FSK OR BPSK, which one is better

hi

I want to do RF communication. Basically i want to sent the data at 9.8kbps to a PC (RS-232 interface). I have two options, either to do FSK or BPSK (digital modulation). I want to know that which one is better and why ?. Which one has better signal to noise ratio.

thanks in advance

The PSK will have 3 dB better performance at the cost of more complex receivers. The reason for the 3 dB is that FSK is orthogonal and PSK is antipodal. This may not mean much to you but the distance between the two signal points is 1.414 times larger for PSK.

FSK IC's are readily available for designated frequency bands and are easy to interface with a microcontroller, e.g. hxxp://www.melexis.com.

Best regards.

Use FSK for making your system power effecient.
If bandwidth effeciency is the main criteria of consideration, use BPSK.