08-16-2017, 10:20 PM
NEW TRENDS IN WIRELESS COMMUNICATION TECHNOLOGY
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Multiple Access techniques
.Goal
.Time Division Multiple Access (TDMA)
.Space Division Multiple Access (SDMA)
.Frequency Division Multiple Access (FDMA)
.Polarization Division Multiple Access (PDMA)
.Code Division Multiple Access (CDMA)
.Interleave Division Multiple Access (IDMA)
.Orthogonal Frequency Division Multiple Access (OFMA)
International Cocktail Party
.FDMA Large room divided up into small rooms with limited microphones. Each pair of people takes turns speaking.
.TDMA Large room divided up into small rooms with limited microphones. Certain pairs of people per room, however, each pair gets limited seconds to speak.
.CDMA No small rooms. Everyone is speaking in different languages with own microphones. If voice volume is minimized, the number of people is maximized.
TDMA System
Each user receives half of the frame and the full bandwidth.
Users can resolve both multipath
Time allocation is independent of power allocation.
Nonlinear ISI cancellation.
Cancel edge effects as well.