Howtosignalprocessing
- What is CDMA in wireless communication?
- What is the maximum capacity of a CDMA system?
- What are the factors that affect the CDMA capacity?
- Is it possible to jam CDMA?
What is CDMA in wireless communication?
CDMA (Code-Division Multiple Access) refers to any of several protocols used in second-generation (2G) and third-generation (3G) wireless communications. As the term implies, CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimizing the use of available bandwidth.
What is the maximum capacity of a CDMA system?
CDMA allows up to 61 concurrent users in a 1.2288 MHz channel by processing each voice packet with two PN codes. There are 64 Walsh codes available to differentiate between calls and theoretical limits. Operational limits and quality issues will reduce the maximum number of calls somewhat lower than this value.
What are the factors that affect the CDMA capacity?
The network capacity (hard capacity) of a CDMA system is limited by two factors: code word length and maximum sender's power. Each code length may sustain only a limited number of orthogonal codes (for example, as determined by the Walsh Set). In addition a receiver sees other user transmissions on the system as noise.
Is it possible to jam CDMA?
CDMA is also resistant to jamming. A jamming signal only has a finite amount of power available to jam the signal. The jammer can either spread its energy over the entire bandwidth of the signal or jam only part of the entire signal. CDMA can also effectively reject narrow-band interference.
