Backscatter Communications for 6G

Abstract: The success of future Internet of Things (IoT) depends on, among the other things, developing energy-effcient communication techniques that can enable information exchange among billions of IoT devices with ultra-low/zero power consumption requirements. Ambient backscatter communications is an emerging technology, which utilizes the ambient Radio Frequency (RF) signal as the carrier to reduce the form-factor, and the battery requirements of low-cost small sensor type communication devices. It is, therefore, regarded as a promising technology for massive IoT paradigm, especially for applications with low data-rate requirements. However, ambient backscatter communications face many challenges, such as the presence of strong interference and channel fading. Additionally, these challenges have to be addressed without increasing the complexity and power consumption of the backscatter communication system. Furthermore, the wide-range of prospective backscatter applications means that the performance of ambient backscatter systems have to be studied in a variety of scenarios. Motivated by this, we study the performance characteristics of ambient backscatter systems using different RF frequencies, data-rates and propagation environments. First, the problem of strong interference is addressed using the well known repetition technique for transmitting the backscatter data. Second, the effects of channel fading are minimized using the scrambling technique. Further, the performance of ambient backscatter systems is studied using a simple quasi-static channel model and a realistic continuous fading channel. The simulations for this purpose are performed using Monte-Carlo simulations in MATLAB. General conclusions are drawn for the relations among different performance metrics, and the effectiveness of the chosen receiver (Rx) structure against channel fading is also evaluated.