I usually plug my HTC Desire to the computer USB to charge during day time and plug it to the AC adapter in the night. And I also carry this Eneloop battery if I need to charge while I’m out. Found some free time on my hand wanted to see how these three perform. So I basically drained the battery completely until the phone shuts down itself and then plug it to the power source. I tried to keep the conditions same for 2 hours of charging, starting from 0% charge. Here are the results: Connected to computer USB: Eneloop battery: AC adapter: Using computer USB and the Eneloop battery both...

First of all, kudos to Amazon for making Kindle available on almost all platforms. There still is no version available for Linux. A little ironic considering the fact that Kindle is based on Linux. But importantly they have an Android version. Many developers embrace iOS but still tend to overlook Android, but Amazon has made a full fledged version for Android too. Now to the features. Sync across multiple platforms – I use Kindle on iPad while at home and use it on my Android when I’m outside. I read to a certain page on the iPad, close the app, then sometime later open Kindle on my...

The internet is overwhelmed with iPhone vs. Android articles. This is post too is an iPhone vs. Android, but I will list up some  other (possibly minor) features which I found out myself. I haven’t used an iPhone, but I have used an iPod Touch since its’ first generation and my two of my immediate family members use iPhones. So I believe that I qualify to pass a judgment on the iPhone compared to Android (HTC Desire in my case). So here goes why I. wont. use. an. iPhone. Freedom – People, mostly iPhone users, chuckle when mentioning about the freedom Android gives. It’s sort...

First things first. I am not a Apple fanboy. Far from it. I am not trying to promote any Apple products but as a student, in this little time I had the iPad with me, what I can say is, I wish I had this couple years earlier. People claim iPad is just a big iPhone. I have not used an iPhone but I have used a first generation iPod Touch since it first came out. Since iPad cannot make any calls, I think it’s fair to say iPad is a big iPod Touch. For me atleast, it isn’t. iPad is ‘magical’, but not for the reasons Steve Jobs is claiming, but for the productiveness it can provide....

This is an important functionality I use in my simulations but when I want it I always have to search for it because I forget the Matlab function name. There are lots of loopy ways using random numbers to get this done, but there is an in-built Matlab function you can use: randperm(n). I often need to choose a set of values from a vector. For example, randomly choosing a set of users. Random numbers cannot be used because they can give you identical numbers. Need a method that would generate different numbers. What randperm does is scrambling a sequence of numbers. For example; randperm(5) = 3 1 4 2...

For some reason I prefer Ubuntu on my iMac 27″ compared to my normal desktop. It just looks good in it. The installation is straight forward. Lucid is still alpha but it feels solid (only one more month to go anyway) and it looks good. The purple theme is gorgeous. I first installed 9.10 and then upgraded. Below I post some pics. For a detailed installation guide refer to my earlier post on the iMac here. But note that MacBook Pro installation is less troublesome, because you do NOT need to go to the safe graphics mode to install. Just hit install Ubuntu. There is a documentation you can...

This is a follow up to the Cyclic Prefix (CP) I did here. There I gave a graphical explanation and here I will discuss how it happens theoretically. I recently came across the derivation in a text [1]. So here goes. Considering an N-point FFT system, a block of data points , is to be transmitted during a symbol time. The data vector is sent to an IFFT module. The operation of the FFT, i.e. the discrete Fourier Transformation (DFT) is given by the following matrix: where denotes the -th entry in the DFT matrix . Then the transmitted data vector after the IFFT operation is. . The normalization factor ...

This column will briefly explain how cyclic prefix (CP) in OFDM works by illustration. I decided to add this topic because the I seldom found a text that simply discussed the operation of CP and its usage. First, lets define a property of Discrete Fourier Transform (DFT) : If x(n) and h(n) time-domain signals, circular convolution between them x(n) © h(n) is equivalent to multiplication in the frequency-domain, X(k).H(k). That is, if we circularly convolve two time-domain signals, it is equivalent to multiplying the respective DFT’s of the time-domain signals in the frequency-domain. Now lets...

Do you even remember this? (http://www.mylivesearch.com/). I didn’t until a moment ago when I saw a cover of a TV series and remembered about this in an eerie way. Whatever became of this, I think I can safely say this is pretty much dead. It came out back in May 2007 and more than 2 years later it is still in beta. And a Google search gives less hits than it would give on my name (Don’t believe me? try it). This came as a direct opponent to Google search. It touted to redefine the way search results are found. It complained that Google results are outdated and it will give you the most...

Linux doesn’t always enjoy the love of hardware manufacturers. But it is blessed with an enthusiastic group of engineers who make life that much easier for the rest of us. BTNX-Button Extension (http://www.ollisalonen.com/btnx/) is such application. This nifty application maps mouse buttons with any combination of keys you want. Days of 3-button mouses are gone (except for Apple who are trying to do without buttons). Mouses now come with lot more buttons now.. I never realized the usefulness of this until I got myself a Logitech MX 1100 which has 8 buttons + scroller (except the 2 dpi buttons)....