不同混沌调制方式在基于超宽带系统的体内信道下的性能表现

混沌调制（differential chaos shift keying，DCSK）技术应用于超宽带（ultra wideband，UWB）短距离传输系统具有潜在的优势。提出了分别基于多元 DCSK（M-ary DCSK，M-DCSK）、调频 DCSK（frequency modulation-DCSK， FM-DCSK）和 QCS-DCSK（quadrature code shifted-DCSK）的超宽带无线体内传输系统，分析了提出的基于最新几种混沌调制的超宽带体内传输系统的 BER（bit error ratio）性能，对影响基于混沌调制的超宽带体内传输系统性能的参数积分时间和保护间隔做了理论研究和仿真分析。通过设置不同的扩频因子，在体内信道下 QCS-DCSK 相比 M-DCSK 及 FM-DCSK 能够确保更好的传输质量，且功率损耗更低。在给定扩频因子β和信号持续时间 Tc 时，存在能使 QCS-DCSK 系统性能达到最优的保护间隔。在设定扩频因子β、信号持续时间 Tc 和保护间隔 Tg 时，存在能够使FM-DCSK 系统性能达到最优的积分间隔。

Performance of different DCSK schemes over the UWB in-body channel

Because of its characteristics,differential chaos shift keying(DCSK)system is well suited for wireless short-range communication system.Based on M-ary DCSK,FM-DCSK and QCS-DCSK respectively,the ultra wideband wireless in-body communication systems are proposed.By deeply analyzing main characteristics about these systems,studying and simulating factors such as guard interval and integration time which affect performance of ultra wideband wireless in-body communication systems based on M-ary DCSK,FM-DCSK and QCS-DCSK,some optimizations have been made for these factors.The BER performance of those three schemes demonstrates that QCS-DCSK can provide better communication quality and require lower power consumption compared to other two DCSK schemes.For given spreading factor βand duration time Tc ,the simulation results of QCS-DCSK over in-body channel with different guard intervals show that the optimal guard interval can ensure the best performance of QCS-DCSK over the UWB in-body channel.With given spreading factor β,duration time Tc and guard in-terval Tg ,the optimal integration interval can improve the performance of FM-DCSK over the UWB in-body channel.