27,884 research outputs found
A Novel Design and Implementation of FBMC Transceiver for Low Power Applications
The complex structure of the Filter Bank Multicarrier (FBMC) communication system is the main drawback affecting the performance of the system and causes a high-power consumption. The complexity arises from using a polyphase filter bank, which consists of fast Fourier Transform/ Inverse Fast Fourier Transform (FFT/IFFT) processors and a filter bank of Finite Impulse Response (FIR) filters. This paper presents the analysis and the implementation of a new design model for FBMC transceiver in which the polyphase filter is removed completely in both transmitter and receiver and uses instead of it, a multi-level cascaded structure of FIR subfilters. The coefficients of each subfilter selected using an optimization algorithm to minimize the amplitude of sidelobes compared to the amplitude of the main lobe in the frequency response of the subfilter. The proposed design reduces the number of multiplications compared to the conventional design by 65%. The field-programmable gate array (FPGA) implementation results indicate that the proposed architecture saves 24% of resources of the FPGA board, works faster, and saves 27% of power consumption compared to conventional FBMC transceiver
Receiver Design for DCT Based Multicarrier Signals
DCT based multicarrier system also known as
fast orthogonal frequency division multiplexing (FOFDM)
is a promising multicarrier transmission technique that
requires half the subcarrier spacing compared to conventional
OFDM technique. The signal processing complexity
and power consumption of such system is also less
due to its real arithmetic operations compared to DFT
based system (OFDM) that require complex arithmetic
operations. However, unlike OFDM, FOFDM requires a
finite impulse response (FIR) front-end pre-filter at the
receiver to achieve single-tap equalization for simplifying
the receiver design. The receiver design can be further
improved using the fact that FOFDM system transmits
real valued symbols compared to complex valued symbols
in conventional OFDM. This fact enabled us to improve the
system performance by exploiting the improperness of such
DCT based multicarrier signals using widely linear processing
(WLP). In this paper, a novel equalization technique
using WLP is proposed to effectively improve the system
performance, and it is shown that the proposed FOFDM
receiver can provide better estimate of the tra
NATURAL ALGORITHMS IN DIGITAL FILTER DESIGN
Digital filters are an important part of Digital Signal Processing (DSP), which plays
vital roles within the modern world, but their design is a complex task requiring a great
deal of specialised knowledge. An analysis of this design process is presented, which
identifies opportunities for the application of optimisation.
The Genetic Algorithm (GA) and Simulated Annealing are problem-independent
and increasingly popular optimisation techniques. They do not require detailed prior
knowledge of the nature of a problem, and are unaffected by a discontinuous search
space, unlike traditional methods such as calculus and hill-climbing.
Potential applications of these techniques to the filter design process are discussed,
and presented with practical results. Investigations into the design of Frequency Sampling
(FS) Finite Impulse Response (FIR) filters using a hybrid GA/hill-climber proved
especially successful, improving on published results. An analysis of the search space
for FS filters provided useful information on the performance of the optimisation technique.
The ability of the GA to trade off a filter's performance with respect to several design
criteria simultaneously, without intervention by the designer, is also investigated.
Methods of simplifying the design process by using this technique are presented, together
with an analysis of the difficulty of the non-linear FIR filter design problem from
a GA perspective. This gave an insight into the fundamental nature of the optimisation
problem, and also suggested future improvements.
The results gained from these investigations allowed the framework for a potential
'intelligent' filter design system to be proposed, in which embedded expert knowledge,
Artificial Intelligence techniques and traditional design methods work together. This
could deliver a single tool capable of designing a wide range of filters with minimal
human intervention, and of proposing solutions to incomplete problems. It could also
provide the basis for the development of tools for other areas of DSP system design
On the eigenfilter design method and its applications: a tutorial
The eigenfilter method for digital filter design involves the computation of filter coefficients as the eigenvector of an appropriate Hermitian matrix. Because of its low complexity as compared to other methods as well as its ability to incorporate various time and frequency-domain constraints easily, the eigenfilter method has been found to be very useful. In this paper, we present a review of the eigenfilter design method for a wide variety of filters, including linear-phase finite impulse response (FIR) filters, nonlinear-phase FIR filters, all-pass infinite impulse response (IIR) filters, arbitrary response IIR filters, and multidimensional filters. Also, we focus on applications of the eigenfilter method in multistage filter design, spectral/spacial beamforming, and in the design of channel-shortening equalizers for communications applications
Finite impulse response filter design using a forward orthogonal least squares algorithm
This paper is concerned with the application of
forward Orthogonal Least Squares (OLS) algorithm to the design of Finite Impulse Response (FIR) filters. The focus of this study is a new FIR filter design procedure and to compare this with traditional methods known as the fir2() routine, provided by MATLAB
NIKEL: Electronics and data acquisition for kilopixels kinetic inductance camera
A prototype of digital frequency multiplexing electronics allowing the real
time monitoring of microwave kinetic inductance detector (MKIDs) arrays for
mm-wave astronomy has been developed. Thanks to the frequency multiplexing, it
can monitor simultaneously 400 pixels over a 500 MHz bandwidth and requires
only two coaxial cables for instrumenting such a large array. The chosen
solution and the performances achieved are presented in this paper.Comment: 21 pages, 14 figure
Design and analysis of a control system for an optical delay-line circuit used as reconfigurable gain equalizer
The design and analysis of a control system for a coherent two-port lattice-form optical delay-line circuit used as reconfigurable gain equalizer is presented. The design of the control system, which is based on a real device model and a least-square optimization method, is described in detail. Analysis on a five-stage device for the 32 possible solutions of phase parameters showed that, for some filter characteristics, the variations in power dissipation can vary up to a factor of 2. Furthermore, the solution selection has influence on the optimization result and number of iterations needed. A sensitivity analysis of the phase parameters showed that the allowable error in the phase parameters should not exceed a standard deviation of /spl pi//500 in order to achieve a total maximal absolute accuracy error not greater than approximately 0.6 dB. A five-stage device has been fabricated using planar lightwave circuit technology that uses the thermooptic effect. Excellent agreement between simulations and measurements has been achieved
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