Abstract An efficient method of channel estimation in MIMO-OFDM system is to use training symbols or pilots transmitted along with data sub-carriers. However these pilots cause inter-antenna interference when transmitted simultaneously from transmitting antennas. The use of null sub-carriers mitigates this but at the cost of spectral efficiency. This paper proposes an efficiency enhancing method in which the estimation of the... An efficient method of channel estimation in MIMO-OFDM system is to use training symbols or pilots transmitted along with data sub-carriers. However these pilots cause inter-antenna interference when transmitted simultaneously from transmitting antennas. The use of null sub-carriers mitigates this but at the cost of spectral efficiency. This paper proposes an efficiency enhancing method in which the estimation of the channel at the receiver is done by adding the signals coming from different transmitters. The performance of the proposed method is evaluated using MATLAB. Read More Read Less

Abstract A Virtual Reality System provides intuitive tridimensional user interface, with distinct interaction when compared to traditional 2D widgets layout, allowing the user to manipulate data similar to real world. Such systems give the users physical and cognitive immersion, by granting a mental model compatible with field operation. This paper presents some development aspects and results of the GT 411 Research and Development project,... A Virtual Reality System provides intuitive tridimensional user interface, with distinct interaction when compared to traditional 2D widgets layout, allowing the user to manipulate data similar to real world. Such systems give the users physical and cognitive immersion, by granting a mental model compatible with field operation. This paper presents some development aspects and results of the GT 411 Research and Development project, involving CEMIG GT and the Federal University of Uberlândia. A VR environment is applied, in novel ways, in the training, operation and control of power systems. Such tool enhances Operations Center interaction capabilities by making use of multisensorial devices, with easy and natural manipulation and a high immersion level. Besides operating generation and transmission actives, the environment presents great potential for the training of operators and other professionals of support and maintenance. Read More Read Less

Abstract The Demand of New Communication techniques arising day by day, due to the Increasing the numbers of users. Many techniques are used like cell sectoring, cell splitting, directional Antenna etc., these all technique has motive only to increase the efficiency the communication system. The Smart Antenna is useful part for, mainly where Interference is Capital problem in the communication system.... The Demand of New Communication techniques arising day by day, due to the Increasing the numbers of users. Many techniques are used like cell sectoring, cell splitting, directional Antenna etc., these all technique has motive only to increase the efficiency the communication system. The Smart Antenna is useful part for, mainly where Interference is Capital problem in the communication system. The smart Antenna plays an important Role to reduce interference in communication Environment. The adoption of smart/adaptive antenna techniques in future wireless systems has impact on the efficient use of the spectrum of network, to reduce the cost of establish new wireless networks. SAs can place nulls in the direction of interference via adaptive updating of weights linked to each antenna element. SAs cancel out the co-channel interference resulting in better quality of reception and reduce the no. of dropped calls. In this paper, we analyze the performance of smart antenna system on LMS and NLMS algorithms. In this paper, the conclusion and analysis section with graphs of comparison is simulated using MATLAB. Read More Read Less