The Research Of BLAST Detection Technology

In recent years, The needs of the user from the data rates, the service quality and thenetwork capacity are increaseing.The MIMO technology has became the one of the mostpromising telecommunication technology which meet these challenges. The system capacityand spectrum utilization are exponentially increased by taking full use of the multi-pathphenomena of the wireless communication channel through this technology.BLAST (Bell Labs Layered Space-Time) of MIMO system, which as the representativeof the spatial multiplexing, takes advantage of the coding structure to approaching theShannon capacity limit theoretical. The detection of BLAST at the receiving end affectssystem performance, and efficient signal detection algorithm or high-performance channelcoding techniques must be used to improve this situation, that’s why BLAST detectionalgorithm is an important research direction. The detection algorithm of traditional BLASTand LR-aided are deeply studied in this paper, the analysis and comparison the advantagesand disadvantages of various detection algorithm are made through MATLAB simulation，andthus we conclude that the LR-aided detection performance is much better than the simpledetection. However, the complexity of the LR-aided detection algorithm is relatively high.Inorder to reduce the complexity of the LR-aided detection algorithm, while maintaining itsexcellent error performance, an improved algorithm is presented in this paper. The first step inthe improved algorithm is to divide the channel matrix into several block. The second step isthat the lattice base of the partitioned matrix is reduced by using the LLL algorithm. At thesame time, the minimum norm is compared in the each layer of the channel matrix in order toget the signal detection sorted.Then, the channel matrix is transformed into upper triangularmatrix by the application of Household orthogonal transformation. Therefore, the improvedalgorithm is used to realize the optimization of the channel matrix and the sorted of signaldetection in lower complexity.Finally, by analyzing the MATLAB simulation result of the improved algorithm’s BER (bit error rate) performance, we find that the loss of error performance in the improveddetection algorithm is very tiny, which has verified the improved algorithm has lowercomplexity, while maintaining a good performance.