Characterization of interference effects in multiple antenna GNSS receivers

The understanding and mitigation of the effects of narrowband interference on the operation of global navigation satellite system (GNSS) receivers are crucial to maintaining a satisfactory performance of these systems. The carrier to noise density ratio (C/N₀) is a measure of the strength of the received signal relative to the noise (including any interference present) and is therefore an important indicator of the achievable performance. Thus a significant amount of work has been done in the case of single antenna receivers to characterize the impact of the narrowband inteference on the C/N₀, leading to the introduction of the Spectral Separation Coefficient (SSC). In this work, we extend these concepts to antenna arrays and introduce the Spectral and Spatial Separation Coefficient (SSSC). In addition to the Doppler separation, the SSSC takes into account the spatial dimension of the antenna array in order to quantify the effect of the interference on the quality of the received signal of interest. As the SSSC increases, the effect of the interference on the desired signal decreases and consequently the C/N₀ improves. We derive closed formulae for both the SSSC and effective C/N₀ in the case of a single narrowband interference and evaluate them using simulations.