In order to solve the problem of the limited number of sequences in the traditional complementary sequence sets

some scholars have proposed the concept of complete complementary code sets(CCCs) with low inter-set cross-correlation in recent years. Complete complementary code sets with low inter-set cross-correlation have perfect aperiodic auto-correlation and cross-correlation properties. As the spreading code in the multi-cell MC-CDMA communication system

CCCs can effectively eliminate intra-cell interference and suppress inter-cell interference. Two constructions of complete complementary code sets with low inter-set correlation are developed

and the resultant complementary sequence sets have the following properties: (1) each set is a complete complementary code set with parameters (N

N

N)?CCC; (2) complementary sequences from different sets have low correlation functions. Finally

an asymptotically optimal quasi-complementary sequence set is obtained when these multiple complete complementary code sets are combined .