CDMA, WCDMA, and LTE

CDMA (Code Division)
===================================
- RSCP: Received Signal Code Power


WCDMA (Code Division)
===================================
- RSCP: Received Signal Code Power
 http://en.wikipedia.org/wiki/RSCP

LTE (OFDM)
===================================
- RSRP: Received Signal Reference Power
- OFDM: Orthogonal Frequency Division Multiplexing
 http://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiplexing

Why is 44.1 kHz sampling in CD or digital music file (mp3 or wma, ...)?

Currently famous digital music file use 44.1 kHz sampling rate.

As you know, 

- Normal human being can hear 20 Hz ~ 20,000 Hz sound.

- And from the Nyquist sampling theorem, 

---------------------------------------------------------------------

 The Nyquist sampling theorem provides a prescription for the nominal sampling interval required to avoid aliasing. It may be stated simply as follows:

 The sampling frequency should be at least twice the highest frequency contained in the signal.Or in mathematical terms:

     fs >= 2 * fc

(http://redwood.berkeley.edu/bruno/npb261/aliasing.pdf)

In this reason, in the digital music need only 40 kHz sampling rate.

Why is 44.1 kHz sampling rate used in the world?
It is based on Video Tape,
1. http://www.cs.columbia.edu/~hgs/audio/44.1.html
2.http://en.wikipedia.org/wiki/44,100_Hz 

Kconfig: help or ---help--- ?

From the http://kernel.org/doc/Documentation/kbuild/kconfig-language.txt

- help text: "help" or "---help---"   This defines a help text. The end of the help text is determined by   the indentation level, this means it ends at the first line which has   a smaller indentation than the first line of the help text.   "---help---" and "help" do not differ in behaviour, "---help---" is   used to help visually separate configuration logic from help within   the file as an aid to developers.

Android - Hotplug Off (Multi-Core enable)

If your device has root permission

adb shell stop mpdecision

adb shell "echo 1 > /sys/devices/system/cpu/cpu1/online"

or

# stop mpdecision

# echo 1 > /sys/devices/system/cpu/cpu1/online

# ...

xda - developers

http://forum.xda-developers.com/showthread.php?t=1216197

update 1/31

Support for hot-pluggable CPUs

CONFIG_HOTPLUG_CPU=y

or # CONFIG_HOTPLUG_CPU is not set

http://cateee.net/lkddb/web-lkddb/HOTPLUG_CPU.html

Enable bootchart in the Android

In the Android source code

STEP 1. ----------

In the device side

1. enable bootchart flag

$ export INIT_BOOTCHART=true

2. and build the Android source code

3. After flashing binary

$ adb shell

$ mkdir /data/bootchart

$ echo 60 > /data/bootchart-start

(It means that bootchart log will be saved until 60 seconds)

$ exit

(exit adb)

4. reboot device

$ adb reboot

You can find some log files in the /data/bootchart/ directory

Tip.

- You can find "bootchart.c & bootchart.h" under the ../init/ directory.

- In the same directory there is a Android.mk file.

INIT_BOOTCHART is used in this make file.

STEP 2. ----------

In the linux system side

install bootchart

$ sudo apt-get install bootchart

STEP 3. ----------

after getting bootchart log files

1. copy log files from the Android device to Linux system

$ adb push /data/bootchart/.

2. compress the all log files

$ tar -czf bootchart.tgt *

3. run bootchart

$ bootchart bootchart.tgz

$ ls

bootchart.png bootchart.tgz

* If you meet the error message,

" ZeroDivisionError: flat division by zero"

Please refer to below site: Error while extracting bootchart.tgz and patch the script files.

Kernel: Linux / Windows

- Monolithic Kernel vs Micro Kernel

http://www.vmars.tuwien.ac.at/courses/akti12/journal/04ss/article_04ss_Roch.pdf

http://en.wikipedia.org/wiki/Kernel_(computing)

http://linuxhelp.blogspot.com/2006/05/monolithic-kernel-vs-microkernel-which.html

- Korean

http://blog.naver.com/PostView.nhn?blogId=sdc4697&logNo=140103690630&redirect=Dlog&widgetTypeCall=true

http://recipes.egloos.com/5365126

http://itislord.tistory.com/tag/%EB%AA%A8%EB%86%80%EB%A6%AC%EB%94%95%20%EC%BB%A4%EB%84%90%28Monolithic%29

- Windows

http://www.driveronline.org/bbs/view.asp?tb=systembbs&GotoPage=1&s_bulu=&s_key=&no=24

http://keon.egloos.com/5202360

http://www.osnews.com/story/22501/Microsoft_Kernel_Engineers_Talk_About_Windows_7_s_Kernel

- Kernel comparision Linux vs Windows

http://widefox.pbworks.com/w/page/8042308/Kernel%20Comparison%20Linux%20vs%20Windows

http://widefox.pbworks.com/w/page/8042290/Architecture

http://jnux.tistory.com/entry/%EC%8A%A4%ED%81%AC%EB%9E%A9-%EB%AA%A8%EB%B0%94%EC%9D%BC-%ED%94%8C%EB%9E%AB%ED%8F%BC%EA%B3%BC-%EB%AA%A8%EB%B0%94%EC%9D%BC-OS%EC%9D%98-%EC%B0%A8%EC%9D%B4

http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=%EC%9C%88%EB%8F%84%EC%9A%B0+%EC%BB%A4%EB%84%90%EA%B3%BC+%EB%A6%AC%EB%88%85%EC%8A%A4+%EC%BB%A4%EB%84%90%EC%9D%98+%EC%B0%A8%EC%9D%B4

OneNand, iNand, and MobiNand

Korean

http://search.naver.com/search.naver?where=nexearch&query=%EC%95%84%EC%9D%B4%EB%82%B8%EB%93%9C+%EB%AA%A8%EB%B9%84%EB%82%B8%EB%93%9C&x=0&y=0&sm=top_hty&fbm=0&ie=utf8

http://gall.dcinside.com/list.php?id=smartphone&no=1437467

1. MLC (Multi Level Cell) / SLC (Single Level Cell)

http://www.navinside.com/bbs/zboard.php?id=forum_istation&no=3359

1.1 MLC type: MoviNand and iNand (same type)

1.2 SLC type: OneNand

2.1 Diff. between MoviNand and iNand

http://people.sarang.net/?document_srl=1104294

http://blog.naver.com/PostView.nhn?blogId=mercurian21&logNo=30047740523

자양이네 (ps3, 타블렛, 리눅스, 안드로이드)

갤럭시s의 oneNAND, moviNAND의 포맷및 파티션 변경

http://blog.naver.com/dowkim10?Redirect=Log&logNo=120119813742

갤럭시 s의 파티션 및 파일 시스템 (rfs/ext2/ext3/ext4)

http://blog.naver.com/dowkim10?Redirect=Log&logNo=120119813742

Samsung Galaxy S Series

http://forum.xda-developers.com/wiki/index.php?title=Samsung_Galaxy_S_Series

RFS

http://www.samsung.com/global/business/semiconductor/products/fusionmemory/Products_RFS_Brochure.html

http://movitool.ntd.homelinux.org/trac/movitool/wiki/RFS

http://www.samsungmomentforum.com/samsung-moment-rooting/bml151617-yaffs2!/