Research On Lte Channel Estimation Technology

In recent years, the mobile communication has been developed rapidly, therefore demand on higher information transmission rate are increasing gradually. Based on the orthogonal frequency division multiplexing (OFMD) and multiple input multiple output (MIMO) technology, broadband wireless mobile communication system will be able to provide high-speed reliable broadband data services using the limited frequency resource. This has become the research hot spot now. Since accuracy of channel estimating will have a direct affect on the performance of the whole communication system, in the receiver side the channel estimation is a very important part. For MIMO-OFDM system, received signal can be gotten by adding several transmitting antenna signals from different channels, so relative to the SISO-MIMO communication system, channel estimation is also becoming more complex. Therefore, channel estimation becomes a key technology for MIMO-OFDM system.Research work in this thesis is involved in channel modeling and channel estimation in broadband wireless mobile communication system, the channel estimation is especially regarded as the research key. First of all, there are some introduction for MIMO and OFDM technology, the characteristics and advantages of these two technologies were discussed from various aspects. Then gradually began to introduce the channel model and channel estimation algorithm related in the research.When the receiving terminal moves fast, wireless MIMO-OFDM communication channel will have fast time-varying characteristics. This will destroy the orthogonality among different subcarriers and will cause Inter-Carrier Interference (ICI), in that case, the system performance will be reduced. This paper analyzed the invariant channel, then on the base of time-varying channel, established several sequence based expansion model, after that, estimated the time domain channel using the pilot in frequency domain. Based on this model, paper estimated time-varying MIMO-OFDM channel using frequency sequence.