amplifiers, in-band signal distortion, and large out-of-band radiation

Inactive Publication Date: 2012-02-01
SOUTH CHINA UNIV OF TECH
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  • Abstract
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  • Application Information

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Problems solved by technology

In order to transmit the peak-to-average ratio signal without distortion, the power amplifier needs to have a large linear range and a large back-off (Back-off), but such a power amplifier is very inefficient, which is harmful to portable and battery-powered devices. Mobile apps are a deadly influence
Therefore, starting from improving the performance of the power amplifier to solve the problem of peak-to-average ratio in the OFDM system has certain limitations
Nevertheless, simple peak clipping methods can produce large out-of-band radiation
At the same time, it will also cause distortion of the in-band signal, resulting in a large bit error rate

Method used

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  • A peak clipping method for adaptive in-band processing
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  • A peak clipping method for adaptive in-band processing

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Embodiment Construction

[0054] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0055] The method provided by the present invention can be realized by FPGA or DSP chip programming. Such as Figure 6 As shown, the 4 times oversampled original OFDM input signal is divided into two paths, and one path is sent to the first FFT transformation module 1, after serial-to-parallel transformation, and then through FFT transformation, the time-domain signal is changed into a frequency-domain signal, and separated out The in-band signal is sent to the adaptive in-band processing module; the other channel is sent to the simple peak clipping module. After peak clipping processing, the output signal is input to the second FFT transformation module 2, and the signal is serially paralleled in the second FFT transformation module 2. After the conversion, the time-domain signal is transformed into a frequency-domain signal through FFT tr...

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Abstract

The present invention provides a kind of peak clipping method of self-adaptive in-band processing, at first, it will change the time domain signal into the frequency domain signal after the (original 4 times of oversampling) OFDM signal that it inputs has higher PAPR value after FFT, simultaneously , the original 4 times oversampled OFDM signal undergoes simple peak clipping, and then transforms the time domain signal into a frequency domain signal through FFT, and performs in-band processing adaptively according to the EVM value obtained from the two frequency domain signals. The out-of-band processing is carried out at the same time as the in-band processing, and then undergoes IFFT transformation to make it an OFDM signal with a lower PAPR value and send it out. This method can not only well suppress the out-of-band radiation of the frequency spectrum after simple peak clipping, but also can well control the EVM value and obtain better PAPR performance. It is a simple and useful peak clipping method.

Description

technical field [0001] The invention belongs to the field of 3G and 4G communication, and relates to the peak-to-average ratio (Peak to Average Power Ratio, PAPR) problem in an Orthogonal Frequency Division Multiplexing (OFDM) communication system, and specifically relates to an adaptive in-band processing Clipping method. Background technique [0002] On the eve of the large-scale commercialization of the third-generation mobile communication system, research on the fourth-generation mobile communication system, namely 4G, has been widely carried out in the communication field. Compared with the previous three generations of mobile communication systems, the data transmission rate provided by 4G has been greatly improved, and it is expected to reach 20Mb / s or even higher. [0003] High-speed data transmission requires a wide spectrum, and the spectrum is the most scarce resource in mobile communication; in addition, because the mobile communication channel is a changeable ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26
Inventor 余荣谢胜利李波戴月腾
Owner SOUTH CHINA UNIV OF TECH
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