Low Power Free Space Optical Communication

This paper is the first to introduce me to a simple physical design of FSO. Describe design and implementation of optical comercial component electronics. The design based on the problems that arise in the use of FSO .

This paper can explain more detail. File Size: 388 KB.

Low Power Free Space Optical Communication in Wireless Sensor Networks Click Here

Found on IEEE explore website

So, Information about this paper according my understanding is

1) Author Name : 

James Mathews, Matthew Barnes and D. K. Arvind

2) Title Of Paper : 

Low Power Free Space Optical Communication in Wireless Sensor Networks

3) Source : 

2009 12th Euromicro Conference on Digital System Design / Architectures, Methods and Tools

4) Summary Of Reported Research :

In this paper, explain about how to design FSO transceiver ( Transmitter and Receiver ).

In Transmitter side,  link using an optical emittier to produce the transmission at a carrier

frequency and a controller to modulate the baseband data for transmission.

In Receiver side an optical detector use to receive the carrier signal, analog circuit use to

recover modulated data from the received signal 

and then digital signal processor to demodulate the received data and perform packet recovery.

The importan result from this paper is

>> Both of receiver and transmitter design with commercial available component. But coverage distance only 10 - 15 meter. Is to short than RF communication.

>> In case of power consumption, in 3 Volt supply and 2 KHz frequency carrier, Idle current around 30.1μA, and active receive current arround  42.2μA . In transmiter side, transmit current arround 100 μA. This is explain that FSO more eficient energy than RF communication. 

As shown in the table below

>> In case of data rate, The maximum data rate of the optical link is limited by the response of the optical components. The data rate of the transceiver implementation was limited by the components selected to maintain current consumption below the 100μA budget, it is not possible to work with high data rate.

>> In case of beam divergence, FSO should guarantee LOS communication. LASER have low beam difergence. The solution of this problem is to expand the surface of the detector receiver. It bad idea because physical size of receiver become larger. Best solution is using transmitter with wider beam divergence. It gave new parameters namely axial and lateral coverage. Placement of node sensor which using FSO communication should consider this aspect.

5) Strength Of Invention:

FSO more eficient energy than RF communication.

6) Weakness :

Design Transceiver is using analog design wich more complex and difficult to analyze. coverage distance only 10 - 15 meter. Is to short than RF communication.

7) Limitation:

This paper propose physical design of FSO communication consider comercial component availability. With several parameter to observed. That is Data Rate, Sensitivity, Power Consumption, Coverage distance ( axial and lateral coverage ).