摘要
广播式自动相关监视(Automatic Dependent Surveillance-Broadcast,ADS-B)广泛应用于空中交通管制,但传播距离远时,ADS-B信号可能十分微弱,不易正确译码。针对此问题,提出低信噪比ADS-B信号的译码算法。该算法计算含噪信号数据块的协方差矩阵,利用该矩阵修正信号起始位置的估计值后,再重新确定新的协方差矩阵,对新的矩阵做奇异值分解,得到脉冲波形估计值;利用脉冲波形估计值与标准脉冲波形分别进行初步译码,并对低置信度比特进行循环冗余纠错。理论计算和仿真表明,在噪声为加性高斯白噪声且前导脉冲位置确定时,该译码算法能明显提高信号的正确接收概率。实验表明,当实测微弱信号的功率为-99 dBm时,正确接收概率为97.9%。
The Automatic Dependent Surveillance-Broadcast(ADS-B)is widely used in air traffic control,but when the transmission distance is far,the ADS-B signal may be very weak and difficult to decode correctly.To solve this problem,a decoding algorithm for low SNR ADS-B signal is proposed.The algorithm first calculates the covariance matrix of the noisy signal data block,uses this matrix to correct the estimated value of the signal starting position,and then re-determines the new covariance matrix,and performs singular value decomposition on the new matrix to obtain the estimation of the pulse waveform.Finally,the estimation of pulse waveform and standard pulse waveform are used for preliminary decoding respectively and perform cyclic redundancy error correction for low confidence bits.The theoretical calculation and simulation show that when the noise is additive white Gaussian noise and the position of the preamble is determined,the algorithm can significantly improve the probability of correct reception.The experiment shows that when the power of the measured weak signal is-99 dBm,the probability of correct reception is 97.9%.
作者
魏子轩
高勇
WEI Zixuan;GAO Yong(College of Electronics and Information Engineering,Sichuan University,Chengdu 610065,China)
出处
《无线电工程》
北大核心
2023年第11期2652-2658,共7页
Radio Engineering
基金
四川大学科研项目资助(0020505501663)。
