DSSS problem

Hi all,
I’ve working with GNU-Radio for a couple of months doing different
modulations and coding related work.
My problem now is that i’m trying to implement DSSS, fist simulated and
then OTA with USRPn210. I’ve done almost the whole system but i’m having
problems with the chip rate.
The thing is that i don’t know how to set two different rates: one for
bits and one for the chips, without facing a two clock problem.
How can i separate each bit of a file source in order to operate an XOR
with each chip of my spreading sequence (Barker’s sequence form 802.11b)
which obviously has a higher rate that my original data.
Any thoughts, ideas or suggestions are welcome.