Secondly, it introduces the frequency selection, EMC(Electromagnetic Compatibility), the basic generation theory and modulation of the third civil signal(L5 signal), including LS ranging code, Forward Error Correction, QPSK modulation and Neuman.

• 其次，介绍了其信号的频段选择、电磁兼容性及其调制和产生的基本原理，包括L5测距码、卷积码、QPSK调制以及Neuman.