Research On Channel Estimation Algorithm In LTE Uplink System And The Realization On Multi-Core DSP

With the increase of demand on the multimedia services,3GPP has proposed its Long Term Evolution (LTE) system. The fundamental targets for LTE concern increased data rates, reduced latency, improved system capacity and coverage as well as reduced operator costs. It is valuable to research on Channel estimation technology, which is one of critical functions in the receiver of LTE system. Accurate Channel estimation technology is not only the basis for MMSE equalization and soft demodulation but also the key to the high transmission performance and ensures the superiority of the system. So this thesis is engaged in the research on the Channel estimation technology for LTE.First, this paper discusses wireless channel, which is main challenge in wireless communication, including various kinds of fading, various kinds of extension, and afterwards wireless modeling technology. After that, we give a brief introduction of key technologies and the process design of uplink receiver in LTE system.As the emphasis of this paper, we discuss the design of channel estimator in LTE Uplink system. Firstly we briefly introduce the process of Channel estimation and different modes of RS(reference signal) interpolation.Then we focus on Channel estimation algorithms, which include Least Square (LS), Minimum Mean Square Estimate (MMSE) and its simplification LMMSE channel estimation algorithms based on pilots and Linear Interpolation, Time-domain Interpolation algorithms, then simulates the system and compares the performance of each algorithm.From simulation results we can conclude, for channel estimation, LS algorithm makes the worst performance and least cost, while MMSE rules and algorithms are opposite. These two algorithms provide valuable references in practical valid condition. While the time-domain interpolation algorithm, based on IFFT/FFT, can get appropriate trade-offs betweenperformance and cost.At last, from the perspective of implementation, the process of the Channel estimation module in LTE uplink is introduced, as well as the DSP platform for the implementation. We mainly focus on the comparison of two algorithm implementation, LS algorithm and frequency interpolation algorithm based MMSE.