| MIMO-OFDM technology can effectively improve the bandwidth utilization andperformance against multipath fading, has become the core of the fourth generation mobilecommunication technology; channel estimation technique is one of the key technologies ofthe MIMO-OFDM system, channel estimation techniques based on MIMO-OFDM systemhave been concerned by many researchers’attention.Study on the simulation LS algorithm, MMSE algorithms and LMMSE algorithm ofOFDM system and MIMO system,and do the simulation of these three algorithms,cause ofthe LS algorithm is simple and does not need to know in advance the characteristics of thechannel,However, the algorithm for the estimation accuracy is not high, the error rate largerdeficiency, combined with the OFDM system having the characteristics of orthogonalityproposed pilot symbols periodically and the interval setting guide is the effective pilot symbol,gradually reducing inter-carrierinterference, reducing the LS algorithm by the inter-carrierinterference, turn it improve the performance of the algorithm.And study on four interpolation methods,then do more research on the DFTinterpolation,because of the DFT interpolation process in the frequency domain to the time domaintransform, DFT interpolation does not take into account the noise on theestimates a channeljoined RLS adaptive filter part in the channel estimation at the RLS algorithm repeatedlyiterative filtering reuse the DFT transform after complement zero the characteristicssuppressed not match filtering of the impact, to reduce the noise to estimate the channel, thisimproved method can be suppressed the influence of the channel estimation performance ofthe noise and inter-carrier interference. |
