# Problem about Nyquest signalling theorem?

A sinusoidal signal with amplitude 20 V and bandwidth 35 kHz is sampled at 2.5 times its Nyquist rate and then quantized using a 128-level quantizer. Determine:

i) The resulting data bit rate?

The Bit rate= 2Wm=2(35K)(7)(2.5)=1.225M bit/s

ii) The Signal to Quantization Noise Ratio (SQNR) in dBs of the resulting sampled signal assuming the sinusoidal signal amplitude covers all levels of the quantizer?

I know the power of the signal , But how to get the noise power.?

iii) The minimum required baseband channel bandwidth needed for transmitting the digital bits assuming that Manchester line coding is used.

The required bandwidth is 2R= 2(1.225M)

Can someone help me solving this problem ?

• A sine wave has a band width of zero theoretically. It may have a frequency of 35 kHz of course. – Andy aka Dec 12 '16 at 11:21