a. Frequency modulation is regarded as a much preferred modulation method over DSB-LC AM for sound radio broadcasting. Give two reasons why FM is preferred over AM in sound radio broadcasting.
b. Do either or both of the reasons you gave in part (a) above also apply to a point to point voice link using frequency modulation?
c. Which parameter of an FM transmission determines whether it is wideband or narrow band?
d. First generation cellular telephones used FM with a 30 kHz RF channel. If the RF channel bandwidth had been 20 kHz, and the maximum audio frequency was kept at 3 kHz, which parameter of the FM modulation would have to be changed? What would be its new value?
e. If the narrower RF channel of 20 kHz were used as in part (d) above, how would the performance of the audio signal at the receiver be changed?© BrainMass Inc. brainmass.com October 25, 2018, 7:44 am ad1c9bdddf
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a. FM is considered superior to AM methods for broadcasting sound (indeed any information) for a number of reasons two of the main ones being
1. AM suffers from noise (static) due to unwanted amplitude variations added when transmitted through the atmosphere. This can result in noisy reception especially amplitude ...
The solution discusses why FM is preferred over AM in sound radio broadcasting.
A radio network is set up with 50 mobile transmit-receive units and a central hub station.The network has ten RF channels for transmissions to the mobile units and ten RF channels for transmissions from the mobile units to the central hub. The network operates in the uhf band.The hub station allocates frequencies to the mobile units when a radio link is established.
a. The 50 mobile units share the ten RF channels. The RF channels have a bandwidth of 30 kHz. Modulation is FM with analog voice signals. Is this a FDM or FDMA system? Does it have fixed access or demand access?
b. One channel is reserved for random access: Why?
c. The network is used for voice communications. Is it possible for one mobile unit to connect to another mobile unit directly? What advantage is there in connecting through the hub?
d. Occasionally the hub has a voice message that is to be sent to all the mobile units. Can the message be sent on a single RF frequency?View Full Posting Details