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.
more »
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Wideband Full-Duplex Wireless via Frequency-Domain Equalization: Design and Experimentation
Full-duplex (FD) wireless can signi�cantly enhance spectrum
e�ciency 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 �lters 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-de�ned 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 con�guration
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 con�rm 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 tradeo�s.
more »
« less
- NSF-PAR ID:
- 10093762
- Date Published:
- Journal Name:
- Mobicom 19
- ISSN:
- 1553-121X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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