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Finding a Good Research Topic

Miscellaneous, Reference 4 Comments »

A student from China recently asked me about how I got interested in relay selection and started obtaining (publishable) results. Since I have some free time on my hands now, I figured I’d share some thoughts on this topic.

I actually don’t think that the way I got interested in relay selection was the ideal strategy in terms of “finding a good research topic.” Instead, I’ll discuss what I think is a better way of “finding a good research topic.” Note that the following is especially relevant for graduate students researching wireless communications (for the obvious reasons).

It’s fairly common for a new graduate student to be overwhelmed by the plethora of potential research topics. When I was starting work on my masters degree, I wanted to do research involving some aspect of wireless networks, since I felt (wrongly, as it turned out) that all of the good point-to-point problems had already been solved. During the summer of 2004, I worked on beamforming for MIMO ad hoc networks, but that ended up being a major dead end. On a related note, I recently perused my research notebook and found that during January 2006, I was interested in cooperative diversity for OFDM networks (my, how things have changed).

This brings up the key question: how should a new graduate student sort through the morass of potential research topics and come up with a good one? I’ll discuss two potential answers.

One approach is to have your advisor answer this question for you, assuming that you have an advisor. In general, you can assume that your advisor has a strong grasp of the current state of research in wireless communications. This knowledge can help him/her determine a topic for you that is 1) interesting, so you won’t be bored stiff for approximately 5 years and 2) worthy of a Ph.D. dissertation, so you will have made a fundamental contribution of some sort by the time you graduate.

The second approach, which I highly recommend, is to take the initiative. To start off, you should do a significant amount of reading. Survey articles in journals such as the IEEE Communications Magazine and the IEEE Signal Processing Magazine can be valuable starting points for the interested yet relatively inexperienced grad student.

A particularly well-written survey article can provide the reader with a good grasp of “what’s been done” on a topic such as “OFDMA power allocation for relay-based networks” and suggest various open problems that are both interesting and important. When reading through these survey articles, one should also scan the list of references to learn about the key papers (and researchers, so you can bookmark their home pages) in a particular area.

It’s then important to read through these key papers to grasp the nuances of the topic that you’re learning about and ask yourself tough questions along the way. For example, do you understand the (technical) paper that you’re reading? Can you justify all of the authors’ assumptions? Can you re-derive every expression (especially the proofs of key theorems) in the paper? I should note that sometimes papers contain typos/gross errors, so you shouldn’t automatically trust everything you read.

If you want to answer these questions in the affirmative, this is a great opportunity for building your technical background. For example, let’s say that the authors are studying a MIMO wireless system and assume that a two-ring scattering model is being employed. If you don’t know what a two-ring scattering model is, you should obtain a copy of a MIMO textbook such as this one by Paulraj et al. and learn more about channel modeling.

Also, let’s say that you’re reading through this famous paper by Gupta and Kumar, and you’re having trouble deriving some (or all, as this paper is actually quite tricky to understand) of the key results. In this case, you might want to strengthen your graph theory background by taking an appropriate class, such as this one at UT-Austin. You might also want to improve your knowledge of random geometry, and you can check your university library for a helpful book such as this one by Bollobas for more coverage of this advanced topic.

As you read through the key technical papers in the area that you’re learning about, you should think of additional open problems and ask yourself more tough questions. For example, you can ponder something like, “the authors’ assumption of a zero-error feedback channel seems a bit restrictive. From my other reading it’s clear that introducing a channel estimation error at the transmitter would better model a practical system. Maybe I can’t obtain an exact expression for the sum capacity given channel estimation errors, since that seems quite complicated, but can I obtain relatively tight bounds?”

Regardless of the approach that you take in terms of finding a good research topic, it’s crucial that you interact with your advisor during this process. Your advisor, who has worked in either the general area that you’re considering or a related area, can help you determine if the open problem you’re considering is either trivial, worthy of multiple dissertations, or actually reasonable for a dissertation. Note that by adopting the second approach I discussed above, your ability to have meaningful dialogue with your advisor during this process is enhanced. In particular, you can evaluate your advisor’s suggestions and converge on a reasonable topic more quickly; this is especially important if your advisor has not worked in the general area that you’re considering.

That’s all I had to say on this subject, at least for now. I welcome comments, especially from my group-mates on this issue of “finding a good research topic.”

Forms for Graduation

WSIL Private 1 Comment »

Chan-Byoung’s recent flurry of blog activity has inspired me to emerge from blogging hibernation.

Many of us wonder what forms need to be signed in order for us to graduate. We’ve heard stories about the “green sheet,” the “gold sheet,” the “pink sheet” and even the mysterious “white sheet.” What, exactly, are these various forms?

I can now say with some certainty that the mysterious “white sheet” is the “Report of ECE Ph.D. Qualifying Exam Committee.” Your qualifying exam committee chair fills out this form and signs it at the bottom. The highlights of this form include: 1) a list of the qualifying exam committee members and 2) the committee’s recommendation (including the dreaded “Other” option).

As for the “green,” “gold” and “pink” sheets, stay tuned (perhaps Kaibin’s defense will shed some light on this).

Adobe Acrobat Fun

WSIL News & Views 2 Comments »

Today I came across an interesting feature in Adobe Acrobat. In the View menu, check out the Read Out Loud option. Try it with some Trans IT papers and see what happens…

Perhaps Robert could record the MIMO song for us!

Grad Student Guide

WSIL News & Views 1 Comment »

Chan-Byoung made a good post on this topic a while back, and I think we should have some discussion of this based on this guide that I’ve started reading recently.

One of my initial observations is that each student should assume most of the responsibility of “being a good graduate student,” but that the advisor should help the student to some extent in this regard. If I had been proactive enough to look for these online guides two (or even four) years ago, hmmm…

Robert, do you have any thoughts on this?

Wearing Suits…Yes or No?

WSIL News & Views 2 Comments »

I suppose I will inaugurate the blog for 2007. Here’s a link to an interesting blog post by Mark Cuban on why he doesn’t wear suits.

Personally I used to really dislike wearing suits, but now I find them to be tolerable. Perhaps we should adopt a compromise solution…dispose of “business formal” attire and only require “business casual” attire.

This reminds me of my experience at Globecom 2004 in Dallas, where I saw one presenter give a talk wearing a hooded sweatshirt, jeans and sneakers.

A Blogging Mulligan

Reference 2 Comments »

Given that my first post was a disaster of sorts, I’ll see if I can get things right this time.

Today was the Motorola SABA visit day and some of us presented posters. My poster consisted of one large 40″x30″ sheet of paper; I used a different WNCG template than the standard 9-slide approach.

Several people (including Robert) wanted to know how I got that to work. You can ask Lori for this template (or I can e-mail it to the group if there is sufficient interest). After making your poster (and saving it in an accessible location), go to the HP Studio Classroom2 in ECJ and log into any computer using your ENGR account. There, you want to use the HP DesignJet 755 CM Color Plotter (you may have to search for this printer and add it). After selecting your preferred paper size and the print quality, you can let the plotter go to work.

Note that the paper size that the plotter uses is much larger than the WNCG posterboard. Also, each of us has a print quota of 1000 pages per semester and each page printed on the plotter is worth 10 pages for the quota. In addition, make sure to roll up your poster after the plotter finishes up to avoid creasing it (you can look at my SABA poster to see how not to transport your poster from ECJ to ENS).

Robert brought up a good point about this template; since everything comes out on one big piece of paper, you don’t have to force 9 slides onto this template. Instead, you have the freedom to experiment and be creative…

I recommend trying this approach when you have the chance (the WNCG Board Meeting and/or the Texas Wireless Summit would be good opportunities).

Thanks to Prof. Vishwanath and Wei Wu for this “big poster” idea.