Resource Allocation and Rate Gains in Practical Full-Duplex Systems

The 25th Annual International Conference on Mobile Computing and Networking

Dastjerdi

Zhou

et al. 2019

Self Cite

Full-duplex (FD) wireless can significantly enhance spectrum efficiency but requires tremendous amount of selfinterference (SI) cancellation. Recent advances in the RFIC community enabled wideband RF SI cancellation (SIC) in integrated circuits (ICs) via frequency-domain equalization (FDE), where RF filters channelize the SI signal path. Unlike other FD implementations, that mostly rely on delay lines, FDE-based cancellers can be realized in small-formfactor devices. However, the fundamental limits and higher layer challenges associated with these cancellers were not explored yet. Therefore, and in order to support the integration with a software-defined radio (SDR) and to facilitate experimentation in a testbed with several nodes, we design and implement an FDE-based RF canceller on a printed circuit board (PCB). We derive and experimentally validate the PCB canceller model and present a canceller configuration scheme based on an optimization problem. We then extensively evaluate the performance of the FDE-based FD radio in the SDR testbed. Experiments show that it achieves 95 dB overall SIC (52 dB from RF SIC) across 20 MHz bandwidth, and an average link-level FD gain of 1.87×. We also conduct experiments in: (i) uplink-downlink networks with inter-user interference, and (ii) heterogeneous networks with half-duplex and FD users. The experimental FD gains in the two types of networks confirm previous analytical results. They depend on the users' SNR values and the number of FD users, and are 1.14×-1.25× and 1.25×-1.73×, respectively. Finally, we numerically evaluate and compare the RFIC and PCB implementations and study various design tradeoffs.

Section: Network-level Fd Gainmentioning

confidence: 96%

“…H SI (f) FD Gain at the Link-and Network-level. At the higher layers, recent work focuses on characterizing the capacity region and rate gains, as well as developing resource allocation algorithms under both perfect [5,9] and imperfect SIC [24,28,37]. Similar problems are considered in FD multi-antenna/MIMO systems [26,38,46].…”

Section: Antenna and Circulatormentioning

confidence: 99%

Wideband Full-Duplex Wireless via Frequency-Domain Equalization

The 25th Annual International Conference on Mobile Computing and Networking

Dastjerdi

Zhou

et al. 2019

Self Cite

“…In [8], we presented the FlexICoN Gen-1 FD transceiver and an FD wireless link, featuring 40 dB RF SIC across 5 MHz. The implemented Gen-1 RF SI canceller emulates its RFIC counterpart that we presented in [6] and modeled and analyzed in [9].…”

Section: Introductionmentioning

confidence: 99%

Demo abstract: Open-access full-duplex wireless in the ORBIT testbed

IEEE INFOCOM 2018 - IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS)

Dastjerdi

Farkash

et al. 2018

Self Cite

In order to support experimentation with fullduplex (FD) wireless, we recently integrated an open-access FD transceiver in the ORBIT testbed [1]. In this report, we present the design and implementation of the FD transceiver and interfaces, and provide examples and guidelines for experimentation. In particular, an ORBIT node with a National Instruments (NI)/Ettus Research Universal Software Radio Peripheral (USRP) N210 software-defined radio (SDR) was equipped with the Columbia FlexICoN Gen-1 customized RF self-interference (SI) canceller box. The RF canceller box includes an RF SI canceller that is implemented using discrete components on a printed circuit board (PCB) and achieves 40 dB RF SI cancellation across 5 MHz bandwidth. We provide an FD transceiver baseline program and present two example FD experiments where 90 dB and 85 dB overall SI cancellation is achieved for a simple waveform and PSK modulated signals across both the RF and digital domains. We also discuss potential FD wireless experiments that can be conducted based on the implemented open-access FD transceiver and baseline program.

“…Note that(18) applies to any variant of H-GMS with fixed access probability α. The lower bound Q LB H-GMS depends on: (i) the ratio between the link arrival rate and access probability λmin αmax , and (ii) the weight function f (·) (through p(·)).…”

mentioning

confidence: 99%

“…N F = 10, N H = 0 Long-term average queue length per link in a heterogeneous HD-FD network with N = 10 and equal arrival rates, under different scheduling algorithms and varying number of FD users, NF : (a) NF = 0, (b) NF = 5, and (c) NF = 10. Both the fundamental and improved lower bounds on the delay are also plotted according to(16) and(18). The capacity region boundary in each HD-FD network is illustrated by the vertical dashed line.…”

mentioning

confidence: 99%

Hybrid Scheduling in Heterogeneous Half-and Full-Duplex Wireless Networks

IEEE INFOCOM 2018 - IEEE Conference on Computer Communications

Diakonikolas

Ghaderi

et al. 2018

Self Cite

Full-duplex (FD) wireless is an attractive communication paradigm with high potential for improving network capacity and reducing delay in wireless networks. Despite significant progress on the physical layer development, the challenges associated with developing medium access control (MAC) protocols for heterogeneous networks composed of both legacy half-duplex (HD) and emerging FD devices have not been fully addressed. Therefore, we focus on the design and performance evaluation of scheduling algorithms for infrastructure-based heterogeneous HD-FD networks (composed of HD and FD users). We first show that centralized Greedy Maximal Scheduling (GMS) is throughput-optimal in heterogeneous HD-FD networks. We propose the Hybrid-GMS (H-GMS) algorithm, a distributed implementation of GMS that combines GMS and a queue-based random-access mechanism. We prove that H-GMS is throughputoptimal. Moreover, we analyze the delay performance of H-GMS by deriving lower bounds on the average queue length. We further demonstrate the benefits of upgrading HD nodes to FD nodes in terms of throughput gains for individual nodes and the whole network. Finally, we evaluate the performance of H-GMS and its variants in terms of throughput, delay, and fairness between FD and HD users via extensive simulations. We show that in heterogeneous HD-FD networks, H-GMS achieves 16-30× better delay performance and improves fairness between HD and FD users by up to 50% compared with the fully decentralized Q-CSMA algorithm.