Just as Broadcom, Marvell and MediaTek-owned Ralink all unveiled 4×4 Multiuser MIMO (MU-MIMO) WiFi chips at the CES event last week, Qualcomm and Quantenna smugly demonstrated the advantages of coming to market a year earlier. As their rivals showed new chips, the early movers were able to boast actual devices from customers committed to deploying their MU-MIMO technologies this year. This is a David and Goliath fight at the front, with tiny start-up Quantenna, heavily focused on WiFi broadcast, up against Qualcomm Atheros. Qualcomm showed off design wins at Amped Wireless, Buffalo, D-Link, NEC, TP-Link, TrendNet and Xiaomi, all of which have committed to using the technology. Meanwhile, Broadcom finally showed its hand with a chip based around a different…