14 research outputs found
Using Massive MIMO Arrays for Joint Communication and Sensing
One of the trends that is gaining more and more importance in the field of
beyond-5G and 6G wireless communication systems is the investigation on systems
that jointly perform communication and sensing of the environment. This paper
proposes to use a base station (BS), that we call \textit{radar-BS}, equipped
with a large-scale antenna array to execute, using the same frequency range,
communication with mobile users and sensing/surveillance of the surrounding
environment through radar scanning. The massive antenna array can indeed both
operate as a MIMO radar with co-located antennas -- transmitting radar signals
pointing at positive elevation angles -- and perform signal-space beamforming
to communicate with users mainly based on the ground. Our results show that
using a massive MIMO radar-BS the communication and the radar system can
coexist with little mutual interference.Comment: 5 pages, 4 figures, presented at 53th Asilomar conference, Nov. 201
Interference Removal for Radar/Communication Co-existence: the Random Scattering Case
In this paper we consider an un-cooperative spectrum sharing scenario,
wherein a radar system is to be overlaid to a pre-existing wireless
communication system. Given the order of magnitude of the transmitted powers in
play, we focus on the issue of interference mitigation at the communication
receiver. We explicitly account for the reverberation produced by the
(typically high-power) radar transmitter whose signal hits scattering centers
(whether targets or clutter) producing interference onto the communication
receiver, which is assumed to operate in an un-synchronized and un-coordinated
scenario. We first show that receiver design amounts to solving a non-convex
problem of joint interference removal and data demodulation: next, we introduce
two algorithms, both exploiting sparsity of a proper representation of the
interference and of the vector containing the errors of the data block. The
first algorithm is basically a relaxed constrained Atomic Norm minimization,
while the latter relies on a two-stage processing structure and is based on
alternating minimization. The merits of these algorithms are demonstrated
through extensive simulations: interestingly, the two-stage alternating
minimization algorithm turns out to achieve satisfactory performance with
moderate computational complexity
Joint Design of surveillance radar and MIMO communication in cluttered environments
In this study, we consider a spectrum sharing architecture, wherein a
multiple-input multiple-output communication system cooperatively coexists with
a surveillance radar. The degrees of freedom for system design are the transmit
powers of both systems, the receive linear filters used for pulse compression
and interference mitigation at the radar receiver, and the space-time
communication codebook. The design criterion is the maximization of the mutual
information between the input and output symbols of the communication system,
subject to constraints aimed at safeguarding the radar performance. Unlike
previous studies, we do not require any time-synchronization between the two
systems, and we guarantee the radar performance on all of the range-azimuth
cells of the patrolled region under signal-dependent (endogenous) and
signal-independent (exogenous) interference. This leads to a non-convex
problem, and an approximate solution is thus introduced using a block
coordinate ascent method. A thorough analysis is provided to show the merits of
the proposed approach and emphasize the inherent tradeoff among the achievable
mutual information, the density of scatterers in the environment, and the
number of protected radar cells.Comment: Submitted to IEEE Transaction on Signal Processing on June 24, 201