What is the purpose of error correction coding?

• A. Introduces redundancy for error detection and correction
• B. Increases data rate
• C. Encrypts data for security
• D. Compresses data

Answer: (A)

Error correction coding adds redundancy to the transmitted data so the receiver can detect and correct errors that occur when the signal passes through a noisy satellite channel. By encoding data with extra parity bits or structured code words, the decoder can infer the most likely original bits even if some are corrupted by noise, interference, or fading. This allows reliable communication without needing retransmission, which is especially important for high-latency links like satellite links. The trade-off is a lower effective data rate due to the added redundancy, but more powerful codes can approach the theoretical maximum reliability. The other options describe encryption, compression, or simply increasing data rate, none of which provide automatic error correction.