On the potential of full duplex performance in 5G ultra-dense small cell networks

Full duplex allows a device to transmit and receive simultaneously in the same frequency band, theoretically doubling the throughput compared to traditional half duplex systems. However, several limitations restrict the promised full duplex gain: non-ideal self-interference cancellation, increased inter-cell interference and traffic constraints. In this paper, we first study the self-interference cancellation capabilities by using a real demonstrator. Results show that achieving ~110 dB of cancellation is already possible with the current available technology, thus providing the required level of isolation to build an operational full duplex node. Secondly, we investigate the inter-cell interference and traffic constraints impact on the full duplex performance in 5^th generation systems. System level results show that both the traffic and the inter-cell interference can significantly reduce the potential gain of full duplex with respect to half duplex. However, for large traffic asymmetry, full duplex can boost the performance of the lightly loaded link.

I. Introduction

The number of devices requiring wireless connection is increasing day by day. Latest forecasts show that the global mobile data traffic will increase approximately eightfold between 2015 and 2020 [1]. An attractive solution to accommodate such traffic demand is full duplex (FD) technology. FD allows a device to simultaneously transmit and receive in the same frequency channel, thus, theoretically, doubling the throughput of traditional half duplex (HD) systems. Given its potential, FD is considered as a technology component of future 5th generation (5G) systems.