Method and device of lowering PAPR (peak to average power ratio) of 60 GHz communication system based on LDPC (low density parity check) coding mechanism

Abstract

The invention is specific to the problem of PAPR (peak to average power ratio) presented by OFDM (orthogonal frequency division multiplexing) modulation of 60 GHz millimeter wave communication system, and provides a method of lowering OFDM signal PAPR by using selectivity mapping combined with LDPC (low density parity check) to generate matrix high density character. By adding a little bit information, PAPR of the millimeter wave OFDM transmission signal is effectively lowered. In a big rate situation, a construction plan of improving an LDPC non-systematic code is provided, which can remarkably lower PAPR and effectively improve the transmission performance in the case of nonlinearity power amplifier distortion of 60 GHz millimeter waves system. Compared with the traditional coding scheme, the invention can remarkably lower PAPR, improve the transmission performance of millimeter wave signal in the presence of device nonlinearity and excels other coding scheme in aspect of anti-power amplifier PA nonlinearity. At the same time, the non-systematic code which is designed and constructed in the method and device can still have a fine performance when the coding rate is big. The arithmetic implementation of the non-systematic code is simple, and parallel computation can be used by the non-systematic code, so that the method and the device of lowering 60 GHz communication system PAPR (peak to average power ratio) based on LDPC (low density parity check) coding mechanism has great practical value in high-speed millimeter waves OFDM system.

Description

technical field [0001] The present invention aims at the peak-to-average power ratio (Peak to Average Power Ratio, PAPR) problem presented by the Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme in the 60GHz millimeter-wave communication system, and proposes a utilization selectivity Mapping (Selected Mapping Principle, SLM) combines the high-density characteristics of LDPC generator matrix to reduce the PAPR method of OFDM signal; on this basis, an improved LDPC non-systematic code construction scheme is proposed, which can significantly reduce PAPR, thereby effectively improving the existing The transmission performance of the 60GHz millimeter-wave system under nonlinear power amplifier distortion is superior to other coding methods in terms of anti-power amplifier (Power Amplifier, PA) nonlinearity. belongs to the field of communication. Background technique [0002] With the rapid development of wireless communication and the continuous improvement of...

AI Technical Summary

Problems solved by technology

However, there are two significant disadvantages in the OFDM system: 1) the receiving performance is very sensitive to the phase; 2) the transmitted signal has a large PAPR

The existing research on LDPC codes mainly focuses on the optimization of the bit error rate performance, and the LDPC code designed in the literature is only 0.0045dB away from the Shannon limit.

At the same time, we noticed that the parity check matrix of LDPC codes is sparse, and its generator matrix has high-density characteristics. However, the existing research rarely uses the characteristic of LDPC high-density generator matrix.

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