软件无线电-相关使用FFT

uhd_cpp/sdr.pro

@@ -5,5 +5,5 @@ CONFIG -= qt
 
 SOURCES += \
 	uhd_the_ark.cpp
-LIBS += -luhd -lpthread -lgomp
+LIBS += -luhd -lpthread -lgomp -lfftw3
 QMAKE_CXXFLAGS_RELEASE += -fopenmp -O3 -fopenmp  -mavx2

uhd_cpp/uhd_the_ark.cpp

@@ -15,7 +15,7 @@
 #include <atomic>
 #include <iostream>
 #include <uhd.h>
-
+#include <fftw3.h>
 static bool stop_signal_called = false;
 static char error_string[1024];
 static char err_msg[1024];
@@ -47,13 +47,13 @@ int return_code = EXIT_SUCCESS;
 
 static const int modraten = 4;
 //Sample rate in Hz
-const double sprate		=  240000 ;
+const double sprate		=  250000 ;
 
 int main(int /*argc*/, char* /*argv*/[])
 {
 	const char dev_args[] = "";
 	//接收频率
-	double rx_freq		= 610e6;
+	double rx_freq		= 200e6;
 	double rx_sprate	= sprate;
 	double rx_gain		= 55.0;
 	bool   rx_agc		= true;
@@ -62,12 +62,12 @@ int main(int /*argc*/, char* /*argv*/[])
 	size_t rx_channel[]	= {0};
 	const char rx_ana[] = "RX2";
 
-	double tx_freq		= 610e6;
+	double tx_freq		= 200e6;
 	double tx_sprate	= sprate;
 	double tx_gain		= 70;
 	double tx_bw		= sprate;
 	//发射信号。MIMO时，可以指定0,1
-	size_t tx_channel[]	= {0};
+	size_t tx_channel[]	= {1};
 	const char tx_ana[] = "TX/RX";
 
 	if (sizeof(rx_channel)>sizeof(rx_channel[0]) || sizeof(tx_channel)>sizeof(tx_channel[0]) )
@@ -196,7 +196,7 @@ int main(int /*argc*/, char* /*argv*/[])
 
 		// Set gain
 		fprintf(stderr, "Setting TX Gain: %f db...\n", tx_gain);
-		UHD_DO(uhd_usrp_set_tx_gain(usrp, tx_gain, 0, ""));
+		UHD_DO(uhd_usrp_set_tx_gain(usrp, tx_gain, tx_channel[0], ""));
 
 		// See what gain actually is
 		UHD_DO(uhd_usrp_get_tx_gain(usrp, tx_channel[0], "", &tx_gain));
@@ -368,7 +368,7 @@ int do_io(
 }
 
 
-static const int amp = 30000;
+static const int amp = 8192;
 static const int spread_ratio = 128;
 static const size_t wav_size = spread_ratio*modraten;
 static short wav_spread[2][wav_size][2];
@@ -474,6 +474,18 @@ void dealer()
 	const unsigned int half_sz = wav_size/2;
 	short (*pBufRx)[2] = rx_buf_ptr.get();
 	double (* ampwin)[2] = new double[wav_size][2];
+	
+	fftw_complex *in[2], *out[2];
+	fftw_plan p[2];
+    
+	in[0] = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * wav_size);
+	out[0] = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * wav_size);
+	p[0] = fftw_plan_dft_1d(wav_size, in[0], out[0], FFTW_FORWARD, FFTW_ESTIMATE);
+	in[1] = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * wav_size);
+	out[1] = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * wav_size);
+	p[1] = fftw_plan_dft_1d(wav_size, in[1], out[1], FFTW_FORWARD, FFTW_ESTIMATE);
+	//fftw_execute(p); /* repeat as needed */
+	double globalMax = 0;
 	while (!stop_signal_called)
 	{
 		if (deal_count + wav_size >= rx_count || rx_count < wav_size )
@@ -489,20 +501,44 @@ void dealer()
 			++deal_count;
 			continue;
 		}
-		double cross[2][2] = {{0,0},{0,0}};
 		unsigned long long start_x = deal_count - wav_size;
 		//xorr
 #pragma omp simd
 		for (size_t i=0;i<wav_size;++i)
 		{
 			const int xb = (start_x + i) % rxbuf_points;
-			cross[0][0] += (pBufRx[xb][0] * wav_xorr[0][i][0] - pBufRx[xb][1] * wav_xorr[0][i][1]);
-			cross[0][1] += (pBufRx[xb][0] * wav_xorr[0][i][1] + pBufRx[xb][1] * wav_xorr[0][i][0]);
-			cross[1][0] += (pBufRx[xb][0] * wav_xorr[1][i][0] - pBufRx[xb][1] * wav_xorr[1][i][1]);
-			cross[1][1] += (pBufRx[xb][0] * wav_xorr[1][i][1] + pBufRx[xb][1] * wav_xorr[1][i][0]);
+			in[0][i][0] = (pBufRx[xb][0] * wav_xorr[0][i][0] - pBufRx[xb][1] * wav_xorr[0][i][1])/16384.0;
+			in[0][i][1] = (pBufRx[xb][0] * wav_xorr[0][i][1] + pBufRx[xb][1] * wav_xorr[0][i][0])/16384.0;
+			in[1][i][0] = (pBufRx[xb][0] * wav_xorr[1][i][0] - pBufRx[xb][1] * wav_xorr[1][i][1])/16384.0;
+			in[1][i][1] = (pBufRx[xb][0] * wav_xorr[1][i][1] + pBufRx[xb][1] * wav_xorr[1][i][0])/16384.0;
+		}
+		fftw_execute(p[0]);
+		fftw_execute(p[1]);
+		double max_abs0 = 0, max_abs1 = 0;
+		for (size_t i=0;i<wav_size;++i)
+		{
+			const double a0 = out[0][i][0]*out[0][i][0] + out[0][i][1]*out[0][i][1];
+			const double a1 = out[1][i][0]*out[1][i][0] + out[1][i][1]*out[1][i][1];
+			if (a0 > max_abs0)
+				max_abs0 = a0;
+			if (a1 > max_abs1)
+				max_abs1 = a1;
+		}
+
+		ampwin[deal_count % wav_size][0] = max_abs0;
+		ampwin[deal_count % wav_size][1] = max_abs1;
+
+		if (globalMax  < max_abs0)
+		{
+			printf("%lf,%lf\n",max_abs0,max_abs1);
+			globalMax = max_abs0;
+		}
+		if (globalMax  < max_abs1)
+		{
+			printf("%lf,%lf\n",max_abs0,max_abs1);
+			globalMax = max_abs1;
 		}
-		ampwin[deal_count % wav_size][0] = cross[0][0]/32768.0*cross[0][0]/32768.0+ cross[0][1]/32768.0*cross[0][1]/32768.0;
-		ampwin[deal_count % wav_size][1] = cross[1][0]/32768.0*cross[1][0]/32768.0+ cross[1][1]/32768.0*cross[1][1]/32768.0;
+
 
 		bool best0 = true, best1=true;
 
@@ -515,23 +551,28 @@ void dealer()
 				if (ampwin[(deal_count +i - wav_size  )% wav_size][1] >= ampwin[(deal_count +half_sz - wav_size  )% wav_size][1])
 					best1 = false;
 			}
-			if (ampwin[(deal_count +i - wav_size  )% wav_size][1]*8 >= ampwin[(deal_count +half_sz - wav_size  )% wav_size][0])
-				best0 = false;
-			if (ampwin[(deal_count +i - wav_size  )% wav_size][0]*8 >= ampwin[(deal_count +half_sz - wav_size  )% wav_size][1])
-				best1 = false;
 		}
+		if (ampwin[(deal_count +half_sz - wav_size  )% wav_size][1]*10 >= ampwin[(deal_count +half_sz - wav_size  )% wav_size][0])
+			best0 = false;
+		if (ampwin[(deal_count +half_sz - wav_size  )% wav_size][0]*10 >= ampwin[(deal_count +half_sz - wav_size  )% wav_size][1])
+			best1 = false;
 
 		if (best0  )
 		{
-			//next_test = deal_count + wav_size - modraten * 4;
+			next_test = deal_count + wav_size/2 - modraten * 16;
 			putchar('0');
 		}
 		else if (best1 )
 		{
-			//next_test = deal_count + wav_size - modraten * 4;
+			next_test = deal_count + wav_size/2 - modraten * 16;
 			putchar('1');
 		}
 		++deal_count;
 	}
 	delete [] ampwin;
+	fftw_destroy_plan(p[0]);
+	fftw_free(in[0]); fftw_free(out[0]);
+	fftw_destroy_plan(p[1]);
+	fftw_free(in[1]); fftw_free(out[1]);
+
 }