Research On Fast Acquisition Of PRIS Code With Low Complexity

In the new generation of Global Navigation Satellite System(GNSS),the modernized navigation signals prefer to adopt Pseudo Random Noise(PRN)codes with a longer period to meet users' more accurate and more precise service requirements.The property of correlation,anti-jamming and anti-deception will be improved with the increment of code length.However,increasing code length inevitably increases the complexity and cost of acquisition.To circumvent this drawback,a new PRN code family,named Pseudo Random Initial State(PRIS)code,was designed.PRIS code is a kind of complex code that can be constructed based on any basic code sequence.It is a special long code and all subsequences can be regarded as the cyclic shift of basic code sequence.The only difference of these subsequences is the initial phase.Therefore,to reduce the computation and complexity of the acquisition of PRIS code,we need to find a new solution to better exploit the characteristics of PRIS code.For the acquisition of PRIS code,this paper designs and implements a Double Basic Code Block(DBCB)acquisition scheme to reduce the complexity and computation.Inspired by Double Block Zero Padding(DBZP)algorithm,this paper design a DBCB acquisition scheme.It also adopts blocking operation,but it uses two signal sub-blocks for the double-block operation.Furthermore,the scheme regards the basic code sequence of PRIS code as the local PRN code by taking advantage of the sequence law of the PRIS code,which greatly reduces the search for the code phase.This paper provides the performance analysis and simulation of DBZP and DBCB acquisition methods.The simulation results show that under the same experimental parameters,the DBCB has a 3dB performance loss in terms of detection probability,compared with the traditional DBZP acquisition method.However,the average computation of DBZP is about 200 times that of the DBCB in terms of computation and complexity.The experimental results demonstrate that the DBCB can provide a new reference for acquisition of PRIS code with low complexity and computation.