Forward Error Correction (FEC) Explained

This page describes forward error correction and its application, and mentions MATLAB codes for different forward error correction techniques. Forward Error Correction is a module used in wireless communication to correct errors at the receiver end.

These errors occur due to interference, noise, or various impairments in the medium between the transmitter and receiver. It is also referred to as FEC for short. As the name suggests, this module avoids retransmission of corrupted data by helping to correct errors at the receiver.

FEC is not bandwidth efficient because it adds some data as overhead at the transmitter end. However, FEC is power efficient compared to its non-FEC counterpart. With the same transmit power, one can achieve a better Bit Error Rate (BER) in an FEC-based communication system.

How it works

FEC adds redundant bits i.e. error correcting codes to the original data before transmission. These extra bits help the receiver to detect and correct errors.

Example :

• Original data : 1011
• With FEC : 1011011
• IF received as : 1011111 (i.e. 1 bit in error), the received uses code structure to correct it back to 1011.

Types of FEC codes

1. Block codes
2. Convolutional code
3. LDPC (Low-Density Parity-Check)
4. Turbo codes
5. BCH codes

Key advantages

• No retransmission needed that saves bandwidth and time
• Improves communication reliability
• Essential in real time applications

Drawbacks

• Adds extra bandwith overhead due to redundancy
• Increases complexity in encoding and decoding parts
• Not as efficient compared to ARQ (Automatic Repeat Request) in very noisy conditions

Summary

Forward Error Correction (FEC) is a method of adding redundant bits to transmitted data so the receiver can detect and correct errors without needing retransmission. It enhances data reliability over noisy channels and is widely used in systems like Wi-Fi, 5G, and satellite communication.