Primary requirements for any wireless mode of communication include high quality of service and data secrecy. Realizing that these two factors are to be fulfilled in the most optimized ways without the costs going too high, CDMA, a spread spectrum based technology came into existence.
Fig. 1: A Representational Image of CDMA Technology
Initially restricted to the armed forces, this technology was commercially launched in 1995 by Qualcomm Telecommunications and now, as per Q4 of the year 2011, CDMA has over 8 billion voice and data customers in the 122 countries that it operates.
Understanding CDMA Terminology
A Figure Representing Bandwidth Before and After Application of Spread Spectrum Technique
Fig. 3: A Diagram Demonstrating Work Process of Code Division Multiple Access
Fig. 4: A Figure Detailing About CDMA
Fig. 6: A Figure Representing Generation of DSSS signals
Fig. 7: A Diagram Representing Advantages of FHSS System Over DSSS System
Fig. 9: A Figure Illustrating the Basic Principle of RAKE Receiver
Fig. 10: A Figure Illustrating Process of Combining Information From Multiple Transmitted Packets