1. Satellite Link Design Using 16 PSK
Communication Lab- Mini ProjectChintan Joshi
Phase-shift keying (PSK) is a digital modulation scheme that conveys data by changing, or
modulating, the phase of a reference signal (the carrier wave).
In this Mini Project, the link design in satellite communication is described and simulated. I have used
16-PSK scheme for modulation of the data.
The 16-PSK Modulator Baseband block modulates using the 16-ary phase shift keying method. The
output is a baseband representation of the modulated signal. The 16-ary number parameter, 16, is the
number of points in the signal constellation.
The block accepts scalar or column vector input signals. Alternative configurations of the block
determine how the block interprets its input and arranges its output, as explained in the following
sections.Integer-Valued Signals and Binary-Valued Signals. When you set the Input type parameter to
Integer, the block accepts integer values between 0 and 16-1.
The following figure represents the Simulink block diagram model of the designed system:

2. The Simulink Model of the satellite link contains following blocks:
Bernoulli Binary Generator:
The Bernoulli Binary Generator block generates random binary numbers using a Bernoulli
distribution. We can generate random binary sequence using Bernoulli distribution with desired
probability.
16PSK Modulator:
The 16-PSK Modulator Baseband block modulates using the 16-ary phase shift keying method. The
output is a baseband representation of the modulated signal. The 16-ary number parameter, 16, is the
number of points in the signal constellation.
Transmission Power, Antenna Gain:
It ises the dB gain block from Math Functions - Math Operations . The dB Gain block multiplies the
input by the decibel values specified in the Gain parameter. For an M-by-N input matrix u with
elements uij, the Gain parameter can be a real M-by-N matrix with elements gij to be multiplied
element-wise with the input, or a real scalar.
Free Space Path Loss:
The Free Space Path Loss block simulates the loss of signal power due to the distance between
transmitter and receiver. The block reduces the amplitude of the input signal by an amount that is
determined in either of two ways:
1) By the Distance (km) and Carrier frequency (MHz) parameters, if you specify Distance and
Frequency in the Mode field
2) By the Loss (dB) parameter, if you specify Decibels in the Mode field
This block accepts a column vector input signal. The input signal to this block must be a complex
signal.
Receiver Thermal Noise:
The Receiver Thermal Noise block simulates the effects of thermal noise on a complex, baseband
signal. You can specify the amount of thermal noise in three ways, according to which Specification
method. Noise temperature specifies the noise in degrees kelvin.

3. AGC:
Automatic gain control (AGC) is an adaptive system in which average output signal level is fed back
to adjust the gain to an appropriate level for a range of input signal levels. In AGC, weaker signals
receive more gain and stronger signals receive less gain.
16-PSK Demodulator:
The 16-PSK Demodulator Baseband block demodulates a signal that was modulated using the 16-ary
phase shift keying method. The input is a baseband representation of the modulated signal. The input
and output for this block are discrete-time signals. This block accepts a scalar-valued or column vector
input signal.
Error Rate Calculation:
The Error Rate Calculation block compares input data from a transmitter with input data from a
receiver. It calculates the error rate as a running statistic, by dividing the total number of unequal pairs
of data elements by the total number of input data elements from one source.
We can use this block to compute either symbol or bit error rate, because it does not consider the
magnitude of the difference between input data elements. If the inputs are bits, then the block
computes the bit error rate. If the inputs are symbols, then it computes the symbol error rate.
Result:
Carrier Freq: 1000MHz Carrier Freq: 5000MHz Carrier Freq: 10000MHz
Conclusion
PSK technique is widely used in digital communication. Here I have designed it’s one of the
application using Simulink. In this mini project, link design in geostationary satellite communication
using 16 PSK is designed and simulated. During simulation it is observed that operating frequency is
very important parameter. as we increase carrier frequency, the probability of error increases rapidly.