数据和导频通道的功率加权联合捕获算法

下一代全球导航卫星系统将采用数据和导频通道功率不等的调制方式,而传统算法多采用数据和导频通道的等权重加权联合进行捕获。当二者功率不相等时,等权重加权联合不能获得最优的捕获性能。因此提出功率加权联合的改进捕获算法,在数据和导频通道的功率分配不等的情况下,进行不同加权系数的联合捕获,并且利用最小二乘的方法进行最优加权系数的拟合估计。利用捕获判决量的特征函数推导检测和虚警概率。仿真实验验证了当数据和导频功率比为1∶3、检测概率为0.8、虚警概率为10-3时,所提出的改进算法能提升0.4 d B的捕获灵敏度。

The Power-Weighted Combing Acquisition Algorithm with Data and Pilot Signals

The modulation with different power of data and pilot channels will be used in the next generation Global Navigation Satellite Systems (GNSS). However, the traditional acquisition algorithms are mostly designed with equal-weighted coefficient of data and pilot channels. Unfortunately, when the power of data and pilot channels are not equal, the traditional algorithms are not suitable for optimizing the performance. The paper proposes a power-weighted combing acquisition algorithm, which uses the different weighted coefficients for data and pilot channels. And uses the Least-Square fitting method to optimize the coefficients. The detection and false-alarm probabilities are derived with characteristic function of decision variable. The simulations prove that the acquisition threshold of the algorithm is improved 0.4 dB, when the power ratio of data and pilot channels is 1:3, and the detection and false-alarm probabilities are 0.8 and 10-3, respectively.