Adjust legend position outside the figure layout

I want to positioned the legend outside in the center of the figure. I have tried the northoutside, northeastoutside and posiiton but didn't get the accurate results. I need your help to resolve this problem.

figure('name','Linearly polarization')
t = tiledlayout(1,4,'TileSpacing','Compact','Padding','Compact');

%Tile1
nexttile
hold on
plot(z,iLpara11,'-k','LineWidth',1.5);
plot(z,iLpara12,'-b','LineWidth',1.5);
plot(z,iLpara13,'-r','LineWidth',1.5);
plot(z,iLpara14,'-g','LineWidth',1.5);

hold on
%title('\fontname{Arial}Homogeneous water cloud');
legend('Case1','Case2','Case3','Case4','position',[.1 .1 .2 .2],'orientation','horizontal','Fontsize',11);
legend boxon
%set(gca,'yscale','log');
xlabel('\fontname{Arial}Height of the cloud(m)');
ylabel('\fontname{Arial}Backscattered signal(unit)');
set(gca,'color','w','Fontsize',10.5,'LineWidth',1,'Fontweight','normal');
set(gca,'box','on','boxstyle','full','Fontname','Arial','Fontsmoothing','on');
set(gca,'xlim',[2005 2155],'xtick',[2005:50:2155],'ylim',[0.*10.^-8 1.4.*10.^-8],'ytick',[0:.35:1.4].*10.^-8);
set(gca,'xgrid','on','ygrid','on','gridcolor','k');
%txt=text(2050,1.3.*10.^-8,'Linear polarization','Color','black','FontSize',11,'FontWeight','normal','FontName','Arial')
nIDs = 1;
alphabet = ('a':'z').';
chars = num2cell(alphabet(1:nIDs));
chars = chars.';
charlbl = strcat('(',chars,')'); % {'(a)','(b)','(c)','(d)'}
text(0.05,0.95,charlbl{1},'Units','normalized','FontSize',14);

%Tile2
nexttile
hold on
plot(z,iLperp11,'-k','LineWidth',1.5);
plot(z,iLperp12,'-b','LineWidth',1.5);
plot(z,iLperp13,'-r','LineWidth',1.5);
plot(z,iLperp14,'-g','LineWidth',1.5);

hold on
%title('\fontname{Arial}Homogeneous water cloud');
%legend('Case1','Case2','Case3','Case4','location','northoutside','orientation','horizontal','Fontsize',11);
%legend boxon
%set(gca,'yscale','log');
xlabel('\fontname{Arial}Height of the cloud(m)');
ylabel('\fontname{Arial}Backscattered signal(unit)');
set(gca,'color','w','Fontsize',10.5,'LineWidth',1,'Fontweight','normal');
set(gca,'box','on','boxstyle','full','Fontname','Arial','Fontsmoothing','on');
set(gca,'xlim',[2005 2155],'xtick',[2005:50:2155],'ylim',[0.*10.^-9 1.2.*10.^-9],'ytick',[0:0.3:1.2].*10.^-9);
set(gca,'xgrid','on','ygrid','on','gridcolor','k');
%txt=text(2050,1.12.*10.^-9,'Linear polarization','Color','black','FontSize',11,'FontWeight','normal','FontName','Arial')
nIDs = 2;
alphabet = ('a':'z').';
chars = num2cell(alphabet(1:nIDs));
chars = chars.';
charlbl = strcat('(',chars,')'); % {'(a)','(b)','(c)','(d)'}
text(0.05,0.95,charlbl{2},'Units','normalized','FontSize',14);

%Tile3
nexttile
hold on
plot(z,iCperp21,'-k','LineWidth',1.5);
plot(z,iCperp22,'-b','LineWidth',1.5);
plot(z,iCperp23,'-r','LineWidth',1.5);
plot(z,iCperp24,'-g','LineWidth',1.5);

hold on
%title('\fontname{Arial}Homogeneous water cloud');
%legend('Case1','Case2','Case3','Case4','location','northoutside','orientation','horizontal','Fontsize',11);
%legend boxon
%set(gca,'yscale','log');
xlabel('\fontname{Arial}Height of the cloud(m)');
ylabel('\fontname{Arial}Backscattered signal(unit)');
set(gca,'color','w','Fontsize',10.5,'LineWidth',1,'Fontweight','normal');
set(gca,'box','on','boxstyle','full','Fontname','Arial','Fontsmoothing','on');
set(gca,'xlim',[2005 2155],'xtick',[2005:50:2155],'ylim',[0.*10.^-8 1.4.*10.^-8],'ytick',[0:.35:1.4].*10.^-8);
set(gca,'xgrid','on','ygrid','on','gridcolor','k');
%txt=text(2050,1.3.*10.^-8,'Circular polarization','Color','black','FontSize',11,'FontWeight','normal','FontName','Arial')
nIDs = 3;
alphabet = ('a':'z').';
chars = num2cell(alphabet(1:nIDs));
chars = chars.';
charlbl = strcat('(',chars,')'); % {'(a)','(b)','(c)','(d)'}
text(0.05,0.95,charlbl{3},'Units','normalized','FontSize',14);

%Tile4
nexttile
hold on
plot(z,iCpara21,'-k','LineWidth',1.5);
plot(z,iCpara22,'-b','LineWidth',1.5);
plot(z,iCpara23,'-r','LineWidth',1.5);
plot(z,iCpara24,'-g','LineWidth',1.5);

hold on
%title('\fontname{Arial}Homogeneous water cloud');
xlabel('\fontname{Arial}Height of the cloud(m)');
%legend('Case1','Case2','Case3','Case4','location','southeast','FontSize',10);
%legend boxoff
%set(gca,'yscale','log');
xlabel('\fontname{Arial}Height of the cloud(m)');
ylabel('\fontname{Arial}Backscattered signal(unit)');
set(gca,'color','w','Fontsize',10.5,'LineWidth',1,'Fontweight','normal');
set(gca,'box','on','boxstyle','full','Fontname','Arial','Fontsmoothing','on');
set(gca,'xlim',[2005 2155],'xtick',[2005:50:2155],'ylim',[0.*10.^-9 2.5.*10.^-9],'ytick',[0:0.625:2.5].*10.^-9);
set(gca,'xgrid','on','ygrid','on','gridcolor','k');
%txt=text(2050,2.35.*10.^-9,'Circular polarization','Color','black','FontSize',11,'FontWeight','normal','FontName','Arial')
nIDs = 4;
alphabet = ('a':'z').';
chars = num2cell(alphabet(1:nIDs));
chars = chars.';
charlbl = strcat('(',chars,')'); % {'(a)','(b)','(c)','(d)'}
text(0.05,0.95,charlbl{4},'Units','normalized','FontSize',14);
% Enlarge figure to full screen.
%set(gcf, 'units','normalized','outerposition',[.3 .3 .6 .6]);
set(gcf, 'units','normalized','outerposition',[.2 .4 .65 .38]);
print(gcf,'figure.tiff','-dtiff','-r300'); 

Answer 1

[Adam Danz]

Since you're using tiledLayout the best option is to specify the layout as shows in this example.

lh =legend(__);

lh.Layout.Tile = 'North'; % <----- relative to tiledlayout

[Wiqas Ahmad]

I have found the answer. I'm using the R2019b in which the legend position is locked. Your answer is feasible with R2020b. Anyway thnak you for your attention.

[Adam Danz]

In future questions, you can fill out the "release" field to indicate which Matlab release you'res using.