How is multiplexing achieved in spread-spectrum modulations like CSS?

1. How does a spread spectrum work?
2. What are the modulation schemes of spread spectrum system?
3. Which of the multiple access technique uses spread spectrum modulation scheme?
4. What are the main benefits of a spread spectrum system how can spreading be achieved?

How does a spread spectrum work?

Spread spectrum is a form of wireless communications in which the frequency of the transmitted signal is deliberately varied. This results in a much greater bandwidth than the signal would have if its frequency were not varied.

What are the modulation schemes of spread spectrum system?

Different types of modulation are used before the DSSS technique is applied. Most common are BPSK and QPSK modulation. The baseband direct sequence spread spectrum system spreads the baseband digital signal using the wide-bandwidth spreading-code signal.

Which of the multiple access technique uses spread spectrum modulation scheme?

4.3. 4 Code Division Multiple Access (CDMA) Code division multiple access (CDMA) is a form of spread spectrum communications that is being used for, among other applications, some second-generation cellular phone systems (others use TDMA). The method is also known as S-CDMA, where the S stands for synchronous.

What are the main benefits of a spread spectrum system how can spreading be achieved?

In the spread spectrum technique, the frequency of the signal to be transmitted is varied by injecting pseudo-random noises into it. This injection increases the bandwidth of signal transmission, and thereby reduces the effects of interference, noise, and signal fading.