Table 1 Summary of the functions and symbols
From: Performance analysis of ultra-reliable short message decode and forward relaying protocols
bpcu | Bit per channel use |
CSI | Channel state information |
DF | Decode and forward |
DT | Direct transmission |
EE | Energy efficiency |
EPA | Equal power allocation |
FB | Finite blocklength |
IFB | Infinite blocklength |
mMTC | Massive machine-type communication |
MRC | Maximum ratio combining |
MTC | Machine-type communication |
OPA | Optimal power allocation |
Probability density function | |
QOS | Quality of service |
RV | Random variable |
SC | Selection combining |
SH | Single hop |
SNR | Signal to noise ration |
URLLC | Ultra-reliable low latency communication |
URR | Ultra reliable region |
fW(.) | Probability density function |
E(.) | Expectation |
Q(.) | Q-function |
C(ρ) | Shannon capacity |
V(ρ) | Channel dispersion |
Q−1(.) | Inverse of Q-function |
e | Exponential Euler’s number |
y | Received signal |
h | Fading channel |
w | AWGN noise |
k | Information bits |
x i | Transmitted signal |
n | Number of channel uses |
log2 | Logarithm to the base 2 |
n S | Number of channel uses for source |
n R | Number of channel uses for relay |
d SD | Distance of source-destination link |
d SR | Distance of source-relay link |
d RD | Distance of relay-destination link |
E | Energy efficiency |
P | Total power |
P R | Power of relay |
P S | Power of source |
P TX | Power of transmitter |
P RX | Power of receiver |
P PA | Power of amplifier |
P succ | Probability of successful transmission |
P max | Maximum total power |
N 0 | Power of noise |
Ω | Instantaneous SNR |
γ | Average SNR |
ρ | Average power constraint |
η | Power allocation factor |
\(\mathcal {R}\) | Maximum coding rate |
ϕ | Drain efficiency |
ε | Outage probability |