Multipath estimation problem

We have some measurements, they are slightly noisy but lets assume noise free for now. Lets also assume the measured signal is the output from a LTI system:

y(t) = a_0 p(t) + a_1 p(t-tau_1)

Here are two versions the problem statement:

P1) Estimate (a_0, a_1, tau_1, p(t)) that best explains y(t) in a least-squares sense

P2) Simpler problem: Lets say I have a model for p(t) that it is of some form (say it is the step-response of a B Hz low pass filter). Then estimate (a_0, a_1, tau_1) assuming p(t) is sort of known.

Not so interested in recovering p(t) -- its more like a unknown nuisance parameter.

Hint (maybe not): constraints on p(t) may be easier to impose in the frequency domain

Checklist for scientific (LaTeX) papers

1. Run spell check

2. Make sure all figures have axes labeled, captions, symbols are consistent with those that appear in the text

3. Make sure references are correctly appearing: especially note capitalization of acronyms. Use {} to get capitals in bibtex title entries.

4. Try to get rid of (embellishing) words like: obviously, basically, actually, really,etc.

5. Make sure equations and text use \mathrm{} for math symbols more than a single letter. Use mathmode for all mathematical variables. Don't use unslanted Roman for single letter symbols, unless really intended.

6. Make sure every equation line has a punctuation at the end

7. Be careful when there is a blank line after an equation, since it starts a new paragraph.

8. Figure sizes should be uniform and appropriate

9. All acronyms are expanded at least once in the paper

10. Make sure title of paper and keywords capture all the aspects of the work concisely and effectively

11. Choose a consistent capitalization scheme (for title, sections, headings, etc.)

12.

--

NOTE: checklist is still in development, suggestions are welcome

installation steps for N810 dev environment maemo

This information can be found at http://maemo.org/.

MAEMO - software dev. environment for the nokia internet tablet which runs a Linux-based operating system on ARM architecture. Basically these are cross-compilation tools that run on a PC environment (Ubuntu or Debian).

1. Install Debian on a spare computer
http://www.debian.org/

2. Install scratchbox as root using script from http://tablets-dev.nokia.com/4.0.1 (seems latest stable version is 4.0.1)
chmod a+x ./maemo-scratchbox-install_4.0.1.sh
./maemo-scratchbox-install_4.0.1.sh

create user account for scratchbox

3. Install SDK (I used debug + complete environment) using non-root account
./maemo-sdk-install_4.0.1.sh

4. Install Nokia binaries if not already done

5. Install Xephyr as root by running at terminal
apt-get install xserver-xephyr

DONE.

Low power wlan devices

Who makes WLAN chips that go into cell-phone/smart-phone? A search leads to some information:

1) Atheros AR6002 (Oct 2007)
- 70 percent less power than competitive solutions on the market in active mode while downloading content
* 100 hours to deplete a standard 3.7V, 800mAh phone battery in continual VoIP mode
* 200 gigabytes of data can be downloaded before depleting the same battery
- Near-Zero Power in Standby (6 µW)
http://www.atheros.com/news/AR6002.htm

2) Broadcom BCM4326 (Oct 2006)
- single-chip 802.11Wi-Fi transceivers and radios with an innovative software architecture that drastically reduces the Wi-Fi subsystem's total power consumption
- exceptional power performance that enables a 54Mbps full-rate active receive power consumption of less than 270 mW
- system battery life enhanced through combination of complete on-chip driver control and other sophisticated software capabilities
http://www.broadcom.com/press/release.php?id=919562

3) ST Microelectonics STLC4550 (Apr 2006)
- 30µW sleep mode
http://www.stmicroelectronic.com/stonline/stappl/cms/press/news/year2006/p2020.htm


Comments:
As the deployment of WiFi increases, it will be adopted in more mobile devices to enable better coverage and also different business models and applications. As a result, I would think
a) the market for wifi chips will grow (and maybe follow the trend of cellphone chips)
b) the winner will likely be the low-energy candidate (assuming all other things are equal)