A computer-readable medium stores instructions causing one or more processors to demodulate a received signal including a plurality of user signals. Respective user data in each of at least some of the plurality of user signals is encoded with a respective finite state machine encoder having a respective number of states Si, wherein i=1, 2, . . . , N, N being the number of users, and wherein at least a first user signal and a second user signal are encoded independently of each other. The instructions cause the processor(s) to calculate distances between transmit symbols in the received signal and an expected joint symbol value, and jointly decode, with a finite state machine decoder, user data in the demodulated received signal, including at least first user data corresponding to the first user signal, based on the calculated distances. The finite state machine decoder has S1*S2* . . . *SN states.