ID 原文 译文
51967 针对啁啾(Chirp)信号参数估计的高复杂度和在低信噪比(SNR)下保持高精度等问题， The Chirp signal parameter estimation has the problems of high computational complexity and low precision under low Signal-to-Noise Ratio(SNR).
51968 文章提出了一种改进的Chirp信号参数估计算法。 In order to solve these issues, an improved Chirp parameter estimation algorithm is proposed.
51969 该算法根据当信号能量和周期长度一定时Chirp信号频谱幅度的平方与调频率成反比的特性， According to the Chirp signal energy and the signal period, the square of the signal spectrum amplitude is inversely proportional to the frequency modulation slope.
51970 不断地产生已知Chirp信号的共轭与未知Chirp信号相乘，找到使相乘后频谱幅度平方最大的已知Chirp信号的调频率。 The Chirp signal is multiplied by the unknown Chirp signal to find the known Chirp signal with the largest square of the spectral amplitude.
51971 为了做到参数估计的高精度，用修正的幅度插值(M-Rife)算法估计中心频率和修正相乘后信号频谱的幅值。 In order to achieve the parameter estimation with high accuracy, the Modified Rife(M-Rife) is used to estimate the center frequency and correct the amplitude of the multiplied signal.
51972 将该算法与短时傅里叶变换(STFT)结合， The algorithm is combined with the Short-Time Fourier Transform(STFT).
51973 首先用STFT估计出调频率的大致范围和信号周期， First, STFT is used to estimate the approximate range and signal period of Chirp.
51974 然后用二分法代替等步长使改进的Chirp信号参数估计算法在这个大致范围内搜索，极大地降低了计算复杂度。 The dichotomy is used instead of the equal step size to allow the improved Chirp signal parameter estimation algorithm to search within this approximate range, resulting in significant complexity reduction.
51975 实验结果表明，在SNR≥-10 dB时，该算法估计调频率归一化均方误差(NMSE)要优于分数阶傅里叶变换(FRFT)约1～2 dB，接近克拉美罗下界(CRLB)。 The experimental results show that when the SNR is not less than-10 dB, the Normalized Mean Square Error(NMSE) of modulation frequency estimated by our proposed algorithm is better than Fractional Fourier Transform(FRFT) by 1～2 dB.
51976 第五代(5G)移动通信系统大规模多输入多输出(MIMO)技术利用信道硬化理论， Massive Multiple-Input Multiple-Output(MIMO) has been identified as a key technology for the upcoming Fifth Generation(5 G) wireless communication systems.