We study the achievable capacity regions of full-duplex links in the single- and multi-channel cases (in the latter case, the channels are assumed to be orthogonal -- e.g., OFDM). We present analytical results that characterize the uplink and downlink capacity region and efficient algorithms for computing rate pairs at the region's boundary. We also provide near-optimal and heuristic algorithms that "convexify" the capacity region when it is not convex. The convexified region corresponds to a combination of a few full-duplex rates (i.e., to time sharing between different operation modes). The algorithms can be used for theoretical characterization of the capacity region as well as for resource (time, power, and channel) allocation with the objective of maximizing the sum of the rates when one of them (uplink or downlink) must be guaranteed (e.g., due to QoS considerations). We numerically illustrate the capacity regions and the rate gains (compared to time division duplex) for various channel and cancellation scenarios. The analytical results provide insights into the properties of the full-duplex capacity region and are essential for future development of scheduling, channel allocation, and power control algorithms.
Various challenges related to FD wireless recently attracted significant attention. These include FD radio system design @cite_9 @cite_16 @cite_23 @cite_19 @cite_10 @cite_11 as well as rate gain evaluation and resource allocation @cite_14 @cite_30 @cite_25 @cite_26 @cite_24 @cite_3 @cite_18 @cite_29 @cite_21 . A large body of (analytical) work @cite_14 @cite_26 @cite_5 focuses on while we focus on the more realistic model of imperfect SIC.
@cite_30 @cite_18 @cite_14 @cite_26 @cite_9 @cite_29 @cite_21 @cite_3 @cite_24 @cite_19 @cite_23 @cite_5 @cite_16 @cite_10 @cite_25 @cite_11
2139015614 2106543408 1503817581 2211825642
Recent works have considered the feasibility of full duplex (FD) wireless communications in practice. While the first FD system by Choi et.al. relied on a specific antenna cancellation technique to achieve a significant portion of self-interference cancellation, the various limitations of this technique prompted latter works to move away from antenna cancellation and rely on analog cancellation achieved through channel estimation. However, the latter systems in turn require the use of variable attenuator and delay elements that need to be automatically tuned to compensate for the self-interference channel. This not only adds complexity to the overall system but also makes the performance sensitive to wide-band channels. More importantly, none of the existing FD schemes can be readily scaled to MIMO systems. In this context, we revisit the role of antenna cancellation in FD communications and show that it has more potential in its applicability to FD than previously thought. We advocate a design that overcomes the limitations that have been pointed out in the literature. We then extend this to a two-stage design that allows both transmit and receive versions of antenna cancellation to be jointly leveraged. Finally, we illustrate an extension of our design to MIMO systems, where a combination of both MIMO and FD can be realized in tandem. In this paper, we present an experiment- and simulation-based study to evaluate the use of full duplex (FD) as a potential mode in practical IEEE 802.11 networks. To enable the study, we designed a 20-MHz multiantenna orthogonal frequency-division-multiplexing (OFDM) FD physical layer and an FD media access control (MAC) protocol, which is backward compatible with current 802.11. Our extensive over-the-air experiments, simulations, and analysis demonstrate the following two results. First, the use of multiple antennas at the physical layer leads to a higher ergodic throughput than its hardware-equivalent multiantenna half-duplex (HD) counterparts for SNRs above the median SNR encountered in practical WiFi deployments. Second, the proposed MAC translates the physical layer rate gain into near doubling of throughput for multinode single-AP networks. The two results allow us to conclude that there are potentially significant benefits gained from including an FD mode in future WiFi standards. Full-duplex (FD) technology has been regarded as a promising solution to improve the spectral efficiency of the 5th generation (5G) wireless communication system. In this paper, we focus on a small-area radio system, where a FD base-station serves two half-duplex users simultaneously with one in the uplink and the other one in downlink direction. However, the self-interference (SI) and the inter-user interference (IUI) may largely degrade the system performance. Therefore we propose a simple but effective inter-user interference cancellation (IIC) strategy to cope with the IUI. This method is based on the fact that the downlink user observes a multiple access channel (MAC) of two user, the BS and the uplink user, respectively. Hence, the downlink user has an opportunity to remove the IUI according to the transmission rates and its received powers. Therefore, we call this method as multi-access channel IIC (MIIC). Then, we analyze the achievable rate region of the FD system with and without MIIC when taking the SI into consideration. To obtain the rate region, analytic power allocation strategies are derived. Simulation results show that, by applying the proposed power allocation strategies, the performance of FD system with MIIC is as good as the system without IUI under the 3GPP assumptions. SC-FDMA has been selected by the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) and LTE Advanced (LTE-A), as the primary multiple access scheme for the uplink of the 4?G wireless communication systems. This article surveys the different state-of-the-art resource allocation algorithms developed to allocate system's subcarriers and users' transmission powers in the uplink of SC-FDMA wireless networks. An objective-driven classification approach is followed where the various resource allocation algorithms are categorized into four major classes based on the ultimate goal objective of the resource allocation process, as follows: (i) throughput optimization, (ii) fairness, (iii) satisfaction of users' QoS requirements, and (iv) joint power and subcarriers allocation. The article summarizes the activities and recent advances on this work-in-progress area, highlights the key features, advantages and disadvantages of each algorithm, and provides a detailed qualitative comparative evaluation of their attributes and characteristics according to several distinct features. Furthermore, it provides some indicative numerical results that better present and quantify the objective and achieved performance of the various algorithms. Finally the problem of resource allocation is discussed, when multicell environment is considered, where issues such as intercell interference mitigation and backhaul rate constraints pose additional challenges.