From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

3G MIMO describes MIMO techniques which have been considered as 3G standard techniques.

MIMO, as the state of the art of Intelligent antenna (IA), improves the performance of radio systems by embedding electronics intelligence into the spatial processing unit. Spatial processing includes spatial precoding at the transmitter and spatial postcoding at the receiver, which are dual each other from information signal processing theoretic point of view. Intelligent antenna is technology which represents smart antenna, multiple antenna (MIMO), self-tracking directional antenna, cooperative virtual antenna and so on.


Spatial precoding of intelligent antenna includes spatial beamforming and spatial coding. In wireless communications, spatial precoding has been developing for high reliability, high rate and lower interference as shown in the following table.

Summary of 3G MIMO[edit]

The table summarizes the history of 3G MIMO techniques candidated for 3G standards. Although the table additionally contains the future part but the contents are not clearly filled out since the future is not precisely predictable.

Generation 3G 3G evolution Beyond 3G Future
Deployment 2003/4 2005~6/2007~8/2009~10 2012~2015 2015~2020
Standard WCDMA HSPA/HSPA+/LTE IMT-Advanced Beyond IMT-Adv
Total rate 384kbit/s 14/42/65~250Mbit/s 1Gbit/s >10Gbit/s
Bandwidth 5 MHz 5 MHz/20 MHz 20~100 MHz >100 MHz
Requirement Paradigm High reliability (High quality) High rate (High capacity) Lower interference High intelligence
Method Spatial diversity Spatial multiplexing Spatial cancellation Ambient intelligence
Spatial coding (SC) Spatial diversity coding Spatial multiplexing coding Spatial cancellation coding Ambient intelligence coding
Spatial beamforming (SB) Single-stream beamforming Multi-stream beamforming Interference nulling beamforming Ambient intelligence beamforming
Examples SC: Alamouti coding, SB: TxAA SC: BLAST coding, SB: SVD SC: DPC, SB: MU-BF Such as cooperative MIMO

IA in ad hoc networking[edit]

IA technology enables client terminals, which have either multiple antennas or a self-tracking directional antenna, to communicate to each other with as high as possible signal-to-interference-and-noise ratio (SINR). Assume that there is a source terminal, a destination terminal, and some candidate interference terminals. Compared to conventional approaches, an advanced IA based terminal will perform spatial precoding (spatial beamforming and/or spatial coding) not only to enhance the signal power at the destination terminal but also to diminish the interfering power at interference terminals. As a human does, the advanced IA terminal is given to know that occurring high interference to other terminals will eventually degrade the performance of the associated wireless network.


Intelligent antenna (IA) vs. Cognitive radio (CR)[edit]

However, it requires intelligent multiple or cooperative antenna array. On the contrary, cognitive radio (CR) allows user terminals to sense the other service usage of spectrum beans to share the spectrum among users, which is so, cognitive spectrum sharing technology. The following table compares the different points between two approach for future wireless systems: Intelligent antenna (IA) vs. Cognitive radio (CR).

Point Intelligence antenna (IA) Cognitive radio (CR)
Interference processing Cancellation by spatial pre/post-coding Avoidance by spectrum sensing
Key cost Multiple or cooperative antenna arrays Spectrum sensing and multi-band RF
Solution Intelligent spatial beamforming/coding tech Cognitive spectrum management tech
Application Ambient Spatial Reuse Open Spectrum Sharing
Applied theory Dirty paper and Wyner-Ziv coding (DP-WZ coding) Software radio and cognition
Summary Intelligent spectrum reuse technology Cognitive spectrum sharing technology

Fundamental concepts and theories[edit]

  • Intelligence is a property of mind that includes many related abilities.
  • Cooperation is the practice of social elements working in common, instead of working individually.
  • Cognition can be interpreted as understanding and responding to the world.
  • Ambient intelligence (AmI) refers to artificial environments that responses to the movement of people, the paradigm of which builds upon Ubiquitous computing.
  • Wireless ubiquitous computing (WUC) is post-desktop computing where information processing is integrated into anytime and anywhere human activities.
  • Game theory is a mathematical theory that studies the strategic interaction between players, which are usually organized into a friend group and an enemy group.

Principal Issues of Research[edit]

The following items list the issues of the multiple antenna research aims to improve the performance of radio communications.

Principal Definitions[edit]


Here are the definition of principal keywords to clarify the objective and the operations of intelligent antenna.

Terminology Definition
Intelligent antenna Antenna technology that uses some sort of electronic intelligence to enhance wireless system performance. Electronic intelligence is implemented by spatial pre/post-coding techniques such as spatial information coding and spatial signal beamforming. Notice that smart antenna has been more widely used to represent the similar meaning.
Smart antenna In the narrow sense, antenna technology that employs array antennas with beamforming techniques to enhance wireless system performance. In the wide sense, equivalent terminology to intelligent antenna.
MIMO Wide sense and well-known: MIMO is the state of the art of IA and SA.
  • Narrow sense: Antenna systems that employ multiple antennas at both the transmitter and the receiver.

Reference Web Sites[edit]

The following items list the web sites related to the multiple antenna research.

Types Antenna configuration Basic solution Advanced solution
Diversity d > wavelength Rx: MRC, MMSE, etc., Tx: STTD, CLTD BLAST (spatial multiplexing)
Phased Array d < wavelength Switched beams Steered beams

See also[edit]


  • Dr. Erik Dahlman, LTE, 3G Long Term Evolution
  • "The WINNER II Air Interface: Refined Spatial-Temporal Processing Solutions" (PDF). WINNER II. 30 Nov 2006. Archived from the original (PDF) on 2009-07-30. Retrieved 2008-09-06.

External links[edit]