Abstract：Universal Filtered Multi-Carrier(UFMC) technology is a 5G candidate waveform to support asynchronous transmission. However, the UFMC systems is sensitive to carrier frequency offset what is the same as the OFDM system.Carrier frequency offset leads to inter-carrier interference(ICI) and inter-band Interference(IBI)，and the performance of the system is decreased dramatically. This paper presents a method to eliminate interference in the Universal Filtered Multi-Carrier(UFMC) system. The method was based on the Least Mean Square algorithm(LMS) that the output of 2N point FFT is mainly processed. The frequency offset error is close to zero in the receiver through the iterative operation and filter processing, which can eliminate the interference caused by frequency offset in the received signal. The simulation results show that the UFMC system has better bit error rate performance after the frequency offset correction.

Abstract：In this paper, the framework of F-OFDM is applied in the traditional LTE system. Using this new waveform, LTE system can support more flexible parameter configuration, which will meet the increasing needs of the forthcoming 5G wireless communication. By designing proper transmit sub-band filters, the out of band leakage can be greatly suppressed. At the receiver, matched filter is used to realize the data decoupling of each sub-band. Finally, the block error rate(BLER) performance of OFDM and F-OFDM is compared through the computer simulation. The results show that the F-OFDM system performances better than the OFDM one in the presence of the adjacent band interference.

Abstract：Polar Codes, a new high-performance coding technology, is a research focus in the 5G mobile communication system, and has been widely concerned. The performance of traditional Successive Cancelation(SC) decoding at short to moderate block lengths is disappointing, in order to improve the performance of polar codes, this paper studies the principle and structure of SC decoding algorithm from two aspects of calculation and storage structure, a modified algorithm of SC decoding called CRC - SCL decoding algorithm. For the aims of decreasing the complexity of the algorithm, this paper introduces the "Lazy Copy" algorithm. The simulation results show that compared with the SC algorithm, the SCL algorithm has significantly improve performance.

Abstract：Based on the understanding of the multiple access in the wireless communication, an implementation scheme of the sparse code multiple access system with a low complexity based on 5G wireless communication is put forward. By using synthesizable Verilog language in the Quartus II and ModelSim platform, the simulation of SCMA system and FPGA verification are realized. The results prove that the design can achieve perfect function ,and it can be applied in practice.

Abstract：The replacement of previous mobile communication technology is based on the goal of higher data rate, and the main difference is the multiple access techniques. While the fifth generation mobile communication is driven by the various application scenarios of mobile Internet and Internet of Things. The application scenario has diverse performance requirements for the technology. Different key technologies may be utilized for dedicated application scenarios. This paper attempts to explain the relationship among application scenarios, technical requirements and key technologies in the fifth generation mobile communication, and gives a brief introduction for some of the physical layer key technologies.