Simulation Link Building And Performance Analysis Of Pdsch Based On LTE-Advanced System

With the development of wireless communication technology, people put forward higher requrements to information gathering. They emphasize the richness of species, the convenience of the channels and the agility of timing. The4th generation mobile communication technology LTE-Advanced could ensure the efficiency of network transmission reliably. It introduces some technologies like multi-carrier aggregation, multi-point collaboration, relay technology and enhanced MIMO technology based on LTE, significantly improves the communication system uplink and downlink peak rate and spectrum efficiency, and effectively improve the performance of the cell edge.As one of the most significant physical channel in LTE-Advanced, the physical shared channel (PDSCH) carries the data from downlink shared transport channel, and is introduced in multiple key technologies in physical layer Achievement to ensure the reliability and effiency of data transmission. Based on physical key technologies in LTE-Advanced PDSCH, this article analyses the technical priciples and do some simulation and analysis through building physical layer link on related technologies. This research work is summarized as follows:(1)Study the processes of PDSCH sender and build the floating-point algorithm simulation model of that. And then probe the receiver algorithm of PDSCH based on sender, including some critical algorithms like MIMO decoder, demodulation, descrambling, rate-matching decoder, channel decoder and so on, and build the floating-point algorithm simulation model of the receiver. Then associate the floating-point model of the sender to make joint simulations and verify its feasibility.(2)Discuss the fixed-point algorithm process of the sender according to the floating-point algorithm model of PDSCH. Based on that, build the fixed-point algorithm simulation model of PDSCH sender and verify the feasibility of fixed-point plan through comparing the waverform of floating-point model with the waveform of fixed-point model. (3)Arithmetic simulation based on the channel model built in different scenarios, such as in different modulation types, different MIMO configurations, system throughput to testify the reliability of the physical layer model and system performance.The simulation results shows conclusions as follows:Firstly, the bit-error-rate performance is not satisfactory in the low signal-noise-rate environment with high order modulation. Secondly, between different MIMO configurations, the reliability are much higher in transmit diversity than in spatial multiplexing. At the same time, the BER performance is better in closed-loop spatial multiplexing than in open-loop spatial multiplexing. The sptial multiplexing performance can be more sensitive to the channel quality with the increasing transmit antennas. Thirdly, there could be much higher spectrum efficiency and system downlink throughput of LTE-Advanced than that of LTE under highest configuration. Its performance differences can reach almost ten times when in the circumstances of better channel quality.