Need help with Telemetry/ Data transmission thru FM or FSK

I'm constructing a telemetry ckt that relays temperature data wirelessly thru rf. My professor suggested FSK or FM, but i'm not sure how to go about it. Can anyone help me with the nessary data/schematics and tell me the book(s) that might be useful in this regard. Thx in advance..

Re: Need help with Telemetry/ Data transmission thru FM or

Check out if you can use "el-cheapo" 433MHz RF modules ..

Cost: less than $10/pair ..

Regards,
IanP

Re: Need help with Telemetry/ Data transmission

I dont think i'm supposed to use a prefabricated(ready made) solution. I'm supposed to build one myself.. could u help me wid a ckt/schematic?

Re: Need help with Telemetry/ Data transmission thru FM or

check communication system engineering by roody and coolen

hi nerdspot i am working on ( design and implementaion of telemetry system for enviromental measurements ) itz my project i have finished up the design and i am implementing it i suggest u to use TWS-433 it costs only 4$ and i advice u to use the compatible ic with it this is my email i hope we can share info
mr_anderson101010@yahoo.com

Re: Need help with Telemetry/ Data transmission thru FM or

An easy way for FSK modulation is to inject the data into the PLL loop filter. The data must be scrambled (DC free, no long strings of 1 or 0) and you can do this with 4B5B encoding, manchetser encoding, or a PRN code.

There are some fractional-N PLLs that lock fast enough so the divider registers can be toggled to produce FSK so you can go down to DC, but the data slicer on the RX side will still be AC coupled so you'll still need scrambling.

For receiving I'd use one of the FSK receiver ICs that has built in mixer, limiters, discriminator, and data slicer. Of course you'll need a PLL too for the recieve LO, and a micro-controller to do clock recovery and de-scrambling.

All this can be done in FPGAs too but that would be wasted resources wasted on FSK.