Avaliação da tecnologia CDMA em enlaces wifi full duplex assimétricos

Abstract

Inband Full Duplex technology represents the state of the art against current wireless half-duplex standards (e.g., IEEE 802.11) as it allows a device to simultaneously transmit and receive within the same communication channel. But the problem of asynchrony in wireless networks poses a great dilemma, since the decision to initiate a transmission while receiving is not trivial, be-cause we do not know if the recipients are suffering interference from another node or not, and may make IBFD unfeasible. As a proposed solution to this problem the use of a medium access technology can mitigate error rates in asymmetric scenarios. Multiple Code Division Access (CDMA) is a scatter media multiple access technology that uses orthogonal scatter codes, ena-bling channel sharing, ie, multiple simultaneous transmissions. This work explores BER error rates under SNR in a Rayleigh channel statistical model through physical layer simulations based on the MC-CDMA model in three asymmetric scenarios. With certain restrictions the CDMA can be a solution for the asymmetric IBFD scenarios, allowing simultaneous transmission of two or more users with lower BER rates, neutralizing the use of the mechanisms and protocols proposed by the MAC-FD literature to solve the dilemma of the asymmetric scenarios . Finally, contributing to the development of new mechanisms and protocols of the MAC-FD layer that explore the capacity of the IBFD reaching higher flows.