3G MIMO describes

MIMO In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wir ...

techniques which have been considered as 3G standard techniques.

, as the state of the art of intelligent antenna (IA), improves the performance of radio systems by embedding electronics

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can b ...

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 Smart antennas (also known as adaptive array antennas, digital antenna arrays, multiple antennas and, recently, MIMO) are antenna arrays with smart signal processing algorithms used to identify spatial signal signatures such as the direction of a ...

, multiple antenna (

), self-tracking directional antenna, cooperative virtual antenna and so on.

Technology

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

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.

IA in ad hoc networking

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.

Principal Issues of Research

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

Smart antenna Smart antennas (also known as adaptive array antennas, digital antenna arrays, multiple antennas and, recently, MIMO) are antenna arrays with smart signal processing algorithms used to identify spatial signal signatures such as the direction of a ...

Digital antenna array Digital antenna array (DAA) is a smart antenna with multi channels digital beamforming, usually by using fast Fourier transform (FFT). The development and practical realization of digital antenna arrays theory started in 1962 under the guidance ...

* Multiple-input multiple-output (MIMO) *

Beamforming Beamforming or spatial filtering is a signal processing technique used in sensor arrays for directional signal transmission or reception. This is achieved by combining elements in an antenna array in such a way that signals at particular angles e ...

Diversity combining Diversity combining is the technique applied to combine the multiple received signals of a diversity reception device into a single improved signal. Various techniques Various diversity combining techniques can be distinguished: * Equal-gain co ...

Diversity scheme In telecommunications, a diversity scheme refers to a method for improving the reliability of a message signal by using two or more Channel (communications), communication channels with different characteristics. Diversity is mainly used in radio ...

Space–time code A space–time code (STC) is a method employed to improve the reliability of data transmission in wireless communication systems using multiple transmit antennas. STCs rely on transmitting multiple, redundant copies of a data stream to the ...

Spatial multiplexing Spatial multiplexing or space-division multiplexing (often abbreviated SM, SDM or SMX) is a multiplexing technique in MIMO wireless communication, fibre-optic communication and other communications technologies used to transmit independent chan ...

* Space-division multiple access (SDMA) * Advanced MIMO communications *

Multi-user MIMO Multi-user MIMO (MU-MIMO) is a set of multiple-input and multiple-output (MIMO) technologies for multipath wireless communication, in which multiple users or terminals, each radioing over one or more antennas, communicate with one another. In cont ...

Precoding Precoding is a generalization of beamforming to support multi-stream (or multi-layer) transmission in multi-antenna wireless communications. In conventional single-stream beamforming, the same signal is emitted from each of the transmit antennas ...

Dirty paper coding (DPC) In telecommunications, dirty paper coding (DPC) or Costa precoding is a technique for efficient transmission of digital data through a channel subjected to some interference known to the transmitter. The technique consists of precoding the data in ...

* Cooperative wireless communications *

Cooperative diversity Cooperative diversity is a cooperative multiple antenna technique for improving or maximising total network channel capacities for any given set of bandwidths which exploits user diversity by decoding the combined signal of the relayed signal and t ...

Principal Definitions

Definitions

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

Reference Web Sites

The following items list the web sites related to the multiple antenna research. * MARS, Bell Laboratories — ** Multiple Antenna Research and Solutions (MARS) is a research group on multiple antenna and space time coding * Lucent — ** The goal of intelligent antennas is to achieve higher capacity noting that advanced solutions provide higher capacity than basic solutions. * IMEC — ** Multiple antenna systems are the key to the high-capacity wireless universe. Indeed, they allow increasing the rate, improving the robustness, or accommodating more users in the cell. * Georgia Institute of Technology — ** A smart antenna is an array of antenna elements connected to a digital signal processor * IEC — ** A smart antenna system combines multiple antenna elements with a signal-processing capability to optimize its radiation and/or reception pattern automatically in response to the signal environment. ** Spatial division multiple access (SDMA) — Among the most sophisticated utilizations of smart antenna technology is SDMA, which employs advanced processing techniques to, in effect, locate and track fixed or mobile terminals, adaptively steering transmission signals toward users and away from interferers. * SearchMobileComputing.com — ** A smart antenna is a digital wireless communications antenna system that takes advantage of diversity effect at the source (transmitter), the destination (receiver), or both. ** MIMO is an antenna technology for wireless communications in which multiple antennas are used at both the source (transmitter) and the destination (receiver). * Smart Antennas Research Group, Stanford Univ. — ** Our research goal is to advance the state-of-the-art in the applications of multiple antennas and space-time signal processing in mobile wireless networks, and to improve network performance and economics. * CDG — ** Smart antennas provide greater capacity and performance benefits than standard antennas because they can be used to customize and fine-tune antenna coverage patterns that match the traffic conditions in a wireless network or that are better suited for complex radio frequency (RF) environments. ** MIMO employs multiple, spatially separated antennas (at both TX and RX) to take advantage of these "virtual wires" and transfer more data. * Nortel — ** MIMO is an antenna technology that is used both in transmission and receiver equipment for wireless radio communication. ** MIMO is the only advanced antenna technology that simultaneously offers high bandwidth, improved range, and high mobility at a lower cost. * Visant Strategies — ** Intelligent antennas are antenna systems that use some sort of computational or electronic resource to enhance system performance. ** According to the amounts of intelligence employed, antenna diversity represents the simplest form in the progressive complexity chain, followed by basic beamforming, which is the process of narrowing radiated energy, which is then followed by the more complex space-time processing and finally by MIMO. * Magnetic Sciences — ** Satellite tracking systems and self-steering antennas are used aboard ships, vehicles, or aircraft to maintain contact with satellites.

References

Dr. Erik Dahlman, LTE, 3G Long Term Evolution
*

External links

Smart Antennas and Related Technologies Briefing
published by Bell Labs, Lucent Technologies {{DEFAULTSORT:3G MIMO IEEE 802 Information theory Radio resource management