Dynamic spectral monitoring for flexible and reconfigurable railways communication systems

Abstract : Opportunistic or cognitive radio system are a key technology able to enable reconfigurability and flexibility of wireless systems in the railway domain in order to answer requirements such as system availability, robustness, and traffic heterogeneity. These technologies will allow dynamic spectrum allocation and very often spectrum reuse especially in rural areas. They required an accurate knowledge of the radio spectrum in which it operates. Blind multi-carrier transmission recognition methods based on the discrimination between single-carrier and multi-carrier modulations to estimate their parameters have been addressed in the literature. Some powerful techniques use autocorrelation and cyclic autocorrelation based features of the transmitted signal. Considering MC-DS-CDMA signals, we first propose a fast spectral monitoring scheme to reduce spectral search to the signals of interest. Secondly, a blind parameters estimation is processed to identify their characteristics. The proposed technique leads to a fast efficient parameters estimation and is insensitive to receiver phase and frequency offsets as it is highlighted in the simulation results.