Because of the random properties of practical communication networks the unique decoding of CCMA codes should include two steps. First, to identify the current system state, and secondly to uniquely decode the added codewords. When no special information is provided to distinguish different system states, the conventionally defined CCMA codes in most previous studies will be no longer uniquely decodable. Based on this consideration, the concept of system state-independent-uniquedecodable (SIUD) CCMA codes is introduced. A construction method of SIUD CCMA codes and the corresponding performance evaluation are also presented.