A Review of Transmission Rate over Wireless Fading Channels: Classifications,Applications, and Challenges

To address the explosive traffic demands, the capacity of the fading channel is increasingly becoming a prime concern in the designing of the wireless communication system. The channel capacity is an extremely important quantity, since it allows the transmission of the data through the channel with an arbitrarily small probability of error. In other words, capacity dictates the maximum rate of information transmission, called as ‘capacity’ of channel, determined by the intrinsic properties of the channel and is independent of the content of the transmitted information. In this paper, we present a comprehensive survey of the existing work related to the channel capacity model over various fading channels. With an elaborated explanation of the theory of channel capacity, definitions of channel capacity based on the channel state information are reviewed. To compliment this, review of the technique to enhance the channel capacity is discussed and reviewed. An effective capacity model to overcome the channel capacity limitation is also explained. Furthermore, as the secure transmission of data is of utmost importance, to address this physical layer security model is also reviewed. We also summarize the work related to channel capacity in various types of wireless networks. We finally cover the future research directions, including less explored aspects of the channel capacity that can be studied to design efficient communication systems.

     

Fuzzy and Deep Belief Network Based Malicious Vehicle Identification and Trust Recommendation Framework in VANETs

Wireless Personal Communications - This work aims to implement a clustering scheme to separate vehicles into a cluster that is based on various parameters, such as the total number of relay nodes,...     

Hungarian algorithm for subcarrier assignment problem using GPU and CUDA

General purpose graphics processing units (GPGPUs) have gained much popularity in scientific computing to speedup computational intensive workloads. Resource allocation in terms of power and subcarriers assignment, in current wireless standards, is one of the challenging problems due to its high computational complexity requirement. The Hungarian algorithm (HA), which has been extensively applied to linear assignment problems (LAPs), has been seen to provide encouraging result in resource allocation for wireless communication systems. This paper presents a compute unified device architecture (CUDA) implementation of the HA on graphics processing unit (GPU) for this problem. HA has been implemented on a parallel architecture to solve the subcarrier assignment problem and maximize spectral efficiency. The proposed implementation is achieved by using the “Kuhn‐Munkres” algorithm with effective modifications, in order to fully exploit the capabilities of modern GPU devices. A cost matrix for maximum assignment has been defined leading to a low complexity matrix compression along with highly optimized CUDA reduction and parallel alternating path search process. All these optimizations lead to an efficient implementation with superior performance when compared with existing parallel implementations.     

Analysis of L-Shaped Slot Loaded Circular Disk Patch Antenna for Satellite and Radio Telecommunication

In the present paper a dual frequency resonance antenna is achieved by introducing L- shaped slot in circular disk patch. It is analysed by using circuit theory concept. The resonance frequency is found to be 5.087 and 8.455 GHz and the 10 dB bandwidth of the proposed antenna for lower and upper resonance frequency is found to be 4.39 and 4.66 % respectively. It is easy to adjust the higher and lower band by changing the dimensions of notch and slot introduced in the antenna. The frequency ratio is found to be 1.6621. The gain and efficiency of the proposed antenna is found to be 9.50 dB at lower resonance however it is 7.0 dB at upper resonance frequency whereas the efficiency at lower and upper resonance is found to be 94.6 and 88.2 %.The theoretical results are compared with IE3D simulation results which are in good agreement.     

Survivability using traffic balancing and backup resource reservation in multi‐domain optical networks

Survivability in the geographically distributed backbone multi‐domain optical networks (MDONs) is critical because of issues related to its size, usage of resources, and domain management policies of the comprising domains. In MDONs, the emerging scheduled traffic is increasingly multivendor, multimedia, and periodic. It is high during the office (working) hours and low during the non‐office (non‐working) hours in a day. A connection failure during the office hours may result in huge amount of information being lost. Towards providing an acceptable level of service even when a connection fails, we first provide traffic balancing (TB) based solutions where the intra/inter‐domain traffic is slided (S1‐TB), shifted (S2‐TB), or slided as well as shifted (S3‐TB) based on the service level agreement between the client and domain service provider. Of the above solutions, the solution based on sliding as well as shifting (S3‐TB) performs best, and hence for further improvement in S3‐TB, we incorporate backup multiplexing with advance backup resource reservation (BRR) and evaluate the performance of the strategy and report results. The performance evaluation of the above strategies is compared with the existing extended path shared protection (EPSP) by a simulator developed in MATLAB and tested on three‐domain and five‐domain standard network topologies, on the metrics of blocking probability, network resource utilization ratio, network capacity utilized by backup route, wavelength link used per backup lightpath, and a newly introduced metric, network resource utilization index. As compared with the existing strategy EPSP, the S3‐TB and S3‐TB with BRR showed improved performance on all the metrics.     

Gold Nanoparticles and g‐C3N4‐Intercalated Graphene Oxide Membrane for Recyclable Surface Enhanced Raman Scattering

Toxic organic pollutants in the aquatic environment cause severe threats to both humans and the global environment. Thus, the development of robust strategies for detection and removal of these organic pollutants is essential. For this purpose, a multifunctional and recyclable membrane by intercalating gold nanoparticles and graphitic carbon nitride into graphene oxide (GNPs/g‐C₃N₄/GO) is fabricated. The membranes exhibit not only superior surface enhanced Raman scattering (SERS) activity attributed to high preconcentration ability to analytes through π–π and electrostatic interactions, but also excellent catalytic activity due to the enhanced electron–hole separation efficiency. These outstanding properties allow the membrane to be used for highly sensitive detection of rhodamine 6G with a limit of detection of 5.0 × 10^?14m and self‐cleaning by photocatalytic degradation of the adsorbed analytes into inorganic small molecules, thus achieving recyclable SERS application. Furthermore, the excellent SERS activity of the membrane is demonstrated by detection of 4‐chlorophenol at less than nanomolar level and no significant SERS or catalytic activity loss was observed when reusability is tested. These results suggest that the GNPs/g‐C₃N₄/GO membrane provides a new strategy for eliminating traditional, single‐use SERS substrates, and expands practical SERS application to simultaneous detection and removal of environmental pollutants.     

A Novel Self-Organizing Approach to Automatic Traffic Light Management System for Road Traffic Network

Wireless Personal Communications - Traffic network is basically a “network of networks” consisting of mainly two types of networks: road network and a travel network. Due to drastic...     

Hybrid connection algorithm: A strategy for efficient restoration in WDM optical networks

In present communication, we propose a modified resource allocation strategy, namely, hybrid connection algorithm, for achieving efficient restoration in WDM optical networks. The main theme of the algorithm is that, while attempting connection establishment, a wavelength is reserved in advance for providing resources for backup lightpaths. The analysis and the comparison of the proposed strategy with other existing strategies has been undertaken using metrics such as, restoration efficiency, number of wavelength links used by primary and backup lightpaths, and the percent link utilization. The proposed strategy provides 100% restoration efficiency and much better performance than the existing techniques.     

Encoding of taxonomic word categories by schizophrenics

Administered to 20 chronic, undifferentiated schizophrenics and 20 paranoid schizophrenic controls the release-from-proactive-interference procedure as developed by D. D. Wickens. Word triads representing 8 conceptual categories were the to-be-remembered stimuli. Proactive interference release was clearly established for both schizophrenic subgroups. These findings are interpreted to imply that chronic, undifferentiated schizophrenics as well as paranoid schizophrenics encode the attributes of conceptual word class in memory. Previous failures of chronic schizophrenics to benefit from categorized to-be-remembered materials in recall tests are probably not the result of an encoding deficiency. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)