Optimized Waveforms for 5G–6G Communication With Sensing: Theory, Simulations and Experiments

Abstract

Joint communication and sensing (JCAS) is an emerging technology for managing efficiently the scarce radio frequency (RF) spectrum, and is expected to be a key ingredient in beyond fifth-generation (5G) networks. We consider a JCAS system, where the full-duplex radar transceiver and the communication transmitter are the same device, and pursue orthogonal frequency-division multiplexing (OFDM) waveform optimization by jointly minimizing the lower bounds of delay and Doppler estimation. This is attained by filling the empty subcarriers within the OFDM frame with optimized samples while reallocating a proportion of the communication subcarriers' power, which essentially controls the fairness between the two functionalities. Both communication and filled radar subcarriers are used for radar processing. The optimized sample values are found analytically, and a computationally feasible algorithm is presented for this task. We also address how the peak-to-average power ratio of the waveform can be controlled and minimized along the optimization process. The results are then numerically evaluated in 5G New Radio (NR) network context, which indicate a tradeoff between the minimization of the lower bounds. The mainlobe width and the peak side-lobe level (PSL) of the range and velocity profiles of the radar image are also analyzed. An inverse relation between the lower bounds and the PSLs is observed, while the main-lobe width can be minimized simultaneously. The trade-off between communication and sensing is investigated, which indicates that the lower bounds can be improved at the cost of the communication capacity. Moreover, over-the-air RF measurements are carried out with unoptimized and optimized 5G NR waveforms at the 28 GHz mm-wave band, to validate the range profile's PSL improvement in an outdoor mapping scenario, depicting considerable performance gain.

Digital medical education empowered by intelligent fabric space

“…The second layer is network transmission layer. It is responsible for the low-latency and high-reliability communication for massive data [50]. In 5G networks, some challenges, such as the highly dynamic changes of the transmission link, will be handled for providing real-time connection services.…”

Performance Analysis of the Full-Duplex Joint Radar and Communication System

“…With the emerging of newly developing applications, such as self-driving cars and UAVs, further contributions have considered the dual-function systems where the radar and communication operations are performed simultaneously sharing the same frequency band and infrastructure [10].…”

Simultaneous Multi-User MIMO Communications and Multi-Target Tracking with Full Duplex Radios

“…Recently, single-antenna FD systems employing joint radar communication and sensing were introduced, where both communication and radar waveforms were studied for sensing performance [14], [15]. FD ISAC operations with mmWave massive MIMO systems were proposed in [16], [17].…”

“…Finally, we design the multi-user digital precoder V BB using block diagonalization such that it maximizes the SNR of the DL users while minimizing the inter-user interference and suppressing the residual SI at node b. The proposed solution for (15) is summarized in Algorithm 1.…”