Strategies and Demonstration to Support Multiple Wireless Protocols with a Single RF Front-End

In an increasingly interconnected world, the demand for smartphones, tablets, and other wireless devices in the IoT has surged over the last few years. This high demand has increased mobile data usage and wireless communication, resulting in an explosion of traffic demand in the limited 2.4 GHz frequency band. This traffic demand and the limitations of existing wireless devices operating in the same frequency range have resulted in a spectrum congestion problem. To utilize the available spectrum more efficiently, it becomes important to detect the desired signals and support flexible communications. After reviewing relevant characteristics of the protocols of interest, this article introduces a new approach for spectrum sharing with a hardware implementation to support the coexistence of WiFi, LTE, and ZigBee in the congested 2.4 GHz band using a single RF front-end. A detection method was developed to resample the preambles of both WiFi and ZigBee to the LTE sampling rate to avoid continuous resampling of the received signal. Further processing steps such as synchronization and demodulation for each protocol are described. Measurement results are provided to demonstrate the techniques showing a low symbol error rate tested over the air in a laboratory environment with interference.