超宽带系统在窄带干扰条件下的性能研究

超宽带（Ultra Wide-Band，UWB）系统发射信号的带宽在一个非常大的频段范围内，易与已存在的窄带无线通信系统的带宽形成重叠。因此，有必要研究UWB系统在频段重合范围内的抗干扰能力。文中首先分析了直接扩频超宽带系统在最小均方误差准则检测方式下，RAKE接收机的比特误码率（Bit Error Rate，BERl，然后研究了普通窄带系统的功率谱密度，最后做出了仿真分析。结果表明，在CM1信道传播下，窄带干扰对UWB系统不会造成很大影响，而在CM2信道传播下会照成一定影响，必须通过其他通信手段如信道编码来降低BER，实现通信的可靠性。

Performance Evaluation of a UWB System in the Narrowband Interference

The UWB(Ultra Wide-Band)transmitted signals spread over a very large frequency band range.They will spread over the frequency bands allocated to the existing narrowband radio systems.So,it is important for us to evaluate the interference issues of these narrowband systems to UWB systems in their overlay bands.In this paper,the BER of a MMSE-RAKE(Minimum Mean Squared Error RAKE)receiver in DS-UWB is analyzed firstly.Then,the Power Spectrum Density(PSD)of a narrowband system is studied.Finally,the system is simulated.The results indicate that given a RAKE receiver with an equalizer,narrowband interference won't have great impact on BER of the UWB system in CM1,nevertheless it will do in CM2.So,other communication techniques such as signal channel coding should be used to depress BER of the UWB system.