Preamble Management And Backoff Algorithms In LTE Random Access

In order to meet the needs of new service and the requirements of high transmission rate of mobile terminal, the third generation partnership project (3GPP) initialize technology standardization work named Long Term Evolution (LTE) by the end of 2004. It is plans to introduce a new air interface and advanced wireless technology to achieve a greater transmission rate, a smaller access delay and a greater system capacity.Random Access is a key technology in Media Access Control (MAC) of communication system. Its performance is directly related to the good or bad of the system performance. In order to meet of the special demand of the LTE system capacity and delay, Random Access has become one important study of the LTE system. The research of Random Access procedure in LTE focused on how to resolve the collision and reduce the access delay.This paper analyzed several common Random Access technologies, described in detail the functions, classification and process of Random Access in LTE, focused on the research of Preamble management and Backoff algorithms in LTE Random Access procedure. In the research of Preamble management, the different proposals about Preamble management schemes are discussed, and a based resource sharing Preamble management scheme is proposed. This scheme combines the advantages of both dynamic management and static management, which reduces the cost of system information about the Preamble allocation, due to broader scope of its application. And the performance on access success ratio of this scheme is verified through mathematical analysis and simulation. In the research of Backoff algorithms, analyzed several common Backoff algorithms, compared their performance on delay and throughput rate through simulation, based on the discussion on the application form of the Backoff algorithm in the LTE, found the Rivest's pseudo-Bayesian algorithm is suitable for application in LTE system. Rivest's pseudo-Bayesian algorithm is applied to the based resource sharing Preamble management scheme and its performance on delay and throughput rate is analyzed through simulation.