The Design And Implementation For Random Access Of LTE Uplink

As a "pre-4G" technology, LTE is proposed by 3GPP under the trend of "mobile broadband tendency". The fundamental targets for LTE are increased data rates, reduced latency, improved system capacity and coverage as well as reduced operator costs. LTE air interfaces use Frequency Division Multiple Access (OFMA/FDMA) instead of using Code Division Multiple Access technology, and use Multiple Input Multiple Output (MIMO) technology and adaptive technology. LTE does not use Radio Network Controller (RNC) as the third generation wireless telecommunication system, and replace that by a flat network structure. These advantages of LTE ensure this technology a hot market prospect for the future.Random Access is the access process before the UE starts to communicate with the network, and it consists of two kinds of access:synchronized Random Access and Non-synchronized Random Access. And the difference is that the latter one isn't synchronized in uplink when access is beginning. What is talked in the paper is Non-synchronized Random Access.The design and implementation for LTE physical random access channel (PRACH) are mainly discussed in this paper. The background knowledge and essential concept of LTE PRACH are introduced at first. Then we analyze the generating process of random access preambles on UE side, especially the features of Zadoff-Chu sequence are addressed at details. Finally Algorithms about random access process are analyzed and organized in this paper, including the FFT implementation of correlation, Chirp-Z transform and interpolation. Therefore,design structure diagrams can be obtained from these analyses. The program described in this paper is designed based on picoArray platform. As a result, combining with the characteristic of picoChip, the detailed design of each modules and resource occupancy are given by this paper. In this program, the parameter-settings of the design, and test vector are obtained by Matlab simulation. The performance of random access preamble detection has been simulated, and the performance of simulation is analyzed in this paper.