RF hero MIMO converts multipath to good


By now you have probably heard about 802.11ac which boasts data rates up to 1.3 Gbps.  If you haven’t I imagine you know about 802.11n.  So what makes these IEEE standards so good?  Well for one thing the “N” standard introduced Multiple Input/Multiple Output or MIMO.  Now hold that thought for a moment…

Back in the days prior to 2009 we had this ugly problem called Multipath.  To an RF signal there are many forces of evil working against successful transmission.  Reflection (RF Energy bounces off a smooth surface predictably), Diffraction (waves bend around sharp objects), and Scattering (RF Energy reflecting off the texture of a varied surface like stucco);  these are just some of the nefarious foes RF faces daily. Multipath is how RF energy waves react when parts of the wireless transmission meet at the antenna with differences in time and geometry.  Back in the beginning of the millennium multipath was a problem that was addressed by using antenna diversity.

If there was really a superhero called MIMO it would be Dr. Greg Raleigh.  The Qualcomm innovator was responsible for the development of MIMO which Qualcomm defines as follows: “MIMO systems divide a data stream into multiple unique streams to take advantage of multipath signal reflections to actually improve radio transmission performance.”  So when MIMO combines with other enhancements like TXBF, STBC, and SGI we see data rates really sky rocket.  To find out more about 802.11n and 802.11ac follow the links below.










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