【作者】 陈星；

【导师】 杨高波； 余小游；

【作者基本信息】 湖南大学 ， 信息与通信工程， 2015， 硕士

【摘要】 雷达通信一体化系统能够实现无线通信与雷达感知功能在信号层面的融合,提高频谱利用率的同时,可以降低车联网节点的复杂度。车载正交频分复用(OFDM)通信系统的工作频点和射频前端电路结构与微波雷达系统越来越接近,车载OFDM通信信号存在实现雷达测距测速功能的潜力。特别是OFDM通信信号中的导频具有与传统雷达信号十分相似的特征,其雷达测距测速能力值得深入研究。本文在分析OFDM导频信号特性的基础上,重点研究车载通信环境下基于OFDM导频信号的测距测速方法。首先,建立车载雷达通信一体化系统结构模型和车载环境下收发信号的数学模型,在分析导频信号频域矩阵的基础上,提出利用导频矩阵的行向量和列向量分别估计目标距离和速度的方法。其次,由于OFDM导频信号的带宽和时宽较雷达信号小,需要利用多重信号分类(MUSIC)超分辨算法提高距离和速度的分辨率,但MUSIC算法在进行谱估计和谱峰搜索时,运算量过大,影响其实用性;为此,本文提出一种基于MUSIC算法的高分辨距离速度估计改进算法,先采用快速傅里叶变换进行快速谱估计,通过粗略的频谱搜索来锁定目标区域,然后利用MUSIC算法实现精确的谱峰搜索和高分辨距离速度估计。最后,为了有效地利用OFDM导频信号进行测距测速,需要对现有标准OFDM信号的导频结构进行改进,提出一种时频连续型导频结构。仿真表明,本文提出的基于OFDM导频的测距测速算法理论上可行,而且具有良好的抗噪声性能;所提出的时频连续型导频结构和基于MUSIC的改进型距离速度估计算法,在保持MUSIC算法高分辨率的基础上,距离速度精度分别为0.36m,0.94m/s,减少了运算量,提高距离速度估计的效率,同时能够保证较强的抗干扰性能和较高的测距测速精度。更多还原

【Abstract】 The radar-communication integration system can realize the fusion of wireless communication and radar perception in the signal level to maximize the spectrum utilization and reduce the complexity of the network nodes.The working frequency and the radio frequency front of circuit structure of the vehicle-mounted OFDM radar-communication integration system become more and more similar to the radar system.The vehicle-mounted OFDM communication signal has the potential to realize the range and velocity measurement of radar.Especially the OFDM pilot signals have the similar feature with the traditional radar signal,the capacity of range and velocity measurement is deserved to research.This paper aims to study the method of range and velocity measurement using OFDM pilot signal in vehicle-mounted communication system.Firstly,the vehicle-mounted radar-communication integration system structure model,send and receive signals model are established.The OFDM pilot signals frequency domain matrix was derived,through analysis the relationship between the range,velocity and the pilot signal matrix based on the matrix,we proposed a method that using the column and row vector to estimate the range and velocity of the target.Secondly,for the problem of the small bandwidth and time width,we must use the MUSIC algorithm to estimate the target range and velocity.However the large computational complexity of spectrum estimation and spectr um peak search Affect the practical when using MUSIC algorithm in vehicle environment.This paper proposes a new method based on MUSIC algorithm to estimate the target’s range and velocity.The method using FFT spectrum approximate estimation and search,r educing search domain,and then using MUSIC algorithm accurately estimates.At last,it is necessary to design the structure of the OFDM pilot signal to realize the measurement of range and velocity using OFDM pilot signal effectively.This paper proposes a time-frequency continuous pilot structure which can be used for the measurement of range and velocity by analyzing the relationship between pilot structure and the range and velocity.Simulation results show that the method using pilot signal to estimate the target’s range and velocity is feasible in theory,and it has good anti-noise performance.The proposed pilot structure and the proposed method based on the MUSIC algorithm can realize the range and velocity measurement effectively at the same time,and the error is small,and the accuracy is large.The accuracy of range and velocity of the new method is 0.36 m and 0.94m/s,respectively,and it reduces computational complexity compared with the traditional algorithm on the basis of maintaining the estimation accuracy of the MUSIC algorithm,greatly improve the estimation efficiency,it maintain the good anti-noise performance and the high range and velocity measurement precision.更多还原