Issue link: https://resources.mouser.com/i/1313794
11 Qorvo 2020 Table 3 802.11n modulation and data rates for single stream streams into parallel independent channels. Channels operating with a width of 40MHz, doubles the channel width and provides twice the PHY data rate over a single 20MHz channel. 802.11n draft allows up to 4 spatial streams with a maximum theoretical throughput of 600Mbps. 20MHz channels have 56 OFDM subcarriers, 52 are data and 4 are pilot tones with a carrier separation of 312.5kHz. Each of these subcarriers can be a BPSK, QPSK, 16QAM or 64QAM. Total symbol duration is 3.6µSec or 4µSec, which includes a guard interval of 0.4µSec or 0.8µSec, respectively. Table 3 lists different modulation and coding schemes for a single stream (for multiple streams, the data rate is multiple of number of streams). 802.11n supports frame aggregation where multiple MAC service data units (MSDUs) or MAC protocol data units (MPDUs) are packed together to reduce the overheads and average them over multiple frames, thereby increasing the user level data rate. Also, 802.11n is backward compatible with 802.11g, 11b and 11a.[3] Qorvo has been a leading provider of 802.11n components, including power amplifiers, low noise amplifiers, switches, and integrated front-end modules (FEMs). 802.11ac Standard 802.11ac revved-up Wi-Fi by providing gigabit speeds per second and this is achieved by extending the 802.11n concepts,which include wider bandwidth (up to 160MHz), more MIMO spatial streams (up to 8), downlink multi-user MIMO (up to four clients) and high-density modulation (up to 256QAM). 802.11ac supports 256QAM at 3/4, 5/6 coding rate (MCS8/9) that required 6dB tougher system level EVM (-34dB) requirements. Qorvo 11ac components were able to easily satisfy those EVM requirements. 802.11ac works exclusively in the 5GHz band, so dual-band access points and clients will continue to use 802.11n at 2.4GHz. The first wave of 802.11ac released in 2013 supported only 80MHz channels and up to three spatial streams delivering up to 1300Mbps at physical layer. Second wave products, or 802.11ac wave 2 products, were released in 2015, support more channel bonding, more spatial streams and MU- MIMO. MU-MIMO is a significant advancement of 802.11ac. While MIMO directs multiple streams to a single user, MU-MIMO can direct spatial streams to multiple clients simultaneously, thus improving network efficiency. Also, 802.11ac uses a technology called beamforming. With beamforming, the antenna basically transmits the radio signals so they are directed at a specific device. 802.11ac routers are backwards compatible with 802.11b, 11g, 11a and 11n, which means all the legacy clients work fine with 802.11ac router.