Research Of Precoding In Lte And Its Evolution Versions

With the growing demand of wireless communication, wireless communication system also received a great development. As the evolution version to 3G, LTE have adopted OFDM and MIMO these two key technologies of physical layer, hence greatly improved the system spectrum efficiency and obtained higher throughput than conventional wireless communication systems. In order to take full advantage of improvement brought by MIMO, LTE introduced MIMO precoding technology, which processes the transmitted data at the transmitter in order to reduce the complexity of receiver or improve system performance.The thesis discusses the precoding technology in LTE system. At first several precoding criteria have been studied and simulated in order to get the feathers of each criteria.The unitary precoding has been further studied because that LTE requires unitary precoding matrix. The simulation shows that the minimum BER criterion is best when unitary precoding is required.Then combining these criteria with limited feedback technology, several reasonable precoding solutions have been proposed. To compare the performance of each solutions, we implemented these solutions in the actual link level simulation platform. The results show that the minimum BER criterion based on average channel information can reduce system BER and complexity and can be applied when the data layer number is equal to rank of channel.At last, the multi-user precoding and multi-cell precoding in LTE-Advance have been studied, and the performance of different criteria is analyzed.