- 2075 Chaitra · 2 marks
Need for channel coding
Short answer
Chanel coding adds redundancy to combat noise and fading, enabling error detection/correction (FEC or ARQ). It reduces bit error rate, provides coding gain, and allows reliable communication near Shannon limit, essential for satellite, deep-space, and broadcast links.
Explain why channel coding is required in data communication.
Real channels add noise, interference and fading, so bits received may differ from those sent. Channel coding adds controlled redundant (parity) bits so that the receiver can detect and correct errors without asking for retransmission (FEC), or at least detect them (ARQ). It lowers the bit error rate for a given signal power (coding gain), permits reliable communication near the Shannon capacity, and is vital where retransmission is costly or impossible, such as satellite and deep-space links and broadcast. Examples: Hamming, CRC, convolutional, Reed-Solomon codes.
✓ Answer checked by Claude Sonnet 5.5
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