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1.问题描述：
<> 异构网络垂直切换算法LTE/WIMAX切换
<>2.部分程序：
<>
%% the simulation of this program is for heterogeneous %%
%% network in vertical handoff; %%
%initial the parameters of network
clear
clc
global fc_LTE fc_Wimax LTE_BS_coordinate Wimax_BS_coordinate ...
Wimax_BS_coordinate LTE_BS_coordinate
service_type=0; %the subscriber type of service
%0 refers to real time service,on the
% contrary,1 refers to nonreal-time service
MS_coordinate=[100,0];
LTE_BS_coordinate=[0,0]; %the coordinate of LTE BS
Wimax_BS_coordinate=[600,0]; %the coordinate of wimaxE BS
MS_speed=10; %the speed of mobile station
fc_LTE=2000*10^6; %the frequency of the carrier for LTE
fc_Wimax=2500*10^6; %the frequency of the carrier for Wimax
Net_state=0; %0 refers to LTE;1 refers to Wimax
handoff_drop=1;
handoff_clock=0;
count_handoff_number=0;
Tc=0.5; %time of measure interval
record_time=0; %record the number of interval time of system
countinue_run=true;
while countinue_run
%################# measure the receieved signal strength ############
%if the mobile station is in the LTE network
if is_in_LTE_coverage(MS_coordinate)
RSS_LTE=calculate_RSS(MS_coordinate,'LTE');
else
RSS_LTE=-inf;
end
%if the mobile station is in the LTE network
if is_in_Wimax_coverage(MS_coordinate)
RSS_Wimax=calculate_RSS(MS_coordinate,'Wimax');
else
RSS_Wimax=-inf;
end
%############### decide whether to handoff according to RSS #########
if Net_state==0&&RSS_LTE<RSS_Wimax
if handoff_clock>handoff_drop
if is_network_performance_meet(service_type)==1||(...
~is_in_LTE_coverage(MS_coordinate)&&...
is_in_Wimax_coverage(MS_coordinate))
%compare the performance of
%new network with the past
%network
count_handoff_number=count_handoff_number+1;
Net_state=1;
handoff_clock=0; %reset the counter
else
handoff_clock=0; %stay in the past network
end
else
handoff_clock=handoff_clock+Tc;
end
elseif Net_state==1&&RSS_LTE>RSS_Wimax
if handoff_clock>handoff_drop
if is_network_performance_meet(service_type)==0||(...
is_in_LTE_coverage(MS_coordinate)&&...
~is_in_Wimax_coverage(MS_coordinate))
%compare the performance of
%new network with the past
%network
count_handoff_number=count_handoff_number+1;
Net_state=0;
handoff_clock=0; %reset the counter
else
handoff_clock=0; %stay in the past network
end
else
handoff_clock=handoff_clock+Tc;
end
else
handoff_clock=0;
end
%##################### decide whether to continue run ################
if is_in_LTE_coverage(MS_coordinate)||...
is_in_Wimax_coverage(MS_coordinate)
%######################## record the data ########################
record_time=record_time+1;
record_RSS_LTE(record_time)=RSS_LTE;
record_RSS_Wimax(record_time)=RSS_Wimax;
record_Net_state(record_time)=Net_state;
MS_coordinate(1)=MS_coordinate(1)+MS_speed*Tc;
else
countinue_run=false;
end
end
%######################## plot the simulation results ####################
t=[1:record_time]*Tc;
plot(t,record_RSS_LTE,'--ro','MarkerEdgeColor','g','MarkerFaceColor','y',...
'MarkerSize',2);
hold on
plot(t,record_RSS_Wimax,'-.ks','MarkerEdgeColor','b',...
'MarkerFaceColor','c','MarkerSize',2);
hold off
grid on
xlabel('time(s)');
ylabel('RSS(dBm)');
legend('LTE','Wimax');
title('the received signal strength about two networks');
figure
plot(t,record_Net_state,'--ro','MarkerEdgeColor','g','MarkerFaceColor','y',...
'MarkerSize',2)
grid on
xlabel('time(s)');
ylabel('mark of network');
text(0,0,'\leftarrow LTE','FontSize',10)
text(0,1,'\leftarrow Wimax','FontSize',10)
title('the state of mobile station in LTE and Wimax network')
%############################END THE PROGRAM ##############################
<>3.仿真结论：
D109