Radio Technologies for Environment-Aware Wireless Communications

Abstract

The contemporary wireless transmitter in addition to information symbols transmits also training symbols in order to help the receivers in the estimation of the information symbols by estimating the channel state information (CSI). In this paper, we look at existing wireless communication technologies in light of environment-aware wireless communications, which is a new concept of wireless communications that queries the time-invariant CSI from the local or global database, using information about the transmitter and receiver location. Thus, this study is the first critical review of the potential of today’s terrestrial wireless communication systems including wireless cellular technologies (GSM, UMTS, LTE, NR), wireless local area networks (WLANs), and wireless sensor networks (WSNs), for estimating CSI, the ratio between training and information symbols and the rate of channel variation, and the potential use of time invariable CSI in environment aware wireless communications. The research reveals, that early communication systems provide means for narrowband channel estimation and the CSI is only available as channel attenuation based on signal level measurements. By increasing the frequency bandwidth of communications, the CSI is estimated in some form of channel impulse response (CIR) in almost all currently used radio technologies, but this information is generally not available outside the communication systems. Also, the CSI is estimated only for the channel with active communications. The new radio technology (NR) offers the possibility of estimating the CIR for non-active channels as well, and thus the possibility of initiating environmentally aware wireless communications.