The Reducing OFDM System Of Papr Technology

Orthogonal frequency division multiplexing is a high-speed information transmission. It has higher spectrum efficiency, a strong anti-frequency-selective fading and anti-jamming capability. But it is a synthesis of multi-path signals. Therefore, it has relatively high average peak power, which will bring many unfavorable factors in the course of transmission. So we must reduce its peak-to-average power ratio through some methods. There exist several methods can reduce the peak-to-average power ratio, such as limiting law, partial transmission sequence method and selective mapping, and so on. However, these methods have some shortcomings, such as larger operation, relatively low transmission rate or hardware more difficult. According to this case, the text did some things on the theoretical analysis about orthogonal frequency division multiplexing of peak-to-average power ratio.Because the method improved operation and hardware complication, reduced a mount of code transmission speed by PTS reducing peak-to-average power ratio. The text proposed a diagonal matrix algorithm to reduce peak-to-average power ratio. The diagonal matrix is used to determine through a kind of logistic or suppositional grouping. This paper proposed a method of reducing the peak-to-average power ratio by the diagonal matrix operation. The diagonal matrix operation is placed before IFFT or after IFFT. Then the method was simulated base on matlab platform. Then the text improved the limiting to reduce the peak-to-average power ratio. The method enhanced the effect of reducing the peak-to-average power ratio and reduced the error rate by simulation. Finally, the text made a detailed about carrier interferencetechnology. Then the text pointed out hardware was more complex if the technology will be applied directly to the OFDM system. If the input data was as phase modulation and CI spreading code was as data transmission, it can reduce the complexity of hardware.