Research On Random Access In LTE

To meet the growing requirements of communication, many advanced technologies emerged. LTE(Long Term Evolution) is a widely concerned technical standard. It pursues more flexibility of system bandwidth, higher data rates and lower latency and introduces new air interface and advanced wireless technologyIn this paper, the transmitting and receiving of random access in LTE are researched in depth. First of all, background of this research is addressed. Status and trend of development of LTE is also investigated briefly. Then, the paper discussed the basic functions of random access, random access mechanism and detailed process of random access. Meanwhile, SC-FDMA signal generation process is studied, including subcarrier mapping and cyclic prefix. Subsequently, It is straightly pointed out the properties of random access preamble (Zadoff-Chu sequence) and provides with an efficient calculation approach of DFT/IDFT. Finally, and most importantly, it focused on the reception of random access signal. And the paper laid more emphasis on the detection algorithm of random access preamble. The principle of time-domain detection and frequency-domain detection is elaborated. Moreover, the algorithm of frequency-domain detection is deduced and simulated deeply. A new detection algorithm, namely random access preamble detection algorithm based on Multi-User Detection technique, is proposed. The new algorithm cancelled the inference brought by the first user and then continued to detect the other users. The paper presented its model and simulated it. It indicated that detection performance of the proposed algorithm was better than frequency-domain detection algorithm.Random access preamble detection algorithm based on Multi-User Detection technique has satisfactory detection performance. It improves the rate of successful detection; thus the throughput of system increases correspondingly. In short, the proposed algorithm is of great significance for random access procedure.