Method for transmitting OFDM signals based on new companding transform

A signal transmission and signal technology, applied in the field of OFDM communication systems, can solve the problems of system BER increase, signal distortion, and difficulty in practical use, and achieve the effect of good PAPR performance and low bit error rate performance.

Inactive Publication Date: 2015-04-15
UNIV OF ELECTRONICS SCI & TECH OF CHINA
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Problems solved by technology

Although these two methods can significantly reduce the PAPR of the signal, the μ-law companding reduces the PAPR at the cost of increasing the average power of the transmitted signal, and the average power value of the signal after companding by this method is closer to the nonlinearity of the power amplifier. area, thus easily causing signal distortion, and exponential companding increases the BER of the system to an unpractical level

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  • Method for transmitting OFDM signals based on new companding transform
  • Method for transmitting OFDM signals based on new companding transform
  • Method for transmitting OFDM signals based on new companding transform

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Embodiment Construction

[0011] Vector S=[S 0 , S 1 ,...,S N-1 ] Indicates the data symbols input in one OFDM data frame, S k (k=0, L, N-1) represents the symbol modulated on the kth subcarrier, then the discrete time domain OFDM signal generated can be represented by the following formula:

[0012] s ( n ) = 1 N Σ k = 0 N - 1 S k · e j 2 πkn / N , n=0,1,...,N-1

[0013] According to the central limit theorem, when the number of subcarriers N is large (N≥64), the real and imaginary parts of s(n) are independent Gaussian distributions, and the magnitude of s(n) satisfies the Rayle...

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Abstract

The technical problem to be solved by the invention is to provide a method for transmitting the OFDM (Orthogonal Frequency Division Multiplexing) signals based on new companding transform, and the method can obtain better balance between PAPR and BER. The method for transmitting the OFDM signals based on new companding transform comprises the following steps: processing the generated OFDM time domain signals through companding distortion, and transmitting by a power amplifier pairs through antennas, wherein the low-amplitude OFDM signals are processed through companding distortion by using arc-cotangent transform; and the large-amplitude OFDM signals are processed through companding distortion by using arc-tangent transform. The invention can enlarge small signals by using the arc-cotangent companding and can compress the large signals by using the arc-tangent signals. Compared with the current companding method, the method can obtain better PAPR (peak-to-average-power ratio) performance and lower code error rate performance.

Description

technical field [0001] The invention belongs to an OFDM communication system and relates to peak-to-average power ratio suppression technology. Background technique [0002] In the OFDM system, before the generated OFDM signal enters the high power amplifier, the OFDM signal is pre-distorted to limit the amplitude of its peak signal, so as to achieve the purpose of reducing PAPR. Among the pre-distortion techniques, what attracts more attention is the companding method, which can use the inverse companding function to restore the signal at the receiving end. [0003] Companding methods that have been proposed so far include μ-law companding and exponential companding. Although these two methods can significantly reduce the PAPR of the signal, the μ-law companding reduces the PAPR at the cost of increasing the average power of the transmitted signal. The average power value of the signal after companding by this method is closer to the nonlinearity of the power amplifier. a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26
Inventor 朱晓东潘文生于延辉
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
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