i just want to know how to make relation between router interface clock rate and QPSK symbol capacity...mean to say if i am having router which is not wireless and if i want to send data in wireless form and i am having QPSK converter and having transmitter on both the end so at that time how we can consider clockrate with the QPSK capacity...
There really is no relationship. What you'll see is a device (like a radio transceiver) that will do a certain amount of bandwidth over the wireless link,
On the other side of our hypothetical "black box" transceiver, you'll get some flavor of standard interface; either an Ethernet/Fast Ethernet/Gig Ethernet or (a little closer to your question) a standard serial interface that'll probably be presented on a v.35 / Winchester connector.
That interface will (probably) be a DCE interface (or maybe several), just like a CSU/DSU (because it probably is that or something similar).
The "black box" will do the signal conversion from serial / V.35 into whatever signaling it uses to make the wireless transmisssion.
In the case of a traditional microwave radio, it was fairly common for them to handle up to three DS3s (45 Mbps each).
So what I'd expect is that if you had a radio system that could handle ~2 Mbps, you'd probably have a single V.35 interface that'd handle a T1/DS1 or E1.
If you had a radio that could handle 1.2 Gig of data wirelessly, then I'd expect a GigE inerface, or perhaps one or more OC3, or an OC12.
There are a variety of wireless systems in practically all bandwidth sizes, on just about any chunk of the RF spectrum, up to and including light (LASER - see the Canon Cannobeam).
Once the wireless bandwidth is deterined, then the router-side interface will be appropriate for that kind of bandwidth.