g a cable modem uses 64-qam modulation mode with baud (symbol) rate 4000 hz and carrier frequency 5 khz. (a) determine the bit rate of the modem. (b) determine the frequency band utilized by the modem. (c) if the carrier frequency needs to be increased further to 20 kh by a frequency converter (mixer local oscillator), what are the possible frequency(s) of the local oscillator? explain.