(Multiple Input/Multiple Output) Pronounced "my-mo," it is the use of multiple transmitters and receivers (multiple antennas) on wireless devices for improved performance. When two transmitters and two or more receivers are used, two simultaneous data streams can be sent, which double the data rate. Multiple receivers alone allow greater distances between devices. The IEEE 802.11n wireless standard, expected in 2009, uses MIMO to increase maximum speed to 100 Mbps and beyond, double the 802.11a and 11g wireless standards.
MIMO, MISO and SIMO
Following are the advantages of using multiple antennas rather than one. The terminology is "M" for multiple, "S" for single, "I" for input and "O" for output; however, the inputs and outputs relate to the air, not the device. This is a peculiar notation; nevertheless, multiple inputs (MI) means multiple transmitters are sending multiple data streams "into" the air. Multiple outputs (MO) means multiple receivers are receiving multiple data streams "out of" the air. See 802.11n, antenna diversity, beamforming and HSPA.
MIMO Wireless Router
This \"Pre-N\" wireless router from Belkin uses two transmitters and three receivers to provide 108 Mbps between its access point and Belkin Pre-N cards in laptops. Introduced in 2004, this was the first \"Preliminary-802.11n\" system on the market (see 802.11n). (Image courtesy of Belkin Corporation, www.belkin.com)
MIMO, MISO and SIMO
Following are the advantages of using multiple antennas rather than one. The terminology is "M" for multiple, "S" for single, "I" for input and "O" for output; however, the inputs and outputs relate to the air, not the device. This is a peculiar notation; nevertheless, multiple inputs (MI) means multiple transmitters are sending multiple data streams "into" the air. Multiple outputs (MO) means multiple receivers are receiving multiple data streams "out of" the air. See 802.11n, antenna diversity, beamforming and HSPA.
ARCHITECTURE AND ADVANTAGES OF
MULTIPLE ANTENNA TECHNOLOGIES
Compared to
Single Antenna
Technologies
Transmit Receive Data
Type Antennas Antennas Rate Distance
MIMO Multiple Multiple Greater Greater range
MISO Multiple Single Same Same range but
More Reliable
SIMO Single Multiple Same Greater range
MIMO Wireless Router
This \"Pre-N\" wireless router from Belkin uses two transmitters and three receivers to provide 108 Mbps between its access point and Belkin Pre-N cards in laptops. Introduced in 2004, this was the first \"Preliminary-802.11n\" system on the market (see 802.11n). (Image courtesy of Belkin Corporation, www.belkin.com)
 | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2009 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- Throughput and Capacity of MIMO WiMAX
- The work in this paper presents physical layer throughput measurement results of a WiMAX link implemented according to IEEE 802.16-2004. The measurements were carried out in an alpine and an urban scenario using the Vienna MIMO Testbed. The paper compares the measured throughput to three different theoretical bounds: the channel...
- White papers 2009-11-04
- Gadget Gal's daily deals: Dell sale, Belkin wireless router, Logitech Mac keyboard
- A sale on Dell computers, a Belkin wireless router, and a Logitech keyboard for Mac. Here are your daily deals for Thursday, September 10, straight from the Gadget Gal: 1. Dell has started it's Signature Event, and there's six days left to catch some deals. For example,...
- Blog posts 2009-09-10
- Mimo UM-720S
- If the Nanovision Mimo UM-720S had a much lower price point, I'd be willing to recommend it. As it stands at $230, it's simply not worth it. The 7-inch minidisplay that act as an ancillary screen to your main screen, has narrow viewing angles, a confusing setup process, and a...
- Product reviews 2009-08-31
- Shots: Mimo UM-720S
- A few closeups pics of the Mimo UM-720S. by CNET News.com
- Image galleries 2009-08-25
- On the Mobile Wireless Access Via MIMO Relays
- While a network with stationary nodes can provide large capacity in many current wireless systems, a network with mobile users suffers from severe performance degradation. This happens due to quick channel variation and its resulting protocol overheads that are especially large for multiuser Multiple-Input Multiple-Output MIMO systems. This paper proposes...
- White papers 2009-07-21
- Palm Golfwits 2.0 (Mobile)
- Every Golfwits application, from the Palm to the desktop version, uses the exact same user-friendly interface. Golfwits uses our exclusive MIMO (Minimum Input, Maximum Output) technology. Record ball position, distance, shot shape, and club used for every shot with just three taps on the screen or clicks of the mouse....
- Software downloads 2009-07-08
- MIMO: From Theory to Reality
- Driven by the even growing demand of higher data rate with the scarce spectrum resource, the theoretical breakthrough has been made and demonstrated significant increase on channel capacity spectral efficiency over MIMO systems. The theoretical MIMO spectral efficiency is verified by MIMO channel measurements and trial systems. Two MIMO mechanisms...
- White papers 2009-07-01
- A WiMAX-Based Implementation of Network MIMO for Indoor Wireless Systems
- It is well known that Multiple-Input Multiple-Output MIMO techniques can bring numerous benefits, such as higher spectral efficiency, to point-to-point wireless links. More recently, there has been interest in extending MIMO concepts to multiuser wireless systems. The focus in this paper is on network MIMO, a family of techniques whereby...
- White papers 2009-07-01
- The MIMOWA Project: A Step Towards the Real Implementation of MIMO Techniques in Future Wireless Systems
- Multiple-Input Multiple-Output MIMO is a radio antenna technology which employs multiple antennas at both transmitter and receiver ends, and provides new enhancements and potentials in communication systems. Under the framework of the MEDEA+ program, the MIMOWA project has two main objectives. First, it aims at the definition, design, and demonstration...
- White papers 2009-05-15
- The wireless escapades: the inevitable journey into frustration
- The wireless escapades: the inevitable journey into frustrationThere is another solution...This isn't a problem I have due to living in a 2 bed flat, but my folks had the same issue when I lived there or rather I did and the way I got round it was using two wireless...
- Discussion threads 2009-05-11
- Low-power 802.11n coming to next-gen Apple iPhone, iPod touch
- Wireless radio component specifications contained within beta distributions of iPhone 3.0 firmware reveal support for a new chip enabling low power 802.11n that's bound for Apple's third-generation iPod touch, and by extension, the next iPhone. AppleInsider is reporting that the version of the...
- Blog posts 2009-04-06
- Mobile Wireless Access Via MIMO Relays
- While a network with stationary nodes can provide large capacity in many current wireless systems, a network with mobile users suffers from severe performance degradation. This happens due to quick channel variation and its resulting protocol overheads that are especially large for multiuser Multiple-Input Multiple-Output MIMO systems. This paper proposes...
- White papers 2009-02-11
- Mimo UM-740 monitor
- Editors' note: The Mimo UM-740 is an accessory and therefore was not put through CNET's usual rigorous monitor testing. Its performance rating should not be compared with other CNET-reviewed monitors.It's not a monitor for everyone. It's definitely not for hardcore gamers. If you use Microsoft Word a lot or are...
- Product reviews 2009-02-09
- Novel Tap-Wise LMMSE Channel Estimation for MIMO W-CDMA
- In this paper, a tap-wise LMMSE channel estimator for MIMO W-CDMA is derived. Descrambling operations applied to delayed versions of the received signal whiten the input signal. The descrambling process thus breaks up the full channel autocorrelation matrix including spatial and temporal correlation into several independent, small autocorrelation matrices that...
- White papers 2008-12-09
- The Business of WiMAX: Impact of Technology, Architecture & Spectrum on the WiMAX Business Case
- The advent of next generation, wireless broadband platforms pairing performance with favorable economics is ushering in a new age of unprecedented connectivity in communities across a diverse range of global markets. Mobile WiMAX, based on the IEEE 802.16e-2005 global standard, leads the evolution roadmap with market ready solutions leveraging the...
- White papers 2008-11-11
- New Wi-Fi chipsets promise up to 2x throughput of current 802.11n devices
- A couple of weeks ago I did a post on the Home Theater blog about Celeno Communications' wireless chip that the company claims can support four different HD streams simultaneously. Now another company has announced its own Wi-Fi technology that promises significant performance improvement over the 802.11n spec. Quantenna's QHS...
- Blog posts 2008-10-14
- Downlink Performance Analysis of Full-Rate STCs in 2×2 MIMO WiMAX Systems
- MIMO techniques play a key role in the current wireless specifications including IEEE 802.11n, IEEE 802.16e, and LTE. Indeed, Spatial Multiplexing SM and Alamouti code are already in use in WiMAX systems based on IEEE 802.16e specifications. But more efficient full-diversity full-rate codes, such as Golden code, are still under...
- White papers 2008-10-12
- Performance Enhancement of WLAN Using 802.11n and MIMO Technology
- 802.11n is IEEE wireless standards that significantly improve throughput and range of Wireless Local Area Networks WLAN compared with other 802.11 standards. It is expected to provide a throughput of over 100 Mbps, which is twice that of 802.11g. This difference is because it is designed to operate in both...
- White papers 2008-10-04
- MIMO Channel Sounder at 3.5 GHz: Application to WiMAX System
- The use of antenna arrays at emission and reception seems to represent a prominent solution for future wireless systems, it improves data rates and enhances the quality of service. The performance of these systems depends mainly on the propagation channel. Therefore, channel's characterization and modeling are crucial. This paper presents...
- White papers 2008-10-01
- MiMo 1 (Windows)
- The MiMo Money In Money Out application is a personal finance application for home use only. Unlimited incoming/expenses categories and accounts are supported. Many different reports are available to display the incomes/expenses data. Current three languages are supported: English, German, and Greek. This version is the first release on CNET...
- Software downloads 2008-09-10
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