抑制超宽带信号对第二代“北斗”卫星信号的干扰,是实现超宽带无线通信系统在机舱环境中应用的前提之一。将虚载波技术应用到超宽带信号中,缩短了舱内超宽带信号发射机和“北斗”卫星导航接收机之间的安全距离,满足了机舱物理空间尺寸限制。在超宽带信号发射功率不变的情况下,利用超宽带信号舱内传播模型,计算了满足“北斗”卫星导航接收机门限接收信干比条件下采用虚载波技术前后的安全距离。理论计算结果显示,虚载波技术将安全距离k/v48m减少到1.8m,仍然能够满足“北斗”卫星导航接收机误码率要求。建立了系统仿真模型,仿真了误码率与安全距离的关系,仿真结果与理论计算结果一致。该方法对舱内超宽带信号干扰有抑制效果,在机舱超宽带无线通信环境中具有可行性和实用性。
Interference suppression for the 2G Beidou navigation satellite signal is the premise of uhra-wideband (UWB) wireless communication applications in airborne environment. Based on the virtual subcarriers in UWB signal, the safe distance between Beidou navigation satellite receiver and UWB transmitter is reduced to eliminate the cabin size limitation. With the Beidou navigation satellite receiver's signal-to-signal ratio(SNR) threshold and the UWB transmitter's total transmission power, the safe distance is calculated before and after using virtual subcarriers according to the UWB channel characteristics in cabin. The safe distances is reduced from 48 m to 1.8 m while the bit error rate(BER) performance of Beidou navigation satellite system receiver is guaranteed at this distance. The theoretical result is verified in Matlab Simulink. It is shown that virtual subcarriers are effec- tive to reduce the interference of UWB signal on the Beidou navigation satellite system signal. They are feasible and practical in UWB wireless communication environment in cabin.