Multi Block Overlapping Zero Padding Algorithm for Weak Signal Acquisition

Global navigation satellite systems (GNSS) can implement high-precision navigation and positioning, requiring rapid and accurate signal acquisition under very weak signal conditions. Double block zero padding (DBZP) is an efficient algorithm for unaided weak signal acquisition. Considering the acquisition problem of weak direct sequence spread spectrum continuous phase modulation signal, the subblock combining and zero padding method is studied in detail. To solve the weakness of fixed number of subblock and fixed number of signal samples in each subblock given frequency resolution and Doppler searching range in DBZP, a multi block overlapping zero padding (MBOZP) algorithm is proposed, which combines with the ideas of data subblock overlapping. This algorithm optimizes the combination of data subblock by introducing the data subblock overlapping, which can increase the length of coherent accumulation and improve the performance of acquisition under the determined frequency resolution and Doppler searching range. Compared with the traditional DBZP, the simulation results show that MBOZP can obtain higher acquisition probability at small frequency offset.