5,180 research outputs found
Cooperative Radar and Communications Signaling: The Estimation and Information Theory Odd Couple
We investigate cooperative radar and communications signaling. While each
system typically considers the other system a source of interference, by
considering the radar and communications operations to be a single joint
system, the performance of both systems can, under certain conditions, be
improved by the existence of the other. As an initial demonstration, we focus
on the radar as relay scenario and present an approach denoted multiuser
detection radar (MUDR). A novel joint estimation and information theoretic
bound formulation is constructed for a receiver that observes communications
and radar return in the same frequency allocation. The joint performance bound
is presented in terms of the communication rate and the estimation rate of the
system.Comment: 6 pages, 2 figures, to be presented at 2014 IEEE Radar Conferenc
An Experimental Study of Radar-Centric Transmission for Integrated Sensing and Communications
This study proposes a dual-function radar and communication (DFRC) system that utilizes radar transmission parameters as modulation indexes to transmit data to the users while performing radar sensing as its primary function. The proposed technique exploits index modulation (IM) using the center frequency of radar chirps, their bandwidths, and polarization states as indexes to modulate the communication data within each radar chirp. By utilizing the combination of these indexes, the proposed DFRC system can reach up to 17 Mb/s throughput, while observing a robust radar performance. Through our experimental study, we also reveal the trade-off between the radar sensing performance and communication data rate, depending on the radar waveform parameters selected in the DFRC system. This study also demonstrates the implementation of the proposed DFRC system and presents its real-time over-the-air experimental measurements. Consequently, the simulation results are verified by real-time over-the-air experiments, where ARESTOR, a high-speed signal processing and experimental radar platform, has been employed
Orthogonal Time Frequency Space for Integrated Sensing and Communication: A Survey
Sixth-generation (6G) wireless communication systems, as stated in the
European 6G flagship project Hexa-X, are anticipated to feature the integration
of intelligence, communication, sensing, positioning, and computation. An
important aspect of this integration is integrated sensing and communication
(ISAC), in which the same waveform is used for both systems both sensing and
communication, to address the challenge of spectrum scarcity. Recently, the
orthogonal time frequency space (OTFS) waveform has been proposed to address
OFDM's limitations due to the high Doppler spread in some future wireless
communication systems. In this paper, we review existing OTFS waveforms for
ISAC systems and provide some insights into future research. Firstly, we
introduce the basic principles and a system model of OTFS and provide a
foundational understanding of this innovative technology's core concepts and
architecture. Subsequently, we present an overview of OTFS-based ISAC system
frameworks. We provide a comprehensive review of recent research developments
and the current state of the art in the field of OTFS-assisted ISAC systems to
gain a thorough understanding of the current landscape and advancements.
Furthermore, we perform a thorough comparison between OTFS-enabled ISAC
operations and traditional OFDM, highlighting the distinctive advantages of
OTFS, especially in high Doppler spread scenarios. Subsequently, we address the
primary challenges facing OTFS-based ISAC systems, identifying potential
limitations and drawbacks. Then, finally, we suggest future research
directions, aiming to inspire further innovation in the 6G wireless
communication landscape
Cost-effective photonic super-resolution millimeter-wave joint radar-communication system using self-coherent detection
A cost-effective millimeter-wave (MMW) joint radar-communication (JRC) system
with super resolution is proposed and experimentally demonstrated, using
optical heterodyne up-conversion and self-coherent detection down-conversion
techniques. The point lies in the designed coherent dual-band constant envelope
linear frequency modulation-orthogonal frequency division multiplexing
(LFM-OFDM) signal with opposite phase modulation indexes for the JRC system.
Then the self-coherent detection, as a simple and low-cost means, is
accordingly facilitated for both de-chirping of MMW radar and frequency
down-conversion reception of MMW communication, which circumvents the costly
high-speed mixers along with MMW local oscillators and more significantly
achieves the real-time decomposition of radar and communication information.
Furthermore, a super resolution radar range profile is realized through the
coherent fusion processing of dual-band JRC signal. In experiments, a dual-band
LFM-OFDM JRC signal centered at 54-GHz and 61-GHz is generated. The dual bands
are featured with an identical instantaneous bandwidth of 2 GHz and carry an
OFDM signal of 1 GBaud, which help to achieve a 6-Gbit/s data rate for
communication and a 1.76-cm range resolution for radar
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