Multiple Access Schemes
FDMA - Frequency Division Multiple Access
- 30 KHz channels are divided into “narrow” 10Khz channels.
TDMA - Time Division Multiple Access
- Only available for digital systems
- Each user allowed a fraction of the broadcast cycle.
CDMA - Code Division Multiple Access
- Frequency Hopping: transmitters change frequencies in a unique pattern sending a little data on each frequency.
- Direct Sequence: Data transmissions are coded for efficiency.