Outage Probability Research Papers - Academia.edu (original) (raw)

We investigate microdiversity-augmented macrodiversity techniques in wireless communication networks. The setup consists of K widely separated access ports each carrying N antennas. The conventional selection macrodiversity (Scheme I) and... more

We investigate microdiversity-augmented macrodiversity techniques in wireless communication networks. The setup consists of K widely separated access ports each carrying N antennas. The conventional selection macrodiversity (Scheme I) and two proposed methods (Scheme II and Scheme III) for port selection are investigated and their performance are compared. Scheme II utilizes the advancement in distributed antennas and radio-on-fiber technologies whereas Scheme III utilizes these technologies in a way similar to the soft handover of CDMA systems. After the port selection, the microdiversity uses n strongest signals (n les N) of the selected port for diversity combining if practical constraints preclude the use of all N signals. Analytical performance expressions for the probability of error and outage probability for Scheme I are developed. Simulations are used to investigate Scheme II and Scheme III and it is observed that these latter schemes exhibit performance superiority over the conventional macrodiversity selection method. The power savings obtained using the proposed architecture and new selection schemes could be used either for coverage extension or to increase capacity in wireless networks

The internet of things (IoT) in 5G and beyond wireless systems is interesting topic since IoT network will be platform to develop applications in the future. IoT will open a door for smart services and new wireless architecture. In this... more

The internet of things (IoT) in 5G and beyond wireless systems is interesting topic since IoT network will be platform to develop applications in the future. IoT will open a door for smart services and new wireless architecture. In this study, we consider multiple access technique applied in two-way cooperative scheme, namely two-way non-orthogonal multiple access (TW-NOMA). We derive expressions of outage probability for considered system using amplify-and-forward (AF) relay protocol, and we show that fixed power allocation factors and target rates are main impacts on performance of AF TW-NOMA. We finally extend many scenarios to evaluate performance of two-user model and outage probability in a two-user scenario are numerically verified. It is confirmed that simulation results show that AF TW-NOMA provides better data rates and user fairness. Keywords: NOMA Outage probability Relay selection This is an open access article under the CC BY-SA license. 1. INTRODUCTION Recently, wireless communications have been developing fast in the world. The fifth-generation (5G) technology has become a most interesting and challenging topic in wireless research in the context of wireless technology. In practice, the demand for system capacity and spectrum efficiency has grown fast to satisfy the rapid development of services and applications in internet of things (IoT) since the traditional orthogonal multiple access (OMA) has not been met the IoT's needs [1-3]. The emerging networks together with NOMA are interesting topics in recent years [4-14]. In OMA, considering frequency division or time division scheme, only one user can be assigned a single radio resource, while multiple users can be shared resource in NOMA. At transmitter side, NOMA uses non-orthogonal transmission to actively introduce interference between users, and at receiver side achieves demodulation signals through the successive interference cancellation (SIC). In order to satisfy the heavy needs for cellular services, NOMA is implemented with massive multiple-input multiple-output (MIMO) [15-17]. NOMA-based two-way relay network is studied with secrecy considerations, in which two users employ trusted relay to transmit/receive their NOMA signals with existences of single and multiple eavesdroppers [18]. The authors in [19] investigated two way-full duplex (TW-FD) relay assisted cognitive radio NOMA (CR-NOMA) networks. Furthermore, the self-interference (SI) of FD can be regarded as a potential source for relay to harvest energy to enhance system energy efficiency. Uplink NOMA transmission has been studied in recent works [20-28]. The authors in [20] presented NOMA-based cognitive radio with power allocation strategies designed for uplink transmission and such system benefits from MIMO.

This paper investigates the outage performance of polarization shift keying (PolSK) based multihop parallel relay assisted free space optics (FSO) system over a strong atmospheric turbulence channel with misalignment fading. An exact... more

This paper investigates the outage performance of polarization shift keying (PolSK) based multihop parallel relay assisted free space optics (FSO) system over a strong atmospheric turbulence channel with misalignment fading. An exact closed form expression is derived for the end-to-end outage probability of the system. The results are compared with the direct transmission and on-off keying (OOK) based FSO systems. The results indicate that the performance of the PolSK based relay-assisted FSO system is much better than the direct transmission and OOK systems. The outage performance is enhanced by increasing the number of relay path between the transmitter and receiver.

... 5: Scalable Video Coding (in integrated form with ITU-T Rec. H.264 | ISO/IEC 14996-10). JointVideo Team (JVT), Doc. JVT-R201, Jan. 2006. 4. Luby, M., Stockhammer, T., Watson, M., Gasiba, T., and Xu, W. Raptor Codes for Reliable... more

... 5: Scalable Video Coding (in integrated form with ITU-T Rec. H.264 | ISO/IEC 14996-10). JointVideo Team (JVT), Doc. JVT-R201, Jan. 2006. 4. Luby, M., Stockhammer, T., Watson, M., Gasiba, T., and Xu, W. Raptor Codes for Reliable Download Delivery in Wireless Broadcast ...

The outage probability of maximal ratio combining diversity with an arbitrary number of antennas in the presence of an arbitrary number of cochannel interferers and thermal noise is derived when the branch gains of the desired user signal... more

The outage probability of maximal ratio combining diversity with an arbitrary number of antennas in the presence of an arbitrary number of cochannel interferers and thermal noise is derived when the branch gains of the desired user signal and interfering signals experience Rayleigh fading and have the same correlation matrix. Two special cases, when the correlation matrix is equicorrelated and when the correlation matrix has different eigenvalues, are considered for both the equal-power cochannel interference case and the unequal-power cochannel interference case. Further, the average bit-error rate of a coherent binary phase-shift keying (BPSK)-modulated cellular system using maximal ratio combining diversity in cochannel interference and correlated Rayleigh fading is derived. The effects of the average signal-to-noise ratio (SNR) and the average signal-power-to-interference-power ratio on the system performance are examined.

This paper investigates the impact of residual transceiver hardware impairments (RTHIs) on cooperative non-orthogonal multiple access (NOMA) networks, where generic α − µ fading channel is considered. To be practical, imperfect channel... more

This paper investigates the impact of residual transceiver hardware impairments (RTHIs) on cooperative non-orthogonal multiple access (NOMA) networks, where generic α − µ fading channel is considered. To be practical, imperfect channel state information (CSI) and imperfect successive interference cancellation (SIC) are taken into account. More particularly, two representative NOMA scenarios are proposed, namely non-cooperative NOMA and cooperative NOMA. For the non-cooperative NOMA, the base station (BS) directly performs NOMA with all users. For the cooperative NOMA, the BS communicates with NOMA users with the aid of an amplify-and-forward (AF) relay, and the direct links between BS and users are existent. To characterize the performance of the proposed networks, new closed-form and asymptotic expressions for the outage probability (OP), ergodic capacity (EC) and energy efficiency (EE) are derived, respectively. Specifically, we also design the relay location optimization algorithms from the perspectives of minimize the asymptotic OP. For non-cooperative NOMA, it is proved that the OP at high signal-to-noise ratios (SNRs) is a function of threshold, distortion noises, estimation errors and fading parameters, which results in 0 diversity order. In addition, high SNR slopes and high SNR power offsets achieved by users are studied. It is shown that there are rate ceilings for the EC at high SNRs due to estimation error and distortion noise, which cause 0 high SNR slopes and ∞ high SNR power offsets. For cooperative NOMA, similar results can be obtained, and it also demonstrates that the outage performance of cooperative NOMA scenario exceeds the non-cooperative NOMA scenario in the high SNR regime.

We study the problem of transmission-side diversity and routing in a static wireless network. It is assumed that each node in the network is equipped with a single omnidirectional antenna and that multiple nodes are allowed to coordinate... more

We study the problem of transmission-side diversity and routing in a static wireless network. It is assumed that each node in the network is equipped with a single omnidirectional antenna and that multiple nodes are allowed to coordinate their transmissions in order to obtain energy savings. We derive analytical results for achievable energy savings for both line and grid network

A generic and novel distribution, referred to as Nakagami, constructed as the product of N statistically independent, but not necessarily identically distributed, Nakagami-m random variables (RVs), is introduced and analyzed. The proposed... more

A generic and novel distribution, referred to as Nakagami, constructed as the product of N statistically independent, but not necessarily identically distributed, Nakagami-m random variables (RVs), is introduced and analyzed. The proposed distribution turns out to be a very convenient tool for modelling cascaded Nakagami-m fading channels and analyzing the performance of digital communications systems operating over such channels. The moments-generating, probability density, cumulative distribution, and moments functions of the N *Nakagami distribution are developed in closed form using the Meijer's G -function. Using these formulas, generic closed-form expressions for the outage probability, amount of fading, and average error probabilities for several binary and multilevel modulation signals of digital communication systems operating over the N *Nakagami fading and the additive white Gaussian noise channel are presented. Complementary numerical and computer simulation performance evaluation results verify the correctness of the proposed formulation. The suitability of the N *Nakagami fading distribution to approximate the lognormal distribution is also being investigated. Using Kolmogorov--Smirnov tests, the rate of convergence of the central limit theorem as pertaining to the multiplication of Nakagami-m RVs is quantified.

We develop and analyze low-complexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks. The underlying techniques exploit space diversity available through cooperating terminals'... more

We develop and analyze low-complexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks. The underlying techniques exploit space diversity available through cooperating terminals' relaying signals for one another. We outline several strategies employed by the cooperating radios, including fixed relaying schemes such as amplify-and-forward and decode-and-forward, selection relaying schemes that adapt based upon channel measurements between the cooperating terminals, and incremental relaying schemes that adapt based upon limited feedback from the destination terminal. We develop performance characterizations in terms of outage events and associated outage probabilities, which measure robustness of the transmissions to fading, focusing on the high signal-to-noise ratio (SNR) regime. Except for fixed decode-and-forward, all of our cooperative diversity protocols are efficient in the sense that they achieve full diversity (i.e., second-order diversity in the case of two terminals), and, moreover, are close to optimum (within 1.5 dB) in certain regimes. Thus, using distributed antennas, we can provide the powerful benefits of space diversity without need for physical arrays, though at a loss of spectral efficiency due to half-duplex operation and possibly at the cost of additional receive hardware. Applicable to any wireless setting, including cellular or ad hoc networks-wherever space constraints preclude the use of physical arrays-the performance characterizations reveal that large power or energy savings result from the use of these protocols.

This research paper aims at evaluating the reliability performance of two units each from Shiroro and Kainji hydro electric power stations of Nigeria. The result of this study is intends to provide the basis for planning generation... more

This research paper aims at evaluating the reliability performance of two units each from Shiroro and Kainji hydro electric power stations of Nigeria. The result of this study is intends to provide the basis for planning generation expansion of hydro electric power stations in Nigeria. Herein reliability evaluation based on the Frequency and Duration (F & D) approach is adopted.

The correlated bivariate generalized-K (KG) distribution, with not necessarily identical shaping and scaling parameters, is introduced and studied. This composite distribution is convenient for modeling multipath/shadowing correlated... more

The correlated bivariate generalized-K (KG) distribution, with not necessarily identical shaping and scaling parameters, is introduced and studied. This composite distribution is convenient for modeling multipath/shadowing correlated fading environments when the correlations between the signal envelopes and their powers are different. Generic infinite series expressions are derived for the probability density function (PDF), the cumulative distribution function (CDF) and the joint moments. Assuming identical shaping parameters, simpler expressions for the PDF, CDF and the characteristic function (CF) are provided, while the joint moments are derived in closed form. Furthermore, the PDFs of the product and ratio of two correlated KG random variables are obtained. Capitalizing on these theoretical expressions for the statistical characteristics of the correlated KG distribution, the performance analysis of various diversity reception techniques, such as maximal ratio combining (MRC), equal gain combining (EGC) and selection diversity (SD), over bivariate KG fading channels is presented. For the SD, the outage probability is studied, while for the MRC and EGC the average bit error probability is obtained. The proposed analysis is accompanied by numerical results, clearly demonstrating the usefulness of the theoretical approach as well as the appropriateness of the KG distribution to model multipath/shadowing fading channels.