Full-duplex transmission in phy and mac layers for 5G mobile wireless networks

As the fourth-generation (4G) standards have been successfully deployed in all 4G-based wireless communication industries and mobile devices, research attention and the efforts of academia and industry have already moved onto fifth-generation (5G) technologies. While the frequency-division duplexing (FDD) and timedivision duplexing (TDD) are widely used in 4G mobile wireless networks, they have their inherent deficiencies of low spectrum efficiency because FDD and TDD are both based on the half-duplex transmission mode. To overcome these problems existing in 4G systems, in this article we propose novel wireless full-duplex transmission schemes in both the PHY and MAC layers for 5G mobile wireless networks to significantly increase the spectrum efficiency. In particular, we first develop the wireless fullduplex model for both bidirectional transmission and unidirectional transmission, respectively, taking into account self-interference mitigation. Then we analyze the traditional half-duplex FDD and TDD modes and show the superiority of the wireless full-duplex mode over the halfduplex FDD and TDD modes, respectively. Using our developed wireless full-duplex model, we develop and evaluate the efficient full-duplex power allocation scheme at the PHY layer. Corresponding to full-duplex transmission at the PHY layer, we also develop and analyze the fullduplex MAC protocol at the MAC layer to implement full-duplex transmission over the entire 5G mobile wireless network architecture. Through simulation experiments we show that our proposed schemes can significantly enhance spectrum efficiency for 5G mobile wireless networks.