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., $L=3$. Nevertheless, we analyze the ABEP of users when the number of users is more than i.e., $L\geq3$, 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

Threshold-based Selective Cooperative-NOMA

In this letter, we propose threshold-based selective cooperative-NOMA (TBS-C-NOMA) to increase the data reliability of conventional cooperative-NOMA (C-NOMA) networks. In TBS-C-NOMA, the intra-cell user forwards the symbols of cell-edge user after successive interference canceler (SIC) only if the signal-to-interference plus noise ratio (SINR) is greater than the pre-determined threshold value. Hence, the data reliability of the cell-edge user is increased by eliminating the effect of the error propagation. We derive closed-form end-to-end exact bit error probability (BEP) of proposed system for various modulation constellations. Then, the optimum threshold value is analyzed in order to minimize BEP. The obtained expressions are validated via simulations and it is revealed that TBS-C-NOMA outperforms C-NOMA and full diversity order is achieved

A Pre-Merger Stage Galaxy Cluster: Abell 3733

The galaxy cluster Abell 3733 (A3733) is a very suitable candidate in addressing dynamical processes throughout galaxy cluster mergers. This study shows structural analysis results of A3733 (z = 0.038) based on X-ray and optical data. According to X-ray luminosity map, A3733 hosts two sub-structures separated in the sky by $\sim$ 0.25 Mpc, and the two distinct clumps are located in the East (A3733E) and the West (A3733W) directions. Both sub-structures are centred on two different brightest cluster galaxies (BCGs), and the X-ray and optical centroids of both BCGs substantially coincide with each other. The intracluster medium (ICM) temperatures of the sub-structures are estimated to be 2.79 keV for A3733E and 3.28 keV for A3733W. Both sub-structures are found to be hosting cool central gas (kT $\sim$ 1.5-2.5 keV) surrounded by hotter gas (kT $\sim$ 3.0-3.5 keV). Besides, the X-ray concentration parameters are found to be c $\sim$ 0.3 for each sub-structure. These results indicate the existence of cool centres for both sub-structures. The optical density map reveals a crowded galaxy population within the vicinity of A3733W. The high probable (% 88.2) dynamical binding model of A3733 suggests that the cores of sub-structures have a 3D separation of 0.27 Mpc and will collide in 0.14 Gyr with the relative in-falling velocity of 1936 km s$^{-1}$. As a conclusion, this study demonstrates some evidence suggesting that the A3733 system is in the pre-merger state.Comment: 9 pages, 7 Figures, published by MNRA

Derivation of the closed-form BER expressions for DL-NOMA over Nakagami-m fading channels

NOMA is as a strong candidate for the Future Radio Access Network (FRA) due to its potential to support massive connectivity and high spectral efficiency. However, the most important drawback of NOMA is the error during Successive Interference Canceller (SIC) is implemented because of the inter-user interferences. In this paper, we derive closed-form exact Bit-Error Rate expressions for Downlink(DL) NOMA over Nakagami-m fading channels in the presence of SIC errors. The derived expressions are validated by the computer simulations. It is shown that the m parameter still represents the diversity order like as OMA systems. Besides, the BER performances of users for NOMA have substantially depended on the power allocation coefficient.Comment: 26.IEEE Signal Processing and Communications Applications Conference,Izmir,Turke

Geomorphological features of Marmara Sea Islands

The Sea of Marmara is located on a continental crust. The Sea of Marmara, which is a remnant of the Sarmasien period of the Miocene Sea, is an inland sea (Okay, 2007). It opens to the Black Sea with the Bosphorus and the Aegean Sea with the Dardanelles. Its surface area is 11 111 km2 (Gazioğlu, et al., 2002) and its average depth ranges from -200 to -500 m (Doğanay, 1997). At the end of the third time, and at the beginning of the fourth time, there were crumbs and crashes arising from the earth crust movements in and around, where this sea lies today (İzbırak, 1996). In the Marmara Sea, the oldest sediments were deposited as a result of the transformation of the Marmara Sea from a lacustrine environment to a marine environment with the Mediterranean Tyrenian transgression at the end of Middle Pleistocene. When the sea level in the Sea of Marmara is at the same or higher than the present day, water passage from the Black Sea has occurred. At the beginning of Late Pleistocene, as a result of a sudden drop in world sea level, the water passage from the Marmara Sea to the Mediterranean was cut and the marine sedimentation environment was replaced by lacustrine sedimentation. At the beginning of Late Pleistocene (between 64.000-59.000 BC), Mediterranean waters entered the Sea of Marmara and the Black Sea with the sudden rise of sea level (Algan, et al., 2011 ). After the transgression, the gulfs and islands in the Sea of Marmara were formed

19. Yüzyılın Birinci Yarısında Aşiretler ve Demografik Yapı : Bayezid Sancağı

Bayezid Sancağı, Osmanlı-İran sınırında bulunan önemli bir serhad şehriydi. XVI. yüzyıldan itibaren Osmanlı-Safevi mücadelesi daha sonraki yüzyıllarda da devam etmiş, Osmanlı-İran sınırında bulunan Bayezid, iki devlet arasındaki bu mücadelelerden olumsuz etkilenmiştir. Savaş veya sulh dönemlerinde iki devlet arasında gerçekleşen sınır hareketliliği Bayezid Sancağı açısından da önem arzetmekteydi. Çünkü bu hareketlilik sancağın siyasi, sosyal ve ekonomik yapısında değişiklikleri meydana gelmesine sebep olmuştur. Örneğin, konar-göçer Kürt aşiretlerin iki devlet arasında sürekli hareket halinde olmaları hem sancak halkını hem de Osmanlı-İran arasındaki ilişkileri olumsuz etkilemekteydi. Bu hareketlilik çoğu zaman iki devlet arasında anlaşmazlıklara ve diplomatik krizlere neden olmaktaydı. Bu çalışmada yukarıda belirtilen sınır hareketliliğinin nedeni ve Osmanlı Devleti’nin sınır hareketliliğinde izlediği politika incelenecektir