S13. What are the properties of CDMA and where is it used? Flashcards
What is CDMA?
Code Division Multiple Access (CDMA) is a wireless communication technology that allows multiple users to share the same frequency spectrum simultaneously.
How does CDMA allow multiple users to share the same frequency?
CDMA uses spread spectrum modulation, where data signals are spread across a wider bandwidth using a unique code for each user. This allows multiple users to transmit and receive data simultaneously on the same frequency band without interfering with each other.
How does CDMA improve on other technologies like FDMA and TDMA?
CDMA provides a significant increase in capacity compared to other multiple access schemes like TDMA and FDMA. By allowing multiple users to share the same spectrum efficiently, CDMA can support a larger number of users within the available bandwidth.
How does CDMA provide security?
CDMA offers inherent security benefits due to the spreading codes assigned to each user. The unique property of the codes make it difficult for unauthorized users to intercept or decode the transmitted signals without knowledge of the specific code.
How is CDMA robust agains interference?
The spreading codes also provide a form of error correction and interference rejection, enhancing the reliability of communication in challenging environments. This makes CDMA systems robust against various types of interference, including narrowband interference and multipath fading.
Where is CDMA used?
CDMA technology finds widespread use in various wireless communication systems. It is a foundational technology used in 2G, 3G, and 4G cellular networks, providing voice and data services to mobile devices. CDMA is utilized in wireless data networks such as WiMAX and some implementations of LTE (Long-Term Evolution). CDMA is also employed in satellite communication systems for both voice and data transmission, enabling efficient use of limited satellite bandwidth.
