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stbc_decoding.m
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stbc_decoding.m
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function [data_decoded] = stbc_decoding(data, coding_mode, gain, receiver_num, modulate_mode)
if strcmp(coding_mode, 'g2')
[len, wid] = size(data);
data_decoded = zeros(len, 1);
for i = 1:2:len
num1 = 0; num2 = -1; num3 = 0; num4 = -1;
for k = 1:receiver_num
num1 = num1 + data(i, k)*conj(gain(i, (k-1)*2+1)) + conj(data(i+1, k))*gain(i, (k-1)*2+2);
num2 = num2 + (abs(gain(i, (k-1)*2+1))^2 + abs(gain(i, (k-1)*2+2))^2);
num3 = num3 + data(i, k)*conj(gain(i, (k-1)*2+2)) - conj(data(i+1, k))*gain(i, (k-1)*2+1);
num4 = num2;
end
if modulate_mode == 2
corres = [abs(num1 - 1)^2 + num2, abs(num1 + 1)^2 + num2; 1, -1];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded(i) = 1;
else
data_decoded(i) = -1;
end
corres = [abs(num3 - 1)^2 + num4, abs(num3 + 1)^2 + num4; 1, -1];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded(i+1) = 1;
else
data_decoded(i+1) = -1;
end
end
if modulate_mode == 4
corres = [abs(num1 - 1)^2 + num2, abs(num1 - 1i)^2 + num2, abs(num1 + 1)^2 + num2, abs(num1 + 1i)^2 + num2; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded(i) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded(i) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded(i) = -1;
else
data_decoded(i) = -1i;
end
corres = [abs(num3 - 1)^2 + num4, abs(num3 - 1i)^2 + num4, abs(num3 + 1)^2 + num4, abs(num3 + 1i)^2 + num4; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded(i+1) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded(i+1) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded(i+1) = -1;
else
data_decoded(i+1) = -1i;
end
end
end
end
if strcmp(coding_mode, 'g3')
[len, wid] = size(data);
data_decoded = zeros(len/2, 1);
for i = 1:8:len
num1 = 0; num2 = -1; num3 = 0; num4 = -1; num5 = 0; num6 = -1; num7 = 0; num8 = -1;
for k = 1:receiver_num
num1_temp1 = data(i, k)*conj(gain(i, (k-1)*3+1)) + data(i+1, k)*conj(gain(i, (k-1)*3+2)) + data(i+2, k)*conj(gain(i, (k-1)*3+3));
num1_temp2 = conj(data(i+4, k))*gain(i, (k-1)*3+1) + conj(data(i+5, k))*gain(i, (k-1)*3+2) + conj(data(i+6, k))*gain(i, (k-1)*3+3);
num1 = num1 + num1_temp1 + num1_temp2;
num2 = num2 + 2*(abs(gain(i, (k-1)*3+1))^2 + abs(gain(i, (k-1)*3+2))^2 + abs(gain(i, (k-1)*3+3))^2);
num3_temp1 = data(i, k)*conj(gain(i, (k-1)*3+2)) - data(i+1, k)*conj(gain(i, (k-1)*3+1)) + data(i+3, k)*conj(gain(i, (k-1)*3+3));
num3_temp2 = conj(data(i+4, k))*gain(i, (k-1)*3+2) - conj(data(i+5, k))*gain(i, (k-1)*3+1) + conj(data(i+7, k))*gain(i, (k-1)*3+3);
num3 = num3 + num3_temp1 + num3_temp2;
num4 = num2;
num5_temp1 = data(i, k)*conj(gain(i, (k-1)*3+3)) - data(i+2, k)*conj(gain(i, (k-1)*3+1)) - data(i+3, k)*conj(gain(i, (k-1)*3+2));
num5_temp2 = conj(data(i+4, k))*gain(i, (k-1)*3+3) - conj(data(i+6, k))*gain(i, (k-1)*3+1) - conj(data(i+7, k))*gain(i, (k-1)*3+2);
num5 = num5 + num5_temp1 + num5_temp2;
num6 = num2;
num7_temp1 = -data(i+1, k)*conj(gain(i, (k-1)*3+3)) + data(i+2, k)*conj(gain(i, (k-1)*3+2)) - data(i+3, k)*conj(gain(i, (k-1)*3+1));
num7_temp2 = -conj(data(i+5, k))*gain(i, (k-1)*3+3) + conj(data(i+6, k))*gain(i, (k-1)*3+2) - conj(data(i+7, k))*gain(i, (k-1)*3+1);
num7 = num7 + num7_temp1 + num7_temp2;
num8 = num2;
end
if modulate_mode == 4
corres = [abs(num1 - 1)^2 + num2, abs(num1 - 1i)^2 + num2, abs(num1 + 1)^2 + num2, abs(num1 + 1i)^2 + num2; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 1) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 1) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 1) = -1;
else
data_decoded((i-1)/2 + 1) = -1i;
end
corres = [abs(num3 - 1)^2 + num4, abs(num3 - 1i)^2 + num4, abs(num3 + 1)^2 + num4, abs(num3 + 1i)^2 + num4; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 2) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 2) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 2) = -1;
else
data_decoded((i-1)/2 + 2) = -1i;
end
corres = [abs(num5 - 1)^2 + num6, abs(num5 - 1i)^2 + num6, abs(num5 + 1)^2 + num6, abs(num5 + 1i)^2 + num6; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 3) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 3) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 3) = -1;
else
data_decoded((i-1)/2 + 3) = -1i;
end
corres = [abs(num7 - 1)^2 + num8, abs(num7 - 1i)^2 + num8, abs(num7 + 1)^2 + num8, abs(num7 + 1i)^2 + num8; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 4) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 4) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 4) = -1;
else
data_decoded((i-1)/2 + 4) = -1i;
end
end
if modulate_mode == 16
temp_a = 0:15;
temp_complex = pskmod(temp_a, 16);
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num1 - temp_complex(i_temp))^2 + num2];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 1) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num3 - temp_complex(i_temp))^2 + num4];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 2) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num5 - temp_complex(i_temp))^2 + num6];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 3) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num7 - temp_complex(i_temp))^2 + num8];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 4) = temp_complex(i_temp);
break;
end
end
end
end
end
if strcmp(coding_mode, 'g4')
[len, wid] = size(data);
data_decoded = zeros(len/2, 1);
for i = 1:8:len
num1 = 0; num2 = -1; num3 = 0; num4 = -1; num5 = 0; num6 = -1; num7 = 0; num8 = -1;
for k = 1:receiver_num
num1_temp1 = data(i, k)*conj(gain(i, (k-1)*4+1)) + data(i+1, k)*conj(gain(i, (k-1)*4+2)) + data(i+2, k)*conj(gain(i, (k-1)*4+3)) + data(i+3, k)*conj(gain(i, (k-1)*4+4));
num1_temp2 = conj(data(i+4, k))*gain(i, (k-1)*4+1) + conj(data(i+5, k))*gain(i, (k-1)*4+2) + conj(data(i+6, k))*gain(i, (k-1)*4+3) + conj(data(i+7, k))*gain(i, (k-1)*4+4);
num1 = num1 + num1_temp1 + num1_temp2;
num2 = num2 + 2*(abs(gain(i, (k-1)*4+1))^2 + abs(gain(i, (k-1)*4+2))^2 + abs(gain(i, (k-1)*4+3))^2 + abs(gain(i, (k-1)*4+4))^2);
num3_temp1 = data(i, k)*conj(gain(i, (k-1)*4+2)) - data(i+1, k)*conj(gain(i, (k-1)*4+1)) - data(i+2, k)*conj(gain(i, (k-1)*4+4)) + data(i+3, k)*conj(gain(i, (k-1)*4+3));
num3_temp2 = conj(data(i+4, k))*gain(i, (k-1)*4+2) - conj(data(i+5, k))*gain(i, (k-1)*4+1) - conj(data(i+6, k))*gain(i, (k-1)*4+4) + conj(data(i+7, k))*gain(i, (k-1)*4+3);
num3 = num3 + num3_temp1 + num3_temp2;
num4 = num2;
num5_temp1 = data(i, k)*conj(gain(i, (k-1)*4+3)) + data(i+1, k)*conj(gain(i, (k-1)*4+4)) - data(i+2, k)*conj(gain(i, (k-1)*4+1)) - data(i+3, k)*conj(gain(i, (k-1)*4+2));
num5_temp2 = conj(data(i+4, k))*gain(i, (k-1)*4+3) + conj(data(i+5, k))*gain(i, (k-1)*4+4) - conj(data(i+6, k))*gain(i, (k-1)*4+1) - conj(data(i+7, k))*gain(i, (k-1)*4+2);
num5 = num5 + num5_temp1 + num5_temp2;
num6 = num2;
num7_temp1 = data(i, k)*conj(gain(i, (k-1)*4+4)) - data(i+1, k)*conj(gain(i, (k-1)*4+3)) + data(i+2, k)*conj(gain(i, (k-1)*4+2)) - data(i+3, k)*conj(gain(i, (k-1)*4+1));
num7_temp2 = conj(data(i+4, k))*gain(i, (k-1)*4+4) - conj(data(i+5, k))*gain(i, (k-1)*4+3) + conj(data(i+6, k))*gain(i, (k-1)*4+2) - conj(data(i+7, k))*gain(i, (k-1)*4+1);
num7 = num7 + num7_temp1 + num7_temp2;
num8 = num2;
end
if modulate_mode == 4
corres = [abs(num1 - 1)^2 + num2, abs(num1 - 1i)^2 + num2, abs(num1 + 1)^2 + num2, abs(num1 + 1i)^2 + num2; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 1) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 1) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 1) = -1;
else
data_decoded((i-1)/2 + 1) = -1i;
end
corres = [abs(num3 - 1)^2 + num4, abs(num3 - 1i)^2 + num4, abs(num3 + 1)^2 + num4, abs(num3 + 1i)^2 + num4; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 2) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 2) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 2) = -1;
else
data_decoded((i-1)/2 + 2) = -1i;
end
corres = [abs(num5 - 1)^2 + num6, abs(num5 - 1i)^2 + num6, abs(num5 + 1)^2 + num6, abs(num5 + 1i)^2 + num6; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 3) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 3) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 3) = -1;
else
data_decoded((i-1)/2 + 3) = -1i;
end
corres = [abs(num7 - 1)^2 + num8, abs(num7 - 1i)^2 + num8, abs(num7 + 1)^2 + num8, abs(num7 + 1i)^2 + num8; 1, 1i, -1, -1i];
ans_m = min(corres, [], 2);
if corres(1, 1) == ans_m(1)
data_decoded((i-1)/2 + 4) = 1;
elseif corres(1, 2) == ans_m(1)
data_decoded((i-1)/2 + 4) = 1i;
elseif corres(1, 3) == ans_m(1)
data_decoded((i-1)/2 + 4) = -1;
else
data_decoded((i-1)/2 + 4) = -1i;
end
end
if modulate_mode == 16
temp_a = 0:15;
temp_complex = pskmod(temp_a, 16);
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num1 - temp_complex(i_temp))^2 + num2];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 1) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num3 - temp_complex(i_temp))^2 + num4];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 2) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num5 - temp_complex(i_temp))^2 + num6];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 3) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:16
temp_result = [temp_result, abs(num7 - temp_complex(i_temp))^2 + num8];
end
max_likelihood = min(temp_result);
for i_temp = 1:16
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)/2 + 4) = temp_complex(i_temp);
break;
end
end
end
end
end
if strcmp(coding_mode, 'h3')
[len, wid] = size(data);
data_decoded = zeros(len*3/4, 1);
for i = 1:4:len
num1 = 0; num2 = -1; num3 = 0; num4 = -1; num5 = 0; num6 = -1;
for k = 1:receiver_num
num1 = num1 + data(i, k)*conj(gain(i, (k-1)*3+1)) + conj(data(i+1, k))*gain(i, (k-1)*3+2);
num1 = num1 + (data(i+3, k) - data(i+2, k))*conj(gain(i, (k-1)*3+3))/2 - conj(data(i+3, k) + data(i+2, k))*gain(i, (k-1)*3+3)/2;
num2 = num2 + abs(gain(i, (k-1)*3+1))^2 + abs(gain(i, (k-1)*3+2))^2 + abs(gain(i, (k-1)*3+3))^2;
num3 = num3 + data(i, k)*conj(gain(i, (k-1)*3+2)) - conj(data(i+1, k))*gain(i, (k-1)*3+1);
num3 = num3 + (data(i+3, k) + data(i+2, k))*conj(gain(i, (k-1)*3+3))/2 + conj(data(i+3, k) - data(i+2, k))*gain(i, (k-1)*3+3)/2;
num4 = num2;
num5 = num5 + (data(i, k) + data(i+1, k))*conj(gain(i, (k-1)*3+3))/sqrt(2) + conj(data(i+2, k))*(gain(i, (k-1)*3+1) + gain(i, (k-1)*3+2))/sqrt(2);
num5 = num5 + conj(data(i+3, k))*(gain(i, (k-1)*3+1) - gain(i, (k-1)*3+2))/sqrt(2);
num6 = num2;
end
temp_a = 0:7;
temp_complex = pskmod(temp_a, 8);
temp_result = [];
for i_temp = 1:8
temp_result = [temp_result, abs(num1 - temp_complex(i_temp))^2 + num2];
end
max_likelihood = min(temp_result);
for i_temp = 1:8
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)*3/4 + 1) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:8
temp_result = [temp_result, abs(num3 - temp_complex(i_temp))^2 + num4];
end
max_likelihood = min(temp_result);
for i_temp = 1:8
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)*3/4 + 2) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:8
temp_result = [temp_result, abs(num5 - temp_complex(i_temp))^2 + num6];
end
max_likelihood = min(temp_result);
for i_temp = 1:8
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)*3/4 + 3) = temp_complex(i_temp);
break;
end
end
end
end
if strcmp(coding_mode, 'h4')
[len, wid] = size(data);
data_decoded = zeros(len*3/4, 1);
for i = 1:4:len
num1 = 0; num2 = -1; num3 = 0; num4 = -1; num5 = 0; num6 = -1;
for k = 1:receiver_num
num1 = num1 + data(i, k)*conj(gain(i, (k-1)*4+1)) + conj(data(i+1, k))*gain(i, (k-1)*4+2);
num1 = num1 + (data(i+3, k) - data(i+2, k))*conj(gain(i, (k-1)*4+3) - gain(i, (k-1)*4+4))/2 - conj(data(i+3, k) + data(i+2, k))*(gain(i, (k-1)*4+3) + gain(i, (k-1)*4+4))/2;
num2 = num2 + abs(gain(i, (k-1)*4+1))^2 + abs(gain(i, (k-1)*4+2))^2 + abs(gain(i, (k-1)*4+3))^2 + abs(gain(i, (k-1)*4+4))^2;
num3 = num3 + data(i, k)*conj(gain(i, (k-1)*4+2)) - conj(data(i+1, k))*gain(i, (k-1)*4+1);
num3 = num3 + (data(i+3, k) + data(i+2, k))*conj(gain(i, (k-1)*4+3) - gain(i, (k-1)*4+4))/2 + conj(data(i+3, k) - data(i+2, k))*(gain(i, (k-1)*4+3) + gain(i, (k-1)*4+4))/2;
num4 = num2;
num5 = num5 + (data(i, k) + data(i+1, k))*conj(gain(i, (k-1)*4+3))/sqrt(2) + (data(i, k) - data(i+1, k))*conj(gain(i, (k-1)*4+4))/sqrt(2);
num5 = num5 + conj(data(i+2, k))*(gain(i, (k-1)*4+1) + gain(i, (k-1)*4+2))/sqrt(2) + conj(data(i+3, k))*(gain(i, (k-1)*4+1) - gain(i, (k-1)*4+2))/sqrt(2);
num6 = num2;
end
temp_a = 0:7;
temp_complex = pskmod(temp_a, 8);
temp_result = [];
for i_temp = 1:8
temp_result = [temp_result, abs(num1 - temp_complex(i_temp))^2 + num2];
end
max_likelihood = min(temp_result);
for i_temp = 1:8
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)*3/4 + 1) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:8
temp_result = [temp_result, abs(num3 - temp_complex(i_temp))^2 + num4];
end
max_likelihood = min(temp_result);
for i_temp = 1:8
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)*3/4 + 2) = temp_complex(i_temp);
break;
end
end
temp_result = [];
for i_temp = 1:8
temp_result = [temp_result, abs(num5 - temp_complex(i_temp))^2 + num6];
end
max_likelihood = min(temp_result);
for i_temp = 1:8
if temp_result(i_temp) == max_likelihood;
data_decoded((i-1)*3/4 + 3) = temp_complex(i_temp);
break;
end
end
end
end