论文部分内容阅读
超宽带脉冲无线电(UWB-IR)在高速通信、高精度定位及穿墙透地等重要领域具有广阔的应用前景,它与认知无线电结合将进一步缓解频谱资源的紧张局势.然而,现有的UWB脉冲难以充分利用其频谱能量,导致其传输性能下降;同时,UWB-IR无法有效而灵活地进行频谱规避,从而无可避免地干扰其余授权用户.从数学插值理论出发,本文基于径向基神经网络提出一种通用频谱成形滤波器,进行合理简化后给出其简单硬件实现.该脉冲设计网络能快速跟踪UWB设备的工作环境,自适应地设计具有特定频谱的UWB-IR脉冲.当无授权用户工作时,它能最大化频谱利用率,改善UWB系统传输性能;当有授权用户时,在最大化非授权频段能量利用率的前提下,它能有效地规避授权频段,实现可靠频谱共享.理论分析和仿真表明,基于神经网络的UWB脉冲在频谱利用率、频谱规避性能及接收性能等方面均优于现有设计方案.
UWB impulse radio (UWB-IR) has broad application prospects in such important fields as high-speed communications, high-precision positioning and penetrating through the wall, and it will further alleviate the tension of spectrum resources with cognitive radio.However, UWB pulse can not make full use of its spectral energy, which leads to the decrease of its transmission performance.At the same time, UWB-IR can not effectively and flexibly perform spectrum avoidance and thus inevitably interfere with other authorized users.Based on mathematical interpolation theory, A generalized spectrum shaping filter is proposed by neural network, which is simplified and simplified hardware implementation is given. The pulse design network can quickly track the working environment of UWB equipment and adaptively design UWB-IR pulse with specific frequency spectrum. When authorized users work, it can maximize the spectrum utilization and improve the transmission performance of the UWB system. When there are authorized users, it can effectively avoid the licensed frequency band and achieve reliable spectrum sharing under the premise of maximizing the energy utilization rate of the unlicensed band The theoretical analysis and simulation show that the UWB pulse based on neural network is superior in spectrum utilization, spectrum avoidance performance and receiving performance Existing design.