| 摘要: |
| 针对四维直接序列扩频调制信号的峰均比（Peak-to-Aaverage Ratio,PAPR）问题，分析了成形滤波器滚降因子对调制信号PAPR的影响，得到了PAPR随滚降因子的变化规律，进一步引入了基于限幅的PAPR抑制方法降低调制信号的PAPR。理论和仿真结果表明，当滚降因子为0.42时，调制信号的PAPR值最小；所引入的PAPR抑制方法能有效降低调制信号的PAPR，同时对系统误码性能的影响极小，当限幅率为4、系统互补累积概率密度为0.1%时，调制信号PAPR降低了0.8 dB，系统误码率为10－5所对应的信噪比损失仅为0.3 dB。 |
| 关键词: 四维直接序列扩频调制 峰均比抑制 希尔伯特变换 滚降因子 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目（61701518） |
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| Peak-to-average ratio suppression of four-dimensional direct sequence spread spectrum modulated signals |
| HUA Bo,MAO Zhongyang,KANG Jiafang,MIAO Xingji,YANG Fan |
| (Aeronautical Communications Teaching and Research Office,Naval Aeronautical University,Yantai 264001,China;Naval Equipment Department,Hanzhong 723213,China) |
| Abstract: |
| The rule about the peak-to-average ratio(PAPR)of four-dimensional direct sequence spread spectrum(DSSS) modulated signal is obtained,which reveals the relationship between the signal PAPR and the roll-off factor of the shaping filter.The influence of roll-off factor of shaping filter on the modulated signal PAPR is analyzed,and the clipping-based PAPR suppression method is further introduced to reduce the modulated signal PAPR.Theoretical and simulation results show that when the roll-off factor is 0.42,the PAPR value of the modulated signal is the smallest;the PAPR suppression method introduced can effectively reduce the PAPR of the modulation signal,and has little impact on the system bit error performance.When the clipping rate is 4 and the system complementary cumulative probability density is 0.1%,the PAPR of the modulated signal is reduced by 0.8 dB,and when the bit error rate is 10－5,the signal-to-noise ratio loss is only 0.3 dB. |
| Key words: four-dimensional direct sequence spread spectrum modulation peak-to-average ratio suppression Hilbert transform roll-off factor |
