This is a research on orthogonal complementary codes, including complete complementary codes, super complementary codes, and generalized pairwise complementary code(GPC code). I discuss the properties of orthogonal complementary codes by the generation of orthogonal matries and realize its auto-correlation and cross-correlation are perfect. Apply orthogonal complementary codes on direct-sequence spreading system and offset stacked spreading system. In these two kinds of transmission, orthogonal complementary codes have the ideal auto-correlation and cross-correlation by way of direct-sequence spreading system, so it can solve multipath interference and multi-access interference effectively. While in offset stacked spreading system, orthogonal complementary codes have ideal cross-correlation. Modulating the offset chip time of offset stacked spreading properly can also solve multipath interference effectively. Moreover, GPC code keeps sub-ideal auto-correlation and cross-correlation, and it forsakes its ideal property to exchange for spreading codes with more users. In Chapter 2, we start to introduce complete complementary codes and its property to resist interferences in different transmission. Chapter 3 is the introduction of super complementary codes and its property to resist interferences in different transmission. Chapter 4 is the introduction of GPC code. We explain that GPC code forsakes its ideal property to exchange for spreading codes with more users. Chapter 5 is the introduce multi-rate orthogonal complementary codes and use 2D OVSF to suport different transmission speed.

This paper present three kinds of nonlinear numerical methods to search for perfect complementary codes, include Newtonian Methods¡BLevenberg-Marquardt Algorithm and Trust-Regions. By searching for the solution of theses nonlinear equations, we can get complementary codes when setting for the length of element codes and the flock size. These search results is very generous. Complete complementary codes¡Bsuper complementary code and poly-phase complementary code are subsets of these searching results¡C These nonlinear equations are set to have ideal auto-correlation and cross-correlation properties, so the searching results of these nonlinear equations are still have perfect orthogonal complementary properties. Because the orthogonal complementary code is obtained via these nonlinear equations, the results are the most generous. So nonlinear numerical method is a good choice to search for another complementary code we don¡¦t know.

First, we proved that the - Columnwise Complementary codes is better than - Columnwise Complementary code in time selective channel by explaining the probability of happening MAI elimination in frequency domain and proposing a method to use - Columnwise Complementary codes in one cell. Furthermore, we proposed the method to increase the capability of resisting of frequency selective fading channel without decreasing the capability of resisting of time selective fading channel. Finally, we showed some simulation results about receiver velocity and MAI elimination in frequency domain.