Peak-to-average ratio restraining method and device in multi-carrier orthogonal frequency division multiplexing system

Abstract

The invention discloses a method for inhibiting the peak-to-average ratio in a multi-carrier orthogonal frequency division multiplexing OFDM system, a pre-formed lengthen core kernel wave shape. The method also comprises: combining the baseband frequency area signal of each carrier as the combined channel signal of the time area multi-carrier on each OFDM sign; extracting the wave cutting noise in the combined channel signal and cutting the analogy pulse signal of the channel length from the lengthen core kernel wave shape according to the position of the multi-carrier combined channel signalin the cutting noise; using the analogy pulse signal multiplying the cutting noise to obtain the offset noise; reversely adding the delayed noise to the multi-carrier combined channel signal to inhibit the peak-to-average ratio. The invention also provides a device for inhibiting the peak-to-average ratio in the OFDM system which can effectively inhibit the peak-to-average ratio in the OFDM system.

Description

Technical field [0001] The present invention relates to Orthogonal Frequeney Division Multiplexing (OFDM) technology, in particular to a method and device for suppressing peak-to-average ratio in a multi-carrier OFDM system. Background technique [0002] Among the existing communication technologies, OFDM technology has become the key to the 4th generation mobile communication due to its high frequency utilization, strong resistance to Inter Symbol Interference (ISI) and Inter Carrier Interference (ICI). technology. [0003] For the single-carrier technology, at the transmitting end of the OFDM signal, if the single carrier includes N sub-carriers, the high-speed data stream is divided into N parallel sub-data streams after serial-to-parallel conversion, and the inverse Fourier transform (IFFT, Inverse Fast Fourier Transform), which converts the frequency domain signal to the time domain. The output of an IFFT with a length of N is N time domain sample signals, which are called OF...

AI Technical Summary

Problems solved by technology

If the same filter coefficients are used for each OFDM symbol for matched filtering, such as designing filter coefficients in high-order modulation, the clipping capability of matched filtering will be very limited, and the peak-to-average ratio of multi-carrier OFDM systems after matched filtering It is still very high, and the filter coefficients are selected with a large error vector magnitude (EVM, Error Vector Magnitude) loss, which will inevitably lead to the subcarriers of the high-order modulation method not meeting the EVM requirements stipulated in the protocol, seriously affecting the link of the system performance

[0008] even if right figure 1 Appropriate improvement of the matched filtering in , such as using different filter coefficients on each OFDM symbol, will also cause serious distortion of some sampling points between two OFDM symbols, resulting in serious out-of-band leakage and inter-symbol interference, This significantly deteriorates the EVM of the high-order modulated subcarriers in the OFDM carrier, and the out-of-band leakage will also make the channel signal after the peak-to-average ratio suppression unable to meet the spectrum template specified in the protocol

[0009] From the above analysis, it can be seen that figure 1 The shown clipping scheme using matched filtering cannot be directly applied to multi-carrier OFDM systems, and there is no effective peak-to-average ratio suppression scheme for multi-carrier OFDM systems

Images