Why Time Reversal for Future 5G Wireless? [Perspectives]
As the demand for wireless voice and data services has continued to grow dramatically, operators struggle to satisfy this demand with acceptable quality of service. The main approach until now was to increase the system bandwidth and spectral efficiency. For instance, there was an almost tenfold increase for each new generation of cellular technology [the first generation (1G) technology can support up to 30 kHz, second generation (2G) around 200 kHz, third generation (3G) around 1.25-5 MHz, and fourth generation (4G) up to 20 MHz]. Meanwhile, technologists have begun seeking more innovative and efficient communication technologies to meet the ever-increasing demand for data traffic with advanced signal processing capabilities for the 5G wireless communication systems. It is expected that 95% of data traffic will come from indoor locations in a few years [1]. Compared to outdoor propagation, wireless medium in an indoor environment often exhibits richer multipath propagation mostly without a strong line-of-sight (LOS) component, which makes the design of 5G indoor communication systems even more challenging.