Spectral compatibility of BOC(5,2) modulation with existing GNSS signals

The modernization in Global Navigation Satellite System (GNSS) has brought a greater change by introducing new signals and services with new availabilities and applications. The primary importance of introducing S and C band services is to improve the timing performance, robustness and accuracy in addition to the existing L band signals. India is also developing its own regional navigation system using BOC(5,2) modulation in the S band. The main objective of the paper is to analyze the spectral characteristics of BOC(5,2) signal and evaluate its spectral compatibility with other existing GPS and GALILEO signals. The spectral properties like spectral separation coefficient (SSC), maximum value of the spectrum (MVS), Effective rectangular bandwidth, Root mean square bandwidth (RMS) and efficiency parameters like power containment factor and spectral efficiency have been considered for comparing different modulation schemes. The spectral separation coefficients (SSC) of the desired and interfering signals are evaluated by normalizing power spectral densities to both infinite and finite transmission bandwidth and integrated within the bandwidth of the receiver. Simulations reveals that BOC(5,2) signal offers good spectral performance and compatibility with existing GNSS signals allowing multiple access transmissions with better spectral separation coefficients.