军民兼容卫导终端中基带处理影响分析

Analysis on the Baseband Cutoff in Military and Civil Compatible GNSS Receiver

在军民兼容GPS接收机中,A/D采样速率取决于军码带宽,民用要求需进行抽取,以有效地节省硬件资源。对此着重分析推导了均匀量化对信噪比的影响、有效字长截取对载噪比和正交性能的影响,并给出了最佳截取方案。GPS卫星信号的实际接收机情况,表明结论正确,能在基本不改变接收机性能的情况下有效地节约硬件资源。

For military and civil compatible GPS receiver, A/D sampling rate is determined by bandwidth of P（y） code. It is needed to lower chip rate C／A code signal in order to saving hardware resource. After analyzing the influence of rounding quantization on the signals of SNR〈0dB, word-length cutoff on CNR and orthogonal performances, the optimal methods are presented. The simulation and experiments based on the signals by military and civil compatible GPS receiver. It is proved correct that the presented method is able to save hardware resource without sacrificing the performances.