Question

Hi, if someone know just the half of the answer it's ok i real need help in this one , it is the 3 rd times i post it and no one answer me :(

Probleme 1:

A cellular phone operates in two modes: an analog mode in the band frequencies of 900 MHz and a digital mode operating in the frequency band
1900 MHz. The cell phone uses a superheterodyne receiver with an intermediate frequency, fIF = 500 MHz, for both modes of operation.
a) In the analog mode, the frequency of the local oscillator, fosc, is above the carrier frequency of the received signal, fRF. We want to tune an analog signal at 935 MHz.
i) What is the frequency of the local oscillator?
ii) What is the frame rate?
b) In the digital mode, the frequency of the local oscillator, fosc, is below the carrier frequency of the received signal, fRF. You want to tune a digital signal at 1955 MHz.
i) What is the frequency of the local oscillator?
ii) What is the frame rate?
c) Explain the advantage of using such a cell phone with single IF frequency?

Answer 1

.fosc-fRF t 가 2935t 50のMHz e. Siano -95% 2(500) s 935 + IO0D lagst 2(560)