对电文翻转不敏感的导航信号载噪比估计算法  

Navigation C/N_(0)Estimation Algorithm Insensitive to Message Flipping

作　　者：王晓君[1] 姚远 WANG Xiao-jun;YAO Yuan(School of Information Science and Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,China)

机构地区：[1]河北科技大学信息科学与工程学院,石家庄050018

出　　处：《科学技术与工程》2023年第13期5616-5622,共7页Science Technology and Engineering

基　　金：河北省省级科技计划(21310402D)。

摘　　要：对于导航接收机而言,获取通道信号载噪比可辅助其提升跟踪精度和定位速度。但在使用传统的宽窄带功率比值法做载噪比估计时,由于该方法对导航电文数据比特的符号翻转敏感,导致其估计精度较低且运算量大。针对这一问题,提出一种对电文翻转不敏感的导航信号载噪比估计算法,该算法立足于在通道稳定跟踪时信号能量集中在I路,且噪声能量均等分散在I、Q两路,使用I、Q路信号能量做载噪比估计。首先,通过公式推导得出其运算表达式,再经计算机仿真确定最佳的单次积分时长和运算组数。结果表明,相较于宽窄带功率比值法,虽然该算法总积分时间略长,但对导航电文翻转不敏感,估计精度可提升5.72 dB或更高。在总积分时间相等的条件下,算法运算量相较于宽窄带功率比值法降低了33.6%。所提算法不仅提高了估计精度,同时降低了运算量,在导航接收机中有一定的应用前景。For the navigation receiver,obtaining the carrier to noise ratio of the channel signal can help it improve the tracking ac-curacy and positioning speed.However,when the traditional wide-narrow band power ratio method is used to estimate the carrier to noise ratio,due to its sensitivity to the symbol reversal of navigation message data bits,its estimation accuracy is low and the amount of computation is large.To solve this problem,a navigation signal carrier to noise ratio estimation algorithm that is insensitive to message rollover was proposed.Based on the fact that the signal energy is concentrated in channel I and the noise energy is equally distributed in channel I and Q when the channel is stable and tracked,the carrier to noise ratio estimation was performed using the signal energy of channel I and Q.First of all,its operation expression was derived through the formula,and then the best single integration duration and the number of operation groups were determined by computer simulation.The results show that although the total integration time of the algorithm is slightly longer than that of the narrow-band power ratio method,it is not sensitive to the navigation message rollover,and the estimation accuracy can be improved by 5.72 dB or more.Under the condition that the total integration time is equal,the cal-culation amount of the algorithm is reduced by 33.6%compared with the wide-narrow band power ratio method.The proposed algo-rithm not only improves the estimation accuracy,but also reduces the amount of computation.It has certain application prospects in navigation receivers.

关 键 词：载噪比估计 导航电文翻转 宽窄带功率比值法 导航接收机 

分 类 号：TN911.72[电子电信—通信与信息系统]