Transmit Antenna Selection for Physical-Layer Network Coding Based on Euclidean Distance

Physical-layer network coding (PNC) is now well-known as a potential candidate for delay-sensitive and spectrally efficient communication applications, especially in two-way relay channels (TWRCs). In this paper, we present the error performance analysis of a multiple-input single-output (MISO) fixed network coding (FNC) system with two different transmit antenna selection (TAS) schemes. For the first scheme, where the antenna selection is performed based on the strongest channel, we derive a tight closed-form upper bound on the average symbol error rate (SER) with $M$-ary modulation and show that the system achieves a diversity order of 1 for $M > 2$. Next, we propose a Euclidean distance (ED) based antenna selection scheme which outperforms the first scheme in terms of error performance and is shown to achieve a diversity order lower bounded by the minimum of the number of antennas at the two users.Comment: 15 pages, 4 figures, Globecom 2017 (Wireless Communications Symposium

Performance Analysis of NOMA-based Cooperative Relaying in {\alpha} - {\mu} Fading Channels

Non-orthogonal multiple access (NOMA) is widely recognized as a potential multiple access technology for efficient radio spectrum utilization in the fifth-generation (5G) wireless communications standard. In this paper, we study the average achievable rate and outage probability of a cooperative relaying system (CRS) based on NOMA (CRS-NOMA) over wireless links governed by the $\alpha$-$\mu$ generalized fading model; here $\alpha$ and $\mu$ designate the nonlinearity and clustering parameters, respectively, of each link. The average achievable rate is represented in closed-form using Meijer's G-function and the extended generalized bivariate Fox's H-function (EGBFHF), and the outage probability is represented using the lower incomplete Gamma function. Our results confirm that the CRS-NOMA outperforms the CRS with conventional orthogonal multiple access (CRS-OMA) in terms of spectral efficiency at high transmit signal-to-noise ratio (SNR). It is also evident from our results that with an increase in the value of the nonlinearity/clustering parameter, the SNR at which the CRS-NOMA outperforms its OMA based counterpart becomes higher. Furthermore, the asymptotic analysis of the outage probability reveals the dependency of the diversity order of each symbol in the CRS-NOMA system on the $\alpha$ and $\mu$ parameters of the fading links.Comment: 16 pages, 7 figures, 1 table, accepted in IEEE International Conference on Communications (ICC) - 2019, Shangha

User-Antenna Selection for Physical-Layer Network Coding based on Euclidean Distance

In this paper, we present the error performance analysis of a multiple-input multiple-output (MIMO) physical-layer network coding (PNC) system with two different user-antenna selection (AS) schemes in asymmetric channel conditions. For the first antenna selection scheme (AS1), where the user-antenna is selected in order to maximize the overall channel gain between the user and the relay, we give an explicit analytical proof that for binary modulations, the system achieves full diversity order of $min(N_A , N_B ) \times N_R$ in the multiple-access (MA) phase, where $N_A$, $N_B$ and $N_R$ denote the number of antennas at user $A$, user $B$ and relay $R$ respectively. We present a detailed investigation of the diversity order for the MIMO-PNC system with AS1 in the MA phase for any modulation order. A tight closed-form upper bound on the average SER is also derived for the special case when $N_R = 1$, which is valid for any modulation order. We show that in this case the system fails to achieve transmit diversity in the MA phase, as the system diversity order drops to $1$ irrespective of the number of transmit antennas at the user nodes. Additionally, we propose a Euclidean distance (ED) based user-antenna selection scheme (AS2) which outperforms the first scheme in terms of error performance. Moreover, by deriving upper and lower bounds on the diversity order for the MIMO-PNC system with AS2, we show that this system enjoys both transmit and receive diversity, achieving full diversity order of $\min(N_A, N_B) \times N_R$ in the MA phase for any modulation order. Monte Carlo simulations are provided which confirm the correctness of the derived analytical results.Comment: IEEE Transactions on Communications. arXiv admin note: text overlap with arXiv:1709.0445

Analysis of the Cost of Emergency Managers\u27 Meeting Load: A Hampton Road Case-Study

Preparation for a disaster is not something that can be done by a single organization thus there is a need for coordination between them. Meetings and joint exercises are one means of coordination used by the emergency management community. Meetings and exercises take time, including transportation of personnel and arrangements, and time is money. With limited budgets, emergency managers need to make hard decisions about how their time is allocated. This paper describes a cost model for meeting analysis and discusses a case study that looks at the holistic time spent on meetings and exercises, by personnel, for the Hampton Roads Region of Virginia. A novel way is used to display this expenditure, e.g., it is shown in terms of monetary cost instead of temporal cost. This analysis highlighted some unexpected results, i.e., the small number of personnel involved in multiple working group meetings and high level of travel costs between the HR and the state capital, Richmond. This cost model approach may provide emergency managers with better mechanisms to show their meetings costs to senior leadership

Planned Reduction in Electrical Energy Use in Nashville - Davidson County, Tennessee: A Preliminary Assessment

An assessment was carried out of the impacts of the various alternative strategies designed to reduce the rate of electrical energy use in the Nashville-Davidson County area, in the light of a potential crisis in supply. Seven strategies were identified among the major categories of voluntary reduction, price regulation, and mandatory reduction. Thirty-three sub-sectors were identified among residential, commercial and industrial users, and the consequences of imposing the strategies were assessed using a cross-impact matrix. The value of the methodology as an aid to public policy formulation lies in its possible extension to allow direct participation of various affected publics