基于MSC8156AMC平台的PRACH基带信号生成

摘要

MSC8156AMC which has a strong signal processing ability is an ideal platform for LTE system.PRACH (physical random access channel) is used in LTE system for physical random access.Its baseband signal generation contains the process of DFT and long sequence IFFT, and has high time complexity.In order to meet the real-time requirements.a scheme of signal processing with low computation should be chosen.According to the characteristics of PRACH preamble sequence, DFT can be implemented by the method of Looking up table after appropriate deformation, which can avoid much complex multiplication operation.The long sequence IFFT operation can be resolved into some short sequences IFFT by CooleyTurkey algorithm.In this way, the computation can be reduced much more.Above mentation signal processing scheme can meet the real-time requirement of systems.%MSC8156AMC具有很强大的处理能力,是LTE解决方案的理想平台,系统基于此平台实现.LTE系统中采用PRACH信道实现物理随机接入,PRACH基带信号生成包含有DFT和长序列的IFFT过程,具有很高的时间复杂度,为满足LTE系统的实时性要求,要选择低运算量的信号处理方案.根据PRACH前导序列的特点,DFT运算可以通过适当的变形采用查表方式实现,避免了大量的复数乘运算.长序列IFFT运算通过Cooley-Turkey算法分解为多级短序列IFFT,减少了运算量.上述方案满足了系统的实时性要求.