Mitigating Multiple Narrowband Interferers in SDR IEEE 802.11g Diversity Receiver

Abstract

Narrowband transmitters such as IEEE 802.15.4 (ZigBee) operating in 2.4 GHz ISM band cause significant degradation of throughput to the co-channel IEEE 802.11g (WiFi). The phenomenon is common in smart factories and smart homes which generously use ZigBee sensors for process monitoring and automation. This interferes with omnipresent WiFi in the same 2.4 GHz ISM band. In our demonstration, we will present Software Defined Radio (SDR) based single antenna and multi-antenna prototype of standard-compliant IEEE 802.11g receiver. Our receiver prototype is capable of significantly reducing the packet error rate while facing multiple co-channel narrowband ZigBee interferers. We also demonstrate a real-time SDR implementation of Soft Bit Maximal Ratio Combiner capable of decoding frames from standard compliant IEEE 802.11g transmitters. This is a first of its kind implementation to the best of author's knowledge. The demonstrations use Ettus B210 as SDR hardware and a combination of signal processing modules from two different SDR packages: GNU Radio and Openairinterface.