57,030 research outputs found
Performance Analysis of SSK-NOMA
In this paper, we consider the combination between two promising techniques:
space-shift keying (SSK) and non-orthogonal multiple access (NOMA) for future
radio access networks. We analyze the performance of SSK-NOMA networks and
provide a comprehensive analytical framework of SSK-NOMA regarding bit error
probability (BEP), ergodic capacity and outage probability. It is worth
pointing out all analysis also stand for conventional SIMO-NOMA networks. We
derive closed-form exact average BEP (ABEP) expressions when the number of
users in a resource block is equal to i.e., . Nevertheless, we analyze the
ABEP of users when the number of users is more than i.e., , and derive
bit-error-rate (BER) union bound since the error propagation due to iterative
successive interference canceler (SIC) makes the exact analysis intractable.
Then, we analyze the achievable rate of users and derive exact ergodic capacity
of the users so the ergodic sum rate of the system in closed-forms. Moreover,
we provide the average outage probability of the users exactly in the
closed-form. All derived expressions are validated via Monte Carlo simulations
and it is proved that SSK-NOMA outperforms conventional NOMA networks in terms
of all performance metrics (i.e., BER, sum rate, outage). Finally, the effect
of the power allocation (PA) on the performance of SSK-NOMA networks is
investigated and the optimum PA is discussed under BER and outage constraints
Receive Spatial Modulation for Massive MIMO Systems
In this paper, we consider the downlink of a massive
multiple-input-multiple-output (MIMO) single user transmission system operating
in the millimeter wave outdoor narrowband channel environment. We propose a
novel receive spatial modulation architecture aimed to reduce the power
consumption at the user terminal, while attaining a significant throughput. The
energy consumption reduction is obtained through the use of analog devices
(amplitude detector), which reduces the number of radio frequency chains and
analog-to-digital-converters (ADCs). The base station transmits spatial and
modulation symbols per channel use. We show that the optimal spatial symbol
detector is a threshold detector that can be implemented by using one bit ADC.
We derive closed form expressions for the detection threshold at different
signal-to-noise-ratio (SNR) regions showing that a simple threshold can be
obtained at high SNR and its performance approaches the exact threshold. We
derive expressions for the average bit error probability in the presence and
absence of the threshold estimation error showing that a small number of pilot
symbols is needed. A performance comparison is done between the proposed system
and fully digital MIMO showing that a suitable constellation selection can
reduce the performance gap
Closed-Form Analysis of the -Beaulieu-Xie Shadowed Fading Channel
The presented research proposes the -modification of the Beaulieu-Xie
shadowed fading channel for wireless communications. For the assumed model the
closed-form analytical description of the basic statistical characteristics is
carried out (i.e., probability density function, cumulative distribution
function, and their asymptotics). The derived statistical description is
exemplified on the problems of the average bit error rate and ergodic capacity
calculation, for which the exact analytic and high signal-to-noise ratio
asymptotic expressions are derived. The performed extensive numerical analysis
demonstrates high correspondence with the analytical work and helps to study
the dependence of the channel nonlinearity effects on the bit error
probability
Modeling and Simulation of Molecular Communication Systems with a Reversible Adsorption Receiver
In this paper, we present an analytical model for the diffusive molecular
communication (MC) system with a reversible adsorption receiver in a fluid
environment. The widely used concentration shift keying (CSK) is considered for
modulation. The time-varying spatial distribution of the information molecules
under the reversible adsorption and desorption reaction at the surface of a
receiver is analytically characterized. Based on the spatial distribution, we
derive the net number of newly-adsorbed information molecules expected in any
time duration. We further derive the number of newly-adsorbed molecules
expected at the steady state to demonstrate the equilibrium concentration.
Given the number of newly-adsorbed information molecules, the bit error
probability of the proposed MC system is analytically approximated.
Importantly, we present a simulation framework for the proposed model that
accounts for the diffusion and reversible reaction. Simulation results show the
accuracy of our derived expressions, and demonstrate the positive effect of the
adsorption rate and the negative effect of the desorption rate on the error
probability of reversible adsorption receiver with last transmit bit-1.
Moreover, our analytical results simplify to the special cases of a full
adsorption receiver and a partial adsorption receiver, both of which do not
include desorption.Comment: 14 pages, 8 figures, 1 algorithm, submitte
- …