LoRa系统仿真_modulationlora_lora_系统仿真_matlablora调制_LoRA仿真

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % LoRa Simulator % % Sakshama Ghoslya % % Research Assistant, IIT Hyderabad % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%* %% clear all; close all; clc; %% Cockpit of the simulator SF = 10; % Spreading Factor from 7 to 12 BW = 125000; % 125kHz Fs = 125000; % Sampling Frequency preamble_len = 8; % Preamble length sync_len = 2; % Sync length total_sym = 10; % total symbols excluding preamble and sync from 1:100 num_samples = Fs*(2^SF)/BW; % Number of samples % 100 symbols to test the simulation :: choose 'total_sym' symbols = [5,100,500,555,1000,200,300,567,100,50,400,222,666,444,777,555,111,999,525,455,345,456,34,678,234,672,123,67,382,588,200,300,1000,100,... 50,400,222,666,444,777,555,111,999,525,455,345,456,34,678,234,500,400,600,800,700,200,300,1000,100,50,400,222,666,444,777,555,111,999,... 525,455,345,456,34,678,234,672,123,67,382,588,200,300,1000,100,50,400,222,666,444,777,555,111,999,525,455,345,456,34,678,234]; lora_total_sym = preamble_len + sync_len + total_sym; % Total transmitted symbols %% Preamble Generation inverse = 0; for i = 1:preamble_len [out_preamble] = LoRa_Modulation(SF,BW,Fs,num_samples,0,inverse); outp((i-1)*num_samples+1 : i*num_samples) = out_preamble; end %% Sync Symble Generation inverse = 1; for i = 1:sync_len [out_sync] = LoRa_Modulation(SF,BW,Fs,num_samples,32,inverse); outp = [outp out_sync]; end %% Symble Generation inverse = 0; for i = 1:total_sym [out_sym] = LoRa_Modulation(SF,BW,Fs,num_samples,symbols(i),inverse); outp = [outp out_sym]; end %% Reverse chirp generation for receiver inverse = 1; [out_reverse] = LoRa_Modulation(SF,BW,Fs,num_samples,0,inverse); % Multiplying with the reverse chirp for n = 1:1:lora_total_sym decoded_out((n-1)*num_samples + 1 : n*num_samples) = (outp((n-1)*num_samples + 1 : n*num_samples).*out_reverse); end %% Calculating FFT for m = 1:1:lora_total_sym FFT_out(m,:) = abs((fft(decoded_out((m-1)*num_samples + 1 : m*num_samples)))); end %% Decoding the received data k=1; for m = preamble_len+sync_len+1:1:lora_total_sym [r,c] = max(FFT_out(m,:)); data_received(k) = c-1; k = k+1; end %% Plotting % Plotting the Spectrogram of Transmitted signal figure(1); samples = num_samples/8; title('Transmitted LoRa symbols'); spectrogram(outp,samples,samples-1,samples*2,Fs,'yaxis'); % Plotting the Spectrogram of Transmitted signal figure(2); samples = num_samples/4; title('Decoded LoRa symbols'); spectrogram(decoded_out,samples,samples-1,samples,Fs,'yaxis'); % Plotting the received frequencies figure(3); samp_time = 0:1:num_samples-1; title('FFT of received LoRa symbols'); for m = 1:1:lora_total_sym plot(samp_time,FFT_out(m,:)); hold on; end grid on;