Abstract:
In this paper,the problem of estimating the large Doppler frequency offset,delay,and channel parameters in the asynchronous band-limited long-code-based uplink of direct sequence-code division multiple access (DS-CDMA) system was considered.The receiving signal model was established that was shaping by square root-raised cosine wave as two parts,one was composition of guide pilot and Doppler,the other was including the delay and complex gain of the multiple channel.Then proposed an unstructured indirect estimating algorithm,that used wave matched-least squares and multiple grade grid searching based on pilot assistance to estimate Doppler and used wave matched greed to estimate the others parameters.The simulation results based on Monte Carlo method show that the model and methods proposed perform well upon the scenario of the large Doppler frequency offset.