How does forward error correction (FEC) allow the receiver to correct data errors?
The correct answer is C: By transmitting redundant information with the data. How forward error correction (FEC) allows the receiver to correct data errors is by transmitting redundant information with the data. FEC adds extra bits that allow the receiver to detect and correct errors without retransmission. For amateur radio operators, this improves reliability. Understanding this helps when operating FEC modes.
Exam Tip
FEC corrects errors = by transmitting redundant information with data. Think 'F'EC = 'F'orward 'E'rror 'C'orrection = 'F'ixes 'E'rrors with 'C'heck bits. FEC adds extra bits that allow receiver to detect and correct errors. Not power control, not Varicode, not just parity - just redundant information.
Memory Aid
"FEC corrects errors = by transmitting redundant information with data. Think 'F'EC = 'F'ixes 'E'rrors with 'C'heck bits. FEC adds extra bits that allow receiver to detect and correct errors. Improves reliability without retransmission."
Real-World Application
Forward error correction: Extra bits (redundant information) are added to the data. The receiver uses these extra bits to detect and correct errors without needing retransmission. For example, if a bit is corrupted, the redundant information allows the receiver to figure out what the correct bit should be. This is how FEC works - redundant information enables error correction.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. FEC doesn't control transmitter power - power control is separate from error correction. Power control isn't FEC.
Option B: Incorrect. FEC doesn't use Varicode character set - Varicode is for PSK31 encoding, not FEC. Varicode isn't FEC.
Option D: Incorrect. FEC doesn't use just a parity bit - FEC uses more sophisticated redundant coding, not just simple parity. Parity bit alone isn't FEC.
题目解析
The correct answer is C: By transmitting redundant information with the data. How forward error correction (FEC) allows the receiver to correct data errors is by transmitting redundant information with the data. FEC adds extra bits that allow the receiver to detect and correct errors without retransmission. For amateur radio operators, this improves reliability. Understanding this helps when operating FEC modes.
考试技巧
FEC corrects errors = by transmitting redundant information with data. Think 'F'EC = 'F'orward 'E'rror 'C'orrection = 'F'ixes 'E'rrors with 'C'heck bits. FEC adds extra bits that allow receiver to detect and correct errors. Not power control, not Varicode, not just parity - just redundant information.
记忆口诀
FEC corrects errors = by transmitting redundant information with data. Think 'F'EC = 'F'ixes 'E'rrors with 'C'heck bits. FEC adds extra bits that allow receiver to detect and correct errors. Improves reliability without retransmission.
实际应用示例
Forward error correction: Extra bits (redundant information) are added to the data. The receiver uses these extra bits to detect and correct errors without needing retransmission. For example, if a bit is corrupted, the redundant information allows the receiver to figure out what the correct bit should be. This is how FEC works - redundant information enables error correction.
错误选项分析
Option A: Incorrect. FEC doesn't control transmitter power - power control is separate from error correction. Power control isn't FEC. Option B: Incorrect. FEC doesn't use Varicode character set - Varicode is for PSK31 encoding, not FEC. Varicode isn't FEC. Option D: Incorrect. FEC doesn't use just a parity bit - FEC uses more sophisticated redundant coding, not just simple parity. Parity bit alone isn't FEC.
知识点
Forward error correction, FEC, Redundant information, Error correction
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.