Talk:Multiple-input multiple-output communications

From Wikipedia, the free encyclopedia

I have reverted this article to the original form. MIMO can be a system analysis or a signal processing technique. The original article talked about the signal processing technique but the redirection pointed to the signal analysis. I think this way is better. I posted a comment in the Signal analysis page without response. --Ncc1701zzz 11:33, 15 Apr 2005 (UTC)

Why is:

"Other new enhancements will include the arrival of 802.11e and 802.11i. 802.11e will prioritize important information on the network (i.e. a voice message takes precedence over email or a webpage). 802.11i will give an increase in security by using WPA2."

in there? It has nothing to do with MIMO.

Can somebody add something more for MIMO. ??

This following paragraph sounds like a cheap plug for Airgo and Raleigh:

"In 1996, Greg Raleigh and Gerard J. Foschini invented new approaches to MIMO which increased its efficiency. Greg Raleigh is the founder of Airgo Networks, which claims to be the inventor of MIMO OFDM, offering a "pre-N" chipset called "True MIMOTM". However, it is unlikely that hardware based on this chipset will be compatible with other devices once the 802.11n standard is ratified."

I agree that Foschini was very influential in MIMO early development. Raleigh's name doesn't belong in this context and neither does Airgo Networks. Has Wikipedia become a place for cheap advertisement?

A FAQ link should be added to external links. Have both devices be MIMO to have an increase in throughput or just having a MIMO base station is enough?

Answer: MIMO is a characteristic of the radio channel, thus both the radios must have multiple antennas in ordr to be ture MIMO.

Contents 1 Title 2 250Mbit real troughput is more than 10 times higher 3 Removing some of the 802.11n stuff 4 This MIMO page needs a major revision

[edit] Title

MIMO has at least two meanings in Electrical Engineering: MIMO Control and MIMO Communications. Avoiding ambiguity is much more important than avoiding the abreviations. This page is about MIMO Communications and the current title is a wrong title for it. The title should be MIMO Communications orMultiple-Antenna Communications. Bidabadi 00:34, 7 March 2006 (UTC)

Call it something like Multiple-input multiple-output (communications) instead, then. This is more in keeping with how we usually name such articles. You'll also need to make Multiple-input multiple-output (disambiguation) and link there to the two articles you referenced on my talk page. Do they both exist? -Splash^talk 00:41, 7 March 2006 (UTC)

[edit] 250Mbit real troughput is more than 10 times higher

250Mbit real troughput is more than 10 times higher than classic 802.11g with its real 25Mbit. For SuperG (40MBit) it is more than 6 times higher. And, speaking of Atheros past expectations for SuperG technology (up to 70MBit theoretical maximum, unapproved) it is just about 3.5 times higher. 802.11 article says the expected maximum is 540Mbit, while manufacturers state it's 650Mbit or 12x speed of 802.11g (in wich they mean higher than 10 times of real 802.11g, and wich is definitely not true as we've seen in previous standard's evolution). That statement definitely needs more approval or is arguable. --GrAndrew 06:39, 4 June 2006 (UTC)

[edit] Removing some of the 802.11n stuff

I removed alot of 802.11n discussions since MIMO is much more than just 802.11n. I also statrted to edit the encoding of MIMO where a general approach was taken with linear precoding. We can continue to add decoding algorithms and different precoders etc

You did put it somewhere else, right? It doens't need to removed the encyclopedia wholesale. -Splash - tk 15:19, 14 June 2006 (UTC)

[edit] This MIMO page needs a major revision

As the suggestion above states, we need to focus less on 802.lln (that has its own entry) and more on MIMO theory. We need to differentiate MIMO from Smart Antennas. What does everyone think about the following outline:

Introduction

how MIMO is exactly defined and how it differs from simple smart antennas

Early research on possibilities

for example Winters and Paulraj

Early Capacity Results

for example Teletar

Diversity techniques and space time codes

Spatial Multiplexing

MIMO technology in the past, present and future

what has and will be built in real systems

References

Obviously this is just a first draft, later we can include tradeoffs between diversity/multiplexing, linear dispersion codes, MIMO receivers, etc.Rcd247 05:46, 12 July 2006 (UTC)

This is certainly a classical approach to MIMO writing. One could 'easily' write a textbook or, in my case, an entire thesis on MIMO, though, so I think the challenge is in not doing that, and working out what actually needs to go in each of those sections in this article, and what can be spun out to more detailed articles. The stuff you leave to later is a set of good candidates for their own articles. On the other hand, I already wrote space-time code and its subsidiary articles (to varying depths e.g. space-time block code). Splash - tk 16:23, 9 November 2006 (UTC)

http://ieeexplore.ieee.org/iel5/49/26726/01192168.pdf states that Winters was not the first to suggest MIMO would increase capacity

Actually, on page 283 the authors say "However, to our knowledge, the first results hinting at the capacity gains of MIMO were published by Winters in [8]". Splash - tk 16:23, 9 November 2006 (UTC)