Optical Code Division Multiple Access Essay Example for Free

Optical Code Division Multiple Access Essay Question: write about Optical Code Division Multiple Access. Introduction and overview, historical background, explanation of the technique, comparison between FDMA, TDMA and OCDMA, explain more on OCDMA, how does it work, why using OCDMA, advantages, what other techniques available other than OCDMA, compare them with OCDMA. Introduction OCDMA is a multiple access technique originating from DS-SS (Direct Sequence Spread Spectrum) and it was originally used for military purposes to ensure that transmission of information I kept safe. It is currently used in wireless communication such as mobile devices. Overview Here we are going to look at the OCDMA technique, how it works, its origin or background, its advantages and compare it with other techniques. History It started in 1941 when George Antheil and Hedy Lamar patented Spectrum communication but it was not implemented then. CDMA was later considered in the late 70’s for cellular mobiles. During this period, CDMA technology was being used for military communications to ensure that there is security in information transmission. It is now a very important technology widely used in wireless communication as 3G/4G Technology. Explanation of the Technique OCDMA is a technique which employs high speed transmission, exchange of data using optical signal processing to realize an all optical communication and networking. Users access the network randomly. It uses a tell-to –go protocol and can support different bitrate traffic. It transmits encrypted information making it secure Comparison between FDMA, TDMA and OCDMA OCDMA is different and advantageous as compared to FDMA and TDMA in that it ensures there is proper use of communication media by giving asynchronous access to every user. In OCDMA technique new users are added to the network with ease because it does not require any scheduling. OCDMA has been known to experience problems as it suffers from different kinds of noise as a result of multiple access interference (MAI). Advantages of OCDMA Allows frequency reuse Provides Variable data rates Allows asynchronous multiple access Provides protection from interference Gives resistance to interception in that no unauthorized listeners can decode the original message Other Techniques OFDMA-This was developed for cable networks which had the problems of narrow band jamming. OFDMA is used for terrestrial video and radio broadcasting. OFDMA was originally designed for cable networks whereas OCDMA is used for wireless communication. WDMA-This is another technique which allows access of channels based on wave-length division multiplexing. It can allow numerous data signals to share a common communication channel. The OCDMA uses fewer devices than WDMA. References International Engineering Consortium. (2005). Annual review of wireless communications. Chicago, Ill: Professional Education International.