垂直切换的仿真（终）

异构网垂直切换的Matlab仿真

异构网中的切换的仿真： 以下为基本的网络图：

LTE BS Wimax BS 涉及到的仿真包括：

1. 接收信号的强度的设计。

2. 大尺度衰落：路径损耗和阴影效应(ShadowGenerate.m)。 3. 小尺度衰落：利用jakes模型进行仿真。

4. 参数有：移动台的运动速度为10m/s;LTE的载波频率是2000MHz，Wimax的载波频率是2500MHz，发射功率分别是33dbm、23dbm。覆盖半径分别为1Km和0.3Km。最小距离为35m。基站的坐标分别为（0,0）和（500,0）。信号的检测间隔为0.4s，切换时延为1s（仿真情况下）。移动台从坐标为（100,0）以10m/s的速度向右运动。

1.只考虑路径衰落的时候，接收信号强度的变化：

the received signal strength about two networks-80LTEWimax-85 -90RSS(dBm)-95-100-105-110 01020304050time(s)60708090100切换的变化：

the state of mobile station in LTE and Wimax network1? Wimax0.90.80.7mark of network

0.60.50.40.30.20.10? LTE01020304050time(s)607080901002.考虑到小尺度衰落的信号接收的变化：

the received signal strength about two networks-80LTEWimax-85

RSS(dBm)-90-95-100-105 01020304050time(s)60708090100切换的变化：

the state of mobile station in LTE and Wimax network1? Wimax0.90.80.7mark of network0.60.50.40.30.20.10? LTE01020304050time(s)607080901003.同时考虑到阴影效应下的接收信号强度变化：

the received signal strength about two networks-75LTEWimax-80

-85RSS(dBm)-90-95-100-105 01020304050time(s)60708090100切换的变化：

the state of mobile station in LTE and Wimax network1? Wimax0.90.80.7mark of network

0.60.50.40.30.20.10? LTE01020304050time(s)60708090100

仿真3的源代码：

1.Main.m

%% 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 large_scale_time_interval... large_scale_LTE large_scale_wimax large_scale_time_start... large_scale_time_end N

service_type=0; %the subscriber type of service

%0 refers to real time service,on the

% contrary,1 refers to nonreal-time service large_scale_time_interval=100; N=10;

large_scale_time_start=0;

large_scale_time_end=large_scale_time_interval; large_scale_LTE=ShadowGenerate(3,0.5,N); large_scale_wimax=ShadowGenerate(3,0.5,N); 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=0.4; %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,MS_speed,'LTE',record_time*Tc,Tc); 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,MS_speed,'Wimax',... record_time*Tc,Tc); else

RSS_Wimax=-inf; end

%############### decide whether to handoff according to RSS #########

if Net_state==0&&RSS_LTEhandoff_drop

count_handoff_number=count_handoff_number+1; Net_state=1;

handoff_clock=0; %reset the counter else

handoff_clock=handoff_clock+Tc; end

elseif Net_state==1&&RSS_LTE>RSS_Wimax if handoff_clock>handoff_drop

count_handoff_number=count_handoff_number+1; Net_state=0;

handoff_clock=0; %reset the counter 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)