PE1-5.5 Cognitive Radio & Spectrum Sensing
You can describe the cognitive radio cycle and architecture, explain spectrum management policy, perform single-node energy detection, and state the challenges of cooperative spectrum sensing.
Cognitive radio is SDR that decides for itself, and its motivating observation is that licensed spectrum sits mostly idle in time and place while unlicensed bands are congested. Energy detection is the simplest sensing method and its weakness is instructive: it cannot tell a signal from a noise-level rise, so it fails at low SNR and under fading. Cooperative sensing fixes that by combining several nodes' observations, and the challenges are the interesting part — the reporting channel costs bandwidth, and a dishonest node can poison the decision.
Work through these
History and background of cognitive radio
Where the idea came from: spectrum is allocated but largely unused at any moment. That observation is the entire motivation.
Communication policy and spectrum management
The rules that govern who may transmit, and how they would have to change. It is a policy problem as much as an engineering one, which is unusual and worth noticing.
The cognitive radio cycle
The loop the radio runs: observe, decide, act, learn. It is the organising idea for everything below.
Cognitive radio architecture
How such a radio is structured, which adds sensing and decision to the ordinary chain. Compare it with the architectures from the earlier topic.
SDR architecture for cognitive radio
Why the software approach is the natural base for this, which ties the two halves of the subject together.
Single node spectrum sensing: energy detection and its limits
The simplest way to tell whether a band is in use, and where it fails: it cannot distinguish a signal from noise at low levels, and it needs to know the noise power.
Introduction to cooperative spectrum sensing and its challenges
Several radios sensing together, which fixes the hidden node problem and creates new ones. The overhead of combining the reports is the honest limitation.
Concepts of 5G and 6G technologies
Where the field is heading, closing the course. Read for direction, since this is the item that will date first.
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