Research on the Strategy and Distance Precision of Mordenized GPS M-code Signal

M code signal by the BOC modulation will be the military signal in the plan of GPS modernization. In the paper, M code military signal strategy is analyzed, the modulation principal, the autocorrelation function of the signal are analyzed and simulated. The specialty of the spectrum-apart, the increased signal power level and the structure of navigation message indicate the improvement of antijamming performance for M code as compare with P/Y code signal, the simulation result of code tracking loops accuracy testify the higher measurement precision of M code compare with P/Y code signal. Keywords-GPS;M code; BOC modulation;auto-correlation function;power spectrum