Weak BeiDou signal acquisition in the presence of sign transition over multiple periods

To improve the acquisition sensitivity of weak BeiDou signal, multiple periods accumulation is applied. However, as the Neumann-Hoffman code is modulated onto the BeiDou MEO/IGSO signal, the sign transition may occur in even 1-ms interval. This paper proposes a modified multiblock zero padding method to solve the sign transition problem for weak BeiDou signal acquisition. The proposed modified multiblock zero padding method applies differentially coherent accumulation to detect the weak signal. To evaluate the performance of the proposed method, the Monte Carlo simulation experiments are conducted. Simulation experiments have demonstrated the validity and availability of the proposed method, which can achieve weak signal acquisition under the BeiDou-challenged environment.