Low complexity soft decision decoding technique for T-user collaborative coding multiple-access channels

The collaborative coding multiple-access (CCMA) scheme permits potentially efficient simultaneous transmission by several users sharing a common channel, without subdivision in time or frequency. A new low complexity soft decision decoding technique is introduced to make use of the CCMA error control capability. The proposed soft decision CCMA (SD CCMA) decoding algorithm for the T-user baseband CCMA adder channel is presented. Theoretical simulation results of the probability of error for a particular two-user CCMA scheme is also given using SD CCMA and hard decision (HD CCMA) decoding techniques.