Spread spectrum modulation in communications and advantages in noise immunity

Spread spectrum techniques originated in answer to the secure communication needs of the military. They are based on signaling schemes which greatly expand the transmitted spectrum relative to the data rate. There is a growing interest in these techniques for use in mobile radio networks and for both communication and positioning applications in satellites. This thesis mainly concentrates on civilian applications of spread spectrum. The objective of this thesis is to introduce the reader to the concept of spread spectrum in 'general' terms and then proceed with a detailed, technical discussion of various signaling techniques, including mathematical derivations. The thesis includes a description of one of the civilian applications such as a cellular code division multiple access (CDMA) system as described by the IS-95: air-interface specification standard which was released in July 1993. This project will introduce the reader to spread spectrum techniques through a theoretical discussion and multiple examples. It will also provide information beyond the introductory materials through a description of specific applications of the spread spectrum technique including noise immunity advantages.