Recent Progress on Shared Spectrum Metrology Research

Yao Ma
Electronics Engineer, Communication Technology Lab
National Institute of Standards and Technology (NIST)
SERC 306
Monday, November 6, 2017 - 11:00
Due to the increased bandwidth demand of wireless services and low efficiency of legacy spectrum usage, spectrum sharing is an increasingly important research topic to enhance spectrum efficiency while keeping mutual interferences to be non-harmful. Shared spectrum metrology (SSM) relates to the science of measurement of spectrum activities and quantification of functional performance of coexisting wireless systems.  The first part of this presentation covers a brief technical overview and highlight of shared spectrum metrology work at National Institute of Standards and Technology (NIST), USA. The second part focuses on recent theoretical and experimental results on coexistence of LTE-LAA (long term evolution-license assisted access) and WLAN (wireless local area network) systems. We point out several problems of an original listen before talk (LBT) scheme used in LAA, including low efficiency, a significant slot boundary tracking error, and a transmission backoff slot jamming (SJ) effect between systems of heterogeneous slot durations. We design new LBT schemes to improve throughput efficiency, and mitigate slot tracking error and SJ effect. We also develop a novel performance analysis method to evaluate effect of heterogeneous slot durations, and   implement software defined radio (SDR) and FPGA programming and automated-test-based experiments.  Comparisons among theoretical, Monte Carlo simulation, and hardware-based experimental results are provided.