====== Antenna Diversity ======

There's a wide variety of how transmit and receive diversity is implemented on various Atheros wireless chips.

===== Overview =====

  * [[dev/ath_hal(4)/AntennaDiversityOverview|An overview of antenna diversity]]
  * [[dev/ath_hal(4)/AntennaDiversityWhatChips|Which chips support which types of diversity]]

===== Implementation =====

  * [[dev/ath_hal(4)/SwitchTableBasics|How the external antenna switch tables work]]
  * [[dev/ath_hal(4)/ClassicDiversity|Classic transmit and (fast) receive diversity using an external antenna switch]]
  * [[dev/ath_hal(4)/LnaDiversity|Diversity using LNA mixing]]
  * [[dev/ath_hal(4)/SlowMimoDiversity|Using an external antenna switch on a MIMO device to add transmit/receive antennas]]
  * [[dev/ath_hal(4)/SectoredAntennas|How the sectored antenna support works]]
  * [[dev/ath_hal(4)/ShiftRegisterDiversity|Using the shift register for antenna diversity on 11n parts]]

===== Programming, Monitoring, Diagnostics =====

  * [[dev/ath_hal(4)/AntennaDiversityAR5212|Antenna Diversity on the AR5212 and related 802.11abg NICs]]
  * [[dev/ath_hal(4)/AntennaDiversityAR5416Slow|(Slow) External Antenna Switch Diversity on the AR5416 and later 802.11n chips]]
  * [[dev/ath_hal(4)/AntennaDiversityAR9285|LNA, Bluetooth and External Antenna Switch Diversity on the AR9285]]
  * [[dev/ath_hal(4)/AntennaDiversityAR9287Bluetooth|External and Bluetooth Antenna Switch Diversity on the AR9287 + Bluetooth Combo NICs]]
  * [[dev/ath_hal(4)/AntennaDiversityAntShiftReg|Using the per-descriptor TX antenna shift register on the AR5416 and later hardware]]

===== More information =====

  * https://en.wikipedia.org/wiki/Diversity_combining
  * https://en.wikipedia.org/wiki/MIMO
  * https://en.wikipedia.org/wiki/Maximal-ratio_combining
  * https://en.wikipedia.org/wiki/Space-time_block_code