- Many Antenna
Many Antennas is a
smart antenna technique, which overcomes the performance limitation of single userMIMO techniques. In cellular communications, the number of the maximum considered antennas for downlink is 2 and 4 to support LTE and IMT-A requirements, respectively. Since the available spectrum band will probably limited while the requirement of data rate will continuously increase in beyond IMT-A to support the mobile multimedia services, it is highly probable that the number of transmit antennas at the base station must be increased up to 8 ~ 64 or more. The installation of many antennas at single base stations can have many challenges so it requires to develop several high technologies: new SDMA engine, new beamforming algorithm and new antenna array.* New SDMA engine:
MU-MIMO , Network MIMO, Coordinate multi-point transmission (COMP), Remote radio equipments (RRE)
* New beamforming: linear beamforming such as MF, ZF and MMSE and nonlinear beamforming such as THP, VP, and DPC
* New antenna array: direct, remote and wireless antenna array
** Direct antenna array: linear and 3d phased array, new structure array, and dynamic antenna array
** Remote and wireless antenna array: distributed antenna array and cooperative beamforming
* Multiple air interfaces: single chip antenna array for a energy efficient short-range transmissionHistory of multiple antennas in cellular communications
The table summarizes the recent history of multiple antenna techniques in cellular communications. The table includes the future prediction as well for IMT-A and beyond.
See also
*
Spatial multiplexing
*Antenna diversity
*Space–time code
*Space–time block code
*Beamforming
*Precoding
*Dirty paper coding (DPC)
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