ITT650hw7 - are aligned in time P.7.9 To address the...

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Darin Wright Due: October 30, 2011 ITT 650 HW 7 P7.1. What is the difference between the guard band and the guard time, and why are they important in a cellular system. Explain clearly. The guard band is used to minimize adjacent channel interface between two adjacent channels. Guard time is used so that path interference caused by propaganda delays can be minimized. They are important because they protect bandwidth and prevent delays. P.7.7. What are the orthogonal Walsh codes? Why is synchronization among the users required for CDMA? Walsh code functions are generated by constructing a Hadamard matrix starting with H 0 = [0]. The CDMA requires synchronization since the waveforms are orthogonal only if they
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Unformatted text preview: are aligned in time. P.7.9. To address the service to be increased in the number of MSs in a CDMA system, it was decided to use TDMA as well. Is it possible to do so? If yes, how; and if no, why not? No, because TDMA’s bandwidth is limited and uses high-precision sync circuits on the MS side. P.7.14. Why does power control become one of the main issues for the efficient operation of CDMA? Power control enables the user to adjust the antenna emitting power to solve the problem. Power control techniques are limited by the physical limitations of transmitter power levels....
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This note was uploaded on 11/22/2011 for the course ITT 650 taught by Professor Zeng during the Fall '11 term at N.C. A&T.

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