Specification for a new RF system !

[awqati]

Dear All,

With many years of Analog experience, I am trying to learn the trade of RF integrated circuit design. I am struggling somewhat with Razavi & Lee as there is little detail in understanding top-level RF architectures and specifications. Their focus is specifically on Rx/Tx designs.......

As such, I hope you can answer or at least point me in the right direction to some material that could help.

Imagine one would like to design a new RF system, from scratch, from a birds-eye-view/perspective. In this context, what factors are involved in specifying:
1. The Carrier Frequency?
2. How many channels ?
3. The data rates of those channels ?
3. Required separation between channels ?
4. Type of modulation to use ?
5 etc....

Any dummies guides would be highly appreciated !!!!!

Many Thanks in advance.

 

[RFDave]

Why don't you start with something like the GSM radio specification. That will give yo a decent starting point, and since it's reasonably documented, you can figure out why things were done.

Dave

 

[radiohead]

Download this book: it will give you a kickstart!

 

[safwatonline]

i am really a newbie in ics but here is my thoughts, may be u find them usefull

it seems that u should start with a specific standard to work on , or if u r not targeting a standard then u should chose some free band ,in the first case this should chose everything for u "carrier, number of channels,, min. SNR,,,etc",
for the 2nd case i guess u would have "Some" degree of freedom but not that much as the band is limited and there are some regulations like FCC for somethings like leakage for instance.

if u are like making ur standard , "well congrats ", but this will have to be limited by many aspects like type of data u r sending, the number of users u expect, this should say what is ur modulation scheme and BW ,, u should also put some power limits "limited by the battery",,,,u should estimate some distance limit u want ur Transceiver to work on, this might put other limits on power and min. SNR also might have some effect on BER "related also to modulation scheme used and type of data u send",,,,,then u should also see some rules from FCC like leakage and blockers ,,,,,,,,,,,,,,,,,,probably much more that i don't know.

wow this seems really big complicated job and seems need really experience Dudes for it.

 

[awqati]

Many thanks for your feedback guys.

RF DAVE,
I think thats a great idea, because i have already researched it to some degree. The problem is that i find many of the prerequisit theories difficult, and the simple introduction material too basic. Is there any comprehensive text written, in a dummies guide format, maybe with some historical background that you recommend ???

RadioHead - Link doesnt exist !!!

Safwatonline,
Type of data = digital control signals to start of with (upto max 1kHz)
= would like as many signals in parralel though ie DATA<0:9>
Number of users = 2 , one Tx one Rx
Power = Not of primary concern
Band = is NOT limited can choose entire spectrum if i want .....
Distance = 3cm

This is generally what i am looking to implement on an RF testchip. Based on the above then, what standard do you guys think i should be looking at ???

Many Thanks in advance.....

 

[radiohead]

Link does exist! be careful when copy pasting the h**p part.

 

[strennor]

try to learn some thing basic of wireless communication system, then do you RF sub system design and give the specs, then do your RF circuits based on the specs. It is a long way!

Or ask the system designers to get specs for RF blocks

 

[RFDave]

Dr. Gu's Book on RF System Design is pretty good, with a reasonable amount of detail. I've got a link here

**broken link removed**

He primarly focuses on GSM/CDMA, and has a decent amout of text. Another book that you might find useful is Dr. Rohde's book on Communications Receivers, also linked to above.

The GSM specifications are available at www.3gpp.org (I think)

You might also want to look at the web sites of Microwave Journal and Microwaves and RF Magazine. These are RF industry trade journals and then have published a large number or tutorial articles over the years on GSM.

Dave