Enhanced Signal Detection in 3GPP LTE System with Successive Interference Cancellation

In this paper we introduced interference cancellation (IC) in the cell search and the detection of physical downlink shared channel (PDSCH) in long term evolution (LTE) of 3rd generation partnership project (3GPP). After user equipment (UE) is turned on, it has to first search the target cell using synchronization channel (SCH). After UE gets timing and cell identification (Cell ID) by cell search process, it can start to transmit and receive data through the traffic channel. In most cases, UE experiences the interference from surrounding neighbor cells, which may result in the degradation of the receiver performance. Not only in time division duplex (TDD) but also frequency division duplex network (FDD), the cells must be deployed with the time aligned to support better successful handover and also provide multemedia broadcast and multicast service (MBMS) efficiently in the network. In synchronous network system, since every cell sends his SCH using shared resource allocation, it is inevitable that two or more neighboring cells can interfere each other in some situation. The cell specific reference signal (CRS) is used for channel estimation in downlink reception. The CRS from neighbor cells may overlap with the resource of PDSCH of the target cell. Hence, the collision of SCH and CRS from the neighbor cells can degrade both the performance of cell search and PDSCH reception at the same time. In this paper, we analyzed the improved performance of the cell search and PDSCH reception by using successive interference cancellation. Simulation results show that the proposed scheme can effectively reduce the mutual interference and improve the performance of the signal detection in view of the cell search and PDSCH reception, respectively.