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OFDMA


OFDMA and Practical Example

OFDMA (Orthogonal Frequency-Division Multiple Access) allows many users to connect at the same time by assigning each user a different group of subcarriers.

The total channel is divided into multiple narrow, orthogonal subcarriers. Each user gets a different subset, allowing simultaneous transmission without interference.


Simple Example

Total subcarriers: 12

Subcarriers per user: 4

Number of users = 12 ÷ 4 = 3 users


Practical Real-World Example (Wi-Fi 6)

Imagine a Wi-Fi 6 router in a coffee shop with 3 connected devices:

  • Phone checking messages
  • Laptop streaming video
  • Smartwatch sending tiny packets

Available subcarriers: 12

OFDMA assignment:

  • Laptop: 6 subcarriers
  • Phone: 4 subcarriers
  • Smartwatch: 2 subcarriers

All devices transmit simultaneously on different subcarriers, improving efficiency and reducing waiting time.


Further Reading

  1. Orthogonal Frequency Division Multiplexing (OFDM)
  2. Other Multiplexing Access Techniques - FDMA, TDMA, & CDMA

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