Detection of LTE Random Access Signals in Multipath Channels with Possibly Large Doppler Shifts

• Main Author: 梁晉源
• Other Authors: Lin, David W.
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/63390893971598600102

碩士 === 國立交通大學 === 電子工程學系 電子研究所 === 102 === The thesis studies the random access detection schemes in LTE-A system. In random access detection procedure, the base station needs to determine whether random access preambles are transmitted by the users. In this thesis, we first develop transmission system model, in which we consider the symbol timing offset (STO), carrier frequency offset (CFO), and multipath channels. Then we formulate the problem by the multiple hypothesis and binary hypothesis testing. Due to high computational complexity for implementation of multiple hypothesis testing, we focus on the binary hypothesis testing formulation. We use the generalized likelihood testing technique (GLRT) as a detection criterion to solve the problem, in which we need to get the maximum likelihood estimate (MLE) of the STO, CFO, and channel. In the derivation, we also propose an approximation of the GLRT to further reduce the computational complexity. In the simulation we verify our proposed GLRT detector performance with difference values of CFO and different kind of channel model including AWGN and Standford University Interim (SUI).