Is the following method of calculating SINR correct

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Syed 2017-5-5

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https://ww2.mathworks.cn/matlabcentral/answers/338814-is-the-following-method-of-calculating-sinr-correct

评论： omar th 2022-1-19

Hi all,

I am trying to implement device-to-device discovery technique. I have written a code for that purpose. I am a bit unsure about the way I have calculated SINR. Can someone spare some moments and let me know if I am right or not?

The following is the code: Loof for the comments of interference vector in particular.

%%constant / parameters 
freq = 2e9; wavelength = (3e8)/freq;
Noise_dB = -121; %dB Noise = 10^(Noise_dB/10);
SINR_th = 2.5;
N_RB = 44; % Number of resrouce blocks
N_Time_slots = 64; % Number of time slots. Total Resources = N_RB * N_Time_slots
Pmax = -7;%dB  (23 dBm)
Rd = 500; % Radius of cirular region aroung device
tagged_user = 0 + 0i;
tic;
      N_devices = 100;
  % There are 'N_devices' devices in total, 
  %Transmit power of 'N_devices-1' devices.
    Pt = ones(1,  N_devices-1)*Pmax;
    users_pos = gen_d2d_devices(tagged_user,  N_devices-1, Rd);
      DUE_pos = [real(users_pos); imag(users_pos)]';
      d = abs(users_pos); %Since location of tagged user is at origin
      D = d./1000; % meters to KM, since the formula below uses distance in km
      PL = 135.5 + 40*log10(D);
      Pr = zeros(1,  N_devices-1);
      discovered_devices = zeros(1,N_devices-1);
    
    %Discovery periods from 1 -> tot_of_disctime
      for td = 1:tot_of_disctime
          % RB allocation => Frequency + 1j*time
          RA_a = randi([1,N_RB], 1, N_devices) + randi([1,N_Time_slots], 1, N_devices).*1i;        
          RA1 = RA_a(1);
          RA_a(1) = [];
          Pr = Pt - PL;
      
    %dB to linear scale
          Pr_a = 10.^(Pr/10);
    %Interference vector
        I = zeros(1, N_devices-1);
          %Making Interference vector: All devices that transmit in the same RB interfere
          for ii=1:N_devices-1
              for jj = 1 : N_devices-1
                  if(ii == jj)
                      continue
                  else                
                      if(RA_a(ii) == RA_a(jj))%if(RA(ii) == RA(jj))
                          I(ii) = I(ii) + Pr_a(jj);
                      else
                          continue;
                      end
                  end
              end
          end        
          %Total Received power, including Interference.
          PrA = Pr_a + I;
    %Calculate SINR
        SINR = PrA ./ (Noise + I);
        valid_devices = 10*log10(SINR)>SINR_th;
          %half duplexing
          SameBTUFRAME = imag(RA1) == imag(RA_a);
          discovered_devices = discovered_devices | and(valid_devices,not(SameBTUFRAME));
      Discovery_ratio(td) = sum(discovered_devices) / (N_devices-1);  
      end
mean_discovery1 = mean(Final_discovery1);