Modulation

In PCM the quantization noise depends on

• sampling rate

• signal strength

• number of quantization levels

• none of the above

Quantization noise occurs in

• FSK

• PCM

• QPSK

• None of above

The modulation method that represents bits as different phase shifts of a carrier is known as

The number of different phase shifts used in QPSK are

16QAM technique is based on .......... and ............parameters of carrier signal

• amplitude

• phase

• frequency

In FSK the frequency of sinusoidal carrier is shifted between .......... discrete values, in response to value of digital signal

• 1

• 2

• 3

• 4

In FSK demodulator, envelope detector are simple ............ which rectify and filter their inputs to generate a dc voltage proportional to ac input.

The baud rate and bit rate for these systems are same

• ASK

• BFSK

• BPSK

• QPSK

• 64QAM

Let us assume using QAM we want to transmit a symbol consisting of 4 bits . So how many different possible symbol can we have

• 4

• 8

• 16

• 32

• 64

32QAM technique is based on .......... and ............parameters of carrier signal

• amplitude

• frequency

• phase