Upper bound on C/A and L1C code spectral separation coefficients

It is well known that the available effective carrier-to-noise density ratio (C/N₀)_effective to a GPS receiver is degraded to a greater degree due to spectral line effects than when spectral line effects are ignored for the Global Positioning System (GPS) coarse acquisition (C/A) codes. ¹²(C/N₀)_effective is an important parameter used to characterize the GPS receiver performance in terms of code acquisition, carrier loss of lock, and data bit error rate. In today´s signal environment, which includes a growing number of Global Navigation Satellite Systems (GNSSs) in the Radio Navigation Satellite System (RNSS) band, there is a need to account for all the interference sources accurately to make sure that the intersystem and intrasystem Radio Frequency Compatibility (RFC) is achieved. Towards this goal many studies in the past considered quasi-analysis and simulation methods to account for the spectral line effects on the GPS C/A code receivers. The spectral separation coefficient (SSC) provides a measure of the amount of interference that can be expected from one signal to the other. An upper bound on C/A code SSC was presented in last year´s IEEE Aeroconference [1]. In this paper we make refinements to the upper bound equations for the C/A codes presented in [1] and also extend the bounds to codes other than the C/A codes. Computational advantage is still retained with the refinement to the equations.