How to build a simple DSSS (direct sequence spread spectrum) transceiver?
There are licensing problems associated with operating your own spread spectrum transceiver. A special dispensation was granted to some US radio amateurs several years ago, but it was rescinded:

http://www.tapr.org/ss_tapr_sta.html

You should approach your regulatory authority about the relevant legislation. Unless you are a licensed radio amateur, it is very unlikely that you will get permission to operate such equipment.