排序方式: 共有9条查询结果,搜索用时 15 毫秒
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根据频率选择性衰落信道的抽头延迟线模型,将针对平坦衰落信道的CS(周期平稳过程理论)频偏盲估计算法扩展到了频率选择性衰落信道,并通过仿真证明这种扩展是可行的.仿真结果还表明CS算法不仅有好的抗平坦衰落能力,而且有很好的抗频率选择性衰落性能. 相似文献
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一种基于PN训练序列的OFDM时频同步算法 总被引:1,自引:0,他引:1
提出了一种基于PN训练序列的OFDM时频同步的新算法.该算法通过构造一种倒序结构的同步训练序列,获得了较好的定时性能;同时利用该序列实现了较精确的频率同步.仿真结果表明,在信噪比为20 dB时,高斯信道条件下的频偏估计方差可达10-7,多径信道下可达10-5,频偏估计范围可以达到整个信号带宽的一半.与传统算法相比, 该算法符号定时更精确,频率同步性更好,具有较好的可行性和实用性. 相似文献
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A new blind frequency offset estimation method based on cyclic prefix and virtual subcarriers in coherent optical orthogonal frequency division multiplexing (CO-OFDM) system is presented. It is able to estimate the fractional part and integral part of frequency offset at the same time. Its estimation range is about [-3.5 GHz, 3.5 GHz]. The influence of the integral frequency offset is comprehensively analyzed in COOFDM system. Its performances in the additive white Gaussian noise (AWGN) channel and the dispersive channel are investigated, respectively. Simulation results indicate that even in the dispersive channel, when the optical signal-to-noise ratio (OSNR) is low, it can still work very well. 相似文献
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Joint scheme for symbol,sampling clock,and carrier frequency synchronization in PDM-CO-OFDM system beyond 100 Gb/s 总被引:1,自引:1,他引:0
We propose a joint scheme for symbol, sampling clock, and carrier frequency synchronization in a polarization division multiplexing coherent optical orthogonal frequency division multiplexing (PDM-CO-OFDM) system. Unlike other existing algorithms designed for specific impairment, the scheme can estimate and compensate for the interactional synchronization errors effectively without extra training overhead by building a comprehensive error model. The simulation shows that symbol synchronization error and sample timing error can be corrected by channel equalizer, and the estimation ranges of sampling frequency offset and normalized carrier frequency offset are about (-2000, 2000) ppm, and (-0.04 (-3.5), 0.04 (3.5)) Ghz, respectively. 相似文献
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提出一种基于训练序列相位差+调频Z变换(CZT)的两级频偏估计算法。该方案采用设计的时域训练序列块并结合块内和块间多次平均平滑噪声影响,以较低开销实现频偏的稳定粗估计,并进一步基于第一级频偏粗估计设定第二级CZT估计范围,以较低计算复杂度完成最终高精度频偏估计。三载波128 GBaud偏振复用十六进制正交幅度调制(PM-16QAM)超奈奎斯特(FTN)波分复用(WDM)系统的仿真结果表明,加速因子为0.95、0.90、0.85时,所提算法训练开销仅为1.56%,即可实现-8~8 GHz范围内的稳定频偏估计,残余频偏分别为2、2.5、3 MHz左右。与估计精度基本相当的传统盲四次方FFT频偏估计算法相比,所提算法的总体计算复杂度显著降低,约为传统算法的8%。 相似文献
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