Peak-to-Average Ratio Suppression Method Based on Cyclic Constellation Shift

Abstract

The invention discloses a peak-to-average power ratio suppression method based on cyclic constellation shift. The method comprises the following steps of: (1) setting initial quadrature amplitude modulation; (2) setting a maximum constellation shift length; (3) initializing an optimal solution; (4) determining an optimal constellation shift length depending on a minimum peak-to-average power ratio and transmitting data; (5) selecting a pilot frequency sequence corresponding to the optimal constellation shift length for superimposed transmission; (6) demodulating by a receiving end through a quadrature amplitude modulation constellation reduced and shifted by maximum likelihood estimation through information of pilot estimation. The method, in comparison with probability algorithms of the prior art, can be used for reducing the computation complexity, and meanwhile effectively reducing the peak-to-average power ratio on the premise of not affecting a bit error rate performance.

Description

technical field [0001] The present invention relates to the technical field of wireless communication, in particular to a peak-to-average Power Ratio (PAPR) suppression method in an Orthogonal Frequency Division Multiplexing (OFDM) system in LTE (Long Term Evolution, Long Term Evolution), which can be used to reduce OFDM The peak-to-average ratio of the system enhances LTE downlink coverage. Background technique [0002] With the birth of Fast Fourier Transform and the rapid development of large-scale integrated circuits, OFDM technology is widely used in various wireless communication systems, such as IEEE802.11a / g, IEEE802.16. In the third generation mobile communication system (3G), due to the use of CDMA technology, many problems have been brought about, such as: strong multipath interference, difficulty in multi-user detection, and low spectrum utilization. Therefore, in the LTE system, the OFDM system is introduced to effectively improve the transmission rate, system ...

AI Technical Summary

Problems solved by technology

The lossy method is relatively simple to implement, but it will generate in-band noise and out-of-band interference, which is proposed on the premise of losing part of the system performance

In the lossless method, the encoding method needs to traverse all the sequences, which has a high computational complexity, and it will also reduce the information transmission rate, which is not suitable for engineering implementation

The selection of sequence mapping and partial transmission sequence is to reduce the peak-to-average ratio probabilistically by transforming the original signal. The disadvantage is that the complexity is high, and the correlation between each transformation is strong, and the effectiveness of the transformation cannot be maximized.

Images