用LMS算法消除开关纹波对WiFi接收机的影响

针对开关电源应用于射频前端模拟电路时的纹波问题,文中提出在数字基带部分采用自适应滤波法消除纹波的方案。在Simulink环境下搭建基于IEEE802.11b无线通信协议的WiFi收发系统,并在数字基带部分使用LMS自适应滤波器来抑制纹波。系统仿真结果表明,自适应滤波器能明显改进信号质量,当纹波幅度低于150 mV时,接收信号能达到协议要求。在此基础上,对自适应滤波器进行了完整的前端及版图设计,并进行功耗分析,最终自适应滤波器在33 MHz时钟频率、1.98 V电源电压的工作条件下功耗仅为1.35 mW,证明了利用开关电源为WiFi接收机供电以节约功耗的可行性。

Eliminate the Influence of SMPS Ripple Noise for WiFi Receiver with LMS Algorithms

ing at the problem of ripple when the switching mode power supply was applied to the RF front-end analog circuit, a scheme of eliminating ripple in the digital baseband by using adaptive filtering was proposed. WiFi transceiver system based on IEEE802.11b wireless communication protocol was established by using simulink, and LMS adaptive filter was utilized in digital baseband to suppress the ripple. Simulation results showed that the signal quality could be significantly improved by the adaptive filter. When the ripple amplitude was within 150 mV, the received signal could meet the protocol requirements. Based on these results, an adaptive filter was designed, including both front end and layout. The power consumption analysis showed that the final adaptive filter consumed only 1.35 mW at 33 MHz clock frequency and 1.98 V supply voltage, validating the possibility of using switching mode power supplies for WIFI receivers to achieve significant power savings.