FPGA Implementation Of Physical Random Access Channel In LTE Systems

In the broadband mobile communications, the popularity of intelligent terminals, anddata services of important background, LTE system will be large-scale commercial, andwithin the next decade or longer time to become an important support for mobilecommunications.In this paper, the physical random access channel (PRACH) in the base station systemis analyzed and studied, and the program, verification, implementation are given on FPGA.In this paper, the LTE structure, LTE physical layer, time-frequency frame structureare studied. Analyze five random access preamble format of0-4different scenarios.In this paper, the second chapter describes the role and classification of random access,and a detailed study of the random access workflow depending on the operating mode. Thethird chapter describes the specific meaning and configuration steps about the keyparameters of receive and transmit the PRACH. Generate preamble sequence and basebandsignal according to the parameters.In this paper, the fourth chapter presents front baseband algorithm of PRACH onFPGA. A random access signal is through frequency shifting, multi-stage filter, CP removal,FFT, multiplying the local sequence, peak search and detection. A specific implementationand plan for each FPGA module for front baseband signal processing is provided, and thealgorithm of each module is improved optimization. Then in the fifth chapter, program ofthe fourth chapter is proposed by the simulation analysis.This article highlights are:(1) move the value spectrum instead of the initial deliveryof the launch of the calculated spectrum move DDS value, improve efficiency, save storagespace;(2) a multi-stage decimation filter, the filter coefficient is calculated and verified;(3)with the increase of the number of cells and the number of antennas, random access datastorage resource consumption increases, adding off-chip memory to save FPGA internalresources.