Finite state machines are widely used in digital circuit designs. Generally, when designing a state machine using an HDL, the synthesis tools will optimize away all states that cannot be reached and generate a highly optimized circuit. Sometimes, however, the optimization is not acceptable. For example, if the circuit powers up in an invalid state, or the circuit is in an extreme working environment and a glitch sends it into an undesired state, the circuit may never get back to its normal operating condition.
為了在CDMA系統(tǒng)中更好地應(yīng)用QDPSK數(shù)字調(diào)制方式，在分析四相相對移相（QDPSK)信號調(diào)制解調(diào)原理的基礎(chǔ)上，設(shè)計(jì)了一種QDPSK調(diào)制解調(diào)電路，它包括串并轉(zhuǎn)換、差分編碼、四相載波產(chǎn)生和選相、相干解調(diào)、差分譯碼和并串轉(zhuǎn)換電路。在MAX+PLUSⅡ軟件平臺上，進(jìn)行了編譯和波形仿真。綜合后下載到復(fù)雜可編程邏輯器件EPM7128SLC84-15中，測試結(jié)果表明，調(diào)制電路能正確選相，解調(diào)電路輸出數(shù)據(jù)與QDPSK調(diào)制輸入數(shù)據(jù)完全一致，達(dá)到了預(yù)期的設(shè)計(jì)要求。
Abstract:
In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase，and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.
NTL is a high-performance, portable C++ library providing data structures and algorithms for manipulating signed, arbitrary length integers, and for vectors, matrices, and polynomials over the integers and over finite fields.
Verilog and VHDL狀態(tài)機(jī)設(shè)計(jì)，英文pdf格式
State machine design techniques for Verilog and VHDL
Abstract : Designing a synchronous finite state Another way of organizing a state machine (FSM) is a common task for a digital logic only one logic block as shown in
engineer. This paper will discuss a variety of issues regarding FSM design using Synopsys Design Compiler . Verilog and VHDL coding styles will be 2.0 Basic HDL coding
presented. Different methodologies will be compared using real-world examples.
The Engineering Vibration Toolbox is a set of educational programs
written in Octave by Joseph C. Slater. Also included are a number of help files,
demonstration examples, and data files containing raw experimental data. The
codes include single degree of freedom response, response spectrum, finite
elements, numerical integration, and phase plane analysis.
Carrier-phase synchronization can be approached in a
general manner by estimating the multiplicative distortion (MD) to which
a baseband received signal in an RF or coherent optical transmission
system is subjected. This paper presents a unified modeling and
estimation of the MD in finite-alphabet digital communication systems. A
simple form of MD is the camer phase exp GO) which has to be estimated
and compensated for in a coherent receiver. A more general case with
fading must, however, allow for amplitude as well as phase variations of
the MD.
We assume a state-variable model for the MD and generally obtain a
nonlinear estimation problem with additional randomly-varying system
parameters such as received signal power, frequency offset, and Doppler
spread. An extended Kalman filter is then applied as a near-optimal
solution to the adaptive MD and channel parameter estimation problem.
Examples are given to show the use and some advantages of this scheme.
In this paper, a new family of Cassinian wave-guides
is proposed, simulating and calculation are finished with CST
Microwave Studio that based on Finite Integral Technique (FIT),
and some results are given. Electromagnetic field mode type of it
is TE, electromagnetic field is stronger near neck region, and
some resonance frequencies appear. The new Cassinian curve
wave-guides will possess higher power than ones of the
rectangular and elliptic wave-guides because the height at the
position where maximal electric field occurs is smaller.
A new cable fault location method based on
wavelet reconstruction is proposed. In this method the
difference between the currents of faulty phase and sound
phase under the high voltage pulse excitation is used as the
measured signal and is decomposed in multi-scale by wavelet
transform, then reconstructed in single scale. Comparing with
traditional fault location method by travelling wave, the
presented method will not be interfered by the reflected wave
from the branch joint of cables or from other positions where
the impedances are not matched and not be influenced by fault
types, otherwise, the reflected waves can be recognized even
the faulty position is near to the measuring terminal, at the
same time, the influence of the wave speed uncertainty can be
reduced. The correctness of the proposed method is proved by
simulation results.
This title demonstrates how to develop computer programmes which solve specific engineering problems using the finite element method. It enables students, scientists and engineers to assemble their own computer programmes to produce numerical results to solve these problems. The first three editions of Programming the Finite Element Method established themselves as an authority in this area. This fully revised 4th edition includes completely rewritten programmes with a unique description and list of parallel versions of programmes in Fortran 90. The Fortran programmes and subroutines described in the text will be made available on the Internet via anonymous ftp, further adding to the value of this title.
