Design And Implementation Of The Simulation System For The LTE Physical Layer Uplink Based On IT++

As the pace of life is accelerating, there has been continuous improvement on the speed requirement to information on, while the original transmission speed of the third generation mobile communication system (3G) can no longer meet the people’s demand. They are eager to find out a new technology, which can provide higher transmission speeds, stronger anti-interference ability, and lower power consumption. And therefore the long-term evolution (Long Term Evolution, LTE) technology comes into being, which is called 4G.In order to verify the performance quota of LTE uplink physical layer, a simulation system is under design. Since simulation on hardware system is, compared to simulation on software system, relatively of higher cost and difficulty, this paper determines to implement simulation on software system. In the field of communication system simulation, MATLAB is dominating during the domestic and foreign research process, because of its powerful function, friendly interface, easiness to use, widely affirmation. Nonetheless, IT++ function library is one library programmed in C++, and one tool that’s open and free to users. Compared with MATLAB, IT++ has the advantages of faster running speed, wide compatible operating system, and so on. So this paper uses IT++ as programming language of the simulation system.This paper first introduces the key technology of LTE physical uplink layer, and then compares SC-FDMA with OFDM, simulates and analyzes each performance of SC-FDMA and OFDM according to their respective principles. Secondly, this paper introduces the physical channel of uplink, and a detailed analysis on the principle of each module in the shared channel, and then function design of the each module is given. This paper exhibits the transmission process of shared channel, draws simulation performance curves, and verifies that this simulation system is substantially able to achieve LTE standard functions. Moreover, leader sequence of the random access channel is described, simulated, and inspected. Then, the author modifies the structure of random access channel receiver and summarizes applicable conditions through experiment results. Simulation on the modified receiver indicates that the restructured receiver is capable of same performance as LTE standard. However, the number of users supported and receiving distance of new receiver proposed is inferior to LTE.