Space-Differential Cooperative acquisition for Galileo E1 OS signals

In modern GNSS, new signal modulations are adopted to satisfy the demand for higher performance service. Based on the composite structure of Galileo E1 signals, which introduces data and pilot channels, some joint strategies are investigated for the acquisition block. Two typical algorithms are Noncoherent Combining (NCC) and Coherent Combining (CC). However, for the longer spreading sequence, the computational load of these two methods increases remarkably. Although the performance of CC is superior to NCC, it becomes unreliable in the weak level Thus, this paper proposes a novel algorithm, namely Space-Differential Cooperative (SDfC) acqusition, which substitutes differential process between data and pilot channel for that of consecutive intervals of one signal. The theoretical scheme and probability characteristics are first discussed in detail. Then, the simulation results by Monte Carlo indicate the feasibility of SDfC algorithm and that it can not only obtain better performance than CC, but also with lower complexity.