Acquisition performance evaluation for fully digital receivers in a band-limited DS-SS CDMA system

CDMA digital modems, utilising DS SS, are currently being implemented for VSAT as well as for mobile and personal communications via satellite. A fundamental aspect for such terminals is the code synchronization and initial acquisition. This paper introduces an analytical formulation to evaluate the performance of the acquisition system in a fully digital modem. The analysis takes into account the presence of interchip interference due to band limitation, thermal noise, synchronous and asynchronous interferers. The analysis is then validated by extensive simulations. The system being considered is the BLQS-CDMA (band limited quasi synchronous CDMA) proposed by ESA, where all users are synchronous at chip level, but the analysis is applicable to any CDMA system. Comparisons with the classical analogue approach are made and easy to use models for a fast, accurate estimate of acquisition times are given