Kodo Shu

Performance evaluation of flexible TDD switching in 3GPP LTE system

LTE TDD has received increasing attention in the next-generation wireless networks, due to its ability of dynamic allocations for uplink and downlink spectrums. In this paper, we evaluate the system performance with a simple flexible TDD switching scheme by system level simulation. The scheme considers switching among three different TDD configuration structures, based on the empty/non-empty buffer conditions of uplink and downlink data traffic, in order to allocate radio resources more efficiently. The system performance is evaluated with a system level simulator, under the practical parameter settings in 3GPP LTE system. The numerical results show that there are certain gains in terms of throughput for both uplink and downlink by the proposed flexible TDD switching scheme, compare with fixed TDD.

An Efficient Synchronization Signal Design for Neighboring Cell Search

In this paper, we focus on a new small cell discovery signal which improves the detection probability in ultra-dense small cell scenario. Due to the severe inter-cell interference, the detection performance of primary synchronization signal (PSS) and secondary synchronization signal (SSS) is deteriorated in future ultra-dense small cell scenario in the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) system. Thus the current supported 504 cell IDs may not be sufficient. To mitigate the impact of such inter-cell interference problems and improve the cell search performance with increasing number of detect target cells, we propose a novel defined auxiliary secondary synchronization signal (A-SSS) in cell search procedure. Our simulation results show that the detection probability of cell search can be improved effectively with the proposed method.