The maximum rate at which information can be transmitted reliably through a communication channel primarily depends on which parameter?
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ACarrier frequency
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BAvailable channel bandwidth
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CTransmission loss along the channel
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DTransmitted power level alone
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EAntenna gain pattern
Answer
Correct Answer: Available channel bandwidth
Explanation
Introduction / Context:Shannon’s communication theory defines limits for information transfer. While many factors affect link quality, the fundamental determinant of capacity is the channel bandwidth and the signal-to-noise ratio (SNR). This question highlights the role of bandwidth.
Given Data / Assumptions:
- Channel capacity formula: C = B * log2(1 + S/N).
- B = channel bandwidth.
- S/N = signal-to-noise ratio.
Concept / Approach:
For fixed SNR, increasing bandwidth linearly increases the number of bits per second that can be carried. Carrier frequency does not directly dictate capacity; losses and power affect SNR but not the structural limit. Bandwidth is the key parameter determining potential data rate.
Step-by-Step Solution:
Recall Shannon formula: C = B * log2(1 + S/N).Observe proportionality: C ∝ B for fixed S/N.Therefore, the maximum reliable information rate depends on channel bandwidth.Verification / Alternative check:
Modern high-data-rate systems (optical, Wi-Fi, 5G) exploit very wide bandwidth allocations, confirming this principle.
Why Other Options Are Wrong:
- Carrier frequency: only indirectly affects propagation, not capacity formula.
- Transmission loss: affects received SNR but not the fundamental dependency.
- Transmitted power: influences SNR but not as directly as bandwidth for maximum rate.
- Antenna gain: improves link margin, not fundamental capacity scaling.
Common Pitfalls:
Confusing carrier frequency allocation with actual usable bandwidth.
Final Answer:
Available channel bandwidth