Research On Discovery Of Small Cells In Heterogeneous Network

The explosive growth of data traffic has made the network requirements changed quietly in the cellular network.A single cellular network can’t meet the complex requirements of user traffic.The advantages of dual-tier heterogeneous networks that combined with macro cells and small cells are becoming more and more prominent in enhancing network coverage,improving network throughput and improving spectrum efficiency.As a potential solution to solve these problems,small cells drew wide range of research and attention,the researchers related to the small cells got on in-depth discussion about deployment architecture and small cells discovery.Small cells include a variety of types,such as micro cells,pico cells,femto cells,relays etc.which are simple compared to macro cells in architecture.In order to achieve the purpose of reasonable deployment,different scenes need different types of small cells.The main research contents of this thesis are how to discovery the small cells quickly and effectively,improve the discovery accuracy and reduce the complexity of the traditional discovery algorithm in the inter-frequency or intra-frequency deployment scenario.Therefore,this thesis builds link level simulation platform of small cell discovery in heterogeneous network,simulates the small cell discovery process under the asynchronous and synchronous scenarios respectively.The main contents of this thesis are as follows:1.Based on the traditional autocorrelation algorithm,a non-uniform autocorrelation algorithm is proposed to reduce the complexity of algorithm at high SNR.In the multipath channel,the performance of maximum transmission energy variety algorithm is better than the autocorrelation algorithm,because consider the multipath effect.However,the maximum transmission energy variety algorithm is affected by transient interference seriously.Increasing the average of the sampling points instead of the instantaneous mean,The results reveal that the modified maximum transmission energy variation algorithm can achieve accurate time-biased estimation in multipath channel.2.Studing the traditional cell ID detection scheme,the joint detection scheme that using primary synchronization signal(PSS)of differential correlation detection and secondary synchronization signal(SSS)of partial correlation detection are proposed in this thesis.Comparing the advantages and disadvantages between the proposed scheme and the traditional small cells discovery scheme by simulation,verifying that the proposed scheme can improve the accuracy of small cells discovery and consider the complexity of algorithm.