Dear all, I am urgently cramming for a course report... I need to write a report on Space Time Coding in 2-3 days... Can anybody recommend some good tutorials and notes on this topic? Consider my poor math, I hope the tutorial/notes will be understandable in a few days... Thanks a lot, -Walala
please recommend good understandable space time coding tutorial/notes?
Started by ●December 2, 2003
Reply by ●December 2, 20032003-12-02
On Mon, 1 Dec 2003, walala wrote:> Dear all, > > I am urgently cramming for a course report... I need to write a report on > Space Time Coding in 2-3 days... Can anybody recommend some good tutorials > and notes on this topic? Consider my poor math, I hope the tutorial/notes > will be understandable in a few days... > > Thanks a lot, > > -Walala >i know about books, but, space-time trellis codes are based on the idea of taking cardinal products of contellations of multiple antennas and applying trellis codes on this new set of constellations. the tarokh paper is quite good on how one should optimize the performance. space-time layered codes are based on interference cancellation. examples are the variants of bell labs' codes. space-time block codes are based on design theory, specifically orthogonal arrays. again, the tarokh paper is quite good, although i may be biased. there is newer work by jafarkhani, and also by fitz, on combining block codes and trellis codes. the main idea is that one can consider the block codes as a map to the space of multiple antennas, so at the end one can apply trellis codes again. so i would say that you should start with trellis codes first, because the other ones are easier to understand once you are familiar with trellis codes. hope that helps, julius -- The most rigorous proofs will be shown by vigorous handwaving. http://www.mit.edu/~kusuma opinion of author is not necessarily of the institute
Reply by ●December 3, 20032003-12-03
On Tue, 2 Dec 2003 09:19:29 -0500, Julius Kusuma <kusuma@mit.edu> wrote:>so i would say that you should start with trellis codes first, because the >other ones are easier to understand once you are familiar with trellis >codes.Julius, Really good comments I felt. I havn't known also where I need to go for first starting to learn this topic. Now, I'll go back to trellis papers, e.g. your space-time coding paper I saw before. By the way, I heard that he is worry about too complex mathmatical descriptions since he don't have much time to do his work. If this fact is really true, rather than to start somehow complex algorithms like trellis codes, I suggest for you to start first STTD (space-time block code) being for just two antenna also called Alamouti code, and next, its extentions for more than two antennas, which are easily founded in 3GPP website as TR25.869. BR, ------ James K. (txdiversity@hotmail.com) - Any remarks, proposal and/or indicator would be greatly respected. - Private opinions: These are not the opinions from my affiliation. [Home] http://home.naver.com/txdiversity
Reply by ●December 3, 20032003-12-03
On Wed, 3 Dec 2003, James K. wrote: [snip]> By the way, I heard that he is worry about too complex mathmatical > descriptions since he don't have much time to do his work. If this > fact is really true, rather than to start somehow complex algorithms > like trellis codes, I suggest for you to start first STTD (space-time > block code) being for just two antenna also called Alamouti code, and > next, its extentions for more than two antennas, which are easily > founded in 3GPP website as TR25.869. > > BR, > ------ > James K. (txdiversity@hotmail.com)james, i am not an expert on space-time coding, but as far as i know, extensions of space-time block codes to the case of more than 2 antennas is based on design theory, which is quite mathematical. on the other hand, space-time trellis codes are based on ungerboeck's (or some would say forney's) framework on using cosets. thus it is somewhat easier to extend to the case of more than two antennas. it just depends on your ability to draw cardinal products of constellations of multiple antennas. with respect to trellis codes, the best reference is the book by divsalar et.al., unfortunately a bit hard to find, which is non-mathematical and very intuitive. to be honest i find it very hard to read standards, plus standards tend to give methods, but don't say why. maybe you've had much more luck with standards than i have! julius -- The most rigorous proofs will be shown by vigorous handwaving. http://www.mit.edu/~kusuma opinion of author is not necessarily of the institute
Reply by ●December 6, 20032003-12-06
On Wed, 3 Dec 2003 10:11:30 -0500, Julius Kusuma <kusuma@mit.edu> wrote:> [snip]After Alamouti codes, people are interested in that area to extend such a space-time code for more than two antennas. To do this, we have some points to be considered before to start the development of this idea. I now want to descried these points in two subpart: one of them is by putting my idea on your last comment, the other is regarding to the fundamental characteristics of the space-time code.>to be honest i find it very hard to read standards, plus standards tend to >give methods, but don't say why. maybe you've had much more luck with >standards than i have!First, about your comments. The fact that you (Julius) pointed above, seems correct with very 100% on my consideration, which, frankly speaking, I forgot at that moment. As you said, up to my experience, people in the standard don't have much interested in mentioning the technical reason for the proposed method. Only a few of them appended the details, but usually briefer than in a paper, to their Tdocs. Second, about the fundamental characteristics of the space-time code, designing new space-time codes, we should consider below: 1. Pure block code for more than 2 antennas provides additional diversity gain, but, effective gains from more than two-order diversity is a very little. (In addition, it was proved that full rank transmission is not possible to send information through more than two antennas). 2. Because of the fact told in the number 1, we can add the coding gain by considering addition of trellis in the conventional two-order diversity, which scheme was noted by Julis in his previous article. 3. One another way to prevent such a fact, to combine some beam-forming feature to the open-loop system. Using both features in a same time, we will take the pros from both systems with little overhead. In brief, I also seconded on Jullis opinion that in standard, not many times to provide in detail reason for reader's technical understanding. Only a part of technical information are founded in the TR (Technical report), like TR25.869 (Tx Diversity) in 3GPP, are nearly not founded in TS (Specification). Additionally, some points to be considered the designing of extended the space time block code were discussed very shortly.
Reply by ●December 6, 20032003-12-06
On Sun, 07 Dec 2003 00:33:57 +0900, James K. <txdiversity@hotmail.com> wrote: (I just revised to this for better understanding, and easy to read.) On Wed, 3 Dec 2003 10:11:30 -0500, Julius Kusuma <kusuma@mit.edu> wrote: Since the Alamouti code was developed, it has been interesting to many researchers for both its good performance and simplicity, and some codes have been considered to extend this code for more than two Tx antennas because the original code was proposed only for two Tx antennas. Regarding to the extended codes, it has been widely announced that we have some facts to be taken into account when developing them. In next two parts, I now describe two issues: one is my answer to the previous comment, and the other is about the fundamental characteristics of the space time code being used as an extended version of Alamouti code.> [snip] >to be honest i find it very hard to read standards, plus standards tend to >give methods, but don't say why. maybe you've had much more luck with >standards than i have!The fact dictated previously by Julius is really true, even on my experience; frankly speaking, at that moment I forgot it for a while. As you said, it seems like that people in the standard are not much interested in mentioning the technical reason for their proposed method. Only a few of them appended the details, but usually briefer than explained in the conference paper, to their Tdocs. Second, I summarize some issues being accounted as fundamental characteristics when designing new extended space time codes: 1. A pure block code for more than 2 antennas provides additional diversity gain, but this gain is not effective as much as gain from the two-order diversity. In addition, it was proved that full rank transmission is not possible to send information through more than two antennas, especially when information are modulated in complex constellation. 2. To resolve the problem in (1), we can combine trellis code into block code and, hence add the coding gain, instead of adding possible full diversity. In the previous article, Julius also said that it has been one of the interesting areas. 3. One another way is to combine some beam-forming feature to it. By combining both features in a same time, we can take both advantages of two schemes, and just with little overhead. In brief, I seconded on Julius opinion that in the documentations of the Standard, not many times it is provided of the detail reason to help reader's technical understanding. Indeed, a little technical information are founded only in the TR (Technical report), e.g. TR25.869 (Tx Diversity), but are not found nearly in TS (Specification). Additionally, some facts being considered when designing the extended space time block code were discussed in very short.
Reply by ●December 7, 20032003-12-07
When consider space time code, I would like talk about hassibi's linear dispersion code. I think it provide a broader scheme to design. Also it is easy to understand. I don't know if I understand it well. However, I think it is a good ideas though we have much things to do to improve it. How do you think about it?
Reply by ●December 8, 20032003-12-08
On Sun, 07 Dec 2003 00:33:57 +0900, James K. <txdiversity@hotmail.com> wrote:>On Wed, 3 Dec 2003 10:11:30 -0500, Julius Kusuma <kusuma@mit.edu> >wrote:>>to be honest i find it very hard to read standards, plus standards tend to >>give methods, but don't say why. maybe you've had much more luck with >>standards than i have!>First, about your comments. The fact that you (Julius) pointed above, >seems correct with very 100% on my consideration, which, frankly >speaking, I forgot at that moment. As you said, up to my experience, >people in the standard don't have much interested in mentioning the >technical reason for the proposed method. Only a few of them appended >the details, but usually briefer than in a paper, to their Tdocs.It is not the job of a standard document to explain why something was standardized, only what the standard is. Sometimes they don't even do that well, but they're often confusing enough just trying to that that sometimes I think it's a good thing that they don't do any more than that. Many standards do contain informative (in addition to the normative) text if is deemed warranted or necessary for someone to properly interpret the intent of what is being standardized. Some standards bodies (like the IEEE) maintain the documentation trail of the "why" part of it, but having gone through that a few times it is extremely tedious. Capturing "why" something got in the standard can often involve years of debate and sorting through several candidate technologies across many companies, etc., etc. Trust me on this one, we really don't want standards to capture why something appears in the standard, only that it does.>Second, about the fundamental characteristics of the space-time code, >designing new space-time codes, we should consider below: >1. Pure block code for more than 2 antennas provides additional >diversity gain, but, effective gains from more than two-order >diversity is a very little.That's true. Adding diversity, any kind of diversity, provides diminishing returns after a point. Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org
Reply by ●December 8, 20032003-12-08
eric.jacobsen@delete.ieee.org (Eric Jacobsen) wrote in message news:<3fd3fd08.181933640@news.west.earthlink.net>...> Capturing "why" something got in the standard can often > involve years of debate and sorting through several candidate > technologies across many companies, etc., etc. Trust me on this one, > we really don't want standards to capture why something appears in the > standard, only that it does.During a session on one of the first acoustics conferences I went to, an anecdote was told about why some acoustics standard ended up like it did. Apparently, two "hotshots" in acoustics, (sorry, I don't remember the names, except one of the debattants was either Bruhl or Kj�r, founder of the Danish acoustics company. I suspect the other part was Sabine, who was an early authority on room acoustics), or even the subject under debate. The deabattants had quarreled over this question to be standardized for ages, they held incompatible views, and everybody else were utterly fed up about it since no one could do any measurements or build any measurment equipment until a standard was established. The matter was setteled during some conference when the two guys were locked into a room and told that they were not let out of there until they had agreed on a standard. And thus the standard was established. Perhaps somebody out there know what this was all about, and can fill in the details? Rune
Reply by ●December 8, 20032003-12-08
Rune Allnor wrote:> eric.jacobsen@delete.ieee.org (Eric Jacobsen) wrote in message news:<3fd3fd08.181933640@news.west.earthlink.net>... > >>Capturing "why" something got in the standard can often >>involve years of debate and sorting through several candidate >>technologies across many companies, etc., etc. Trust me on this one, >>we really don't want standards to capture why something appears in the >>standard, only that it does. > > > During a session on one of the first acoustics conferences I went to, an > anecdote was told about why some acoustics standard ended up like it did. > > Apparently, two "hotshots" in acoustics, (sorry, I don't remember the > names, except one of the debattants was either Bruhl or Kj�r, founder > of the Danish acoustics company. I suspect the other part was Sabine, > who was an early authority on room acoustics), or even the subject under > debate. The deabattants had quarreled over this question to be standardized > for ages, they held incompatible views, and everybody else were utterly > fed up about it since no one could do any measurements or build any > measurment equipment until a standard was established. > > The matter was setteled during some conference when the two guys were > locked into a room and told that they were not let out of there until > they had agreed on a standard. And thus the standard was established. > > Perhaps somebody out there know what this was all about, and can fill > in the details? > > RuneIt sounds like the choosing of a pope. The story goes that long ago, the College of Cardinals would meet in a convenient town and harangue there until the local food was exhausted, then move on to another. After the entire countryside was denuded -- sometimes after more than a year -- they would somehow manage to agree on one candidate. When they reached one cathedral city -- Sienna? -- early in one selection process, irreverent townspeople locked them into the cathedral, allowing no one in or out until a pope was chosen. The cardinals were provided with two kinds of fuel; one made black smoke, the other, white. White smoke signaled that a pope had been elected, and the doors were unbarred. The practice has become a tradition, and electing a new pope has seldom taken long since then. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
