Active, Passive, and Absorptive RIS-Aided 6G Network Under Non-Orthogonal CCI

Recei ed 2 June 2025; accep ed 19 June 2025. Da e o publica ion 26 June 2025;
da e o cu en e sion 1 Augus 2025. The e iew o his a icle was coo dina ed by Edi o Ping Wang.
Digi al Objec Iden i ie 10.1109/OJVT.2025.3583545
Ac i e, Passi e, and Abso p i e RIS-Aided 6G
Ne wo k Unde Non-O hogonal CCI
VOLKAN ÖZDURAN 1(Senio Membe , IEEE), EHSAN SOLEIMANI-NASAB 2,
NIKOLAOS NOMIKOS 3(Senio Membe , IEEE), IMRAN SHAFIQUE ANSARI 4(Senio Membe , IEEE),
AND PANAGIOTIS TRAKADAS 3
1˙
Is anbul Uni e si y-Ce ahpa¸sa, 34320 Is anbul, Tü kiye
2Depa men o Elec ical and Compu e Enginee ing, G adua e Uni e si y o Ad anced Technology, Ke man, I an
3Resea ch and De elopmen Depa men , Fou Do In ini y, 16777 Elliniko, G eece
4James Wa School o Enginee ing, Uni e si y o Glasgow, G12 8QQ Glasgow, U.K.
CORRESPONDING AUTHOR: VOLKAN ÖZDURAN (e-mail: [email p o ec ed]).
This wo k was suppo ed by he 6G-LEADER P ojec unded by Sma Ne wo ks and Se ices Join Unde aking h ough he Eu opean Union’s Ho izon Eu ope
Resea ch and Inno a ion P og amme (6g-leade .eu) unde G an 101192080.
ABSTRACT This pape in es iga es he impac o andomly deployed non-o hogonal co-channel in e -
e ence (CCI), o igina ing om he in o ma ion exchange p ocess among non-o hogonal mul iple access
(NOMA) use s, in an ac i e, passi e, and abso p i e econ igu able in elligen su ace (RIS)-assis ed dual-
hop ne wo k. Mo e speci ically, he s udy conside s ha he in o ma ion exchange p ocess in ol es he
sou ce u ilizing ac i e, passi e, o abso p i e RIS a chi ec u e, along wi h a line o sigh (LOS)/non-line
o sigh (NLOS) link be ween sou ce and des ina ion e minals. Addi ionally, his s udy conside s he
limi ed non-o hogonal CCI a ec ing he des ina ion e minal in an independen and iden ically dis ibu ed
(i.i.d.) non-o hogonal CCI scena io. Theo e ical insigh s and Mon e Ca lo-based simula ions collec i ely
demons a e ha non-o hogonal CCI se e ely deg ades sys em pe o mance, pa icula ly in high signal-
o-noise a io condi ions, leading o no able losses in sys em coding gain. Meanwhile, esul s also e eal
ha inc easing he numbe o RIS elemen s s abilizes he sys em and mi iga es he impac o CCI on i s
pe o mance.
INDEX TERMS Recon igu able in elligen su ace, ac i e, passi e, abso p i e, co-channel in e e ence,
pe o mance analysis.
I. INTRODUCTION
As millime e and e ahe z-wa es a e suscep ible o ad-
ing be ween building blocks, he econ igu able in elligen
su ace (RIS) a chi ec u e has eme ged as an essen ial com-
ponen o imp o ing wi eless p opaga ion in six h-gene a ion
(6G) wi eless mobile communica ions [1],[2]. The e olu ion
ini ia ed by passi e RISs [1] is now ad ancing wi h he in o-
duc ion o ac i e [3],[4],[5], hyb id [6],[7], abso p i e [8],
dis ibu ed, ze o-ene gy [9], and simul aneous ansmission
and e lec ion (STAR)-RIS pa adigms [10]. RIS echnology
dis inguishes i sel om adi ional elaying by p o iding no-
able ad an ages in spec um and ene gy e iciency. Unlike
elays, passi e RIS uni s solely e lec ecei ed signals wi h-
ou p ocessing, di e en ia ing hem om elay modes, such
as hal -duplex (HD) [11] and ull-duplex (FD) [12]. No ably,
elay ope a ing modes s ill con end wi h challenges like he
p e-log ac o and loop-in e e ence d awbacks [13].In e-
cen yea s, ac i e RIS has also ecei ed g ea a en ion due
o i s capabili y o ampli y he inciden signal and e lec o
o he di ec ion [3],[5],[14],[15]. Meanwhile, academic and
indus ial s akeholde s in he elecom domain a e expec ing
a d ama ic inc ease in he numbe o mobile e minals [16].
This end is an icipa ed o inc ease co-channel in e e ence
(CCI) occu ences in he nea u u e. P ominen examples
© 2025 The Au ho s. This wo k is licensed unde a C ea i e Commons A ibu ion 4.0 License. Fo mo e in o ma ion, see h ps://c ea i ecommons.o g/licenses/by/4.0/
2048 VOLUME 6, 2025
include leakage in e e ence om beam o ming side lobes
and in o ma ion exchange among non-o hogonal mul iple ac-
cess (NOMA) use s [17].1
The eby, some o he s udies in he li e a u e sc u inize
his issue and in es iga e he de imen al e ec s o CCI on
RIS-assis ed sys ems. The s udy in [18] in es iga es he sys-
em ou age pe o mance o a mul iple decode-and- o wa d
(DF)-based HD elay-assis ed communica ion unde Rayleigh
ading. In addi ion, [18] conside s ha he sou ce e minal
has N e lec ing elemen s and elay-des ina ion e minals ex-
pe ience CCI. Mo eo e , [18] p esen s an oppo unis ic elay
selec ion s a egy o minimize he sys em ou age pe o mance
and o e head. The au ho s in [19] conside a wi eless ne -
wo k wi h a RIS-assis ed sou ce, which has N1 e lec ing
elemen s, communica ing wi h a des ina ion ia KRIS-assi ed
mul iple HD-DF elay nodes, ha ing N2 e lec ing uni s. Fu -
he mo e, [19] conside s ha elay and des ina ion e minals
a e a ec ed by an a bi a y numbe o CCI e minals unde
Rayleigh ading condi ions. Meanwhile, oppo unis ic elay
selec ion is adop ed in [19], which is based on succeeded
he decoding ecei ed signal. Finally, esul s e eal ha he
p oposed selec ion algo i hm achie es inc eased coope a i e
di e si y o de and he in e e ence a he des ina ion is mo e
de imen al han he in e e ence a he elay e minal on he
sys em ou age pe o mance. The pape in [20] in es iga es
he cons uc i e in e e ence e ec s on a downlink ne wo k,
whe e a mul i-an enna base s a ion (BS) communica es wi h
Kmobile e minals ia a RIS wi h M e lec ing elemen s.
To enhance he sys em’s e o - a e pe o mance, op imiza ion
echniques a e employed o edesign he phase shi s a he
RIS uni , also u ilizing a g eedy algo i hm o minimize he
e o loo s a medium- o-high signal- o-noise a io (SNR).
Then, he wo k in [21] in es iga es he CCI e ec s on he
ou age and bi e o a e (BER) pe o mance o RIS and
DF-based HD elay-assis ed mixed ee-space op ical com-
munica ion and adio equency sys ems. In addi ion, he
au ho s assume ha he des ina ion e minal is a ec ed by a
limi ed numbe o CCI e minals subjec o Rayleigh ading
condi ions. He e, he di ec -link be ween sou ce and des i-
na ion e minals does no exis due o excessi e ading and
pa h-loss.
Re e ence [22] in es iga es he sys em pe o mance o RIS-
assis ed wi eless powe ed in e e ence-limi ed ne wo ks. In
g ea e de ail, he des ina ion e minal is a ec ed by a limi ed
numbe o CCI and he di ec -link be ween sou ce and des i-
na ion e minals does no exis . Meanwhile he au ho s assume
Gene alized-Kand Nakagami-m ading en i onmen s o he
RIS and in e e ence links, espec i ely. The s udy in [23]
ocuses on a opology whe e he sou ce communica es wi h
he des ina ion h ough a RIS uni , which has N e lec ing
uni , unde Rayleigh ading condi ions. A he same ime,
1I is wo h no ing ha while p ac ical RIS implemen a ions o en en-
coun e signi ican in e e ence om quan iza ion lobes due o disc e e phase
shi s, ou ocus emains on analyzing he CCI a ising om he in o ma ion
exchange among NOMA use s. Expanding he scope o include mul i-an enna
in e e ence sou ces and he impac o RIS quan iza ion lobes would undoub -
edly en ich he analysis; howe e , such conside a ions a e le o u u e wo k.
he pape does no conside a di ec -link be ween he sou ce
and des ina ion and communica ion is es ablished only ia he
RIS uni . Mo eo e , [23] conside s ha he des ina ion e mi-
nal is a ec ed by a limi ed numbe o independen , equally
powe ed CCIs. Since he a o emen ioned sys em ope a es in
in e e ence-limi ed egime, [23] neglec s he he mal noise
e ec s o e he sys em pe o mance. [23] in es iga es he
sys em pe o mance by means o ou age p obabili y, e o
p obabili y, and a e age channel capaci y. [23] also p o ides
asymp o ic analysis o ge mo e insigh o he de i ed analy i-
cal esul s. In addi ion, [23] u ilizes bina y phase shi keying
and di e en ial phase shi keying modula ions o in es iga es
he sys em BER pe o mance. Mo eo e , [23] also akes in o
conside a ion he ideal and p ac ical phase shi e e cs on
he sys em ou age pe o mance in he p esence o CCI. [23]
in es iga es he e ec s o he di e en numbe s and powe s
o in e e e s and also di e en numbe s o e lec ing uni
e ec s on he sys em pe o mance. Nex , he wo k in [24]
in es iga es he ou age and a e age bi e o a e pe o mance
o single and mul iple RIS-assis ed dual-hop ne wo ks wi hou
a di ec -link. The p esen ed analysis and pe o mance e al-
ua ion conside ha he des ina ion e minal is a ec ed by
a limi ed numbe o independen and iden ically dis ibu ed
(i.i.d.) CCI subjec o Rayleigh ading. Addi ionally, a bes
RIS selec ion algo i hm o he mul iple RIS-assis ed sys em
is p esen ed, enhancing he ne wo k’s eliabili y.
The au ho s in [25] shed ligh on how CCI, which is caused
by ac i e uplink ansmissions, can be minimized by using
RISs in he RIS-aided FD ne wo ks. The au ho s conside
wo scena ios, wi h and wi hou di ec -link, and adop a ious
op imiza ion echniques. Resul s e eal ha a la ge RIS is
equi ed o e icien CCI cancella ion. Ano he wo k in es i-
ga es he ou age and achie able- a e pe o mance o passi e
RIS-aided dual-hop ne wo k [26]. The in es iga ion conside s
ha sou ce and des ina ion e minals do no ha e a di ec -link
and all in o ma ion exchange is comple ed ia passi e RIS
and des ina ion e minal is a ec ed by a limi ed numbe o
CCI. The pape in [27] in es iga es he CCI e ec s on he
RIS-aided mul iple-inpu single ou pu wi eless communica-
ion sys em. He e he ou age p obabili y, bi -e o a e, and
e godic capaci y pe o mance me ics a e analyzed. The s udy
in [28] in es iga es he pe o mance o RIS-aided FD ne -
wo k. The au ho s assume ha use s and RIS e minal a e
a ec ed by CCI and because o he FD in o ma ion exchange
p ocess, use e minals su e om he sel -in e e ence ha
is caused by ansmi ing and ecei ing a he same ime.
In his se ing, he au ho s ocus on he analysis o he ou -
age and e godic capaci y pe o mance o he RIS-aided FD
ne wo k. Fu he mo e, he au ho s in [29] s udy a ne wo k
whe e mobile e minals in oduce CCI on a passi e RIS-aided
dual-hop ne wo k. Mo e speci ically, i is conside ed ha he
des ina ion e minal is a ec ed by a limi ed numbe o mo-
bile CCI e minals. The ob ained esul s e eal ha mobile
CCI has se e e e ec s on he sys em pe o mance com-
pa ed o s a ic CCI. Then, he s udy in [30] in es iga es he
pe o mance o RIS-aided sys ems in he p esence o in e -
e ence. Aiming o educe phase adjus men o e heads, he
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ÖZDURAN ET AL.: ACTIVE, PASSIVE, AND ABSORPTIVE RIS-AIDED 6G NETWORK UNDER NON-ORTHOGONAL CCI
au ho s adop quasi-s a ic phase shi ing whe e he phase
shi s do no a y wi h he ins an aneous channel s a e in o -
ma ion (CSI), o e ing an a ac i e pe o mance-complexi y
ade-o . Vega-Sánchez e al. [31] in es iga es he achie -
able sec ecy pe o mance o RIS-aided dual-hop ne wo k in
he p esence o a single ea esd oppe . The in es iga ion also
conside s ha RIS e minal is a ec ed by elec omagne ic
in e e ence. The wo k in [32] ocuses on he pe o mance
o RIS-aided downlink powe -domain NOMA in Nakagami-m
ading channels wi h CCI. Conside ing he Gamma app oxi-
ma ion, hey p o ide closed- o m exp essions o he e godic
capaci y and ou age p obabili y, unde he impac o CCI.
Mo eo e , Mon e Ca lo simula ions a e p esen ed highligh -
ing ha RIS-NOMA ou pe o ms RIS-OMA o a ying
numbe s o use s and e lec ing elemen s.
Finally, he au ho s in [33] in es iga e he pe o mance o
passi e RIS-aided downlink wo-use s NOMA ne wo k. The
in es iga ion conside s ha BS has an access o use one ia
IRS e minal while i has a di ec access o use wo. The
in es iga ion also conside s ha wo NOMA use s a e a ec ed
by a limi ed numbe o CCI. Likewise, [34] in es iga es he
ou age pe o mance o passi e and abso p i e RIS-aided up-
link NOMA ne wo ks in he p esence o CCI a ec ing he BS.
The li e a u e compa ison able is p esen ed in Table I.
Aiming o build on p io wo ks in RIS-aided NOMA ne -
wo ks, in his s udy, we in es iga e he impac o andomly
deployed non-o hogonal CCI, in oduced om NOMA com-
munica ion be ween di e en use s, in a dual-hop RIS-aided
ne wo k. Fu he mo e, we analyzed he pe o mance unde
h ee di e en RIS modes, i.e. ac i e, passi e, and abso p i e.
While p io s udies ha e analyzed RIS-assis ed sys ems unde
gene alized ading and ha dwa e impai men s [35],[36],[37],
[38], hese wo ks ypically add ess speci ic ading en i on-
men s o ha dwa e limi a ions in isola ion, wi hou join ly
conside ing he in e play be ween RIS ope a ion modes and
non-o hogonal CCI. In con as , ou s udy de elops a uni ied
analy ical amewo k compa ing ac i e, passi e, and abso p-
i e RIS ope a ion unde andomly deployed non-o hogonal
CCI, a ealis ic and p ac ically mo i a ed in e e ence scena io
ha has no been join ly add essed in he RIS li e a u e. Mo e
speci ically, his wo k p o ides he ollowing con ibu ions:
Aiming o p o ide a gene alized iew on RIS-aided ne -
wo ks, we include in ou s udy h ee di e en RIS ope -
a ion modes. The i s mode co esponds o N e lec ing
elemen equipped ac i e RIS, wi h powe ampli ie s and
no signal p ocessing capabili ies, hen, we p esen an
analysis on passi e RISs, and inally we p esen e-
sul s o abso p i e-RISs, he wi eless opology we ocus
he ein consis s o a line-o -sigh (LOS)/di ec -link and
non-LOS (NLOS), be ween sou ce and des ina ion.
To ca e o eal-wo ld impai men s, we assume ha he
des ina ion is a ec ed by a limi ed numbe o andomly
deployed i.i.d. non-o hogonal CCI subjec o Rayleigh
ading. Di e en ly om [23], ins ead o cons an ans-
mi powe , he in es iga ion in his pape conside s
p opo ional ansmi powe associa ed wi h sou ce
FIGURE 1. Ac i e, passi e, and abso p i e RIS-assis ed dual-hop ne wo k
in he p esence o non-o hogonal CCI.
e minal’s ansmi powe and Euclidean dis ance o he
in e e ence.
Fo his opology, we p o ide a ho ough heo e ical
analysis, in e ms o ou age p obabili y (OP), e o
p obabili y (EP), h oughpu , ene gy and spec al e i-
ciency. Analy ical and asymp o ic de i a ions ega ding
he a o emen ioned pe o mance me ics a e p o ided
and e i ied by means o Mon e-Ca lo based in ensi e
compu e simula ions.
The emaining pa s o he in es iga ion a e as ollows:
Sec ion II p o ides de ailed desc ip ions ega ding he in es-
iga ed sys em model along wi h channel s a is ics. Sec ion III
p esen s he analy ical and asymp o ic de i a ions o pe -
o mance me ics. Then, Sec ion IV p esen s he nume ical
esul , and inally Sec ion Vconcludes he in es iga ion. The
lis o ac onyms and No a ions a e p esen ed in Tables Iand
III, espec i ely.
No a ions: Th oughou he pape , he supe sc ip s “a”, “p”,
and “abs” deno e he ope a ing modes o ac i e, passi e,
and abso p i e RIS, espec i ely. The Fh(.) ep esen s he
cumula i e dis ibu ion unc ion (CDF) o a andom a iable
(RV) h.The h(.) e m ep esen s he p obabili y densi y
unc ion (PDF) o a andom a iable h.(.) is he Gamma
unc ion [39, Eq. (8.310.1)].γ(a,b) is he lowe incomple e
Gamma unc ion [39, Eq. (8.350.1)] and (a,b) is he uppe
incomple e Gamma unc ion [39, Eq. (8.350.211)].B(x,y)is
he Be a unc ion [39, Eq. (8.384.1)].(a)nis he Pochham-
me symbol [39] and x
yis he Binomial coe icien [39].
All log a e base 2 unless s a ed o he wise. The ope a o
E[.] s ands o expec a ion, while P (.) ep esen s p oba-
bili y. Gm,n
p,q[.] is he Meije ’s G-Func ion [39, Eq. (9.301)].
pFq(a1,...,ap;b1,...,bq;x) is he gene alized hype geome -
ic unc ion [39, Eq. (9.14)].TheCN(μ, σ2) is complex
Gaussian RV wi h mean o μand a iance o σ2.
II. SYSTEM MODEL & CHANNEL STATISTICS
Fig. 1p esen a RIS-aided ne wo k, unde non-o hogonal
CCI, whe e h ee di e en ope a ion modes a e adop ed, i.e.
2050 VOLUME 6, 2025
TAB LE 1. Compa ison o Exis ing Wo ks and This S udy
VOLUME 6, 2025 2051
ÖZDURAN ET AL.: ACTIVE, PASSIVE, AND ABSORPTIVE RIS-AIDED 6G NETWORK UNDER NON-ORTHOGONAL CCI
TAB LE 2. Lis o Ac onyms
ac i e RIS wi h powe ampli ie s, wi hou signal p ocessing
capabili ies, passi e RIS, and abso p i e RIS. Mo eo e , a
single an enna equipped mobile e minal (MT) makes in o -
ma ion exchange wi h a single an enna equipped des ina ion,
which is BS, ia RIS wi h NLOS and RIS wi h LOS/di ec -
link be ween sou ce.
In his s udy, we assume a single-an enna BS o analyze he
undamen al impac o RIS ope a ional modes in a NOMA-
based ne wo k. While mode n 5G and 6G ne wo ks equen ly
employ massi e mul iple-inpu mul iple-ou pu (MIMO), he
single-an enna BS model emains ele an in scena ios such
as low-powe edge nodes, small cells, and In e ne o Things
(IoT) applica ions, whe e la ge an enna a ays may no be
easible. Addi ionally, his assump ion allows o analy ical
ac abili y and closed- o m pe o mance de i a ions wi hou
excessi e complexi y [40].
I is wo h no ing ha while p ac ical RIS implemen a-
ions may in oduce addi ional ac o s such as sca e e s,
beam o ming side lobes, quan iza ion lobes, and ene gy
losses, ou s udy adop s an idealized model o ocus on he
TAB LE 3. Lis o No a ions
undamen al pe o mance impac o ac i e, passi e, and ab-
so p i e RIS modes in a NOMA-based communica ion sys-
em. This app oach is widely used in analy ical s udies o
de i e closed- o m exp essions and undamen al insigh s [41],
[42]. The ene gy e lec ion coe icien o RIS elemen s is
assumed o be 1 in passi e mode, ollowing con en ional
models ha es ablish heo e ical pe o mance limi s be o e
inco po a ing p ac ical impai men s [42]. While losses due o
ha dwa e cons ain s and mul iplica i e ading a e alid con-
ce ns, analyzing hem in de ail would signi ican ly inc ease
model complexi y and equi e nume ical e alua ions, which
all ou side he scope o his wo k. Howe e , ex ending his
2052 VOLUME 6, 2025

analysis o include such impai men s could be an in e es ing
di ec ion o u u e esea ch [43],[44].
The RV hi,∀i=1,...,N, ep esen s he channel impulse
esponse be ween MT →RIS. hiis a complex Gaussian
RV wi h ze o mean and σ2
hid−ν
MT−RIS a iance. i.e. hi∼
CN(0,σ2
hid−ν
MT−RIS), whe e dMT−RIS is he dis ance be ween
MT →RIS and νis he pa hloss exponen and akes alues
be ween 2 −6[45].gi∼CN(0,σ2
gid−ν
RIS−BS) is he channel
impulse esponse RIS →BS, whe e dRIS−BS is he dis-
ance be ween RIS →BS. Nex , ∼CN(0,σ2
d−ν
MT−BS)is
he channel impulse esponse be ween MT and BS, whe e
dMT−BS is he dis ance be ween MT →BS. In addi ion,
mj∼CN(0,σ2
mjd−ν
mj−BS), ∀j=1,...,M, is he channel im-
pulse esponse be ween j h CCI →BS, whe e dmj−BS is
he dis ance be ween j h CCI →BS. The dis ances, chan-
nel impulse esponses, and powe alloca ion coe icien s o
he CCI e minals a e so ed as: dmj−BS ≤,...,≤dmM−BS,
|mj|2≥,...,≥|mM|2, and 1 >α
j≥,...,≥αM>0, whe e
M
j=1αj=1, espec i ely. The ampli udes o all channels a e
dis ibu ed acco ding o Rayleigh dis ibu ion. I should be
no ed ha he i.i.d. case is conside ed o modeling he CCI
subjec o Rayleigh ading.
Acco ding o Fig. 1, MT ansmi s in o ma ion o he
des ina ion ia ac i e, passi e, and abso p i e RIS wi h
LOS/di ec -link. The ecei ed signals a BS o he ac i e,
passi e, and abso p i e RIS modes a e w i en as ollows:
ya+d
BS =Ps x+Ps
N

i=1
hiθigix+
N

i=1
niθigix
+
M

j=1Pjαjmjaj+wn,(1)
yp+d/abs+d
BS =Ps x+Ps
N

i=1
hiθigix
+
M

j=1Pjαjmjaj+wn,(2)
whe e Psis he ansmi powe o MT. xis he ansmi in o -
ma ion, which has a uni a iance E[|x|2]=1. The niis he
noise e m om he ampli ie a i h e lec ing elemen which
ollows CN 0,σ2
ni.θi=ρiejφi,∀i=1,...,N, and =
diag ρ1ejφ1,...,ρ
iejφi,...,ρ
NejφN ep esen e lec ing
phase shi ing ma ix o RIS. The e m ρiis he ene gy
coe icien s o he i h elemen o e lec ing esponses. The
e m φi∈[0,2π) is he adjus able phase a he i h e lec ed
uni in he RIS. Conside ing ρi=ρ[4], he e m can be
w i en as: =ρdiag ejφ1,...,ejφi,...,ejφN. In p ac i-
cal implemen a ions, he phase shi φia each RIS elemen is
ypically op imized based on CSI o enhance ecei ed signal
s eng h. In his s udy, we assume an idealized con inuous
phase shi model, which p o ides an uppe -bound pe o -
mance analysis and allows o analy ical ac abili y. Howe e ,
in p ac ical RIS ha dwa e, disc e e phase shi s a e o en em-
ployed due o quan iza ion cons ain s, which can in oduce
addi ional pe o mance losses [46]. While ou model does
no explici ly inco po a e phase quan iza ion, i s undamen al
insigh s emain applicable. By se ing ρ>1, he ac i e mode
is ob ained. Con e sely, by se ing he e m ρ o 1 and σ2
ni
o 0, he passi e mode is ob ained. Likewise, in abso p i e
mode, which nei he in ol es an ampli ica ion p ocess a he
RIS no ampli ies noise, he e m ρ akes alues in he ange
0≤ρ≤1[8],[47].P
jis he ansmi powe a j h CCI. aj,
whe e E[|aj|2]=1, is he ansmi in o ma ion o he j h
CCI. wnis he he mal noise a BS and modeled as addi i e
whi e Gaussian noise (AWGN). U ilizing (1), he signal- o-
in e e ence plus noise a io (SINR) a BS is w i en as:
γa+d
BS =
Ps| |+ρN
i=1|hi||gi|
2
ρ2N
i=1σ2
ni|gi|2+M
j=1Pjαj|mj|2+σ2
wn
(3)
By se ing he e m ρ o 1 and σ2
ni o 0, he SINR exp ession
o he passi e and abso p i e modes is ob ained as:
γp+d/abs+d
BS =
Ps| |+ρN
i=1|hi||gi|
2
M
j=1Pjαj|mj|2+σ2
wn
(4)
No e ha passi e and abso p i e modes ha e he same SINR
exp ession wi h a di e en ρ alue. In passi e mode, ρ e m
is se o 1 and in abso p i e mode, ρ e m is a alue be ween
0≤ρ≤1.
III. PERFORMANCE ANALYSIS
This sec ion p o ides he analy ical and asymp o ic de i a-
ions o ou age p obabili y, e o p obabili y, h oughpu ,
ene gy and spec al e iciency pe o mance me ics.
A. OUTAGE PROBABILITY
Below, an ou age analysis is p esen ed o he conside ed dual-
hop RIS-aided ne wo k unde he impac o non-o hogonal
CCI.
Pa+d
ou (γ)=1
(ρb)a+1 (a+4)σ2
ngN(PJm)M(M)(N)γ
Psa+3
2∞

k=0
(1+k)(3/2+k)
(3/2)
((a+4)/2+k)((a+5)/2+k)
((a+4)/2)((a+5)/2) k!−γ
2Ps k
×∞

u=0
(a+2k+5
2)
(u+1)(a+2k−2u+5
2)
u

=0u
ρ2(u− )(N+u− )
1
σ2
ngN+u−
(M+ )
1
PJmM+ (5)
VOLUME 6, 2025 2053
ÖZDURAN ET AL.: ACTIVE, PASSIVE, AND ABSORPTIVE RIS-AIDED 6G NETWORK UNDER NON-ORTHOGONAL CCI
P oposi ion 1: The OP analy ical de i a ions a e p esen ed
a he op o he nex page. No e ha o he case o ac i e RIS
wi h di eck link (5) shown a he bo om o he p e ious page,
passi e RIS wi h di ec link (6) shown a he bo om o his
page, ac i e RIS wi hou di ec link (7) shown a he bo om
o his page, and passi e RIS wi hou di ec link (8) shown a
he bo om o his page.
P oo : See Appendix A.
B. ERROR PROBABILITY
Wi h he help o [48, Eq. (27)], he CDF-based EP pe o -
mance me ic can be o mula ed as
¯
Pe=p
2q
π∞
0
exp (−qx)
√xF(x)dx,(9)
whe e p=q=1 ep esen s he bina y phase shi keying
(BPSK) and p=q=2 ep esen s quad a u e phase shi key-
ing (QPSK) modula ions.
The analy ical de i a ions o he EP pe o mance me ic
a e p esen ed in he ollowing p oposi ion.
P oposi ion 2: The EP o he p oposed model is de i ed in
he ollowing exp essions, which a e p esen ed in he middle
o he nex page. Fo he case o ac i e RIS wi h di ec link
(10) shown a he bo om o his page, passi e RIS wi h di ec
link (11) shown a he bo om o his page, ac i e RIS wi hou
di ec link (12) shown a he bo om o he nex page, and
passi e RIS wi hou di ec link (13) shown a he bo om o
he nex page.
P oo : See Appendix B.
C. THROUGHPUT
The CDF-based h oughpu pe o mance me ic is o mula ed
wi h he help o [49, Eq. (15(a))] as:
τBS =R h 1−FγBS (γ h)(14)
Subs i u ing (3) and (4) in o (14), he h oughpu analy i-
cal exp essions a e ob ained. Due o space limi a ions, he
de i a ions a e omi ed and only u ilized in he pe o mance
e alua ion esul s in Sec ion IV.
Pp+d
ou (γ)=1
(ρb)a+1 (a+4)(M)(PJm)Mγ
Psa+3
2∞

k=0
(1+k)(3/2+k)
(3/2)
((a+4)/2+k)((a+5)/2+k)
((a+4)/2)((a+5)/2) k!−γ
2Ps k
×∞

u=0
(a+2k+5
2)
(u+1)(a+2k−2u+5
2)
(M+u)
1
PJmM+u(6)
Pa
ou (γ)=1
ρaba+1(a+1)(a+1)(M)(N)σ2
ngN(PJm)Mγ
Psa+1
2∞

u=0
(a+3
2)
(u+1)(a+3−2u
2)
×
u

=0u
ρ2(u− )(N+u− )
1
σ2
ngN+u−
(M+ )
1
PJmM+ (7)
Pp
ou (γ)=1
ρaba+1(a+1)(a+1)(M)(PJm)Mγ
Psa+1
2∞

u=0
(a+3
2)
(u+1)(a+3−2u
2)
(M+u)
1
PJmM+u(8)
¯
Pea+d =1
2√π(ρb)a+1 (a+4)Pa+3
2
sσ2
ngN(PJm)M(M)(N)
∞

k=0
(1+k)(3/2+k)
(3/2)
((a+4)/2+k)((a+5)/2+k)
((a+4)/2)((a+5)/2) k!
×−1
2Ps k∞

u=0
(a+2k+5
2)
(u+1)(a+2k−2u+5
2)
u

=0u
ρ2(u− )(N+u− )
1
σ2
ngN+u−
(M+ )
1
PJmM+ (a+2k+4
2) (10)
¯
Pep+d =1
2√π(ρb)a+1 (a+4)Pa+3
2
s(PJm)M(M)
∞

k=0
(1+k)(3/2+k)
(3/2)
((a+4)/2+k)((a+5)/2+k)
((a+4)/2)((a+5)/2) k!−1
2Ps k
×∞

u=0
(a+2k+5
2)
(u+1)(a+2k−2u+5
2)
(M+u)
1
PJmM+u(a+2k+4
2) (11)
2054 VOLUME 6, 2025
D. ENERGY EFFICIENCY
By de ini ion, he ene gy e iciency (EE) is calcu-
la ed as he sys em h oughpu o e he o al powe
consump ion [50, Eq. (3)].
EE =τBS
Ps
,(15)
E. SPECTRAL EFFICIENCY
The spec al e iciency (SE) is measu ed in bi s/s/Hz and o -
mula ed as [51],[52].
SE =τBS
B,(16)
whe e B is he bandwid h used in he ansmission.
F. ASYMPTOTIC ANALYSIS
To ge addi ional insigh s om he de i ed analy ical esul s,
his subsec ion ocuses on he high SNR egime. In g ea e de-
ail, we e alua e he asymp o ic pe o mance o he ollowing
pe o mance me ics:
1) OUTAGE PROBABILITY
Conside ing he small alues o j,k e ms, he asymp o ic
ou age ep esen a ions a e ob ained o he case o ac i e RIS
wi h di ec link (17), passi e RIS wi h di ec link (18), ac i e
RIS wi hou di ec link (19), and passi e RIS wi hou di ec
link (20), all shown a he bo om o his page.
¯
Pea=1
2√πρaba+1(a+1)(a+1)Pa+1
2
sσ2
ngN(PJm)M(M)(N)
∞

u=0
(a+3
2)
(u+1)(a+3−2u
2)
×
u

=0u
ρ2(u− )(N+u− )
1
σ2
ngN+u−
(M+ )
1
PJmM+ a+2
2(12)
¯
Pep=1
2√πρaba+1(a+1)(a+1)(M)(PJm)MPa+1
2
s
∞

u=0
(a+3
2)
(u+1)(a+3−2u
2)
(M+u)
1
PJmM+ua+2
2(13)
Pa+d,∞
ou (γ)=1
(ρb)a+1 (a+4)σ2
ngN(PJm)M(M)(N)γ
Psa+3
2
×
1

k=0
(1+k)(3/2+k)
(3/2)
((a+4)/2+k)((a+5)/2+k)
((a+4)/2)((a+5)/2) k!−γ
2Ps k1

u=0
(a+2k+5
2)
(u+1)(a+2k−2u+5
2)
×
u

=0u
ρ2(u− )(N+u− )
1
σ2
ngN+u−
(M+ )
1
PJmM+ (17)
Pp+d,∞
ou (γ)=1
(ρb)a+1 (a+4)(M)(PJm)Mγ
Psa+3
21

k=0
(1+k)(3/2+k)
(3/2)
((a+4)/2+k)((a+5)/2+k)
((a+4)/2)((a+5)/2) k!−γ
2Ps k
×
1

u=0
(a+2k+5
2)
(u+1)(a+2k−2u+5
2)
(M+u)
1
PJmM+u(18)
Pa,∞
ou (γ)=1
ρaba+1(a+1)(a+1)(M)(N)σ2
ngN(PJm)Mγ
Psa+1
21

u=0
(a+3
2)
(u+1)(a+3−2u
2)
×
u

=0u
ρ2(u− )(N+u− )
1
σ2
ngN+u−
(M+ )
1
PJmM+ (19)
Pp,∞
ou (γ)=1
ρaba+1(a+1)(a+1)(M)(PJm)Mγ
Psa+1
21

u=0
(a+3
2)
(u+1)(a+3−2u
2)
(M+u)
1
PJmM+u(20)
VOLUME 6, 2025 2055
ÖZDURAN ET AL.: ACTIVE, PASSIVE, AND ABSORPTIVE RIS-AIDED 6G NETWORK UNDER NON-ORTHOGONAL CCI
2) ERROR PROBABILITY
Following a simila p ocedu es as in he OP asymp o ic
ep esen a ions, he EP asymp o ic ep esen a ions a e also
ob ained. The ob ained de i a ions a e omi ed, being only
applied in Sec ion IV.
3) THROUGHPUT
Conside ing he asymp o ic OP ep esen a ions and u iliz-
ing i in he h oughpu o mula, he asymp o ic h oughpu
ep esan a ion is ob ained. To ensu e eadabili y, he ob ained
de i a ions a e omi ed, being only u ilized in Sec ion IV.
4) ENERGY EFFICIENCY
Conside ing he asymp o ic h oughpu exp essions and using
i in he (15), he asymp o ic EE ep esen a ion is ob ained. As
o he p e ious wo pe o mance me ics, he de i a ions a e
omi ed, being only e alua ed in Sec ion IV.
G. DIVERSITY ORDER ANALYSIS
The ela ion be ween di e si y o de and coding gain is ex-
p essed as [53]
Pou =(Gcγ)−Gd,(21)
whe e Gdis he di e si y o de and Gcis he coding gain.
Rega ding he passi e RIS wi h NLOS, i s sys em asymp o ic
CDF de i a ion, when Ps→∞,1
(PJm)M,( 1
PJm)M+u, and
(1
Ps)a+1
2 e ms app oxima e ze o and become neglible, and
γbecomes dominan . The powe o γ, which is a+1
2, yields
he di e si y o de . No e ha , as i is clea ly exp essed in
Appendix A, he a e m is dependen on he numbe o
e lec ing elemen s. In o he wo ds, he numbe o e lec ing
elemen s de ines he di e si y o de . Subs i u ing he alues
o a e m in Appendix A,a+1
2is calcula ed as 0.8N.The
ob ained esul is consis en wi h he di e si y o de analysis.
On he o he hand, he emaining cons an e ms, which a e
p esen ed in he ollowing, ep esen he sys em coding gain,
which is Gp
c=1
ρaba+1(a+1)(a+1)(M)1
u=0
(a+3
2)(M+u)
(u+1)(a+3−2˜u
2).
Rega ding he asymp o ic pe o mance o he ac i e RIS
wi h NLOS, when Ps→∞,1
(PJm)M,( 1
PJm)M+ , and ( 1
Ps)a+1
2
app oxima e ze o and become neglible, and γbecomes dom-
inan . The powe o γ, which is a+1
2, yields he di e si y
o de . Subs i u ing he alues o a e m in Appendix Asec ion,
a+1
2is calcula ed as 0.8N. The ob ained esul is consis en
wi h he di e si y o de analysis. The emaining cons an
e ms, which a e p esen ed below, ep esen he sys em cod-
ing gain, which is Ga
c=1
ρaba+1(a+1)(a+1)(M)(N)(σ2
ng)N×
1
u=0
(a+3
2)
(u+1)(a+3−2˜u
2)u
=0u
ρ2(u− )(N+u− )(M+ )
(1
σ2
ng)N+u− .
Rega ding he asymp o ic pe o mance o he passi e RIS
wi h LOS, when Ps→∞,1
(PJm)M,( 1
PJm)M+ ,(
1
Ps)a+1
2,
and (−1
2Ps )k=0app oxima e o ze o and become neglible
and he γ e m becomes dominan . The powe o γ, which
is a+3
2+k, yields he di e si y o de . Subs i u ing he al-
ues o a e m in Appendix Asec ion, a+3
2is calcula ed as
TAB LE 4. Sys em Con igu a ions
1+0.8N. The ob ained esul is consis en wi h he di e -
si y o de analysis. The emaining cons an e ms, which a e
p esen ed below ep esen s he sys em coding gain, which is
Gp+d
c=(a+2)
(ρb)a+1(a+1)(a+1) (a+4)(M)1
u=0
(a+5
2)(M+u)
(u+1)(a−2u+5
2).
Rega ding he ac i e RIS wi h LOS asymp o ic pe o -
mance, when Ps→∞,1
(PJm)M,( 1
PJm)M+ ,(1
Ps)a+1
2, and
(−1
2Ps )k=0 e ms app oxima e o ze o and become neglible
and γ e m becomes dominan . The powe o γ, which
is a+3
2+k, yields he di e si y o de . Subs i u ing he al-
ues o a e m in Appendix Asec ion, a+3
2is calcula ed as
1+0.8N. The ob ained esul is consis en wi h he di e -
si y o de analysis. The emaining cons an e ms, which
a e p esen ed below ep esen s he sys em coding gain,
which is Ga+d
c=(a+2)
(ρb)a+1(a+1)(a+1) (a+4)(σ2
ng)N(M)(N)×
1
u=0
(a+5
2)
(u+1)(a−2u+5
2)u
=0u
ρ2(u− )(N+u− )(M+ )
(1
σ2
ng)N+u− .
IV. NUMERICAL RESULTS
This sec ion alida es he analy ical and asymp o ic de i a-
ions by means o Mon e-Ca lo-based compu e simula ions.
The Ma lab©en i onmen is conside ed o he ela ed pe -
o mance analysis and 106channel ealiza ions a e gene a ed.
The ollowing pa ame e s a e conside ed o he sys em model
con igu a ion. The numbe o e lec ion uni , which is N,isse
o 2, 4, 6, 12, 30, 50, 60, and 100 o di e en pe o mance
me ics. The numbe o CCI e minals, which is M,isse o
0, 1, and 2. The pa ame e s dMT−RIS,dRIS−BS, and dMT−BS
a e se o 10. Since he non-o hogonal CCI e minals a e
andomly deployed, dmj−BS is se o 1 and 10 o nea and
a NOMA use s, espec i ely. Fu he , he e m is se o 2
and 3. The ansmi powe o he sou ce e minal, which is
Ps, is se o P and he ansmi powe o he j h in e e e ,
which is Pj,isse oP
jd−
mj−BS. The a ge a e, which is
R h, is se o 10 bps/Hz. The ρ e m is se o 1.1, 1, and 0.5
o ac i e, passi e, and abso p i e modes, espec i ely. The
simula ion pa ame e s a e also p esen ed in Table IV.The
2056 VOLUME 6, 2025
×∞
0
(γF+1)a+3
2+kγM−1
Fe−γF
PJmdγF
 
I7
.(34)
By means o [39, Eq. (1.110)],I7is u he simpli ied as
∞

u=0
(a+2k+5
2)
(u+1)(a+2k−2u+5
2)∞
0
γM+u−1
Fe−γF
PJmdγF
 
I8
.(35)
By means o [39, Eq. (3.381.4)], he in eg al exp ession in
I8is sol ed as
I8=(M+u)
1
PJmM+u.(36)
In summa y, he inal exp ession is ob ained as in (6).
Rega ding he sys em model ha communica es ia ac i e
RIS wi h NLOS, bypassing he di ec link in (3),(22), and
(23), he ollowing exp ession is w i en
Fa
A(γ)=P ρ
N

i=1|hi||gi|≤γ
=P N

i=1|hi||gi|≤γ
ρ
=γ
0
FN
i=1|hi||gi|γ
ρdγ
=1
ba+1(a+1)ρaγ
0
γaexp −γ
ρbdγ. (37)
By means o [39, Eq. (3.381.1)],(37) is sol ed as
ρ
(a+1)γa+1,γ
ρb.(38)
By de ini ion [60, Eq. (11)],(38) is ob ained as:
Fa
A(γ)=ρ−ρ
(a+1,γ
ρb)
(a+1) .(39)
By means o [59, Eq. (06.06.06.0001.02)],Fa
A(γ)=
ρ(γ
ρb)a+1/(a+1)(a+1). U ilizing he ob ained esul s in
(39), ollowing exp essions a e ob ained.
Fγa
BS (γ)=Fa
Aγ
Psρ2γG+γF+11
2.(40)
In his ega d, subs i u ing he app oxima ed (39) in o (40),
he ollowing in eg al exp ession is ob ained
Fγa
BS (γ)=1
ρaba+1(a+1)(a+1) γ
Psa+1
2
×∞
0∞
0ρ2γG+γF+1a+1
2 γG(γG) γF(γF)dγGdγF
 
I9
.
(41)
Subs i u ing he ela ed PDF exp essions in o (41),I9is
w i en as
1
σ2
ngN1
PJmM1
(M)(N)
×∞
0∞
0ρ2γG+γF+1a+1
2
 
×γN−1
Ge−γG
σ2
ngγM−1
Fe−γF
PJmdγGdγF
 
I10
.(42)
By means o [39, Eq. (1.110)],I10 is u he simpli ied as:
∞

u=0
(a+3
2)
(u+1)(a+3−2u
2)∞
0∞
0ρ2γG+γFu
 
×γN−1
Ge−γG
σ2
ngγM−1
Fe−γF
PJmdγGdγF
 
I11
.(43)
No e ha since (a+1)/2 is no an in ege in a+1
2
u,x
y=
(x+1)
(y+1)(x−y+1)[39] is u ilized o u he simpli ica ion. By
pe o ming basic algeb aic manipula ions and using [39, Eq.
(1.111)],I11 is u he simpli ied as
u

=0u
ρ2(u− )∞
0
γN+u− −1
Ge−γG
σ2
ngdγG
 
×∞
0
γM+ −1
Fe−γF
PJmdγF
 
I12
.(44)
By means o [39, Eq. (3.381.4)], he in eg al exp essions in
I12 a e sol ed as
I12 =(N+u− )
1
σ2
ngN+u−
(M+ )
1
PJmM+ .(45)
In summa y, he CDF exp ession o ac i e-RIS wi h NLOS
is p esen ed in (8).
Rega ding he passi e RIS wi h NLOS coun e pa , by
se ing he ac i e RIS ampli ica ion coe icien o 1 in (37)
and also elimina ing he ac i e-RIS companen in (40), he
ollowing passi e exp ession is ob ained. No e ha he e m
ρis e ained in he de i a ions o he abso p i e coun e pa .
Fγp
BS (γ)=Fp
Aγ
Ps
(γF+1)1
2,(46)
Subs i u ing he app oxima ed (39), which is Fp
A(γ)=
ρ(γ
ρb)a+1/(a+1)(a+1), in o (46), he ollowing exp es-
sion is ob ained
Fγp
BS (γ)=1
ρaba+1(a+1)(a+1) γ
Psa+1
2
VOLUME 6, 2025 2063

ÖZDURAN ET AL.: ACTIVE, PASSIVE, AND ABSORPTIVE RIS-AIDED 6G NETWORK UNDER NON-ORTHOGONAL CCI
×∞
0
(γF+1)a+1
2 γF(γF)dγF
 
I13
.(47)
Subs i u ing he ela ed PDF exp essions in o (47),I13 is
w i en as
1
PJmM1
(M)
×∞
0
(γF+1)a+1
2γM−1
Fe−γF
PJmdγF
 
I14
.(48)
By means o [39, Eq. (1.110)],I14 is u he simpli ied as
∞

u=0
(a+3
2)
(u+1)(a+3−2u
2)∞
0
γM+u−1
Fe−γF
PJmdγF
 
I15
,(49)
Since (a+1)/2 is no an in ege in a+1
2
u,x
y=
(x+1)
(y+1)(x−y+1)[39] is u ilized o he u he simpli ica ion.
By means o [39, Eq. (3.381.4)], he in eg al exp essions in
I15 a e sol ed as
I15 =(M+u)
1
PJmM+u.(50)
APPENDIX B
PROOF OF PROPOSITION 2
S a ing wi h he ac i e RIS when he sou ce has a LOS link
wi h he des ina ion e minal, subs i u ing he ela ed CDF
exp ession, (5), in o EP o mula, (9), ollowing in eg al ex-
p ession is ob ained
¯
Pea+d=1
2√π∞
0
γa+2k+2
2exp(−γ)dγ. (51)
By means o [39, Eq. (3.381.4)],(51) is sol ed as:
a+2k+4
2. The inal exp ession is w i en as in (10).Like-
wise, o passi e RIS wi h LOS/di ec -link, ollowing a
simila p ocedu e and u ilizing (6) and (9), and also sol ing
he in eg al exp ession, a+2k+4
2is ob ained. The inal EP
exp ession o passi e RIS wi h LOS / di ec -link is p esen ed
in (11).
Rega ding he sys em model wi hou a di ec link o ac i e
and passi e RIS modes, using (7) and (8) in (9) and also sol -
ing he in eg al exp ession wi h [39, Eq. (3.381.4)], he inal
EP exp essions o he ac i e and passi e RIS-aided wi hou a
di ec -link a e ob ained as in (12) and (13), espec i ely.
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VOLKAN ÖZDURAN (Senio Membe , IEEE)
ecei ed he g adua ion deg ee om he Depa -
men o Elec onics, Söke Technical High School,
Aydın, Tü kiye, in 1997, he A.Sc. (wi h Fi s
Hons.) deg ee in indus ial elec onics, and he
B.Sc., M.Sc., and Ph.D. deg ees in elec ical and
elec onics enginee ing om Is anbul Uni e si y,
Is anbul, Tü kiye, in 2002, 2005, 2008, and 2015,
espec i ely. Du ing he Ph.D. s udies he was
wi h he Depa men o Elec ical Enginee ing,
Dynamic Spec um Managemen (DSM) esea ch
g oup led by P o . D . John M. Cio i, bes known as he “ a he o DSL”,
S an o d Uni e si y, S an o d, CA, USA, and Depa men o Elec ical En-
ginee ing, Cali o nia Ins i u e o Technology, Pasadena, CA, and P ince on
Uni e si y, P ince on, NJ, USA, espec i ely. His esea ch ocuses on a ious
aspec s o he 6G wi eless ne wo ks. He ecei ed he Doçen i le om he
Tu kish In e uni e si y Council, Anka a, Tü kiye in 2022.
VOLUME 6, 2025 2065
ÖZDURAN ET AL.: ACTIVE, PASSIVE, AND ABSORPTIVE RIS-AIDED 6G NETWORK UNDER NON-ORTHOGONAL CCI
EHSAN SOLEIMANI-NASAB ecei ed he B.Sc.
deg ee in elec ical enginee ing om he I an Uni-
e si y o Science and Technology, Teh an, I an, in
2006, and he M.Sc. and Ph.D. deg ees in commu-
nica ion sys ems om he K. N. Toosi Uni e si y
o Technology, Teh an, I an, in 2009 and 2013,
espec i ely. F om Ap il 2012 o Oc obe 2012,
he was a Visi ing Resea che wi h he Depa men
o Signals and Sys ems, Chalme s Uni e si y o
Technology, Go henbu g, Sweden. F om June 2014
o Augus 2014, he wo ked as a Resea ch Asso-
cia e wi h he Depa men o Elec ical and Elec onics Enginee ing, Özye˘
gin
Uni e si y, Is anbul, Tü key. Since 2014, he has been wi h he G adua e Uni-
e si y o Ad anced Technology, Ke man, whe e he is cu en ly an Associa e
P o esso . F om 2022 o 2023, he was a Gues Resea che wi h he Depa -
men o Elec ical and Elec onics Enginee ing, Koç Uni e si y, Is anbul,
Tu key. He has au ho o coau ho o mo e han 60 jou nal and con e ence
publica ions. His esea ch in e es s include op ical wi eless communica ions,
adio wi eless communica ions, and signal p ocessing in communica ions.
He was on he echnical p og am commi ees o a ious IEEE con e ences.
He has been on he edi o ial boa d o FRONTIERS IN COMMUNICATIONS AND
NETWORKS. He is an ac i e e iewe o a ious IEEE TRANSACTIONS and
o he jou nals.
NIKOLAOS NOMIKOS (Senio Membe , IEEE)
ecei ed he Diploma in elec ical enginee ing and
compu e echnology om he Uni e si y o Pa as,
Pa as, G eece, in 2009, and he M.Sc. and Ph.D.
deg ees om he In o ma ion and Communica ion
Sys ems Enginee ing Depa men , Uni e si y o
he Aegean, Samos, G eece, in 2011 and 2014,
espec i ely. Since 2025, he has been an Assis an
P o esso o Mobile and Sa elli e Communica ions
Sys ems, Depa men o In o ma ion and Commu-
nica ion Sys ems Enginee ing, Uni e si y o he
Aegean, Samos, G eece. Mo eo e , he is a P ojec Manage wi h Fou Do
In ini y P.C. His esea ch in e es s include coope a i e communica ions, non-
o hogonal mul iple access, non- e es ial ne wo ks, and machine lea ning
o wi eless ne wo ks op imiza ion. P o . Nomikos is an Edi o o IEEE
TRANSACTIONS ON COMMUNICATIONS and Associa e Edi o o F on ie s in
Communica ions and Ne wo ks. He is a Membe o he IEEE Communica-
ions Socie y and he Technical Chambe o G eece.
IMRAN SHAFIQUE ANSARI (Senio Mem-
be , IEEE) ecei ed he B.Sc. deg ee in com-
pu e enginee ing om he King Fahd Uni e si y
o Pe oleum and Mine als (KFUPM), Dhah an,
Saudi A abia, in 2009 (wi h Fi s Hono s) and
he M.Sc. and Ph.D. deg ees om King Abdullah
Uni e si y o Science and Technology (KAUST),
Saudi A abia, in 2010 and 2015, espec i ely.
Since 2018, he has been a Lec u e (Assis an P o-
esso ) wi h Uni e si y o Glasgow, Glasgow, U.K.
He has been a ilia ed wi h IEEE since 2007 and
was in a ious capaci ies. He is cu en ly on IEEE Eu opean Public Pol-
icy Commi ee om 2023 o 2024 and IEEE LEO Sa S Fu u e Di ec ions
since 2022. He was on he IEEE Nomina ions and Appoin men s (N&A)
Commi ee om 2020 o 2021 and IEEE Communica ion Socie y Young
P o essionals (ComSoc YP) Boa d om 2016 o 2021. Sicne 2017, he has
been a pa o he IEEE 5G Tech Focus Publica ions Edi o ial Boa d. He
is an ac i e e iewe o EPSRC esea ch g an s, a ious IEEE T ansac ions
and a ious o he jou nals. He has au ho ed o coau ho ed mo e han 100
jou nal and con e ence publica ions. His cu en esea ch in e es s include
ee-space op ics (FSO), sa elli e communica ions, unde wa e communica-
ions, physical laye sec ecy issues, and econ igu able in elligen su aces /
in elligen e lec i e su aces (RIS / IRS), among o he s. He was also a TPC
o a ious IEEE con e ences. He is a ecipien o app ecia ion o an exem-
pla y e iewe o IEEE T ansac ion on Communica ions (TCOM) in 2018
and 2016, espec i ely, a ecipien o app ecia ion o an exempla y e iewe
o IEEE Wi eless Communica ions Le e s (WCL) in 2017 and 2014. He
was also he ecipien o Pos doc o al Resea ch Awa d (PDRA) ( i s cycle)
wi h Qa a na ional esea ch ounda ion (QNRF) in 2014, KAUST Academic
Excellence Awa d (AEA) in 2014, and IEEE Richa d E. Me win S uden
Schola ship Awa d in 2013. He has co-o ganized he GRASNET’2016, 2017,
2018 wo kshops in conjunc ion wi h IEEE WCNC’2016, 2017 and IEEE
Globecom 2018.
PANAGIOTIS TRAKADAS ecei ed he Dipl.
Ing. deg ee in elec ical and compu e enginee ing
and he Ph.D. deg ee om he Na ional Techni-
cal Uni e si y o A hens (NTUA). He has wo ked
wi h Hellenic Ae ospace Indus y (HAI), as a Se-
nio Enginee , on he design o mili a y wi eless
elecommunica ions sys ems, and he Hellenic Au-
ho i y o Communica ions Secu i y and P i acy,
whe e he was he he Di ec o o he Di ision
o he Assu ance o In as uc u es and Telecom-
munica ions Se ices P i acy. He is cu en ly an
Associa e P o esso wi h he Na ional and Kapodis ian Uni e si y o A hens,
and a Technical Manage wi h Fou Do In ini y P.C. He has been ac i ely
in ol ed in many EU FP7 and H2020 Resea ch P ojec s. He has au ho ed
o coau ho ed mo e han 130 pape s in magazines, jou nals, and con e ence
p oceedings. His esea ch in e es s include he ields o wi eless and mobile
communica ions, wi eless senso ne wo king, ne wo k unc ion i ualiza-
ion, and cloud compu ing. He is a e iewe in se e al jou nals, including
IEEE TRANSACTIONS ON COMMUNICATIONS and IEEE TRANSACTIONS ON
ELECTROMAGNETIC COMPATIBILITY jou nals.
2066 VOLUME 6, 2025