- Many antennas
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Many antennas,[1] is a smart antenna technique, which overcomes the performance limitation of single user multiple-input multiple-output (MIMO) techniques. In cellular communication, the maximum number of considered antennas for downlink is 2 and 4 to support 3GPP Long Term Evolution (LTE} and IMT Advanced 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 space-division multiple access (SDMA) engine: multi-user MIMO, network MIMO, coordinate multi-point transmission (COMP) (Cooperative diversity), remote radio equipments (RRE).
- New beam-forming: linear beam-forming such as MF, ZF and MMSE and non-linear beam-forming (precoding) such as Tomlinson-Harashima precoding (THP), vector perturbation (VP), and Dirty paper coding (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 beam-forming.
- Multiple air interfaces: single chip antenna array for an energy efficient short-range transmission.
History 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.
Standards WCDMA HSDPA LTE IMT Advanced Deployment 2003 2006 2012 2015 Peak rate (bit/s) 384 k 14 M 100–320 M 1 G Bandwidth (MHz) 5 5 20 40–100 Tx antennas in a macro-cell 2 2 2–4 4–8 Paradigm Reliability Data rate Peak rate Average rate Spatial processing Spatial diversity: circuit Spatial diversity: packet Spatial multiplexing (2–4) Spatial division (2–4) References
- ^ Hassibi, B. Hochwald, B. Shokrollahi, A. Sweldens, W. (2000). "Codes for differential signaling with many antennas". Wireless Communications and Networking Conference, 2000. WCNC. 2000 IEEE.
See also
- Dynamic single frequency networks (dsfn)
- Spatial multiplexing
- Antenna diversity
- Single-frequency network (sfn)
- Space–time code
- Space–time block code
- Beamforming
- Precoding
- Dirty paper coding (DPC)
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