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In the past three decades, Field Programmable Gate Arrays (FPGAs) have emerged to be the backbone of digital signal processing, especially in high-speed communication systems. However, today, these devices are clocked below 1GHz and improvement in performance stays a big challenge on all abstraction layers, right from system architecture down to physical technology. Far and wide, myriad number of researches are done on methodologies and techniques which can deliver higher throughput with lower operating frequencies. Towards this projected objective, in this paper an efficient modulation technique like Quadrature Amplitude Modulation (QAM) along with mixed time and frequency domain approach and Forward Error Correction (FEC) technique have been utilized to employ a generic scalable FPGA based QAM transmitter with filter parallelization being executed in mixed domain. The system developed in this paper achieves an effective throughput of 12.8Gb/s for 256-QAM with 16 parallel inputs having an operating frequency of 201.25MHz, while a 18.7Gb/s effective throughput is realized with 32 parallel inputs at 146MHz. Thereby, it paves down a promising methodology for applications where having higher clock frequencies is a hard limit.

A promising candidate for sensitive imaging of breast cancer is 3D Ultrasound Computer Tomography (3D USCT). So far its clinical applicability for diagnosis has been limited by the duration of the demanding image reconstruction. In this paper we investigate how signal processing and image reconstruction can be accelerated for diagnosis by using heterogeneous hardware. Additionally, the time and costs for real-time system for a future diagnosis and therapy device is estimated. Reusing the device's built-in FPGA-based data acquisition system (DAQ) through reconfiguration results in a speed-up by a factor of 7 for signal processing and by a factor of 2 for image reconstruction. Applying cutting-edge single FPGAs and GPUs, speed-ups by a factor of 10 (FPGA) and 6 (GPU) for signal processing and 15 (FPGA) and 37 (GPU) for image reconstruction were achieved compared to a recent quad-core Intel Core-i7 CPU. Using quad-core CPUs and a cluster of eight GPUs allowed us for the first time to calculate volumes in less than 30 min with an overall speed-up by a factor of 47, enabling a first clinical study. Based on these results we extrapolated that real-time reconstruction for a therapeutic 3D USCT will be possible in the year 2020 if the trend in density follows the ITRS roadmap.

The need for efficient Finite Impulse Response (FIR) filters in high-speed applications targets Field Programmable Gate Arrays (FPGAs) as an effective and flexible platform for digital implementation. Although FIR filter offer advantages like linear phase characteristic, no feedback loops and good system stability, its convolution nature poises a challenge in parallelization due to data dependency and computational complexity. To resolve this, we propose a novel FPGA-based reconfigurable filter architecture, which processes several data samples in parallel and breaks down data interdependency in a spiral fashion. This generic pipelined-parallel filter is parameterizable in terms of filter order and degree of parallelization. Experimental results show a throughput of 7.2 GSPS with an operating frequency of only 450 MHz for a filter length of 11 with 16 parallel inputs. With parallelization of 4, it is 4.64 times faster than the state-of-the-art solution for a filter length of 16 and a promising 41% increase in throughput is achieved for a higher order of 61.

Virtual FPGAs add the benefits of increased flexibility and application portability on bitstream level across any underlying commercial off-the-shelf FPGAs at the expense of additional area and delay overhead. Hence it becomes a priority to tune the architecture parameters of the virtual layer. Thereby, the adoption of parameter recommendations intended for physical FPGAs can be misleading, as they are based on transistor level models. This paper presents an extensive study of architectural parameters and their effects on area and performance by introducing an extended parameterizable virtual FPGA architecture and deriving suitable area and delay models. Furthermore, a design space exploration methodology based on these models is carried out. An analysis of over 1400 benchmark-runs with various combinations of cluster and LUT size reveals high parameter sensitivity with variances up to \(\pm 95.9\%\) in area and \(\pm 78.1\%\) in performance and a discrepancy to the studies on physical FPGAs.

The flexibility of Field Programmable Gate Arrays (FPGAs) as well as their parallel processing capabilities make them a good choice for digital signal processing in communication systems. However, today, further improvements in performance hang in mid-air as we run into the frequency wall and FPGA based devices are clocked below 1 GHz. New methodologies which can cater performance optimization within the frequency wall limitation become highly essential. In this context, efficient modulation techniques like Quadrature Amplitude Modulation (QAM) and mixed time and frequency domain approach have been utilized in this paper to employ a generic scalable FPGA based QAM transmitter with the filter parallelization being executed in mixed domain. The system developed in this paper achieves a throughput of 4 Gb/s for QAM-16 format with a clock frequency as low as 62.5 MHz, thereby, paves down a promising methodology for applications where having higher clock frequencies is a hard limit.

The growing demands on high-speed data transmission over long distances require optimized communication systems with bandwidth efficient modulation techniques like Quadrature Amplitude Modulation (QAM). However, the various design parameters of these QAM based systems conflict each other and the complex interdependence makes it difficult and time consuming to appropriately tune the parameters towards an optimal solution for a given set of constraints. Therefore, throughout this paper we analyze various conflicting design parameters of QAM and derive objective optimized trade-offs. More specifically, we study in detail the effects and interdependencies of parameters in the matched filter, the Forward Error Correction (FEC) code pair and the modulation order and span the design and solution space through experimental and numerical results. We discuss the observed effects and show how a selection of parameters can be concluded under various constraints. Furthermore, a pareto optimality search on our design space points out the best combinations of modulation order, filter and FEC design parameters for maximizing the performance under various Signal-to-Noise Ratio (SNR) conditions of the channel. For instance, if the channel is constrained by a SNR of 10dB and the tolerable Bit Error Rate (BER) is 10−3, then 16-QAM with a required 2/3 FEC yields 33.3% higher performance than 64-QAM with a required 1/3 FEC. Thus, the outcomes of this paper are a comprehensive elaboration on the cross-effects of conflicting design parameters and a set of optimized solutions under various constraints.

Due to the ever-increasing complexity of embedded system design and the need for rapid system evaluations in early design stages, the use of simulation models known as Virtual Platforms (VPs) has been of utmost importance as they enable system modeling at higher abstraction levels. Since a typical VP features multiple interdependent components, VP libraries have been utilized in order to provide off-the-shelf models of commonly-used hardware components, such as CPUs. However, CPU power estimation is not adequately supported by existing VP libraries. In addition, existing power characterization techniques require architectural details which are not always available in early design stages. To address this issue, this paper proposes a technique for power annotation of CPU models targeting SystemC/TLM libraries in order to enable the accurate power estimation at higher abstraction levels. By using a set of benchmarks on a power-annotated SystemC/TLM model of Xilinx Microblaze soft-processor, it is shown that the proposed approach can achieve accurate power estimation in comparison to the real-system power measurements as the estimation error ranges from 0.47% up to 6.11% with an average of 2%.

This paper presents an on-going collaboration project, named TEAChER for providing breakthrough knowledge to students and young researchers on reconfigurable computing and advanced digital systems. The project is intended to cover topics like architectures and capabilities of field-programmable gate arrays, languages for the specification, modeling, and synthesis of digital systems. Furthermore design methods, computer-aided design tools, reconfiguration techniques and practical applications are taught. The virtual laboratory enables the remote students to easily interact with a set of reconfigurable platforms in order to control experiments through the internet. By using the user-friendly interface, the remote user can change predefined system parameters and observe system response either in textual, or graphical format. In addition such a virtual laboratory includes a booking system, which enables remote users to conduct experiments in advance.

Today, digital signal processing systems for applications like audio or video production are restricted as they do not exhaust the possibilities given by modern hardware. Reconfigurable hardware exploits a huge degree of parallelism and provides flexibility at an affordable energy budget, thus becoming a competitive alternative for high performance Digital Signal Processing (DSP) applications, previously dominated by general purpose processing cores and Application-Specific Integrated Circuits (ASICs). This paper describes the design and evaluation of a novel concept for adaptive signal processing on reconfigurable hardware by using an adaptive reverberation algorithm targeting real time streams. Novel solutions were adopted in several critical parts of the signal processing chain in order to achieve a high level of accuracy under real time constraints. Experimental results show the efficiency of the introduced implementation on a Virtex-7 FPGA, as we can provide reality accurate reverberation with ultra low latency of \(\sim 20.8\,\mu {}s\).

Field Programmable Gate Arrays (FPGA) are widely used to accelerate parallel applications by specialized hardware. Especially for data flow intensive applications FPGAs are very well suited to design application specific data paths with a certain degree of parallelism. Since most of applications also need control flow, the most common method is to design complex state machines that are realized in hardware. However, this often leads to very high and inefficient resource utilization on the target architecture for design parts that are not performance critical nor relevant for more efficient realizations. In this paper, we propose a generic VLIW-inspired Slot Architecture (ViSA), which combines two efficient objectives, the performance of parallel hardware and the low area utilization of custom processors. Furthermore, we introduce the methodology for mapping and debugging applications on the efficient ViSA architecture.We present experimental results of two corner case applications showing that our approach is suitable for ultra low power as well as high performance computing. Using the presented co-design methodology, we will conclude that ViSA enables the realization of multi-objective design spaces for various target domains. ViSA has extreme throughput at low operating frequencies leading to significant power and energy savings over state of the art architectures.

Field programmable Gate Arrays (FPGAs) promise a low power flexible alternative for implementing parallel applications. Compared to CPUs and GPUs, they suffer from slow development cycles due to the high complexity of application development and hardware incompatibilities. Towards this direction, we propose a platform-independent methodology and the supporting framework targeting efficient run-time application mapping onto FPGAs. Experimental results show that the introduced solution performs application placement and routing of multiple applications without any performance penalty as compared to state of art tools. Scalability of the framework was verified by mapping up to 73 applications per minute when it is executed on an 8 core system.

Partial reconfiguration is possible to deliver virtually unlimited hardware resources since it enables dynamic allocation and de-allocation of tasks onto a reconfigurable architecture, while the rest tasks continue to operate. However, in order to benefit from this flexibility, partial reconfiguration has to be appropriately applied. Among others, the placement of partial configuration data is a critical issue since it affects the fragmentation of hardware resources. In this paper we introduce a novel methodology for supporting partial reconfiguration with the usage of a Just-in-Time (JIT) Compilation framework. Experimental results with a number of benchmarks showed that the introduced solution performs application PaR 7.34× faster, as compared to the state-of-the-art tools, while it also leads to significant lower fragmentation of hardware resources.

System design, especially for low power embedded applications often profit from a heterogeneous target hardware platform. The application can be partitioned into modules with specific requirements e.g. parallelism or performance in relation to the provided hardware blocks on the multicore hardware. The result is an optimized application mapping and a parallel processing with lower power consumption on the different cores on the hardware. This paper presents a heterogeneous platform consisting of a microprocessor and a field programmable gate array (FPGA) connected via a standard AMBA bus. The novelty of this approach is that the FPGA is realized as virtual reconfigurable hardware upon a traditional off the shelf FPGA device. The advantage with this approach is that the specification of the virtual FPGA stays unchanged, independent to the underlying hardware and provides therefore features, which the exploited physical host FPGA cannot provide. A special feature of the presented virtual FPGA amongst others is the dynamic reconfigurability which is for example not available with all off the shelf FPGAs. Furthermore the concept of FPGA virtualization enables the re-use of hardware blocks on other physical FPGA devices. This paper presents the hardware platform and describes the tool chain for the heterogeneous system on chip.

The execution runtime usually is a headache for designers performing application mapping onto reconfigurable architectures. In this article we propose a methodology, as well as the supporting toolset, targeting to provide fast application implementation onto reconfigurable architectures with the usage of a Just-In-Time (JIT) compilation framework. Experimental results prove the efficiency of the introduced framework, as we reduce the execution runtime compared to the state-of-the-art approach on average by 53.5×. Additionally, the derived solutions achieve higher operation frequencies by 1.17×, while they also exhibit significant lower fragmentation ratios of hardware resources.