Hi everyone,(adsbygoogle = window.adsbygoogle || []).push({});

I am a new engineer just work in the real industry, so I would like to collect more experience from the real project.

I am working on the Multipath problem, but I've not done before in the University, and really do not know how to solve it.

During the discussion from the professor which I can wrote down from the pdf file (attached below).

My responsibility: how to detect multipath?

Here are what I have?

0. Choose the simplest situation that is 1 direct signal and 1 multipath signal.

1. Center frequency of the TV station: fc = 533 MHz, and bandwidth: B = 6 MHz

2. Equation for electromagnetic: k = 2*pi/λ

3. Distance between 2 RX antennas : d1 = 10 cm (Software Define Radio with dual antenna)

4. Time delay indoor : ζ from 10 - 1000 (ns)

5. Angle θ = ± pi/2 ( everytime turn the angle pi/2 or -pi/2) (angle between RX and TX)

6. Distance between 2 RX antenna to TX antenna d2 = 4.3 km

7. Amplitude: a0 = 1 (a0 is amplitude for direct signal LOS)

a1 = [0 1) (a1 is amplitude for multipath signal 1)

8. Equation for multipath: MUL = ∑ an * exp(j*(k*(x*cosθ + y*sinθ) - w( t - ζ )))

I do not know I did right or wrong? But If anyone who has done this before, please confirm with me, I would appreciate so much.

and If I did not do right, how I can fix it. Please give me suggestions.

Thank you very much.

Code (Matlab M):

% *****************************************************************

%%%%%%%%%%%% here is my code and plot %%%%%%%%%%%%%%

% *****************************************************************

%% multipath with 2 signals : Direct signal (Light Of Sight) and reflected signal

clear all; %close all

f_c = 533e6;

speed_of_light = 3e8 ; % m/s

d = 0.01; % distance between 2 rx antenna 10cm

lamda = speed_of_light / f_c; % wave length

k = (2 * pi) / lamda; % notation for electro-magnetic

w = 2 * pi * f_c;

a = [1 1/3]; % attenuation

x = [-d/2 d/2];

y = [0 0];

alpha = [0 pi/2]; % turn every time by (pi/2)

tau = [0 0.1e-6]; % time delay

t = 0 : (pi / 100) : (pi * 1);

N_path = length(tau);

% *****************************************************************

% %%%%%%%%%%%%%% simple calculation %%%%%%%%%%%%%

% *****************************************************************

a0 = a(1);

a1 = a(2);

x0 = x(1);

x1 = x(2);

y0 = y(1);

y1 = y(2);

tau0 = tau(1);

tau1 = tau(2);

alpha0 = alpha(1);

alpha1 = alpha(2);

plane0 = x0 * cos(alpha0) + y0 * sin(alpha0); %

plane1 = x1 * cos(alpha1) + y1 * sin(alpha1); % 3.417721599179047e-18

complex0 = k * plane0 - w * (t - tau0);

z_Direct_signal = a0 * exp(j*complex0);

complex1 = k * plane1 - w * (t - tau1);

z_Reflected_signal = a1 * exp(j*complex1);

z_total = z_Direct_signal + z_Reflected_signal;

figure, subplot(2,2,1)

plot(real(z_Direct_signal),'r')

title('Direct Signal in Real');

subplot(2,2,2)

plot(imag(z_Direct_signal))

title('Direct Signal in Imaginary');

subplot(2,2,3)

plot(abs(z_Direct_signal));

title('Magnitude of LOS');

subplot(2,2,4)

plot(angle(z_Direct_signal));

title('Phase of LOS');

figure, subplot(2,2,1)

plot(real(z_Reflected_signal),'r')

title('Reflected Signal in Real');

subplot(2,2,2)

plot(imag(z_Reflected_signal))

title('Reflected Signal in Imaginary');

subplot(2,2,3)

plot(abs(z_Reflected_signal));

title('Magnitude of Reflected');

subplot(2,2,4)

plot(angle(z_Reflected_signal));

title('Phase of Reflected');

figure, subplot(2,2,1)

plot(real(z_total),'r')

title('total Signal in Real');

subplot(2,2,2)

plot(imag(z_Reflected_signal))

title('total Signal in Imaginary');

subplot(2,2,3)

plot(abs(z_Reflected_signal));

title('Magnitude of total');

subplot(2,2,4)

plot(angle(z_Reflected_signal));

title('Phase of total');

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# How to detect multipath?

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