Comparison of coded-BOC and uncoded BOC modulation for radionavigation

Modern global navigation satellite systems (GNSS) use Binary Offset Carrier (BOC) modulation to provide better spectral separation and code tracking accuracy, as compared to the BPSK modulation. In this paper, error control coding is combined with the BOC. These techniques primarily avoid interference by using modulation techniques that place energy at relatively vacant frequency slots in the occupied radinavigation band. Two variations of BOC - Alt BOC and Coded BOC are presented. These techniques combine coding with BOC modulation without increasing bandwidth requirement. The coded - BOC modulation scheme improves the robustness of radionavigation signals against additive noise than the conventional uncoded BOC modulation scheme.