Wireless Communication Systems Practice Test: Multiple Access Techniques — Flashcards

Multiple access techniques are methods for allocating signaling dimensions to specific users. Multiple access methods perform differently in different multiuser channels. Co-channel interference is a problem that can occur in many wireless communications systems due to spectrum sharing and multiple access. It is mainly caused by multiple radios transmitting on the same frequency band at the same time.

Here are some examples of multiple access techniques:
Frequency division multiple access (FDMA): A common analog method that divides the frequency band into channels of equal bandwidth. Each conversation is carried on a different frequency.
Time-division multiple access (TDMA): A digital transmission technology that divides time into periodic and non-overlapping frames. Each frame is then divided into several time slots. TDMA is important in WSN because of its low power consumption and collision-free operation.
Code division multiple access (CDMA): A technique where multiple transmitters use a single channel to send information simultaneously.
Spread spectrum: A channel access method used primarily by mobile communication technologies. It allows multiple access, meaning several transmitters can send information simultaneously over a single communication channel.
Carrier sense multiple access with collision detection (CSMA/CD): A network multiple access method where nodes attempt to avoid collisions by transmitting only when the channel is sensed to be idle. 
 

Topics include: Multiple Access Basics, FDMA, TDMA, SSMA, Packet Radio, & Cellular Systems Capacity.