Peak-to-average power ratio inhibition method of phase shift for OFDM grouped subcarriers in time domain

Abstract

The invention relates to a peak-to-average power ratio inhibition method of phase shift for OFDM grouped subcarriers in a time domain. The method includes the steps that frequency domain parallel baseband signals after mapped are grouped, then IFFT calculation is conducted separately to acquire grouped subcarrier time domain equivalent basebands, and summation is conducted to acquire 4N time domain sampling values of OFDM signals; if the peak value is less than a preset limiting threshold, direct output is conducted; if the peak value is greater than the maximum of the limiting threshold, initialization of v = 2 is conducted, and the next step is implemented; a cyclical phase shift of p sampling points is conducted on the 4N sampling points of a vth grouped subcarrier according to a cyclical function, and then the next step is implemented; the peak value of the OFDM signals is detected, if the peak value is less than the limiting threshold, direct output is conducted, and if the peak value is greater than the limiting threshold, the last step is implemented in a splitting mode; when v = V, v = 2 and p = 2*p; when v <= (V-1), v = v+1 and p remains unchanged; the last two steps are cyclically implemented, and when the output OFDM signals satisfy the limiting threshold, the phase shift is ceased; otherwise, Q times of the cyclical phase shift is conducted, and if the peak value of the OFDM signals is still greater than the limiting threshold, the minimum signal of the peak value in the OFDM signals with the Q times of the phase shift is output.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a peak-to-average ratio suppression method for subcarrier phase shift of OFDM grouping in the time domain. Background technique [0002] The equivalent baseband complex number of an OFDM (orthogonal frequency division multiplexing) signal containing N subcarriers is: [0003] [0004] In the formula, a n is the baseband signal that modulates the subcarrier, a n The value of is a random variable, N is the total number of OFDM symbol subcarriers, ω n is the angular velocity of subcarrier n. x(t) represents the waveform of an OFDM signal, then the PAPR (peak-to-average ratio) of the OFDM signal is: [0005] [0006] In the above formula, max{|x(t)| 2} represents the maximum instantaneous power of x(t), E{|x(t)| 2} represents the average power of x(t). According to the central limit theorem, when N is large, the real and imaginary parts of x(t) are Gaussia...

AI Technical Summary

Problems solved by technology

Existing probabilistic technologies include selective mapping SLM, partial transmission sequence PTS and their improved algorithms, etc. These algorithms preprocess OFDM signals in the frequency domain to reduce the signal PAPR value, and all of them have high complexity problems

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