What the syllabus asks you to cover
Equalization and diversity techniques, Spread Spectrum modulation, Multiple Access techniques.
Start here for the core ideas. A dedicated GitBook topic page was not available; this original guide is introductory. Use the syllabus checklist and references below to study the remaining details.
Read the actual syllabus scope
Although this topic is titled “Signal and system,” its listed scope is equalization, diversity, spread spectrum and multiple access. Study those wireless techniques here; the general signals-and-systems foundations belong in chapter 8.
Compare the techniques
Equalization compensates for channel-induced distortion and intersymbol interference. Diversity combines or selects observations that fade differently, using time, frequency or space. Spread-spectrum techniques distribute energy across a wider band using an agreed structure. Multiple-access methods organize how different users share resources, such as time, frequency, codes or orthogonal subcarriers.
Try it
Two receive antennas may observe different fades. Diversity can reduce the chance of both observations being weak at once, but the benefit depends on correlation and the combining method.
Check your understanding
Explain why equalization and diversity solve different problems. Compare FDMA, TDMA, CDMA and OFDMA at a conceptual level. Do not equate spread spectrum with encryption or assume orthogonality eliminates all practical interference.
Pause and recall
Without looking back, explain the main idea, recall a key definition or formula, and describe when it applies. Include assumptions and units where relevant. Revisit any step you could not explain.