DSP Implementation And Symbol Synchronization Research On Wavelet Packet Transform Based Multicarrier Modulation Communication System

Multi-carrier modulation has become an important technique with the increasing needs of high-quality video and multimedia services in 4G wireless mobile communication. It provides higher frequency efficiency and has potential prospect. Wavelet packet based multi-carrier modulation is a technique combining wavelet analysis theory and multi-carrier modulation perfectly. It provides high frequency efficiency, better immunity against inter-symbol interference and inter-carrier interference.In the first part , we mainly concentrate on the DSP implementation of wavelet packet based multi-carrier modulation communication system. Research at home and abroad mostly lies in algorithm . However ,this paper presents a whole system scheme. Principles and DSP implementation algorithm of the base-band function modules are explained . The system is simulated in CCS environment and BER is tested on the TMS320C6701 EVM board. The results indicate the system can reach theoretical performance.In the second part symbol synchronization of the system is studied. The estimate algorithm, interpolation algorithm and control methods are discussed. Then system performance under timing error effects is set forth. Simulation results show that the system has better immunity against inter-symbol interference than OFDM. At the same time we compare several different wavelet packet function under timing error effects. At last we present a Maximum Likelihood Decision-Directed symbol synchronization scheme and simulate it in the system.The theoretical analysis and simulation results indicate that wavelet packet based multi-carrier modulation has a promising prospect as a kind of new technique.