An Acquisition Algorithm for DS/FH TTC Signal Using Subband-Accumulation Method

摘要

The problem of fast acquisition of Direct Sequence/Frequency Hopping (DS/FH) spread spectrum signal is studied.With the existence of ionospheric dispersion,the carder phase continuity of a phase-coherent FH system is disrupted and the complexity of acquisition is drastically increased.By searching the Total Electron Count (TEC),i.e.the electron density,along the path length,the receiver is capable of compensating for the phase pattern of local replica FH signal and performing quasi-coherent acquisition.A new acquisition strategy named Band Division Accumulation is proposed.It is proved that the strategy can broaden the TEC search period and thus reduce search complexity.The connection between the number of sub-bands and energy loss is analyzed.The accumulation loss of acquisition can be adjusted by altering the number of sub-bands,providing flex-ibility to design of receivers.