793 research outputs found
RECONFIGURABLE LOW POWER AND AREA EFFICIENT ESPFFIR FILTER USING VHBCSE MULTIPLIER
Reconfigurable Even Symmetric Parallel Fast Finite Impulse Response (RESPFFIR) filter shall be utilized as the Processing Element (PE) in Software Defined Radio (SDR) design to improve the throughput. The number of multipliers required in RESPFFIR filter increases when parallelism length increases. The Constant Multiplier (CM) technique is used to diminish the power consumption in FIR filters by reducing the number of Logical Operators (LO) and Logical Depth (LD). Binary Common Subexpression Elimination (BCSE) method is suitable to exploit symmetric coefficient in FIR filters. The Vertical Horizontal Binary Common Subexpression Elimination (VHBCSE) technique based Constant Multiplier (CM) design further diminish the number of LO and LD. The 2-bit BCSE algorithm has been applied vertically across neighboring coefficients and HCSE makes use of CSs that arise within each coefficient to eradicate redundant computations, which intern reduce logical operator in constant multiplier. This paper presents the design of Reconfigurable Even Symmetric Parallel Fast Finite Impulse Response (RESPFFIR) filter using VHBCSE based CM multiplier, which is reconfigurable with reduced power and area consumption without degrading the throughput. The power consumption reduces by 12% and the area required gets reduced by 24% in the proposed design when compared with existing CSE Hcub-n Multiple Constant Multiplier based ESPFFIR filter design. The analysis is done using Cadence RC synthesize tools
An Alternative Carry-save Arithmetic for New Generation Field Programmable Gate Arrays
In this work, a double carry-save addition operation is proposed, which is efficiently synthesized for 6-input
LUT-based eld programmable gate arrays (FPGAs). The proposed arithmetic operation is based on redundant number
representation and provides carry propagation-free addition. Using the proposed arithmetic operation, a compact and
fast multiply and accumulate unit is designed. To our knowledge, the proposed design provides the fastest multiply-add
operation for 6-input LUT-based FPGA systems. A nite impulse response lter implementation is given to show the
performance of the proposed structure. The proposed implementation provides a dramatic performance increase, which
is at least 2 times faster than conventional binary multiply-add implementations
Algorithms and architectures for the multirate additive synthesis of musical tones
In classical Additive Synthesis (AS), the output signal is the sum of a large number of independently controllable sinusoidal partials. The advantages of AS for music synthesis are well known as is the high computational cost. This thesis is concerned with the computational optimisation of AS by multirate DSP techniques. In note-based music synthesis, the expected bounds of the frequency trajectory of each partial in a finite lifecycle tone determine critical time-invariant partial-specific sample rates which are lower than the conventional rate (in excess of 40kHz) resulting in computational savings. Scheduling and interpolation (to suppress quantisation noise) for many sample rates is required, leading to the concept of Multirate Additive Synthesis (MAS) where these overheads are minimised by synthesis filterbanks which quantise the set of available sample rates. Alternative AS optimisations are also appraised. It is shown that a hierarchical interpretation of the QMF filterbank preserves AS generality and permits efficient context-specific adaptation of computation to required note dynamics. Practical QMF implementation and the modifications necessary for MAS are discussed. QMF transition widths can be logically excluded from the MAS paradigm, at a cost. Therefore a novel filterbank is evaluated where transition widths are physically excluded. Benchmarking of a hypothetical orchestral synthesis application provides a tentative quantitative analysis of the performance improvement of MAS over AS. The mapping of MAS into VLSI is opened by a review of sine computation techniques. Then the functional specification and high-level design of a conceptual MAS Coprocessor (MASC) is developed which functions with high autonomy in a loosely-coupled master- slave configuration with a Host CPU which executes filterbanks in software. Standard hardware optimisation techniques are used, such as pipelining, based upon the principle of an application-specific memory hierarchy which maximises MASC throughput
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Efficient FPGA implementation and power modelling of image and signal processing IP cores
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Field Programmable Gate Arrays (FPGAs) are the technology of choice in a number ofimage
and signal processing application areas such as consumer electronics, instrumentation,
medical data processing and avionics due to their reasonable energy consumption, high performance, security, low design-turnaround time and reconfigurability. Low power FPGA
devices are also emerging as competitive solutions for mobile and thermally constrained platforms. Most computationally intensive image and signal processing algorithms also consume a lot of power leading to a number of issues including reduced mobility, reliability concerns and increased design cost among others. Power dissipation has become one of the most important challenges, particularly for FPGAs. Addressing this problem requires optimisation and awareness at all levels in the design flow. The key achievements of the
work presented in this thesis are summarised here. Behavioural level optimisation strategies have been used for implementing matrix product and inner product through the use of mathematical techniques such as Distributed Arithmetic (DA) and its variations including offset binary coding, sparse factorisation and novel vector level transformations. Applications to test the impact of these algorithmic and arithmetic transformations include the fast Hadamard/Walsh transforms and Gaussian mixture models. Complete design space exploration has been performed on these cores, and where appropriate, they have been shown to clearly outperform comparable existing implementations. At the architectural level, strategies such as parallelism, pipelining and systolisation have been successfully applied for the design and optimisation of a number of
cores including colour space conversion, finite Radon transform, finite ridgelet transform and circular convolution. A pioneering study into the influence of supply voltage scaling for FPGA based designs, used in conjunction with performance enhancing strategies such as parallelism and pipelining has been performed. Initial results are very promising and indicated significant potential for future research in this area.
A key contribution of this work includes the development of a novel high level power macromodelling technique for design space exploration and characterisation of custom IP cores for FPGAs, called Functional Level Power Analysis and Modelling (FLPAM). FLPAM
is scalable, platform independent and compares favourably with existing approaches. A hybrid, top-down design flow paradigm integrating FLPAM with commercially available design tools for systematic optimisation of IP cores has also been developed
FFT and FIR Filter implementations for the DSL MODEMS
Broad band digital communication that operates over a standard copper wires. It requires
the DSL modems which splits the transmissions into 2 frequency bands. The lower frequencies for
voice and the higher frequencies for digital data (internet) in order to transmit the data to larger
distances through a copper cable we need modulation techniques. Generally in this DSL modems
modulation used is QAM technique. The output of the QAM is complex data this complex data we
cannot transfer directly through a copper cable because the data should be in time domain or
otherwise the phase of the data which is in frequency domain can be lost, in copper cable so this
data should be converted in time domain by using IDFT technique. As IDFT requires more
number of complex multiplications and more number of complex additions in comparison to IFFT
so to reduce the additions and multiplications IFFT technique is used. At the receiver side we can
retrieve the same data by using FFT technique. In this section the implemented FFT architecture is
fully efficient and this architecture will require less area. And before we have to transmit through
the copper line we have to do interpolation or decimation by using the Filtering operation. The
implemented poly phase architecture for the filtering is fully efficient, symmetrical and it requires
less number of multipliers
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