| 摘要: |
| 多进制相移键控(Multi-phase Shift Keying,MPSK)信号在各种数字通信系统中被广泛应用，但当收发两端存在相对运动速度时，引发的多普勒频偏会影响相干解调的准确性。针对这一问题，提出了一种基于传统多次方谱估计的频偏估计算法。该算法采用非数据辅助方法去除调制信息，利用傅里叶系数插值算法得到小数频偏粗估计值，并通过频域内最大谱线以及其左右±0.5处谱线插值优化处理获得小数频偏精估计值。在信号采样点数为512，信噪比大于6 dB的情况下，该算法与传统多次方谱估计算法相比，其归一化频偏估计的均方误差降低了15 dB左右，相干解调误码性能也趋于理论曲线，且具有更高的稳定性和适应性。 |
| 关键词: MPSK信号 频偏估计 多次方谱估计 插值算法 |
| DOI：10.20079/j.issn.1001-893x.230426001 |
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| 基金项目:国家自然科学基金资助项目(61901502，61971439，U22B2002);江苏省自然科学基金(BK20191329) |
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| A Frequency Offset Estimation Algorithm with Multi-spectral Line Interpolation Optimization |
| ZHANG Yuli,XIE Shijun,AN Kang,YAO Changhua |
| (1.School of Electronic & Information Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China;2.The 63rd Research Institute of National University of Defense Technology,Nanjing 210007,China) |
| Abstract: |
| Multi-phase shift keying (MPSK) signals are widely applied in various digital communication systems.However,when there is relative motion between the transmitter and receiver,the resulting Doppler frequency offset adversely affects the accuracy of coherent demodulation.To address this issue,a frequency offset estimation algorithm based on conventional multi-order spectral estimation is proposed.The algorithm employs a non-data-aided method to remove the modulation information.It utilizes a Fourier coefficient interpolation algorithm to obtain an approximate fractional frequency offset estimation.Further optimization is achieved by interpolating the maximum spectral line within the frequency domain and its neighboring spectral lines at ±0.5,resulting in a refined fractional frequency offset estimation.With a signal sampling point of 512 and a signal-to-noise ratio exceeding 6 dB,the proposed algorithm exhibits a reduction in the mean square error of normalized frequency offset estimation by approximately 15 dB compared with the conventional multiple-order spectrum estimation algorithm.Moreover,the coherent demodulation error performance approaches the theoretical curve,while exhibiting enhanced stability and adaptability. |
| Key words: MPSK signal frequency offset estimation multi-order spectrum estimation interpolation algorithm |
