Differentiate between CDMA and TDMA ?

b.) CDMA and TDMA

CDMA

- Power limited system
- While people talking, random noise band playing occurs
- Conversation need to be extracted from the background din
- GP is high when people speak different languages, which is easier to distinguish individual speakers
- It is difficult for distinguishing individuals, when GP is low.
- The system performance will be degraded for every user when the number of users increases.
- Fading would be reduced with wide frequency spectrum
- Need to have separate multipath signals with different delays by “chip” unit.

TDMA

- Receiving or transmission is allowed for only one user in a given slot
- All slots are assigned cyclically
- The transmission is non-continuous
- It is essential to use digital data and modulation
- Data rate overhead is between 20% – 30%
- Overhead tradeoffs are size of data payload and latency
- Multiple users are shared with single carrier frequency
- Handoff is made simpler by using non-continuous transmission
- All slots are assigned on demand
- Due to reduced inter user interference, the power control is less stringent.