Research On LTE Random Access Detection Technology

Over the last 20 years, radio communication has developed from initial analog communication to the phase of LTE technology. Compared with 3G network, LTE has various technique advantages such as larger system capacity, lower network latency, higher transmission rate, lower operating costs and broader system coverage. As one of the key technologies in LTE, random access technology is very different from it is in 3G network. Research on the improvements of LTE random access technology can provide certain theoretical basis for LTE product upgrades, which brings great research values.This paper mainly studies the detection performance of LTE random access in different scenarios. The working process of random access and the sending and receiving of random access leading sequence are analyzed and discussed in detail, from which this paper accomplished the following work: First, the fact that false alarm rate of traditional algorithm may rise when UE(User Equipment) in mid-low speed mode is analyzed, and an improved detection algorithm using frequency offset estimation is given. Second, when UE is in high speed mode, algorithm of cyclic shift limited set is analyzed in its validity and its deficiency when UE is in ultra-high speed mode, based on which an improved detection scheme is adopted. The improved scheme is able to solve the problem of rising false alarm rate which is caused by multiple fake peaks in this setting.In matlab simulation platform, random access detection performances in different speed settings are simulated and verified. Simulation results show that in mid-low speed mode, the performance of frequency offset estimation algorithm has certain improvement compared with traditional detection algorithm. In high speed mode, cyclic shift limit set algorithm can eliminate the effect of frequency offset. But in ultra-high speed mode, the improved detection algorithm has an obvious advantage over cyclic shift limit set algorithm. The simulation results verified the superiority of performance of the improved scheme.