Assessment of Pilot Pollution Problem for Multi-Cell Multi-User MIMO
Anahita Araghi,
Mehran Mehran Pasebanpoor
Issue:
Volume 6, Issue 5, October 2018
Pages:
120-128
Received:
6 October 2018
Accepted:
26 October 2018
Published:
26 November 2018
Abstract: Focused research and standardization work in wireless throughput, subscribers will increase day by day. One can prospect that, millions of users in a mega city will want to transmit and receive data, for instance, 100 megabits per second per user. Massive MIMO (Large Scale Antenna Systems) is a new technology which will be used for resolving the mentioned issue. Spectral efficiency improvements over fourth generation (4G) technology are frequently mentioned. Adding more antennas is always beneficial for increased throughput, reduced radiated power, increase the capacity everywhere in the cell and greater simplicity in signal processing. In these days the main problem is RF interference and noise which can be generated by almost any device that produces an electro-magnetic signal, such as cordless phones to Bluetooth headsets, microwave ovens, repeaters and even smart phones, which is caused call drop and bad quality in the network. In this article, the Signal-to-interference-plus-noise ratio (SINR) and the value of mean capacity in the Non-cooperative cellular wireless have been increased by using infinite number of base station antennas. While employing advanced features, this is illustrated by network densification, Multi-cell Multi-User MIMO and inter cell interference mitigation techniques. The propagation model is not clear for both terminals and base stations which is calculated taking in to consideration path loss, specular reflection, environment models, earth’s elevation, fast fading, log-normal shadowing fading and geometric attenuation. The conjugate transpose of the channel estimation is used for forward and reverse precoding. Numerical results show that, by using unlimited number of antennas in the base station, the inter-cell interference, the effect of uncorrelated noise and fast fading have been vanished, although the inter-cell interference that caused by reuse of the pilot sequence in other cells does not disappear. And also average capacity improves with increment of base station antennas. In this study, MATLAB based simulation tool has been developed to calculate the SIR and also the mean capacity.
Abstract: Focused research and standardization work in wireless throughput, subscribers will increase day by day. One can prospect that, millions of users in a mega city will want to transmit and receive data, for instance, 100 megabits per second per user. Massive MIMO (Large Scale Antenna Systems) is a new technology which will be used for resolving the me...
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Experimental Validation of Roll Angle Estimates Using Atmospheric Temperature Sensors
David John Broderick,
Adrian Mateusz Felczak,
Christopher Glenn Wilson
Issue:
Volume 6, Issue 5, October 2018
Pages:
129-134
Received:
16 October 2018
Accepted:
31 October 2018
Published:
26 November 2018
Abstract: Accurately estimating the position and orientation is critical for the control systems of both airborne and ground-based unmanned vehicles. In many cases, GPS-derived data provides a suitable absolute measurement. Unfortunately, many unmanned vehicles may have to operate in GPS-denied environments, thus a suitable method for obtaining an absolute attitude measurement is highly desired. Thermal emissivity sensors have been experimentally shown to successfully estimate pose of airborne vehicles at high altitude or during continuously rolling maneuvers. Previous work has shown through simulation that the roll angle can be estimated with the vehicle orientation static using three or four thermal emissivity sensor arrays. The closed form estimation method previously presented for three and four sensor arrays is expanded to a six-sensor array. An array of eight sensors is developed to allow for simultaneous experimental data collection for all three arrays. The data is collected in a realistic and non-ideal environment and then processed with the proposed estimation algorithm for each of the three arrays. The results demonstrate that three-sensor arrays do allow for estimation of roll angle, with improved error bounds for increasing number of sensors in the array. Thus, low altitude absolute roll estimation is possible with a thermal emissivity sensor array and may be suitable for certain applications.
Abstract: Accurately estimating the position and orientation is critical for the control systems of both airborne and ground-based unmanned vehicles. In many cases, GPS-derived data provides a suitable absolute measurement. Unfortunately, many unmanned vehicles may have to operate in GPS-denied environments, thus a suitable method for obtaining an absolute a...
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Transmission Line Galloping Prediction Based on Numerical Weather Prediction Results
Li Shuai,
Li Zhe,
Liang Yun,
Liu Shanfeng
Issue:
Volume 6, Issue 5, October 2018
Pages:
135-141
Received:
10 December 2018
Published:
11 December 2018
Abstract: With the expansion and extension of power grid scale, the impact of catastrophic weather on the safe operation of power grids is increasing, and strengthening the prediction and early warning of catastrophic weather processes, which have a serious impact on power grid production, can effectively improve the efficiency and ability of power grids to cope with catastrophic weather. In this paper, using multi-data source data processing technology, the monitoring data of the transmission line micro-meteorological monitoring device is applied to the refinement numerical prediction calculation to improve the accuracy of the numerical weather forecast results in Henan province, and based on this research to establish the transmission line dance Prediction model, Predict the occurrence probability of transmission line dance under different meteorological environment conditions. Through the fine regional numerical prediction system and dynamic reduction scale technology, the hourly meteorological factor forecast of 1 km resolution in Henan Province in the next 3 days is predicted, the statistical revision of the forecast field of meteorological elements around the transmission line is established, and based on this, the prediction model of transmission line dance can greatly improve the prediction accuracy of transmission line dance, To form a more precise and accurate dance prediction results, to facilitate the power sector to carry out different time scales of transmission line dance early warning work.
Abstract: With the expansion and extension of power grid scale, the impact of catastrophic weather on the safe operation of power grids is increasing, and strengthening the prediction and early warning of catastrophic weather processes, which have a serious impact on power grid production, can effectively improve the efficiency and ability of power grids to ...
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