8 research outputs found
Improved Rate-Energy Trade-off For SWIPT Using Chordal Distance Decomposition In Interference Alignment Networks
This paper investigates the simultaneous wireless information and power
transfer (SWIPT) precoding scheme for K-user multiple-input-multiple-output
(MIMO) interference channels (IC), for which interference alignment (IA)
schemes provide optimal precoders to achieve full degrees-of-freedom (DoF)
gain. However, harvesting RF energy simultaneously reduces the achievable DoFs.
To study a trade-off between harvested energy and sum rate, the transceiver
design problem is suboptimally formulated in literature via convex relaxations,
which is still computationally intensive, especially for battery limited nodes
running on harvested energy. In this paper, we propose a systematic method
using chordal distance (CD) decomposition to obtain the balanced precoding,
which improves the trade-off. Analysis shows that given the nonnegative value
of CD, the achieved harvested energy for the proposed precoder is higher than
that for perfect IA precoder. Moreover, energy constraints can be achieved,
while maintaining a constant rate loss without losing DoFs via tuning the CD
value and splitting factor. Simulation results verify the analysis and add that
the IA schemes based on max-SINR or mean-squared error are better suited for
SWIPT maximization than subspace or leakage minimization methods
Design and Analysis of Wideband In-Band-Full-Duplex FR2-IAB Networks
This paper develops a 3GPP-inspired design for the in-band-full-duplex (IBFD)
integrated access and backhaul (IAB) networks in the frequency range 2 (FR2)
band, which can enhance the spectral efficiency (SE) and coverage while
reducing the latency. However, the self-interference (SI), which is usually
more than 100 dB higher than the signal-of-interest, becomes the major
bottleneck in developing these IBFD networks. We design and analyze a
subarray-based hybrid beamforming IBFD-IAB system with the RF beamformers
obtained via RF codebooks given by a modified Linde-Buzo-Gray (LBG) algorithm.
The SI is canceled in three stages, where the first stage of antenna isolation
is assumed to be successfully deployed. The second stage consists of the
optical domain (OD)-based RF cancellation, where cancelers are connected with
the RF chain pairs. The third stage is comprised of the digital cancellation
via successive interference cancellation followed by minimum mean-squared error
baseband receiver. Multiuser interference in the access link is canceled by
zero-forcing at the IAB-node transmitter. Simulations show that under 400 MHz
bandwidth, our proposed OD-based RF cancellation can achieve around 25 dB of
cancellation with 100 taps. Moreover, the higher the hardware impairment and
channel estimation error, the worse digital cancellation ability we can obtain