Designing of a transmitter and receiver for a communication system using Simulink

Hi everyone,

I wanted to model a transmitter and a receiver in a communication system using the help of Simulink but couldn't do it as I am new to simulink. Your help would be highly appreciated. I wanted to perform these steps in:

1. Generate an analog message signal and convert it into digital bits.
2. Perform source encoding onto the digital converted bits.
3. Perform Channel encoding onto the source encoded bits.
4. Perform pulse modulation using any of the modulation schemes.
5. Perform Bandpass modulation onto the modulated signal.

Once this is achieved, I would like to perform these steps in reverse order for designing the receiver.

Since I am new to Matlab and Simulink, your help would be highly appreciated. Looking forward to a positive response and Thanks in advance.

Answer 1

[Animesh]

Hi Hammad,

Let's see a sample process step by step.

Designing the Transmitter:

1. Generate an Analog Message Signal: You can use the Sine Wave block to generate an analog signal. Find it in the Library Browser under Sources. Drag and drop the Sine Wave block into your model.
2. Convert Analog Signal to Digital Bits: Use the Analog to Digital Converter (ADC) block from the Data Converter library. Connect the output of the Sine Wave block to the input of the ADC block.
3. Source Encoding: Source encoding in Simulink can be a bit abstract since it typically involves algorithmic compression or formatting. You may simulate this by simply ensuring your data is in a binary format. Consider using a MATLAB Function block for custom encoding scripts.
4. Channel Encoding: Channel encoding adds redundancy for error correction. You can use "General CRC Generator" Simulink block for cyclic redundancy check (CRC) code bits for each input data frame . For more information on this, consider going through the Error Detection and Correction documentation (https://mathworks.com/help/comm/ug/error-detection-and-correction.html).
5. Pulse Modulation: For pulse modulation, you can use blocks like Pulse Generator or a PWM Generator from the Sources or SimPowerSystems library, respectively. Adjust the parameters according to the modulation scheme you're interested in (e.g., PAM, PWM).
6. Bandpass Modulation: Lastly, to perform bandpass modulation, you might use the Modulator block found under Communications System Toolbox. Choose a modulation scheme (e.g., QAM, PSK).

Designing the Receiver:

The receiver essentially performs the inverse operations of the transmitter:

1. Demodulate the Signal: Use a corresponding Demodulator block from the Communications System Toolbox.
2. Pulse Demodulation: Depending on your pulse modulation scheme, you'll need to appropriately process the signal to demodulate it.
3. Channel Decoding: Use blocks a corresponding decoder from the Error Detection and Correction library.
4. Source Decoding: If you implemented a specific source encoding, reverse that process here, potentially using a MATLAB Function block for custom decoding logic.
5. Digital to Analog Conversion (DAC): Finally, use a Digital to Analog Converter block to convert the digital signal back to an analog format.

I hope this helps!

Animesh

[Hammad]

Hi Animesh,

I hope this message finds you well. I wanted to extend my heartfelt thanks for the assistance you provided on the forum regarding my issue in designing of a transmitter and receiver in a communication system using Simulink. Your guidance was incredibly valuable and made a significant difference in resolving the problem.

I also apologize for the delay in my response. Life has been quite hectic lately, but I wanted to make sure to take the time to properly thank you for your help.

Your expertise and willingness to assist are greatly appreciated. Thank you once again!

Best regards,

Hammad Manzoor