Research On Key Technologies In Physical Layer Link Of 3GPP LTE

Just as people were surprised about the rapid rise of WiMAX technology,3GPP has started the long-term evolution of UMTS technology (Long Term Evolution, LTE).China Mobile indicates that 2011 will be the first year of commercial TD-LTE, some people think that 4G will be able to conduct business quickly, in fact not the case.3GPP LTE project is just a long-term evolution of 3G. 3GPP LTE is not the mind of the 4G, that is only a transition between 3G and 4G technologies.LTE is the global standard for 3.9G, which uses OFDM and MIMO technologies as the sole criterion for the evolution of wireless networks to improve further enhanced 3G air access technology,3GPP LTE is also within the context of 3G standard, but closer to 4G, but 3GPP LTE-Advanced is a 4G technology.3GPP LTE can increase cell capacity, reduce system latency and improve the performance of the cell edge users. In 20MHz spectrum bandwidth it can provide peak rate in downlink: 326Mbit/s and in uplink: 86Mbit/s.For the development of 3 GPP LTE standard,3GPP establishes a clear timetable. The standard development process is divided into two stages:research stage and work stage. The first stage finishes the definition of target requirements, as well as the definitude concept of 3GPP LTE, etc. Then collects candidate technical proposals, and evaluates technical proposals to determine whether they can meet the target demand. The end of the first stage is in mid of 2006.Work stage of the project established in mid of 2006 and began the establishment of 3GPP LTE standards. Work stage would be to discuss and study the details of this standard until the middle of 2007. Compared to the 3G standards, LTE standard was in an accelerated pace, mainly because of the market demand. At the same time of the broadband technology innovation,3GPP will launch the latest technology in the shortest time. This brings new opportunities for operators, faster wireless communications services can be realized in the nearly future.In the context of this study, key technologies of 3GPP LTE, such as OFDM technology and handoff mechanism has also been the concern of more and more researchers,3GPP LTE technology will be a research hotspot.Based on the above, this paper studies and researches the related knowledges of 3GPP LTE, such as 3GPP LTE network architecture, system performance requirements, protocol architecture and core technologies.This paper proposes an OFDM-PTS algorithm based on optimisation of composite number sub-block sequences. Compared with the traditional algorithm, this algorithm can reduce the computational complexity and suppress the papr dynamically, then reach a good compromise results that can better meet the engineering application.Finally, this paper studies the handoff technology in 3GPP LTE physical layer downlink. Study the handoff process and handoff classification,then propose and design the handoff algorithm under the situation of same frequency, different frequency and different systems, we can obtaine basic performance under different parameter settings. The network environment is changing, the parameter settings will also change, In this paper, we study the influence of CIO about the success rate and the the ping-pong effect.