Single scattering turbulence model based on the division
of effective scattering volume for ultraviolet
communication
Tao Shan (山 涛)
1,2
, Jianshe Ma (马建设)
1
, Tianfeng Wu (吴天峰)
1
,
Zanqiu Shen (沈赞秋)
1,2
, and Ping Su (苏 萍)
1,
*
1
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
2
Department of Precision Instrument, Tsinghua University, Beijing 100084, China
*Corresponding author: su.ping@sz.tsinghua.edu.cn
Received February 7, 2020; accepted September 4, 2020; posted online October 23, 2020
In this Letter, a single scattering turbulence model in a narrow beam case for ultraviolet (UV) communication is
proposed based on the division of the effective scattering volume. This model takes the variation of atmospheric
scattering, absorption, and turbulence in different paths into account. Meanwhile, the applicable transceiver
configurations of this model are provided by analyzing path loss error caused by the single scattering assumption
in the UV channel. Furthermore, we investigate the effect of turbulence on the probability density function of the
arriving power in both coplanar and non-coplanar scenarios. The averaging effect of multipath propagation on
the arriving power’s fluctuations is presented. Then, the bit-error-rate performance is also studied. This work
provides an efficient way for UV turbulence channel estimation.
Keywords: ultraviolet communication; single scattering; approximate model; atmospheric turbulence.
doi: 10.3788/COL202018.120602.
With the recent advances of ultraviolet (UV) sources and
detectors in the solar-blind wavelength band, UV commu-
nication has attracted more attention for its potential
advantages. The channel modeling of UV communication
is of great significance in the research of UV communica-
tion
[1–3]
. In the past few decades, various UV communi-
cation channel models have been proposed, e.g., the
single scattering models
[4–6]
and the multiple scatter-
ing models
[7–9]
. However, these models are confined to
non-turbulent conditions. With the extension of the
communication range, atmospheric turbulence leads to
an unneglectable error with the effect of irradiance fluc-
tuation and scintillation attenuation
[10]
. To improve accu-
racy, UV communication channel models are modified by
applying the atmospheric turbulence theory. Some single
scattering turbulence models have been derived by assum-
ing that the channel characteristics of scattering, absorb-
ing, and turbulence are constant in the whole effective
scattering volume
[11–13]
. Moreover, the multiple scattering
turbulence models have been developed, in which the ef-
fect of turbulence on each photon’s path is considered
[14,15]
.
However, the exploitation of UV communication avail-
ability in terms of geometrical configurations and atmos-
pheric conditions is still needed
[16]
.
In this Letter, we derive a single scattering turbulence
model in a narrow beam case by dividing the effective scat-
tering volume. Each sub-volume is approximated as a
layer of the spherical crown (SC)
[6]
. In the case of weak
or moderate optical turbulence, the arriving power
through each sub-volume can be considered as a lognormal
random variable and be obtained using the turbulence
model in Ref. [
13]. The probability distribution of the total
arriving power can be obtained by summing these lognor-
mal random variables up with the aid of the Wilkinson’s
method
[17,18]
. Since the transceiver configuration affects the
path loss error, which is caused by approximating the ac-
tual arriving power with the single scattering power, we
analyze the applicable transceiver configuration by simu-
lating the proportion of the single scattering power in the
total power. Based on this applicable configuration, we
present the probability distribution of the arriving power
in both coplanar and non-coplanar scenarios. Further-
more, the bit-error-rate (BER) performance is studied.
Compared with the existing single scattering turbulence
models
[11–13]
, the proposed model is more effective. This
is because the proposed mode l considers the variance of
UV propagation characteristics in different paths. The
averaging effect of the multipath propagation on the ar-
riving power’s fluctuations is presented. The effect of
the non-coplanar scenario on the UV channel is also ana-
lyzed. In addition, the method of the transceiver configu-
ration analysis prevents the path loss error of the single
scattering model from being overestimated. Compared
with the Monte-Carlo turbulence models
[14,15]
, the pro-
posed model requires much less calculation time. In the
following, a detailed derivation of the proposed turbulence
model is presented.
Figure
1 shows a typical non-line-of-sight (NLOS) UV
communication geometry, in which the effective single
scattering volume refers to the common volume intersected
by the transmitted beam and t he field of view (FOV). The
distance from the transmitter (T) to the receiver (R),
i.e., the communication range, is r. As in Ref. [
6], the
common volume is divided into N sub-volumes, each of
COL 18(12), 120602(2020) CHINESE OPTICS LETTERS December 2020
1671-7694/2020/120602(5) 120602-1 © 2020 Chinese Optics Letters