In recent years, there has been a rapid growth of mobile devices such as smart phones and wearables. As the major approach of exchanging information with the outside world, wireless communication plays an essential role for these mobile systems. Although we have already used several wireless communication designs for years, demands exist in scenarios requiring higher network performance and more application-specific features.

In this thesis, we first investigate solutions to improve performance of today's wireless networks. Specifically, we designed a TDMA-like MAC to improve the WLAN performance and a compact full duplex radio to increase the spectrum efficiency for mobile devices. Second, we leverage wireless communication technologies to advance mobile applications. Specifically, we designed an acoustic communication and a visible light communication method to increase indoor localization accuracy. Further, we proposed a new wireless channel based on electromagnetic radiation, which can be leveraged for light-weight device-to-device communication.