Multiplexing principle: Radio broadcasting with multiple stations in the same area is primarily an example of which multiplexing technique?
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ASpace multiplexing
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BTime multiplexing
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CFrequency multiplexing
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DNone of the above
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ECode multiplexing
Answer
Correct Answer: Frequency multiplexing
Explanation
Introduction / Context:Broadcast radio assigns different stations to different carrier frequencies so that many programs can be transmitted simultaneously without mutual interference, provided receivers are tuned to one carrier at a time.
Given Data / Assumptions:
- Conventional AM/FM analog broadcasting scenario.
- Single antenna may radiate one station per frequency; many stations share the spectrum.
- Receivers select one station by tuning to its frequency.
Concept / Approach:
This is classic Frequency Division Multiplexing (FDM): separate information channels occupy distinct, non-overlapping frequency bands simultaneously. Time or code division are not used in legacy analog broadcast systems.
Step-by-Step Solution:
Identify how multiple stations coexist: by frequency separation.Map to multiplexing type: frequency multiplexing (FDM).Select the corresponding option.Verification / Alternative check:
Broadcast band plans assign channel center frequencies and bandwidths; receivers use selective IF filtering to extract the chosen station.
Why Other Options Are Wrong:
- Time multiplexing: would interleave in time (not typical in analog broadcasting).
- Space multiplexing: relies on spatial separation/antennas; not the core method here.
- Code multiplexing: associated with CDMA-type systems, not analog broadcast radio.
Common Pitfalls:
- Confusing modern digital broadcast multiplexes (e.g., OFDM subcarriers) with analog radio channelization; the principle remains frequency separation.
Final Answer:
Frequency multiplexing