how can replace randi instead randint?

hi ;i have a question please help me , i want to replace randi instead randint in ofdm_basic code in r2017a , but i dont know how i must do it . please answer and help me . this is that line :

X=randint(1,Nused*Nframe,M); % bit: integer vector

Answer 1

[Jan]

Do you mean randint from the Communications Toolbox or is this from Octave code?

I assume, for both the answer is the same: It depends on what M is.

• [0, range-1] if range is a positive integer
• [range+1, 0] if range is a negative integer
• Between min and max, inclusive, if range = [min,max] or [max,min]

% X = randint(1, Nused*Nframe, M)
if length(M) == 1
  if M > 0
    Range = [0, M-1];
  else
    Range = [M+1, 0];
  end
else
  Range = [min(M), max(M)];
end

X = randi(Range, 1, Nused*Nframe);

I do not have this toolbox, but I guess that you should find something like this, if you look into the randint function:

edit randint

[mohamad gholami]

thank my friend . in next answer i explain . please read that

Answer 2

[Geoff Hayes]

mohamad - which ofdm_basic code are you referring to? Is this something found on the MATLAB FileExchange or something else? From Communications System Toolbox Release Notes, it looks like randint has been removed from the Communications System Toolbox and is to be replaced with randi.

If we assume that the code

 X=randint(1,Nused*Nframe,M)

creates a 1x(Nused*Nframe) matrix with integers in the interval [0,M-1], then we can replace the above with

 X = randi(M, 1, Nused*Nframe) - 1;

I think that will work...

[mohamad gholami]

hi my friend . this code is from this book : MIMO-OFDM Wireless Communications with MATLAB . this is the source code :

%OFDM_basic.m
clc
clear all 
close all
NgType=1; %NgType=1/2 for cyclic prefix/zeropadding
    if NgType==1, nt='CP'; 
    else
    end
        if NgType==2, nt='ZP'; 
        end
        Ch=0; %Ch=0/1 for AWGN/multipath channel 
            if Ch==0, chType='AWGN'; Target_neb=100; 
            else chType='CH'; Target_neb=500;
            end
figure(Ch+1),clf
PowerdB=[0 -8 -17 -21 -25]; %channel tap power profile 'dB' 
Delay=[0 3 5 6 8]; %channel delay 'sample' 
Power=10.^(PowerdB/10); %Channel tap power profile 'linear sample' 
Ntap=length(PowerdB); %Channel tap number 
Lch=Delay(end)+1; %Channel length
Nbps=4;
M=2^Nbps; %Modulation order =2//4/6for QPSK/16QAM/64QAM
Nfft=64; %FFT SIZE 
Ng=Nfft/4; %GI(Guard interval)length(Ng= for no GI) 
Nsym=Nfft+Ng; %Symbol duration
Nvc=Nfft/4; %Nvc=0: noVC(Virtual Carrier)
Nused=Nfft-Nvc;
EbN0=[0:5:30]; %EbN0 
N_iter=1e5; %Number of iterations for each EbN0 
Nframe=3; %Number of symbols per frame
sigPow=0; %Signal power initialization 
file_name=['OFDM_BER_' chType '_' nt '_''GL' num2str(Ng) '.dat'];
fid=fopen(file_name,'w+'); 
norms=[1 sqrt(2) 0 sqrt(10) 0 sqrt(42)];%BPSK 4-QAM 16-QAM 
        for i=0:length(EbN0)
            rng(0,'v5uniform');
            rng(0,'v5normal');
            %Ber2=ber(); %BER initialisation 
            Neb=0;
            Ntb=0; %Initialise the number of error/total bits 
            for m=1:N_iter %Tx__________________________________________________________________ 
                X=randint(1,Nused*Nframe,M); %bit:integer vector 
                Xmod=qammod(X,M,0,'gray')/norms(Nbps);
               % if Ngtype~=2, x_GI=zeros(1,Nframe*Nsym+Ng); %Extend an OFDM symbol by Ng zeros
                end
                kk1=[1:Nused/2];
                kk2=[Nused/2+1:Nused];
                kk3=1:Nfft;kk4=1:Nsym;
                for k=1:Nframe
                    if Nvc~=0, X_shift=[0 Xmod(kk2) zeros(1, Nvc-1) Xmod(kk1)];
                    else X_shift=[Xmod(kk2) Xmod(kk1)];
                    end
                    x=ifft(X_shift);
                    x_GI(kk4)=guard_interval(Ng,Nfft,NgType,x);
                    kk1=kk1+Nused;
                    kk2=kk2+Nused;
                    kk3=kk3+Nfft;
                    kk4=kk4+Nsym;
                end
                if Ch==0, y=x_GI; %No channel else %
                    multipath Fading channel=(randn(1,Ntap)+j*randn(1,Ntap)).*sqrt(Power/2);
                    h=zeros(1,Lch); h(Delay+1)=channel;%cir:channelimpulse response 
                    y =conv(x_GI,h);
                end
                if 1i==0 %only to measure signal power for adding AWGN noise 
                    y1= y(1:Nframe*Nsym);
                    sigPow=sigPow+y1*y1';
                    continue;
                end
                %Add AWGN noise________________________________________________ 
                snr = EbN0(i)+10*(Nbps*(Nused/Nfft)); %SNR vs Eb/N0 by Eq.(4.28) 
                noise_mag = sqrt((10.^(-snr/10))*sigPow/2);
                y_GI = y+ noise_mag*(randn(size(y)) +1j*randn(size(y)));
                %Rx________________________________________________________________________ 
                kk1=(NgType==2)*Ng+[1:Nsym];
                kk2=1:Nfft; 
                kk3=1:Nused; 
                kk4=Nused/2+Nvc+1:Nfft;
                kk5(Nvc~=0)+[1:Nused/2];
                if Ch==1
                    H=fft([h zeros(1,Nfft-Lch)]);%Channel frequency response 
                    H_shift(kk3)=[H(kk4) H(kk5)];
                end
                for k=1:Nframe
                    Y(kk2)= fft(remove_GI(Ng,Nsym,NgType,y_GI(kk1)));
                    Y_shift= [Y(kk4) Y(kk5)];
                    if Ch==0, Xmod_r(kk3)=Y_shift; 
                    else
                        Xmod_r(kk3)= Y_shift./H_shift;%Equaliser-channel compensation
                    end
                    kk1=kk1+Nsym; 
                    kk2=kk2+Nfft; 
                    kk3=kk3+Nused; 
                    kk4=kk4+Nfft;
                    kk5=kk5+Nfft;
                end
                X_r=qammod(Xmod_r*norms(Nbps),M,'gray');
                Neb=Neb+sum(sum(de2bi(X_r,Nbps)~=de2bi(X,Nbps)));
                Ntb=Ntb+Nused*NFrame*Nbps;%[BER,Neb,Ntb] =ber(bit_Rx,bit,nbps);
                if Neb>Target_neb,break;
                end
            end
            if 1i==0,sigPow=sigPow/Nsym/Nframe/N_iter;
            else
                Ber =Neb/ntb;
                fprintf('EbN0=%3d[db],BER=%4d/%8d=%11.3e\n', EbN0(1i),Neb,Ntb,Ber)
                fprintf(fid,'%d\t%11.3e\n', EbN0(1i), Ber); 
                if ber<1e6,% break; 
                end
            end

          if(fid~=0),fclose(fid);
          end
          plot_ber(file_name,Nbps);

[Geoff Hayes]

ok, so try replacing with the line

 X = randi(M, 1, Nused*Nframe) - 1;

I subtract one since randi will generate integers from the interval [1,M] and not the [0,M-1] that randint seems to be using.

[mohamad gholami]

thanks a lot . but please explain this line and this change for me

[Geoff Hayes]

ummm...see randi and then replace your one line of code with this one...

Answer 3

[Mochan Yang]

bitstream=randi(2,1,N)-1

[Walter Roberson]

bitstream = randi([0 1], 1, N);

or

bitstream = rand(1,N) >= 0.5;

Answer 4

[Yusuf lamah]

thank you very much

Answer 5

[khalil nasri]

randn( )>0;

[Walter Roberson]

Normal distribution has peak probability at 0 exactly. Does testing for strict greater than give 50% exactly?

Answer 6

[HONG CHENG]

you can look at this link

randint to randi

https://ww2.mathworks.cn/matlabcentral/answers/523161-how-to-make-randi-and-randint-give-out-same-data#answer_952570

Specifically

You just need to change the order of paramters

a=randint(3,4,[1,4]);
a=randi([1,4],3,4);