Architecture and DSP Implementation of a DVB-S2 Baseband Demodulator

This paper presents the design and implementation of a baseband demodulator for DVB-S2 satellite receivers. In order to meet the requirements of different complex and multi-domain signal processing stages of the DVB-S2 baseband signal-flow, the presented architecture is based on efficient fixed-point implementation of the various demodulation algorithms and on the use of a dynamic time-sharing scheduler for the various DSP software tasks. The prototyping of the demodulator and its verification in the design of a complete digital DVB-S2 satellite receiver using a versatile testbed is also presented

Multipath Characterization of Indoor Power Line Networks

The time- and frequency-varying behavior of an indoor power-line network is the result of variable impedance loads connected to its termination points. In fact, any signal transmitted through such a communications network is subject to time-varying multipath fading. In this paper, an analytical calculation method is presented, which can be used to determine the multipath components of any point-to-point channel in the indoor power-line environment. The method calculates all transmission characteristics of the network and, therefore, it can be exploited in the process of designing proper transmission algorithms for optimizing system performance. The proposed method is applied to an example network to demonstrate its usefulness in explaining the network's time-dependent behavior and in estimating channel parameters, such as subchannel bandwidth, multipath delay spread, fading conditions, etc

From Protocol Models to Their Implementation: A Versatile Testing Methodology

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ADSL Binder Modeling: Signaling and Data Transmission

This paper presents a simulation model of a binder of asymmetric digital subscriber lines (ADSL). The model is developed in the Simulink environment and enables the investigation of multicarrier communication aspects in the complex system of a loop binder interconnecting the customer premises with the nearby central office. Key features of the model architecture are the update of the model block parameters during simulation and the interconnection of the simulation environment with a reprogrammable hardware platform that facilitates the substitution of selected model components with prototype circuit modules. The mixedlevel setup of the ADSL binder model and the hardware platform constitutes a versatile environment for the development and investigation of new single-modem and/or centralized algorithms for the ADSL technology

Transmission Systems Prototyping Based on Stateflow/Simulink Models

In this paper we describe an efficient methodology for rapid prototyping of data transmission systems based on Stateflow/Simulink models using a multi-level system development and testing approach. Transmission systems incorporate multi-domain functions and algorithms, i.e. physical layer circuits and communication protocol controllers. The Stateflow/Simulink environment enables the development of precise simulation models that include signal and protocol processing units. The proposed prototyping methodology is based on the progressive translation of high-level model blocks into hardware/software modules of the prototype architecture using custom and/or automated code generation tools. A custom data exchange and synchronization interface between the Stateflow/Simulink workspace and the circuit modules enables the integration of the simulation model and the prototyping platform into a complete functional system. The application of the proposed methodology in the development of an ADSL modem in a custom prototyping platform is also described

A Software-based Instrument for Testing and Monitoring Multi-processing Communications Devices

This paper presents a software-based instrument for testing and monitoring the behavior of complex communications systems that employ a number of interconnected DSPs. The instrument is based on a dynamic architecture that incorporates a set of distributed software probes for signal capturing and a central data acquisition unit for acquiring and post-processing of data. A high level application that is executed on a host computing machine enables command and control of the instrument’s mode of operation and performs the necessary post-processing for the analysis and visualization of the measurements data. The application of this approach in the design and development of a DVB-S2 receiver using a software-radio platform is presented