Lte Random Access Zc Sequence Generation And Detection

In order to realize the goal of wireless access technology to communicating at therate of100Mbps for downlink, and50Mbps for the uplink, the3GPP Organizationproposed long-term evolution (LTE) research framework. Passing the IMT-Advancedstandard on January18,2012in the International telecommunications Union (ITU)wireless communication session, LTE has now become one of4G standards. Theprocess of LTE random access is on the uplink. The main purpose of random access isto build uplink synchronization and allocating frequency resource for UE(UserEquipment). In the random access process, the agreement standard empolyesZadoff-Chu sequence as preamble. In the base station, the sequence of Zadoff-Chu sentby test terminal needs to do sliding detection with multiple Zadoff-Chu root sequence.However, when the random process is realized as well as terminal producespreamble, the length of the Zadoff-Chu sequence which is mapped by sub-carrier is24576points, the utimate launch of the signal should do IDFT towards24576points,which has a lot of restrictions for the terminal that demands low cost. In themeantime, due to a small area at most has64different ZC sequences sentsimultaneously, therefore at the receiving termial,when the base station tests all thetermial sending preamble in the small area, it should be related with64different localZadoff-Chu sequence. Therefore, in the process of random access, the algorithm ofthe sender and terminal has high complexity, which is necessary to improve.There is an algorithm in this thesis, which focuses on reducing the complexity ofthe algorithm, when terminal produces preamble and base station receives inspection inthe process of random access.What’s more, the adopted method can be executed inparallel and is suitable to be realized in multiple processors.First, for the IDFT transform of the Zadoff-Chu sequence, this thesis presents anew method which can get DFT transform result by a small number ofdotproduct,add operation and memory space. For the IDFT transform ofZadoff-Chu long sequence which is mapped by sub-carrier, this thesis improves in thebase of the Cooley-Turkey algorithm, with using its characteristics of sparse sequence.And a new method is presented, compared with the Cooley-Turkey, it makesthe times of complex multiplication and addition reduced by26.1%and36.7%respectively.Second, in this thesis, we find a new way to do IDFT for the sparse data which ismade by the ZC sequence after sub-carrier mapping.Third, we find a simplified Algorithm for ZC sequence detection, which Reducethe complexity for ZC sequence detection.This thesis will bring new ideas for Algorithm reaserch for Random AccessProcedure in LTE.