3,967 research outputs found
Joint radar-communication waveform designs using signals from multiplexed users
Joint radar-communication designs are exploited in applications where radar and communications systems share the same frequency band or when both radar sensing and information communication functions are required in the same system. Finding a waveform that is suitable for both radar and communication is challenging due to the difference between radar and communication operations. In this paper, we propose a new method of designing dual-functional waveforms for both radar and communication using signals from multiplexed communications users. Specifically, signals from different communications users multiplexed in the time, code or frequency domains across different data bits are linearly combined to generate an overall radar waveform. Three typical radar waveforms are considered. The coefficients of the linear combination are optimized to minimize the mean squared error with or without a constraint on the signal-to-noise ratio (SNR) for the communications signals. Numerical results show that the optimization without SNR constraint can almost perfectly approximate the radar waveform in all the cases considered, giving good dual-functional waveforms for both radar and communication. Also, among different multiplexing techniques, time division multiple access is the best option to approximate the radar waveform, followed by code division multiple access and orthogonal frequency division multiple access
Towards Dual-functional Radar-Communication Systems: Optimal Waveform Design
We focus on a dual-functional multi-input-multi-output (MIMO)
radar-communication (RadCom) system, where a single transmitter communicates
with downlink cellular users and detects radar targets simultaneously. Several
design criteria are considered for minimizing the downlink multi-user
interference. First, we consider both the omnidirectional and directional
beampattern design problems, where the closed-form globally optimal solutions
are obtained. Based on these waveforms, we further consider a weighted
optimization to enable a flexible trade-off between radar and communications
performance and introduce a low-complexity algorithm. The computational costs
of the above three designs are shown to be similar to the conventional
zero-forcing (ZF) precoding. Moreover, to address the more practical constant
modulus waveform design problem, we propose a branch-and-bound algorithm that
obtains a globally optimal solution and derive its worst-case complexity as a
function of the maximum iteration number. Finally, we assess the effectiveness
of the proposed waveform design approaches by numerical results.Comment: 13 pages, 10 figures. This work has been submitted to the IEEE for
possible publication. Copyright may be transferred without notice, after
which this version may no longer be accessibl
Towards Integrated Sensing and Communications for 6G: A Standardization Perspective
The radio communication division of the International Telecommunication Union
(ITU-R) has recently adopted Integrated Sensing and Communication (ISAC) among
the key usage scenarios for IMT-2030/6G. ISAC is envisioned to play a vital
role in the upcoming wireless generation standards. In this work, we bring
together several paramount and innovative aspects of ISAC technology from a
global 6G standardization perspective, including both industrial and academic
progress. Specifically, this article provides 6G requirements and ISAC-enabled
vision, including various aspects of 6G standardization, benefits of ISAC
co-existence, and integration challenges. Moreover, we present key enabling
technologies, including intelligent metasurface-aided ISAC, as well as
Orthogonal Time Frequency Space (OTFS) waveform design and interference
management for ISAC. Finally, future aspects are discussed to open various
research opportunities and challenges on the ISAC technology towards 6G
wireless communications.Comment: 7 pages, 5 figure
- …