Research On Physical Layer Of The LTE Links

LTE, as the new generation communications technology besides3G, will be built widely in China Mainland in recently days. It was proposed in2004and the researches on performance or characteristics of LTE have still been being taken on. For the mobile communication system, LTE raised new demands, and thus gave birth to the evolution of existing technology, as well as the new technologies. In uplinks, the LTE system selected a new technology called single carrier frequency division multiple access (SC-FDMA) as an uplink access scheme, which is considered as an improvement of orthogonal frequency division multiplexing (OFDM) technology. The new technology will have a great advantage in reducing the peak to average power system ratio (PAPR). The advantage has a high practical significance which means a lower cost of mobile terminal and compatibles with existing battery technology, this paper will focus on this and take researches and analysis on it.The other existing technology is introduced in LTE is multiple input multiple output technology (MIMO). MIMO has a very long study history. In LTE system, the spatial diversity technique, the spatial multiplexing and beamforming of MIMO have been widely used. In third part of the paper, we will take main concern on the basic principles of MIMO technology and make the appropriate inquiry and discussion on the performance and the configuration of LTE-MIMO. The main contribution and innovation of this dissertation could be summarized as follows:1In uplinks, we take researches and analysis on performances of the SC-FDMA and OFDMA. We proved the ascendant position of SC-FDMA in uplinks from the performance of PAPR and bit error rate (BER). Besides, we explore the two different mapping methods of modulation of SC-FDMA. Also, we have Simulation Verifications.2Due to the poor performance of LFDMA, we propose a new PAPR reduction algorithm to the LFDMA links. Besides, we present the simulation of the new PAPR to verify the performance of the algorithm. Also, the BER is considered。3We also concentrate on the fairness of the OFDM and SC-FDMA links。Our research will consist of two algorithms to estimate the performance of links4We take concern on the on the basic principles of MIMO technology and analysis the improvement of MIMO in LTE. And we also explore and study the LTE-MIMO data transmission model by focusing on the study of channel capacity and signal to noise ratio. Still, we have Simulation Verifications.