Abstract
It was recently studied how to achieve the optimal degrees of freedom (DoF) in a multi-antenna full-duplex system with partial channel state information (CSI). In this paper, we revisit the DoF of a multiple-antenna full-duplex system using opportunistic transmission under the partial CSI, in which a full-duplex base station having M transmit antennas and M receive antennas supports a set of half-duplex mobile stations (MSs) having a single antenna each. Assuming no self-interference, we present a new hybrid opportunistic scheduling method that achieves the optimal sum DoF under an improved user scaling law. Unlike the state-of-the-art scheduling method, our method is designed in the sense that the scheduling role between downlink MSs and uplink MSs is well-balanced. It is shown that the optimal sum DoF of is asymptotically achievable provided that the number of MSs scales faster than , where SNR denotes the signal-to-noise ratio. This result reveals that, in our full-duplex system, better performance on the user scaling law can be obtained without extra CSI, compared to the prior work that showed the required user scaling condition (i.e., the minimum number of MSs for guaranteeing the optimal DoF) of . Moreover, the average interference decaying rate is analyzed. Numerical evaluation is performed to not only validate our analysis but also show superiority of the proposed method over the state-of-the-art method.
Highlights
We introduce a new hybrid opportunistic scheduling method that achieves the optimal sum degrees of freedom (DoF) of the full-duplex system addressed in Section 1.1, i.e., the full-duplex system consisting of a 2M-antenna full-duplex base stations (BSs) and N single-antenna half-duplex mobile stations (MSs), under an improved user scaling law
In such a partial channel state information at the transmitter (CSIT) scenario, how to achieve the optimal DoF is a challenging task, especially for full-duplex systems since, with the existing opportunistic scheduling methods, it is not straightforward to effectively manage the inter-terminal interference that does not appear in half-duplex systems
A new hybrid opportunistic scheduling method was presented in multi-antenna full-duplex systems with partial CSIT where the effective channel gain information is only available at the transmitter
Summary
With the increasing demands for high-speed communications, full-duplex technologies have been taken into account as a promising solution for boosting the spectral efficiency in multiuser wireless communications systems [1]. A certain user scaling law for achieving one DoF per user was examined for (n, K )-interference channels [15]. Such opportunism was utilized in multi-cell broadcast channels (or, equivalently, interfering broadcast channels) by using multi-cell random beamforming [16,17] and opportunistic interference alignment [18]. Took advantage of the zero-forcing (ZF) receiver for uplink to achieve the full DoF since ZF filtering at the BS is sufficient to guarantee M DoF for uplink, which results in infinitely large sum-rates with increasing SNR It was shown in [26] that the required user scaling law to achieve the optimal DoF is given by SNR2M−1. There have been extensive studies on scheduling and resource optimization in a variety of network scenarios including wireless networks with energy harvesting [27,28,29] and cognitive networks [30]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
