Research On Broadband Communication Technology Based On The Wavelet Packet Division Multiplexing

Wavelet Packet Division Multiplexed(WPDM)technology is a new type of multi-carrier modulation technology that uses wavelet packet transform in multi-carrier modulation systems.The orthogonality of the time-frequency domain of the wavelet packet function makes the WPDM system have higher spectrum efficiency and good anti-fading,non-uniform channel partitioning and other characteristics.Compared with the OFDM system,the WPDM system has better bandwidth utilization and power spectrum out-of-band attenuation.Speed and anti-fading interference capabilities are better suited for transmission in multiple complex environments in broadband communications.This article mainly focuses on the research of broadband communication system using WPDM technology.The research contents mainly include the following aspects:Firstly,the basic theory of WPDM technology is introduced.Based on this,a WPDM transmission system model in broadband communication is proposed.The power spectrum density,spectrum utilization,and fading resistance performance of the system are analyzed and demonstrated.OFDM system,WPDM system is more suitable for complex broadband communication transmission,and also lays the foundation for analyzing the performance impact of the disappearance moment and peak-to-average power ratio of wavelet function on WPDM system.Secondly,the influence of the vanishing moments of different wavelet functions and wavelet functions on the performance of the WPDM system is studied.Then,the performance of the WPDM system is limited to the vanishing moment of the wavelet in the multipath interference environment.The wavelet packet pruning optimization algorithm is used in the Without increasing the vanishing moment length of wavelet,the anti-multipath interference capability of the system is improved.The wavelet packet tree structure optimized by pruning is the optimal wavelet packet basis of the WPDM technology in broadband communication transmission system.Finally,the Peak-To-Average Power Ratio(PAPR)was studied in theWPDM system.Aiming at the shortage of WPDM system with high bit error rate due to traditional clipping and windowing algorithm,this paper proposes a joint algorithm based on Prune-Proper wavelet packet tree and improved clipping and windowing to improve WPDM system performance,theoretical analysis and simulation.The results show that the joint algorithm not only reduces the PAPR at the sending end of the WPDM system,but also improves the error performance of the WPDM system and reduces the system computational complexity.