%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DV-Hop算法 ~~~~~~~~~~~~~~~~~~~~~~~~

%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

% BorderLength-----正方形区域的边长，单位：m % NodeAmount-------网络节点的个数 % BeaconAmount---信标节点数

% Sxy--------------用于存储节点的序号，横坐标，纵坐标的矩阵 ?acon----------信标节点坐标矩阵;BeaconAmount*BeaconAmount %UN-------------未知节点坐标矩阵;2*UNAmount

% Distance------未知节点到信标节点距离矩阵;2*BeaconAmount %h---------------节点间初始跳数矩阵

%X---------------节点估计坐标初始矩阵,X=[x,y]'

% R------------------节点的通信距离，一般为10-100m function AccuracyAve=DVHOP_dif_tiaoju(R) NodeAmount=100; BorderLength=100; for Z=1:19

Rate(Z)=(5*Z)/NodeAmount; BeaconAmount=5*Z;

UNAmount=NodeAmount-BeaconAmount;

h=zeros(NodeAmount,NodeAmount);%初始跳数为0；BeaconAmount行NodeAmount列

X=zeros(2,UNAmount);%节点估计坐标初始矩阵 loop=150;

BeaconAmount

for kk=1:loop %多次循环取平均值，避免偶然误差

%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~在正方形区域内产生均匀分布的随机拓扑~~~~~~~~~~~~~~~~~~~~

C=BorderLength.*rand(2,NodeAmount); %带逻辑号的节点坐标 Sxy=[[1:NodeAmount];C];

Beacon=[Sxy(2,1:BeaconAmount);Sxy(3,1:BeaconAmount)];%信标节点坐标

UN=[Sxy(2,(BeaconAmount+1):NodeAmount);Sxy(3,(BeaconAmount+1):NodeAmount)];%未知节点坐标

%~~~~~~~~~~~~~~~~~~~~~~~~~~~~初始化节点间距离、跳数矩阵~~~~~~~~~~~~~~~~~~~~~~ for i=1:NodeAmount for j=1:NodeAmount

Dall(i,j)=((Sxy(2,i)-Sxy(2,j))^2+(Sxy(3,i)-Sxy(3,j))^2)^0.5;%所有节点间相互距离

if (Dall(i,j)<=R)&(Dall(i,j)>0) h(i,j)=1;%初始跳数矩阵 elseif i==j h(i,j)=0; else h(i,j)=inf; end end end

%~~~~~~~~~~~~~~~~~~~~~~~~~最短路经算法计算节点间跳数~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ for k=1:NodeAmount for i=1:NodeAmount for j=1:NodeAmount

if h(i,k)+h(k,j)

%~~~~~~~~~~~~~~~~~~~~~~~~~求每个信标节点的校正值~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ h1=h(1:BeaconAmount,1:BeaconAmount); D1=Dall(1:BeaconAmount,1:BeaconAmount); for i=1:BeaconAmount

dhop(i,1)=sum(D1(i,:))/sum(h1(i,:));%每个信标节点的平均每跳距离 end

ò=Dall(1:BeaconAmount,(BeaconAmount+1):NodeAmount);?aconAmount行UNAmount列

%for i=1:BeaconAmount % for j=1:UNAmount

% if min(D2(:,j))==D2(i,j)

% Dhop(1,j)=dhop(i,1);%未知节点从最近的信标获得校正值 % end % end %end

%Dhop

%~~~~~~~~~~~~~~~~~~~~~~~~~~~用跳数估计距离~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

hop1=h(1:BeaconAmount,(BeaconAmount+1):NodeAmount);%未知节点到信标跳数，BeaconAmount行UNAmount列

Distance=zeros(BeaconAmount,UNAmount); %不初始化的话他默认第一次循环的时候的行列数，等到后面执行到此处会出错 %for i=1:UNAmount

%hop=Dhop(1,i);%hop为从最近信标获得的校正值 %Distance(:,i)=hop*hop1(:,i);%?acon行UN列； %end

for i=1:BeaconAmount hop=dhop(i,1); for j=1:UNAmount

Distance(i,j)=hop*hop1(i,j); %未知节点到信标节点的距离用每个信标节点的平均每跳距离计算 end end

% %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~最小二乘法求未知点坐标~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ d=Distance; for i=1:2

for j=1:(BeaconAmount-1)

a(i,j)=Beacon(i,j)-Beacon(i,BeaconAmount); end end

A=-2*(a'); % d=d1';

for m=1:UNAmount

for i=1:(BeaconAmount-1)

B(i,1)=d(i,m)^2-d(BeaconAmount,m)^2-Beacon(1,i)^2+Beacon(1,BeaconAmount)^2-Beacon(2,i)^2+Beacon(2,BeaconAmount)^2; end

X1=inv(A'*A)*A'*B; X(1,m)=X1(1,1); X(2,m)=X1(2,1); end UN; X;

for i=1:UNAmount

error(1,i)=(((X(1,i)-UN(1,i))^2+(X(2,i)-UN(2,i))^2)^0.5); end

error=sum(error)/UNAmount; Accuracy(1,kk)=error/R; end

AccuracyAve(Z)=sum(Accuracy)/loop end end