| 摘要: |
| 针对现有信道估计方案导致正交时频空间(Orthogonal Time Frequency Space,OTFS)调制系统峰均功率比(Peak-to-Average Power Ratio,PAPR)高或频谱效率(Spectral Efficiency,SE)低的问题，提出一种多叠加导频的低PAPR、高SE信道估计方法。发送端利用时域正交性和离散傅里叶域相位的随机性，在时延多普勒域中嵌入与数据相叠加的5导频符号的导频图案实现低PAPR，提高SE。接收端以数据符号与噪声之和的能量均值为基准，实现导频信号检测，同时根据每个导频的不同位置信息恢复出存在相位旋转的数据信号。基于能量准则，利用多个独立的接收信号进行联合信道估计，以降低数据符号的干扰，并采用消息传递算法进行数据恢复。仿真结果表明，该方法比单叠加导频信道估计的PAPR低，同时较嵌入式导频信道估计的SE提高约14.4%。 |
| 关键词: 正交时频空间(OTFS)调制 信道估计 时延多普勒域 多叠加导频 |
| DOI：10.20079/j.issn.1001-893x.231108001 |
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| 基金项目: |
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| Low PAPR Channel Estimation for Multi-superimposed Pilots OTFS Systems |
| HE Jiai,LIU Tao,WANG Le,WANG Chanfei |
| (School of Computer and Communication,Lanzhou University of Technology,Lanzhou 730050,China) |
| Abstract: |
| For the problems of high peak-to-average power ratio(PAPR) and low spectral efficiency(SE) in orthogonal time frequency space(OTFS) modulation systems due to the existing channel estimation schemes,a low PAPR and high SE channel estimation scheme with multi-superimposed pilots is proposed.The transmitter utilizes the orthogonality of the time domain and the randomness of the phase of the discrete Fourier domain to embed a pilot pattern of five pilot symbols superimposed with the data in the delay-Doppler domain to achieve low PAPR and improve SE.The receiver takes the energy mean of the sum of the data symbols and the noise as the benchmark to realize the pilot signal detection,and at the same time recovers the data signal with phase rotation according to the different position information of each pilot.According to the energy criterion,a plurality of independent received signals are used to estimate the joint channel to reduce the interference of the data symbols,and the message passing algorithm is used for data recovery.The simulation results show that the proposed method achieves a lower PAPR than single superimposed pilot channel estimation,and about 14.4% higher than the SE of embedded pilot channel estimation. |
| Key words: orthogonal time frequency space(OTFS) modulation channel estimation delay-Doppler domain multiple-superimposed pilots |
