Code division multiple access with code assignments using information classes

The authors propose a new method of code allocation in code division multiple access, based on information classes. Transmitters choose spreading codes based on the type of message they are transmitting, and receivers listen to codes corresponding to the type of message they are interested in. The performance of this approach can exceed that of both receiver-directed codes or broadcast codes in environments where there are several multicast groups (in which a given message is of interest to more than one node), or where it is difficult to know what types of messages (out of a fixed set of message types) a receiver is interested in at any particular time. Performance is further enhanced when receivers can simultaneously attempt to correlate multiple spreading codes