Types of multiple access techniques

Multiple access method is based on the multiplexing method. It is also called the channel access method. In a telecommunication system, the channel access method permits various terminals to connect to the same multi-point transmission medium to transmit over it and share its own capacity.

Through 'channel access' it is possible to share the communication capacity of the cellular system among a large number of base station.


The three main multiple or channel access method used to share the bandwidth in a wireless communication system, which generally falls into the following categories in the channel access method. 
  1. FDMA
  2. TDMA
  3. CDMA
  • FDMA full form is Frequency division multiple access (FDMA), it is the most common analog channel access method. Individual channels are assigned to individual users and each user is allocated a unique frequency band or channel.
  • TDMA full form is Time division multiple access (TDMA), It is digital wireless telephony transmission techniques. In TDMA system divide the radio spectrum time slot only one user is allowed to transmit or receive. It can easily adapt to the transmission of data as well as voice transmission.
  • CDMA full form is Code division multiple access (CDMA), The narrowband message signal multiplied by a large bandwidth called spread signal. This spreading signal is actually a pseudo noise code sequence and it has a higher rate than a data rate of the message signal.it is mostly used in cell phone standard. The user has to access the whole bandwidth for the entire duration.