Question 1

QPSK sends ________ bit(s)per clock cycle.&#10;A)1&#10;B)2&#10;C)4&#10;D)16

Accepted Answer

QPSK (Quadrature Phase Shift Keying) is a modulation technique that can send 2 bits per clock cycle. In QPSK, each symbol represents a combination of two bits, which are then phase-shifted by 90 degrees and modulated with a carrier wave. This allows for a higher data rate than traditional modulation techniques that send only 1 bit per clock cycle. Therefore, the correct answer is B.

Question 2

QAM uses ________ levels.&#10;A)loudness&#10;B)frequency&#10;C)both A and B&#10;D)neither A nor B

Accepted Answer

A

Question 3

In QAM,if you have eight possible amplitudes,how many bits can you send per clock cycle?&#10;A)3&#10;B)6&#10;C)8&#10;D)16

Accepted Answer

QAM stands for Quadrature Amplitude Modulation. In general, the number of bits that can be sent per clock cycle in QAM is given by log2(M), where M is the number of possible amplitudes. In this case, there are 8 possible amplitudes, so log2(8) = 3 bits can be sent per clock cycle. Therefore, the correct choice is B) 6, since two amplitudes are sent per clock cycle (one in the in-phase channel and one in the quadrature channel), so the total number of bits per clock cycle is 3 x 2 = 6.

Question 4

BPSK uses ________ phase levels.&#10;A)2&#10;B)4&#10;C)8&#10;D)15

Accepted Answer

BPSK stands for Binary Phase Shift Keying, which uses only two phase levels. It modulates the carrier signal by shifting the phase of the signal to 0° or 180° depending on the bit being transmitted. Therefore, the best choice is only A).

Question 5

QAM uses ________.&#10;A)amplitude modulation&#10;B)phase modulation&#10;C)both A and B&#10;D)neither A nor B

Accepted Answer

QAM stands for Quadrature Amplitude Modulation which uses both amplitude modulation and phase modulation to encode and transmit data.

Question 6

In QAM,if you have four possible amplitudes,you have ________ possible states.&#10;A)4&#10;B)8&#10;C)16&#10;D)none of the above

Accepted Answer

QAM (Quadrature Amplitude Modulation) uses both amplitude and phase to represent digital data. With four possible amplitudes, we can represent 2 bits of information (2^2=4). Similarly, with four possible phases, we can represent another 2 bits. Thus, using both amplitude and phase, we can represent a total of 4x4=16 possible states.

Question 7

In QAM,if you have eight possible amplitudes,you have ________ possible states.&#10;A)4&#10;B)8&#10;C)16&#10;D)none of the above

Accepted Answer

The answer of In QAM,if you have eight possible amplitudes,you...

Question 8

Amplitude modulation uses two ________ levels.&#10;A)loudness&#10;B)frequency&#10;C)both A and B

Accepted Answer

Amplitude modulation (AM) uses two different loudness levels, typically referred to as the "carrier" and the "modulating" signal. The carrier signal is a high-frequency wave that is constant in amplitude and represents the baseline for the transmitted signal. The modulating signal is a lower frequency wave that varies in amplitude and is used to convey information (such as sound) on top of the carrier wave. Thus, AM is a type of modulation that varies the amplitude (or "loudness") of the carrier wave to encode the modulating signal.

Question 9

BPSK modulation uses two ________.&#10;A)amplitudes&#10;B)frequencies&#10;C)phases&#10;D)none of the above

Accepted Answer

BPSK modulation stands for Binary Phase Shift Keying, which means that two distinct phases (180 degrees apart) are used to represent the two binary symbols, typically 0 and 1. Therefore, the correct answer is C) phases.

Question 10

Frequency modulation uses two loudness levels.

Accepted Answer

Frequency modulation uses two frequency levels, not loudness levels.

Question 11

Phase modulation uses two ________ levels.&#10;A)loudness&#10;B)frequency&#10;C)wave&#10;D)none of the above

Accepted Answer

The answer of Phase modulation uses two ________ levels.&#10;A)loudness&#10;B)frequency&#10;C)wave&#10;D)none of...

Question 12

QPSK modulation uses ________ phases.&#10;A)2&#10;B)4&#10;C)8&#10;D)15

Accepted Answer

The answer of QPSK modulation uses ________ phases.&#10;A)2&#10;B)4&#10;C)8&#10;D)15...

Deck 13: Module B More on Modulation