Multi-layered architecture. OFDM modulator.

In previous article I briefly describe multi-layered architecture design pattern. In this post I want to show you some code which implement multi-layered architecture.

/* Main program */
int main()
{
	/* Declare layers */

	/* Infrastructure layer */
	Cworking_Infrastructure_Layer cworking_infrastructure;

	/* Application layer */
	Cworking_Application_Layer cworking_application;

	/* Presentation layer */
	Cworking_Presentation_Layer cworking_presentation;

	/* Declare input data */
	Cworking_Matrix_Data cworking_input_data;

	/* Declare modulated data */
	Cworking_Matrix_Data cworking_modulated_data;

	/* Declare output data */
	Cworking_Matrix_Data cworking_output_data;

	/* Initialize input and output data */
	cworking_infrastructure.cworking_allocate_matrix( cworking_input_data  );
	cworking_infrastructure.cworking_allocate_matrix( cworking_modulated_data );
	cworking_infrastructure.cworking_allocate_matrix( cworking_output_data );

	/* Load and parse input file */
	cworking_infrastructure.cworking_create_random_data( cworking_input_data );

	/* Plot chart */
	printf("\n-----------------------Input frame-----------------------\n\n");
	cworking_presentation.cworking_show_data( cworking_input_data );

	/* Run application */
	cworking_application.cworking_process_OFDM_modulation( cworking_input_data, cworking_modulated_data );

	printf("\n-----------------------Modulated frame-----------------------\n\n");
	cworking_presentation.cworking_show_data( cworking_modulated_data );

	/* Run application */
	cworking_application.cworking_process_OFDM_demodulation( cworking_modulated_data, cworking_output_data );

	printf("\n-----------------------Demodulated frame-----------------------\n\n");
	cworking_presentation.cworking_show_data( cworking_output_data );

	/* Clean memory */
	cworking_infrastructure.cworking_delete_matrix( cworking_input_data  );
	cworking_infrastructure.cworking_delete_matrix( cworking_modulated_data );
	cworking_infrastructure.cworking_delete_matrix( cworking_output_data );

	return 0;
}

In this listing we could distinguish infrastructure, application and presentation layers.

Infrastructure layer is responsible for data delivery. In this case it creates random radio frame with QPSK symbols. Furthermore infrastructure layer allocates and cleans memory.

Application layer is responsible for OFDM modulation and demodulation processes. OFDM modulator it is nothing other than the IFFT algorithm. Similarly OFDM demodulator it is exactly the FFT algorithm. Fast Fourier Transformation and its inverse version are implemented in separate digital signal processing library available on my GIT Hub profile [click].

Presentation layer prints the input, modulated and demodulated frames. Demodulated frame should be exactly the same as the input frame. Full code of this example is available also on my GIT Hub profile [click]. I encourage you to download the code. It will be still developed and I hope that in an interesting way.

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Multi-layered Architecture

Multi-layered architecture is a software architecture where different product responsibilities are handled by separate layers. The most common layers used are: user interface and presentation layers, application and business layers, infrastructure layer. Each of them might have its own sub-layers.

User interface and presentation layers provide some multi-modal interfaces which allow users to communicate with the designed system using different methods e.g: keyboard and mouse, speech, gestures and others. Please find that this layer might be implemented as a part of a web-service, stand-alone application with or without graphical user interface. Furthermore, multi-layered architecture allows to create presentation layer before others. It might be interesting especially for the people who want to improve a usability, appearance so these parts of the product which often mostly affect customers.

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