GNSS接收机射频前端电路相位噪声评估方法

Phase noise estimation method for RF front-end circuit of GNSS receiver

相位噪声是影响全球卫星导航系统(global navigation satellite system,GNSS)接收机性能的一个重要因素,在高性能的接收机设计中,射频前端电路的相位噪声评测是不可忽略的。传统观测相位噪声的方法主要是利用频谱分析仪等专业仪器来实现,其无法观测GNSS接收机射频前端电路(包含模数(analog-digital,AD)转换器)的相位噪声。分析了接收机相位噪声和热噪声在信号复平面域的表现特征,提出了在信号复平面域评估GNSS接收机射频前端电路相位噪声的方法,并对该方法进行了仿真验证和实测验证。利用相位噪声对信号在复平面实部和虚部影响不同的特点,对采集到的信号数字中频数据进行相干积分处理,定量估算接收机射频系统的相位噪声。结果表明,该方法具有较高的评估准确度,可以用于测量与评估GNSS接收机射频前端电路(包含AD转换器)的设计质量,预测接收机性能。

Phase noise is an important factor affecting the performance of global navigation satellite system(GNSS)receivers.In the high-performance receiver design,the phase noise evaluation of RF front-end circuits can not be ignored.The traditional methods mainly use professional instruments such as spectrum analyzers,which cannot analyze the phase noise of the RF front-end circuit of GNSS receivers which including the analog-digital(AD)converter.In this paper,the performance characteristics of the phase noise and the thermal noise of the receiver signals in the complex domain are analyzed.A method for evaluating the phase noise of the RF front-end of GNSS receiver in the signal complex system was proposed.The method is verified by simulation and test on receiver hardware platform.Based on the different effects of phase noise on the real part and imaginary part of the signal,the digital intermediate frequency data of the collected signal are processed by coherent integration,and the phase noise of the receiver RF system is quantitatively calculated.The results show the method has high evaluation accuracy and can be used to measure and evaluate the design quality of GNSS receiver radio frequency(RF)front-end circuits(including AD converters),to predict the receiver performance.