Qualcomm once again this week waved its MU-MIMO (Multiuser MIMO) WiFi implementation and repeated its claim that this can support speeds up to three times faster than those of “traditional” WiFi. WiFi’s performance is so situation-specific that it is notoriously hard to back up claims in the real world, and some other WiFi players have urged us to ignore MU-MIMO, saying that it is only of real benefit in high density environments like stadiums. But Qualcomm is sticking to its guns, a year after it first launched the capability, and insists that this is twice as fast as SU-MIMO most of the time, and three times faster some of the time. The actual new announcements from Qualcomm Atheros were twofold…