IEEE - Aerospace and Electronic Systems - September 2023 - 13

Ksi ˛e_zyk et al.
Table 5.
Quantitative Metrics for the SAF of 5G Signals
Waveform
Max
value
[dB]
SSB
PSLR
[dB]
active and passive) is given as
Vb 2
4Tdist 4Tdist
;
ISL
[dB]
2.328415:5905 24.2335
Type#0-PDCCH2:18843:7130 22.4489
SIB1
9.035213:3599 20.3376
:
(3)
Table 6 illustrates the unambiguous velocity range for
available SSB periodicity for typical frequencies in a 5G
network. As can be seen, the lower the frequency, the
wider the range of velocity. The best performances from
the pulse 5G-based radar are obtainable for the lowest
band, for example, fc ¼ 750 MHz. However, in this case
the available bandwidth is also narrower and, in turn, better
radar range resolution can be achieved for millimeter
waves, where even 2 GHz ofbandwidth is obtainable.
grated sidelobe level (ISL). The presented values were
calculated according to distributions in Figure 10, that is,
for the delay from10 to 10 ms and the Doppler shift
from200 to 200 kHz.
As can be seen, the best performance is obtained
for the SIB1 where the maximum value is the highest
and the ISL has the lowest value. Such properties
result from the best bandwidth and integration time
product. In the analyzed scenario, SIB1 uses the highest
number of subcarriers and its duration is the longest.
Thus, the best integration gain is certainly
expected. The PSLR is slightly worse than for the
SSB, which probably results from the squared envelope
of the waveform. The Type#0-PDCCH has the worst
correlation properties among the analyzed waveforms.
The obtained SAF has strong side lobes at the level of
3:713 dB below the main peak, whose value is the
lowest among the compared signals.
Among the signals in question, only SSBs are broadcasted
periodically in every network configuration in all
beams every TSSB
dist ¼f5; 10; 20; 40; 80; 160g ms. The
default, and most often used, SSB periodicity is 20 ms.
However, it is possible to shorten it to 5 ms to obtain a
wider velocity unambiguity in 5G network-based radar.
The unambiguous velocity in pulse-based radar (both
Table 6.
Unambiguous Velocity (In [m/s]) for Different Carrier Frequencies fc and the SSB Periodicity TSSB
TSSB
dist
fc [MHz]
750
3440
5900
25,000
60,000
SEPTEMBER 2023
5
20
4.36
5.17
0.60
0.25
10
1020
5
2.18
2.59
0.30
0.13
1.09
1.29
0.15
0.06
IEEE A&E SYSTEMS MAGAZINE
4080
2.50
0.54
0.64
0.08
0.03
1.25
0.27
0.32
0.04
0.02
160
0.63
0.13
0.16
0.02
0.01
13
dist .
OPPORTUNITIES AND LIMITATIONS OF 5G-BASED
RADAR
In this section, the opportunities and limitations for 5G
communications and sensing applications are presented.
In the first section, the signal processing challenges are
discussed, the second section presents the study on the
possible obtaining ranges for sensing applications, and in
the last section, the 5G-based sensing concept validation
is presented, showing the proof of using 5G illumination
for passive radar applications.
SIGNAL PROCESSING
The use of 5G signals in radar sensing is possible in many
ways. The authors of this article have identified and shown
in Figure 2 four possible signal processing paths. The
authors' work so far has been focused on passive bistatic
radar using two receiver channels: the PCL [7] and the
pulse radar-based processing techniques (paths 2 and 3,
respectively). A very interesting concept (path number 4),
which is a modification of path 3, is the use of a single
receive channel [25], [26]. This places additional demands

IEEE - Aerospace and Electronic Systems - September 2023

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