跪求大神帮忙解答！

调用程序
function error_num = Error_Num(block_size,ber)
%%%%%%%%%%%%%% 传输过程中的出错位数 %%%%%%%%%%%%%
error_num = 0;
for i = 1:block_size
if rand() < ber
error_num = error_num + 1;
end
end

调用程序
function throughput = Throughput(ber,t);
%设置缓冲器大小
%buffberr_sizber = 128;
BER = ber; %设置错误率 %设置错误率
block_size = 510; %设置块大小
correct_bits = t; %设置可纠错位数
alternate = 0; %设置重传选择,0表示重传P_I，1表示重传I
send_cnt = 0; %设置发送和接收数据块个数计数器
recev_cnt = 0;
retrans_ability = 128; %设置最大重传次数N
Msg_Num=1000;%正确接收到Msg_Num个数据块后停止
for i = 1:Msg_Num
%%%%%%%%%%%%%%%%%%%%%%%%% 发送端 %%%%%%%%%%%%%%%%%%%%%%%%
send_cnt = send_cnt + 1;
%%%%%%%%%%%%%%%%%%%%%%%%% 接收端 %%%%%%%%%%%%%%%%%%%%%%%%
error_num = Error_Num(block_size,BER); %获取出错位数个数
if error_num == 0
recev_cnt = recev_cnt + 1;
else
%%%%%%%%%%%%%% 重传 %%%%%%%%%%%%%
retrans_cnt = 0; %设置重传次数计数器
refuse = 0;%设置拒绝标志，0表示拒绝，1表示接受
while refuse == 0 && retrans_cnt < retrans_ability
%重传P(I) alternate为0表示重传P_I，1表示重传I
if alternate == 0 && refuse == 0
send_cnt = send_cnt + 1;%发送的数据块次数包含重传的次数
PI_Enum = Error_Num(block_size,BER);
if error_num + PI_Enum <= correct_bits
refuse = 1;
else
error_num = PI_Enum ;
end
end
alternate = ~alternate;
%重传I
if alternate == 1 && refuse == 0
send_cnt = send_cnt + 1;
I_Enum = Error_Num(block_size,BER);
if error_num + I_Enum <= correct_bits
refuse = 1;
else
error_num = I_Enum;
end
end
alternate = ~alternate;
end
if refuse == 1
refuse = 0;
recev_cnt = recev_cnt + 1; %经过纠错后正确接收到数据包的个数
end
alternate = 0;%新的数据包从I开始传
end
end
throughput = recev_cnt / send_cnt;

小白想知道主程序中的t n N分别代表的是什么？先谢过各位大神了！

你好请问你有这个的源代码吗