Estudo comparativo entre WiFi 802.11 N e 802.11 AC, em relação as técnicas de modulação utilizada e fluxos espaciais MIMO

Abstract

Faced with the need of enhancements in wireless data transmissions and with the increase in broadband access by the population, the standard WI-FI were evolving in order to achieve higher data transmission rates and ensure systems more robust to multipath fading channel, being the latest standards 802.11n and 802.11ac. These standards look to optimize the use of the magnetic spectrum through modulation techniques (64-QAM,256-QAM), transmission mode OFDM and use of multiple antennas transmitting and receiving (MIMO).The objective of this study is to compare these standards WI-fI through modulation techniques used, relating the probability of bit error (BER) on the signal to noise ratio (SNR), and obtain comparisons through spatial streams MIMO, comparing the BER on the number of samples in relation to different quantities of antennas transmitting and receiving. With this, it is possible to demonstrate the superiority of standard ac, reaching high data rates up to 6.9 Gbps, obtaining a better spectral efficiency in channel.