How to solve the RESHAPE error ?

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Supratik Das 2022-3-24

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链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1679204-how-to-solve-the-reshape-error

评论： Stephen23 2022-3-24

CODE:

%% *Nakagami-m Fading Channel*
clc;clear all;close all;
N = 10^6; % number of bits or symbols
Eb_N0_dB = (0:25); % multiple Eb/N0 values
nTx = 2;
nRx = 2;
m = 2;
for ii = 1:length(Eb_N0_dB)
    
    % Transmitter
    ip = rand(1,N)>0.5; % generating 0,1 with equal probability
    s = 2*ip-1; % BPSK modulation 0 -> -1; 1 -> 0
    
    sMod = kron(s,ones(nRx,1)); %
    sMod = reshape(sMod,[nRx,nTx,N/nTx]); % grouping in [nRx,nTx,N/NTx ] matrix
    
    h = nak_m(m,nRx,nTx);  % Nakagami-m channel
    n = 1/sqrt(2)*(randn(nRx,N/nTx) + 1j*randn(nRx,N/nTx)); % white gaussian noise, 0dB variance
    
    % Channel and noise Noise addition
    y = squeeze(sum(h.*sMod,2)) + 10^(-Eb_N0_dB(ii)/20)*n;
    
    % Receiver
    
    % Forming the Zero Forcing equalization matrix W = inv(H^H*H)*H^H
    % H^H*H is of dimension [nTx x nTx]. In this case [2 x 2]
    % Inverse of a [2x2] matrix [a b; c d] = 1/(ad-bc)[d -b;-c a]
    hCof = zeros(2,2,N/nTx)  ;
    hCof(1,1,:) = sum(h(:,2,:).*conj(h(:,2,:)),1);  % d term
    hCof(2,2,:) = sum(h(:,1,:).*conj(h(:,1,:)),1);  % a term
    hCof(2,1,:) = -sum(h(:,2,:).*conj(h(:,1,:)),1); % c term
    hCof(1,2,:) = -sum(h(:,1,:).*conj(h(:,2,:)),1); % b term
    hDen = ((hCof(1,1,:).*hCof(2,2,:)) - (hCof(1,2,:).*hCof(2,1,:))); % ad-bc term
    hDen = reshape(kron(reshape(hDen,1,N/nTx),ones(2,2)),2,2,N/nTx);  % formatting for division
    hInv = hCof./hDen; % inv(H^H*H)
    
    hMod =  reshape(conj(h),nRx,N); % H^H operation
    
    yMod = kron(y,ones(1,2)); % formatting the received symbol for equalization
    yMod = sum(hMod.*yMod,1); % H^H * y
    yMod =  kron(reshape(yMod,2,N/nTx),ones(1,2)); % formatting
    yHat = sum(reshape(hInv,2,N).*yMod,1); % inv(H^H*H)*H^H*y
    
    % receiver - hard decision decoding
    ipHat = real(yHat)>0;
    
    % counting the errors
    nErr(ii) = size(find([ip- ipHat]),2);
    
end
simBer = nErr/N; % simulated ber
EbN0Lin = 10.^(Eb_N0_dB/10);
theoryBer_nRx1 = 0.5.*(1-1*(1+1./EbN0Lin).^(-0.5));
p = 1/2 - 1/2*(1+1./EbN0Lin).^(-1/2);
theoryBerMRC_nRx2 = p.^2.*(1+2*(1-p));
close all
figure
semilogy(Eb_N0_dB,theoryBer_nRx1,'bp-','LineWidth',2);
hold on
semilogy(Eb_N0_dB,theoryBerMRC_nRx2,'kd-','LineWidth',2);
semilogy(Eb_N0_dB,simBer,'mo-','LineWidth',2);
axis([0 25 10^-5 0.5])
grid on
legend('theory (nTx=1,nRx=1)', 'theory (nTx=1,nRx=2, MRC)', 'sim (nTx=2, nRx=2, ZF)');
xlabel('Average Eb/No,dB');
ylabel('Bit Error Rate');
title('BER for BPSK modulation with 2x2 MIMO and ZF equalizer (Nakagami-m Channel)');

ERROR:

Error using reshape

To RESHAPE the number of elements must not change.
hMod =  reshape(conj(h),nRx,N); % H^H operation

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Supratik Das 2022-3-24

Size of conj(h) to be 2x1e6

Stephen23 2022-3-24

在 MATLAB Online 中打开

Using the values provided in your original question and the function you provided in this comment:

nTx = 2;
nRx = 2;
m = 2;
h = nak_m(m,nRx,nTx) % please explain how h should have size 2x1e6.
h = 
  -0.4009 + 0.1983i  -0.2413 + 1.1134i
  -1.0830 + 0.1033i   0.4586 - 0.6362i
function H3=nak_m(m,nRx,nTx)
n=zeros(nRx,nTx);
for i=1:2*m
    n=n+randn(nRx,nTx).^2;
end
n=n/(2*m);
phi=2*pi*rand(nRx,nTx);
H3=(n.^0.5).*cos(phi)+1j*(n.^0.5).*sin(phi);
end