Transmitter and receiving unit

Hi there,

For my final year project, i am required to do a transmitting and receiving device.


How it works :
The transmitter is worn on the user's wrist, the receiving unit will be connected to blinking LEDs.

When the user wearing the transmitter goes near the receiving unit, it will send signal to the receiving unit, therefore causing the LEDS to blink. The range between the transmitter and receiver is 0-25m.

The problem i faced was, i found out the distance was too short, any idea how could i increase the range of the device?



Thanks in advance. =)

25m is tough with any reasonable sized battery.

What frequency are you using?
What type of receiver?

Maybe it is meters? Have you thought about using IR?