Video Embed Test

Just wanna try.. :D

This is the circuit I'm going to build,
From a main oscillator of frequency (f_m), a frequency divider (IC1A) supplies values of f_m/2, f_m/8, and f_m/16. Acceptable values of f_m depend on the selected CMOS technology. The circuit has been tested at f_m = 2 MHz with basic CMOS logic, and at 20 MHz with HCMOS.

Dibits are formed from a digital input (PCM signal) in shift register IC2B, and in the dual flip-flop IC3. The different phases of 0º, 90º, 180º, and 270º are produced at outputs QA, QB, QC, and QD of the four-bit shift register, IC2A.

Finally, the dibits (on pins A and B of IC4) control the multiplexer (data selector) output. This is a selected phase from D0, D1, D2, or D3, according to the dibit combinations. The rest of the circuit is a simple band-pass filter that eliminates dc levels and shapes the pulse, plus an amplifier to set the desired output level. The QPSK output frequency is f_m/8.

New Topic

My research topic about WiMAX now has changed because of something. And now I'm trying to start my new research about Power Line Communication.
This technology isn't a new technology, but it's been founded by 1920. But for that time, the communication only for KWh meter or other measurement tools. And for now this technology has been used to connect computers to worldwide web.
At this research I'll make my own modem, with my research group I'm trying to implement a telephone using power line cables.

Lapindo Mud Crisis

Java island especially East Java are sinking because of Lapindo Brantas mud crisis. For more than 10 months mud has flowed from an exploratory well near Porong, inundating 25 square kilometers, putting more than 1000 people in hospital with breathing difficulties and forcing more than 10,000 from their homes. It has cut roads, covered train lines and threatens the rail link between Jakarta and Surabaya, Indonesia's busiest port.

A police investigation has found seven Lapindo employees were suspected of criminal negligence over the drilling. An emergency cabinet meeting on Thursday night decided that all measures must be taken to protect and compensate people living in the area, safeguard basic infrastructure, preserve East Java's economy and lessen the environmental damage. Lapindo should meet all expenses, cabinet ordered.
The Geological research until now still doesn't know how to stop the mud, one way has done that is to put big balls that linked each other to the hole but it's failed to stop and even the flow debit become more and more every day. For this case, the team of research told the flow will stop normally for 30 years, but at the time the mud stop flowing the East Java Province will full of mud.
Yesterday the new flow that contain water and sands occurs not far from the main flow, and until today none has been done to stop this although the flow has reach 7 meters from the ground or it has reached 500% bigger than first time the flow found.

Love?

Love bade me welcome: yet my soul drew back,
Guilty of dust and sin.
But quick-eyed Love, observing me grow slack
From my first entrance in,
Drew nearer to me, sweetly questioning
If I lacked anything.

"A guest," I answered, "worthy to be here":
Love said, "You shall be he."
"I, the unkind, ungrateful? Ah, my dear,
I cannot look on thee."
Love took my hand, and smiling did reply,
"Who made the eyes but I?"

"Truth, Lord; but I have marred them; let my shame
Go where it doth deserve."
"And know you not," says Love, "who bore the blame?"
"My dear, then I will serve."
"You must sit down," says Love, "and taste my meat."
So I did sit and eat.

Microprocessor

One of my interest at computer technology is microprocessor development. This is also my practicum subject at University of Indonesia. As an assistant at the Lab, I must improve my knowledge about microprocessor especially Intel, Zilog, and Motorola.

Basically every microprocessor has a sub-processor like ALU (Arithmetic Logic Units), control unit, registers, and this sub-processor become more and more as this technology always improves time by time. Registers is a part that the data will be proceed, this part also known as an internal memory of microprocessor. At Intel microprocessor there is 4 kind of this registers; one is general purpose registers, stack registers, flag registers, and index registers. All of this registers has it's own specific function.

General purpose registers is some registers for general use. This register usually has it's own function such as AX is a accumulator register, BX is a Base register (used as a base address of a memory), CX is a count register (used as a counter for loop processes), DX is a data register (used as a MSB for multiply and divide processes).

Flag registers is some registers to provide the status of environment that the program executes. this register is not for storing data that will be proceed, but this register contains the status of the CPU real time. Parity, overflow, carry, auxiliary carry, etc is some of this registers

Index registers used to store the address of string data that stored on the memory. SI (Source Index contain the source address of the string data) and DI (Destination Index contain the destination address of the string data) are two kinds of this register.

Stack registers used to store data with LIFO (Last In First Out) algorithm.

WiMAX as my research..

This is my research about WiMAX.. a technology standard issued by IEEE 802.16

WiMAX (Worldwide Interoperability Microwave Access) is a wireless networking system based on the IEEE 802.16 standards family. The version 802.16-2004, published in October 2004, supports various kinds of network topology. One of topology is called PMP (Point-To-Multipoint).

Within this topology every Mobile Station (MS) communicate directly via Base Station (BS). The second topology is denoted MESH. In this mode, two MSs communicate without employment of BS. The 802.16-2004 does not support handovers between cells. Consequently, 802.16-2004 allows only a fixed or nomadic access. Handover procedures are implemented in newest version of 802.16e,standardized in September of 2005. This version specifies handovers for portability and simple or full mobility of users.

WiMAX uses OFDM for it's modulation which is known as the best modulation method for a wireless access networking, but it's very complicated, so it is my problem to continue my research. I'm stuck here!

My point is to know about QoS of this WiMAX and try to simulate the system with software MATLAB 7.0.4 (simulink).