Improvement of data transfer confidence in MIMO systems

DOI: 10.31673/2412-9070.2019.055054

Abstract

Ways to expand the signal spectrum are considered: frequency division of channels, time division of channels and code division of channels. The structure of MIMO technology and the statistical characteristics of the MIMO channel are investigated. Investigation of empirical radio wave propagation models and their use for predicting radio propagation losses on WiMAX and LTE networks. The method allowed to determine the estimated magnitude of losses in the speed of information transmission when changing the characteristics of the propagation path of radio waves. A feature of the proposed method of estimating the quality of the communication channel with intentional interference is the dependence of the accuracy of the estimates on the quality of the real communication channel (signal/interference ratio): at a sufficiently high probability of making erroneous decisions, there may be a shift in the obtained estimates and, as a consequence, a decrease in the control accuracy channel quality. The simulation analysis showed that with the increase in the number of antennas, space-time coding allows to overcome the negative impact of spatial correlation due to the spatial spacing of the emitted signal vectors, thus providing redundancy in space and time. Therefore, an increase in the number of transmitting antennas contributes to an increase in the reliability of information transmission in the radio system. Thus, the simulation allows the design of point-to-point and point-to-point networks using AirMax technology. The transmission speed of the link will be 75 Mbps in one direction. This network can be further developed by installing new client devices without changing the overall structure of the network.

Keywords: efficiency; bandwidth; modulation; MIMO; LTE; multiple access; coding; diversity; SIMO; OFDMA; model; communication channel; power.

References
1. Современные беспроводные сети: состояние и перспективы развития / И. А. Гепко, В. Ф. Олейник, Ю. Д. Чайка [и др.]: под ред. В. Ф. Олейник. Київ, ЕКМО, 2009. 672 с.
2. Sesia S., Toufik I., Baker M. LTE – The UMTS Long Term Evoluton. From Theory to Practice // West Sussex: John Wiley & Sons, 2009. 626 p.
3. Holma H., Toskala A. HSDPA/HSUPA for UMTS: High Speed Radio Access for Mobile Communications // New York: John Wiley & Sons,2006. 268 p.
4. Alamouti S. Space-time block coding // IEEE Journal on Selected Areas in Communications. 2008. Vol. 16. P. 1451–1458.
5. Abe T., Tomisato S., Matsumoto T. A MIMO turbo equaliser for frequency selective channels with unknown interference // IEEE Transactions on Vehicular Technology. 2003. Vol. 52 (3). P. 476–482.