NEARLY OPTIMAL MULTIUSER CODES FOR THE BINARY ADDER CHANNEL

Coding schemes for the T-user binary adder channel are investigated, R ecursive constructions are given for two families of mixed-rate, multi user codes, It is shown that these basic codes can be combined by time -sharing to yield codes approaching most rates in the T-user capacity region, In particular, the best codes constructed herein achieve a sum -rate, R(1) +...+ R(T), which is higher than all previously reported c odes for almost every T and is within 0.547-bit-per-channel use of the information-theoretic limit. Extensions to a T-user, Q-frequency adde r channel are also discussed.