What is QAM and QPSK?

The primitive difference between the QAM and QPSK is that the spectral width of QAM is narrower than the QPSK. The QPSK is very much similar to the PSK the only difference between PSK and QPSK is that in basic PSK the phase shift occurs in every 180° degrees while in QPSK the phase shift occurs in multiple of 90°.

What is difference between modulation and demodulation?

The key difference between modulation and demodulation is that modulation is done at the transmitter side while demodulation is done at the receiver side of a communication system. Modulation is basically done to transmit data to longer distance whereas demodulation is done to regain the original message signal.

What are the types of QPSK?

There are three major classes of digital modulation techniques used for transmission of digitally represented data:

• Amplitude-shift keying (ASK)
• Frequency-shift keying (FSK)
• Phase-shift keying (PSK)

What are the types of QAM?

QAM, Quadrature amplitude modulation is widely used in many digital data radio communications and data communications applications. A variety of forms of QAM are available and some of the more common forms include 16 , 32 , 64 , 128 and 256 QAM.

What is the advantage of QAM?

Benefits or advantages of QAM ➨The major benefit of QAM modulation variants is efficient usage of bandwidth. This is due to the fact that QAM represent more number of bits per carrier. For example, 16QAM maps 4 bits per carrier, 64QAM maps 6 bits per carrier, 256QAM maps 8 bits per carrier and so on.

Which is better BPSK or QPSK?

QPSK has advantages of having double data rate compare to BPSK. This is due to support of two bits per carrier in QPSK compare to one bit per carrier in the case of BPSK. While QPSK is used for data transmission to provide higher data rate.

How is demodulation done with QPSK in MATLAB?

The simulation involves, generating random message bits, modulating them using QPSK modulation, addition of AWGN channel noise corresponding to the given signal-to-noise ratio and demodulating the noisy signal using a coherent QPSK receiver. The waveforms at the various stages of the modulator are shown in the Figure 4.

How is the waveform simulation for QPSK done?

The complete waveform simulation for the aforementioned QPSK modulation and demodulation is given next. The simulation involves, generating random message bits, modulating them using QPSK modulation, addition of AWGN channel noise corresponding to the given signal-to-noise ratio and demodulating the noisy signal using a coherent QPSK receiver.

What kind of phase modulation technique is QPSK?

This technique is also known as quaternary PSK, quadriphase PSK or 4-PSK. QPSK refers to a type of phase modulation technique where there are four states involved. It uses four points on the constellation diagram, equispaced around a circle.

How is Euler relation used in QPSK modulation?

Readers are presented with step-by-step derivations showing the operation of QPSK modulation and demodulation. The transition from analog communication to digital has advanced the use of QPSK. Euler’s relation is used to assist analysis of multiplication of sine and cosine signals.