The Research Of Papr Reduction Scheme In FBMC-OQAM Systems

With the continuous development of network information service correnlly, the requirement of mobile communication technology is getting higher and higher, and the new demand is. endless. For the development of future mobile communications,the main concerns are high spectrum utilization, fast transmission rate, good resource utilization and excellent energy efficiency performance. Multi-Carrier Modulation (MCM), as the underlying technology of communication system, has been developing continuously with the improvement of modern hardware and computing power. As a representative of multi-carrier modulation technology,orthogonal frequency division multiplexing (OFDM) is widely used in 4G/LTE. However, there is a need for cyclic prefixes to combat multipath fading in OFDM systems. It requires high synchronization and requires orthogonality between subcarriers, which limits the flexibility of using spectrum. Filter Bank Multicarrier with Offset Orthogonal Amplitude Modulation (FBMC-OQAM) is considered to be an effective way to solve the above problems.However, the high peak-to-average power ratio (PAPR) is an important problem in the FBMC-OQAM system. The high PAPR value will come to a challenge to the receiving end of the demodulation and hardware design and implementation. However, the traditional PAPR suppression algorithm in OFDM system is not directly applicable to FBMC-OQAM system due to the characteristics of overlapped structure inherent in FBMC-OQAM signal.In this paper, two methods of suppressing the PAPR value of FBMC-OQAM signal are proposed. Firstly, a multi-block SLM (MBSLM)architecture based on joint optimization of real data blocks is proposed.This algorithm can increase the randomness of scrambling code by converting the object of data processing to real data. At the same time, it makes use of the overlapping of adjacent data blocks in FBMC-OQAM signal to combine multiple real data blocks, which further improves the performance of PAPR. At the same time, using the time-frequency focusing of the prototype filter and selecting the optimal phase rotation factor vector, only some of the data blocks are processed to achieve the effect of reducing the complexity.Secondly, a new PAPR suppression technique is proposed for FBMC-OQAM system. The algorithm is a PTS algorithm based on grid structure model (TB-PTS). The overlapped structure of FBMC-OQAM signal is described by the mathematical model of grid structure. Based on this model the traditional PTS algorithm is improved. At the same time,through the use of dynamic programming algorithm, the process of finding the optimal phase rotation factor is optimized.At the end of this paper, the whole paper is summarized, and the future research work is prospected.