共查询到20条相似文献,搜索用时 31 毫秒
1.
Vidhyacharan Bhaskar 《International Journal of Wireless Information Networks》2007,14(4):237-250
This paper formulates a finite-state Markov channel model to represent received signal-to-noise (SNR) ratios having lognormal,
K-distribution, chi-square (central) and chi-square (non-central) distributions in a slow fading channel. The range of the
SNRs is partitioned into a finite number of states following earlier works in literature. Performance measures like level
crossing rates, steady-state probabilities, transition probabilities, and state-time durations are derived, and numerical
results are plotted and discussed for the FSMC models for all the distributions.
相似文献
Vidhyacharan BhaskarEmail: |
2.
In this paper, a closed-form expression for the probability of error in a coherent BPSK system over Generalized Rayleigh fading
channels is derived. An L-branch equal gain combining diversity scheme is used. Theoretical results for the probability of error are plotted for various
values of the number of degrees of freedom (n) and diversity order (L). A simulation is performed and the simulated results are found to match very well with the theoretical results.
相似文献
Vidhyacharan BhaskarEmail: |
3.
This work presents an M-ary multiple access code-selected direct sequence (DS) ultra wideband (UWB) communication system. A high data rate multiple
access UWB system can be obtained by a code selection mechanism. In the proposed system, each user is assigned a DS code set
with M/2 DS code sequence and a particular DS code sequence can be selected by the log2 (M/2) bits from the DS code set. More importantly for this M-ary UWB communication system, with the increase of the modulation level M, it allows to reduce the required transmitter power maintaining the number of users, the data transmission rate and the multiple
access performance. In this paper, we also introduce the detailed algorithm to compute the bit error rate (BER) over the AWGN
channel and correlation receivers.
相似文献
Kyungsup KwakEmail: |
4.
The foundations for the definition of the network of the future should be based on a correct user and community characterizations
to minimize the fragmentation of the experiences during the global interactions with information communication infrastructures.
This paper describes some of the complex objectives and main challenges that telecommunication solution and services have
to deal with in order to respect both specific requirements of global user interactions, habits and personalization, and framework
requirements about green environments.
相似文献
Pasquale DonadioEmail: |
5.
F. Angarita M. J. Canet T. Sansaloni A. Perez-Pascual J. Valls 《Journal of Signal Processing Systems》2008,52(2):181-191
In an orthogonal frequency division multiplexing-based wireless local area network receiver there are three operations that
can be performed by a unique coordinate rotation digital computer (CORDIC) processor since they are needed in different time
instants. These are the rotation of a vector, the computation of the angle of a vector and the computation of the reciprocal.
This paper proposes a common architecture of CORDIC algorithm suitable to implement the three operations with a reduced increase
of the hardware cost with respect to a single operation CORDIC. The proposed architecture has been validated on field programmable
gate-arrays devices and the results of the implementation show that area saving around 28% and throughput increment of 64%
are obtained.
相似文献
J. VallsEmail: |
6.
The measurement of the reverse breakdown voltage for power rectifier is an important test. Two test methods for the reverse
breakdown voltage measurement are employed in the industry, namely the forced voltage test (FVT) and the forced current test
(FCT). In this work, we perform a systematic study to explain the different breakdown voltages obtained from the two test
methods and the possible damage mechanisms to the device under test during FVT and FCT. The study shows that FVT has a much
shorter test time while FCT is less destructive to the device under test.
相似文献
Cher Ming TanEmail: |
7.
This paper is concerned with the problem of delay-dependent H
∞ control for two-dimensional (2-D) discrete state delay systems described by the second Fornasini and Marchesini (FM) state-space
model. Based on a summation inequality, a sufficient condition to have a delay-dependent H
∞ noise attenuation for this 2-D system is given in terms of linear matrix inequalities (LMIs). A delay-dependent optimal state
feedback H
∞ controller is obtained by solving an LMI optimization problem. Finally, a simulation example of thermal processes is given
to illustrate the effectiveness of the proposed result.
相似文献
Li Yu (Corresponding author)Email: |
8.
V. Torres A. Pérez-Pascual T. Sansaloni J. Valls 《Journal of Signal Processing Systems》2009,56(1):17-23
Timing recovery in communication systems with linear modulations is usually performed with a non-data-aided feedback loop
based on a fractional interpolator timing corrector and the Gardner’s timing error detector. The contribution of this paper
is twofold. First, some design rules are given to predict the behaviour of the loop if pipeline is used. Second, it is shown
that pipelining can be used to reduce power consumption in a timing feedback loop. A timing recovery loop has been implemented
in an FPGA device and power consumption measures indicates that by including 16 extra registers in the loop the power consumption
decreases a 63% and the synchronizer can process up to 66.5 MSPS.
相似文献
J. Valls (Corresponding author)Email: |
9.
Low Capture Switching Activity Test Generation for Reducing IR-Drop in At-Speed Scan Testing 总被引:1,自引:1,他引:0
Xiaoqing Wen Kohei Miyase Tatsuya Suzuki Seiji Kajihara Laung-Terng Wang Kewal K. Saluja Kozo Kinoshita 《Journal of Electronic Testing》2008,24(4):379-391
At-speed scan testing, based on ATPG and ATE, is indispensable to guarantee timing-related test quality in the DSM era. However,
at-speed scan testing may incur yield loss due to excessive IR-drop caused by high test (shift & capture) switching activity.
This paper discusses the mechanism of circuit malfunction due to IR-drop, and summarizes general approaches to reducing switching
activity, by which highlights the problem of current solutions, i.e. only reducing switching activity for one capture while
the widely used at-speed scan testing based on the launch-off-capture scheme uses two captures. This paper then proposes a
novel X-filling method, called double-capture (DC) X-filling, for generating test vectors with low and balanced capture switching activity for two captures. Applicable to dynamic & static
compaction in any ATPG system, DC X-filling can reduce IR-drop, and thus yield loss, without any circuit/clock modification, timing/circuit overhead, fault coverage
loss, and additional design effort.
相似文献
Xiaoqing WenEmail: |
10.
A new bit-parallel systolic multiplier over GF(2m) under the polynomial basis and normal basis is proposed. This new circuit is constructed by m
2 identical cells, each of which consists of one two-input AND gate, one three-input XOR gate and five 1-bit latches. Especially,
the proposed architecture is without the basis conversion as compared to the well-known multipliers with the redundant representation.
With this proposed multiplier, a parallel-in parallel-out systolic array has also been developed for computing inversion and
division over GF(2m). The proposed architectures are well suited to VLSI systems due to their regular interconnection pattern and modular structure.
相似文献
Che Wun ChiouEmail: |
11.
H.264/AVC is the latest video coding standard adopting variable block size motion estimation (VBS-ME), quarter-pixel accuracy,
motion vector prediction and multi-reference frames for motion estimation. These new features result in much higher computation
requirements than previous coding standards. In this paper we propose a novel most significant bit (MSB) first bit-serial
architecture for full-search block matching VBS-ME, and compare it with systolic implementations. Since the nature of MSB-first
processing enables early termination of the sum of absolute difference (SAD) calculation, the average hardware performance
can be enhanced. Five different designs, one and two dimensional systolic and tree implementations along with bit-serial,
are compared in terms of performance, pixel memory bandwidth, occupied area and power consumption.
相似文献
Philip H. W. Leong (Corresponding author)Email: |
12.
This letter deals with robust direction of arrival (DOA) estimation based on the recursive H
∞ algorithm for the forward linear predictor. This recursive H
∞ criterion is different from traditional H
2 estimation criterions which minimize the squared prediction error. The forward linear predictor with recursive H
∞ algorithm is a worst case optimization approach, which minimizes the total effect of the worst disturbances on the prediction
error. Some computer simulation examples are provided for illustrating the effectiveness of the proposed method.
相似文献
Ann-Chen ChangEmail: |
13.
Xianwei Zhou Lin Lin Jianping Wang Xuesong Zhang 《Wireless Personal Communications》2009,49(1):123-131
In this paper, the cross-layer design routing in cognitive radio(CR) networks is studied. We propose a colored multigraph
based model for the temporarily available spectrum bands, called spectrum holes in this paper. Based on this colored multigraph
model, a polynomial time algorithm with complexity O(n
2) is also proposed to develop a routing and interface assignment, where n is the number of nodes in a CR network. Our algorithm optimizes the hop number of routing, meanwhile, the adjacent hop interference
(AHI) is also optimized locally.
相似文献
Lin Lin (Corresponding author)Email: |
14.
Chia-Hsin Cheng Jen-Yung Lin Chao-Kai Wen Jyh-Horng Wen 《Wireless Personal Communications》2009,48(2):311-325
In this paper, a convenient signaling scheme, called orthogonal on–off BPSK (O3BPSK), along with a simple one-shot linear decorrelating detector (LDD) and a whitening Rake bank, is proposed for near–far
resistant detection in asynchronous DS/CDMA systems. Based on the maximum multi-path spreading delay, a minimum duration of
“off” is suggested, during which the temporally adjacent bits (TABs) that contain multi-user interference (MUI) and inter-symbol
interference (ISI) from different users at the receiver are decoupled. The O3BPSK signaling scheme is combined with the whitening Rake receiver to preserve multi-path diversity gain in multi-path fading
CDMA channels. The scheme offers low complexity, no detection delay, near–far resistance, and compensation for fading channels.
相似文献
Jyh-Horng Wen (Corresponding author)Email: |
15.
János Szigeti Ricardo Romeral Tibor Cinkler David Larrabeiti 《Photonic Network Communications》2009,17(1):35-47
Providing resilient inter-domain connections in multi-domain optical GMPLS networks is a challenge. On the one hand, the integration
of different GMPLS domains to run traffic engineering operations requires the development of a framework for inter-domain
routing and control of connections, while keeping the internal structure and available resources of the domains undisclosed
to the other operators. On the other hand, the definition of mechanisms to take advantage of such automatically switched inter-domain
connectivity is still an open issue. This article focuses on the analysis of applicability of one of these mechanisms: P-cycle-based protection. The proposed solution is based on the decomposition of the multi-domain resilience problem into two
sub-problems, namely, the higher level inter-domain protection and the lower level intra-domain protection. Building a P-cycle at the higher level is accomplished by certain tasks at the lower level, including straddling link connection, capacity
allocation and path selection. In this article, we present several methods to realize inter-domain P-cycle protection at both levels and we evaluate their performance in terms of availability and spent resources. A discussion
on a proposal of implementation of signalling based on extensions of existing protocols such as RSVP-TE and the PCE architecture
illustrates the practical viability of the approach.
相似文献
David LarrabeitiEmail: |
16.
In this paper, we deal with delay-independent and delay-dependent H
∞ filtering problems for a class of two-dimensional (2-D) discrete time-invariant systems with state delays. The 2-D systems
are described by local state-space (LSS) Fornasini–Marchesini (FM) second model. First, delay-dependent bounded real lemma
is proposed through introducing free weighting matrices. Then the delay-independent and delay-dependent H
∞ filtering designs are developed to assure the stability and H
∞ performance γ of filtering error systems via LMIs’ feasibility. Furthermore, the minimum H
∞ norm bound γ can be obtained by solving linear convex optimization problems. Numerical examples demonstrate the effectiveness and advantages
of our results.
相似文献
Xinping GuanEmail: |
17.
Yung-Chia Lin Chia Han Lu Chung-Ju Wu Chung-Lin Tang Yi-Ping You Ya-Chaio Moo Jenq-Kuen Lee 《Journal of Signal Processing Systems》2008,51(3):269-288
The compiler is generally regarded as the most important software component that supports a processor design to achieve success.
This paper describes our application of the open research compiler infrastructure to a novel VLIW DSP (known as the PAC DSP
core) and the specific design of code generation for its register file architecture. The PAC DSP utilizes port-restricted,
distributed, and partitioned register file structures in addition to a heterogeneous clustered data-path architecture to attain
low power consumption and a smaller die. As part of an effort to overcome the new challenges of code generation for the PAC
DSP, we have developed a new register allocation scheme and other retargeting optimization phases that allow the effective
generation of high quality code. Our preliminary experimental results indicate that our developed compiler can efficiently
utilize the features of the specific register file architectures in the PAC DSP. Our experiences in designing compiler support
for the PAC VLIW DSP with irregular resource constraints may also be of interest to those involved in developing compilers
for similar architectures.
相似文献
Jenq-Kuen Lee (Corresponding author)Email: |
18.
A. Pérez-Pascual T. Sansaloni V. Torres V. Almenar J. Valls 《Journal of Signal Processing Systems》2009,56(1):35-40
This paper shows that when a digital receiver is designed utilizing two clock scopes, the digital down-converter can be designed
to be efficient in terms of area and power consumption. The main design parameter that contributes to make the design efficient
is the relationship between the transition band of the designed filter and its sampling frequency.
相似文献
J. VallsEmail: |
19.
As high-speed networks grow in capacity, network protection becomes increasingly important. Recently, following interest in p-cycle protection, the related concept of p-trees has also been studied. In one line of work, a so-called “hierarchical tree” approach is studied and compared to p-cycles on some points. Some of the qualitative conclusions drawn, however, apply only to p-cycle designs consisting of a single Hamiltonian p-cycle. There are other confounding factors in the comparison between the two, such as the fact that, while the tree-based approach is not 100% restorable, p-cycles are. The tree and p-cycle networks are also designed by highly dissimilar methods. In addition, the claims regarding hierarchical trees seem to contradict earlier work, which found pre-planned trees to be significantly less capacity-efficient than p-cycles. These contradictory findings need to be resolved; a correct understanding of how these two architectures rank in terms of capacity efficiency is a basic issue of network science in this field. We therefore revisit the question in a definitive and novel way in which a unified optimal design framework compares minimum capacity, 100% restorable p-tree and p-cycle network designs. Results confirm the significantly higher capacity efficiency of p-cycles. Supporting discussion provides intuitive appreciation of why this is so, and the unified design framework contributes a further theoretical appreciation of how pre-planned trees and pre-connected cycles are related. In a novel further experiment we use the common optimal design model to study p-cycle/p-tree hybrid designs. This experiment answers the question “To what extent can a selection of trees compliment a cycle-based design, or vice-versa?” The results demonstrate the intrinsic merit of cycles over trees for pre-planned protection. 相似文献
20.
Lennart Yseboodt Michael De Nil Jos Huisken Mladen Berekovic Qin Zhao Frank Bouwens Jos Hulzink Jef Van Meerbergen 《Journal of Signal Processing Systems》2009,57(1):107-119
Wireless sensor nodes span a wide range of applications. This paper focuses on the biomedical area, more specifically on healthcare
monitoring applications. Power dissipation is the dominant design constraint in this domain. This paper shows the different
steps to develop a digital signal processing architecture for a single channel electrocardiogram application, which is used
as an application example. The target power consumption is 100 μW as that is the power energy scavengers can deliver. We follow
a bottleneck-driven approach: first the algorithm is tuned to the target processor, then coarse grained clock-gating is applied,
next the static as well as the dynamic dissipation of the digital processor is reduced by tuning the core to the target domain.
The impact of each step is quantified. A solution of 11 μW is possible for both radio and DSP running the electrocardiogram
algorithm.
相似文献
Jef Van MeerbergenEmail: |