modulation scheme for transmitting CDMA signal

I want to trasmit a baseband signal with 1kbps data rate using CDMA technique.
Transmission need to be done at 4GHz.
If I choose chip rate of 16chips per second .
What will be my Bandwidth reqirement at 4GHz frequency.?
Which modulation scheme to be used to spread this data in this bandwidth?
By what factor power transmitted will increase in cdma
wrt single carrier modulation scheme?