scholarly journals Energy and Spectrally Efficient Modulation Scheme for IoT Applications

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4382 ◽  
Author(s):  
Hany Hussein ◽  
Mohamed Elsayed ◽  
Mahmoud Fakhry ◽  
Usama Sayed Mohamed

Due to the Internet of Things (IoT) requirements for a high-density network with low-cost and low-power physical (PHY) layer design, the low-power budget transceiver systems have drawn momentous attention lately owing to their superior performance enhancement in both energy efficiency and hardware complexity reduction. As the power budget of the classical transceivers is envisioned by using inefficient linear power amplifiers (PAs) at the transmitter (TX) side and by applying high-resolution analog to digital converters (ADCs) at the receiver (RX) side, the transceiver architectures with low-cost PHY layer design (i.e., nonlinear PA at the TX and one-bit ADC at the RX) are mandated to cope with the vast IoT applications. Therefore, in this paper, we propose the orthogonal shaping pulses minimum shift keying (OSP-MSK) as a multiple-input multiple-output (MIMO) modulation/demodulation scheme in order to design the low-cost transceiver architectures associated with the IoT devices. The OSP-MSK fulfills a low-power budget by using constant envelope modulation (CEM) techniques at the TX side, and by applying a low-resolution one-bit ADC at the RX side. Furthermore, the OSP-MSK provides a higher spectral efficiency compared to the recently introduced MIMO-CEM with the one-bit ADC. In this context, the orthogonality between the in-phase and quadrature-phase components of the OSP are exploited to increase the number of transmitted bits per symbol (bps) without the need for extra bandwidth. The performance of the proposed scheme is investigated analytically and via Monte Carlo simulations. For the mathematical analysis, we derive closed-form expressions for assessing the average bit error rate (ABER) performance of the OSP-MSK modulation in conjunction with Rayleigh and Nakagami-m fading channels. Moreover, a closed-form expression for evaluating the power spectral density (PSD) of the proposed scheme is obtained as well. The simulation results corroborate the potency of the conducted analysis by revealing a high consistency with the obtained analytical formulas.

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Zongsheng Zhang ◽  
Jinlong Wang ◽  
Qihui Wu ◽  
Xurong Pi

The outage performance with best relay selection is proposed for cognitive relay networks with multiple primary users in independent nonidentical distributed Nakagami-m fading channels. Specifically, we take the interference temperature and fading severity into consideration. Exact closed-form expression of outage probability is derived. Based on the exact closed-form expression, we can evaluate the impact of interference temperature, fading severity, number of relays, and number of primary users on the secondary network. Finally, the effects of fading severity, number of relays, number of primary users, and interference temperature on the system performance are examined through some representative numerical plots, and the Monte Carlo results match perfectly with theory results which validates our theory analysis.


2015 ◽  
Vol 24 (03) ◽  
pp. 1550040 ◽  
Author(s):  
V. Vinod Kumar ◽  
M. Meenakshi

This paper presents the design and simulation results for a Federal Communication Committee (FCC) complaint current starved delay line based Ultra Wide Band (UWB) Gaussian pulse transmitter, which is designed for operating in the 3.1–10.6 GHz range. The wavelet is a mono cycle Gaussian impulse wave, which is practically well suited for low cost, low power, low data rate wireless data transfer such as in wireless body area network (WBAN) applications. The transmitter operating frequency and bandwidth (BW) is controlled using a dc voltage provided at the input stage of a voltage controlled delay line (VCDL) and this aspect can be exploited for increasing the communication coverage area without compromising on the power consumption. A Gaussian wave shaping is performed for FCC compliance and the simulation has been carried out with 130 nm technology. The simulation of our design suggests an average dynamic power consumption of 1.11 mw for an energy efficiency of 14.2 pJ/pulse. The proposed IR-UWB transmitter design though a bit inferior in terms of the power efficiency, can claim superior performance with respect to tuning the BW, which is very relevant in a cognitive wireless networking scenario with other interfering signals.


Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 998 ◽  
Author(s):  
Sheng-Hong Lin ◽  
Rong-Rong Lu ◽  
Xian-Tao Fu ◽  
An-Ling Tong ◽  
Jin-Yuan Wang

In this paper, the physical layer security over the M-distributed fading channel is investigated. Initially, an exact expression of secrecy outage probability (SOP) is derived, which has an integral term. To get a closed-form expression, a lower bound of SOP is obtained. After that, the exact expression for the probability of strictly positive secrecy capacity (SPSC) is derived, which is in closed-form. Finally, an exact expression of ergodic secrecy capacity (ESC) is derived, which has two integral terms. To reduce its computational complexity, a closed-from expression for the lower bound of ESC is obtained. As special cases of M-distributed fading channels, the secure performance of the K, exponential, and Gamma-Gamma fading channels are also derived, respectively. Numerical results show that all theoretical results match well with Monte-Carlo simulation results. Specifically, when the average signal-to-noise ratio of main channel is larger than 40 dB, the relative errors for the lower bound of SOP, the probability of SPSC, and the lower bound of ESC are less than 1.936%, 6.753%, and 1.845%, respectively. This indicates that the derived theoretical expressions can be directly used to evaluate system performance without time-consuming simulations. Moreover, the derived results regarding parameters that influence the secrecy performance will enable system designers to quickly determine the optimal available parameter choices when facing different security risks.


2018 ◽  
Vol 134 ◽  
pp. 99-106 ◽  
Author(s):  
M. Tresanchez ◽  
A. Pujol ◽  
T. Pallejà ◽  
D. Martínez ◽  
E. Clotet ◽  
...  

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