sigsetpl.m

数字通信第四版原书的例程

function z=sigsetpl(nir, air, pir);
%SIGSETPL Plots the ASK/PSK constellation.
%       SIGSETPL(NIR, AIR, PIR) plots the QASK circle constellation with the
%       number in each circle specified in NIC (Number_In_Circle); amplitude
%       in each circle specified in AIC (Amplitude_In_Circle); and phase in
%       each circle specified in PIC (Phase_In_Circle);
%
%       SIGSETPL(NIR, AIR) plots the QASK circle constellation with default
%       zero PIC.
%
%       SIGSETPL(NIR) plots the QASK circle constellation with default unit
%       increment for each circle AIC.
%
%       Y = SIGSETPL(...) outputs a complex vector with its real part as the
%       in-phase value and the imaginary part as the quadrature value.
%
%       See also MODMAP, DMOD, DMOCE.

%       Wes Wang 5/3/94, 10/11/95.
%       Copyright (c) 1995-96 by The MathWorks, Inc.
%       $Revision: 1.1 $  $Date: 1996/04/01 18:03:20 $

if nargin <= 0
    disp('usage: SIGSETPL(NIR, AIR, PIR)');
    return
end;

m = length(nir);
if nargin <= 1
    air = [1:m];
end;

if nargin <= 2
    pir = zeros(1,m);
end;

cax = newplot;
hold_state = ishold;
j=sqrt(-1);
z = exp(j*[0:100]*pi/50);
x=real(z); y=imag(z);
plot(x*max(air), y*max(air));
if ~hold_state
    hold on
end;
zz=axis*1.05;
plot(zz(1:2),[0,0],'w');
plot([0,0],zz(3:4),'w');
z=[];
for i = 1:m
    for k = 1:nir(i)
        z = [z air(i)*exp(j*((k-1)*2*pi/nir(i)+pir(i)))];
    end;
    if (i ~= m)
        plot(x*air(i), y*air(i));
    end;
end;
% plot the ASK/PSK signal.
plot(z,'*r');

if ~hold_state
    axis('equal');
    axis('off');   
    text(zz(1)+(zz(2)-zz(1))/8, zz(3)-(zz(4)-zz(3))/30, 'ASK/PSK Signal Set Design Pattern');
    hold off;
end;