Consider a BPSK and a QPSK system for the following two cases: 1) The probability that the symbol 1 is sent and the probability that the symbol 0 is sent are all the same. 2) The probability that the symbol 1 is sent is two times than the probability that the symbol 0 is sent. Assume that the noise is Gaussian distributed with mean=0 and 2 = 1.
Main program running when workpiece is ready on deferent belt(deferent_ready=ture).
* Call Square_Wave subroutine to generate 0.5ms square wave on P1.2 to drive
* electromotor,then drive deferent belt step forward. When it steps to the measure
* zone, it stops to be measured. Then call A_D subroutine to transform analog
* signals to digital signals , after then call serial subroutine to transfer
* digital signals to PC. Call square wave subroutine to drive deferent belt step to
* original position waitting for defere ready flag to run the next circle.
function [R,k,b] = msc(A)
% 多元散射校正
% 輸入待處理矩陣，通過多元散射校正，求得校正后的矩陣
%% 獲得矩陣行列數
[m,n] = size(A);
%% 求平均光譜
M = mean(A,2);
%% 利用最小二乘法求每一列的斜率k和截距b
for i = 1:n
a = polyfit(M,A(:,i),1);
if i == 1
k = a(1);
b = a(2);
else
k = [k,a(1)];
b = [b,a(2)];
end
end
%% 求得結果
for i = 1:n
Ai = (A(:,i)-b(i))/k(i);
if i == 1
R = Ai;
else
R = [R,Ai];
end
end
The term economics is generally understood to mean sound
management. This is associated with openness, good faith, accurate
figures and integrity in company accounts, with transparency ensured
through satisfactory standards of good practice in relation to investors
and the clients who have placed their trust in an organization’s
managers.
This paper presents a Hidden Markov Model (HMM)-based speech
enhancement method, aiming at reducing non-stationary noise from speech
signals. The system is based on the assumption that the speech and the noise
are additive and uncorrelated. Cepstral features are used to extract statistical
information from both the speech and the noise. A-priori statistical
information is collected from long training sequences into ergodic hidden
Markov models. Given the ergodic models for the speech and the noise, a
compensated speech-noise model is created by means of parallel model
combination, using a log-normal approximation. During the compensation, the
mean of every mixture in the speech and noise model is stored. The stored
means are then used in the enhancement process to create the most likely
speech and noise power spectral distributions using the forward algorithm
combined with mixture probability. The distributions are used to generate a
Wiener filter for every observation. The paper includes a performance
evaluation of the speech enhancer for stationary as well as non-stationary
noise environment.
Telecommunications is today widely understood to mean the electrical means of
communicating over a distance. The first form of telecommunications was that of
the Telegraph, which was invented quite independently in 1837 by two scientists,
Wheatstone and Morse. Telegraphy was on a point-to-point unidirectional basis and
relied on trained operators to interpret between the spoken or written word and the
special signals sent over the telegraph wire. However, the use of telegraphy did
greatly enhance the operations of railways and, of course, the dissemination of news
and personal messages between towns.
This is a book on wireless communication. That usually means communica-
tion by radio, though ultrasound and infrared light are also used occasion-
ally. The term “wireless” has come to mean nonbroadcast communication,
usually between individuals who very often use portable or mobile equip-
ment. The term is rather vague, of course, and there are certainly borderline
applications that are called wireless without falling exactly into the above
definition.
