Diff: Library_Cntrl/PRBS.cpp

Revision:

12:8ea956a5c1d8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Library_Cntrl/PRBS.cpp	Wed Apr 28 13:10:16 2021 +0000
@@ -0,0 +1,209 @@
+/*
+   PRBS: pseudo random binary sequence generator
+
+    instantiate option: PRBS(int n)
+    
+    hints: - the output delivers a new excitation signal with the values -1 or 1.
+           - after 2^n-1 samples the sequenz repeats infinite
+
+        n:  create a sequence of length 2^n-1
+            n = 2...19 is supported
+
+        autor: M.E. Peter
+*/
+
+#include "PRBS.h"
+#include "mbed.h"
+#include "math.h"
+
+using namespace std;
+
+PRBS::PRBS(int n)
+{
+    this->n = n;
+    Nprbs = (int)pow((float)2, (float)n) - 1;
+    getPrbsIndex(n);
+    reset();
+}
+
+PRBS::~PRBS() {}
+
+void PRBS::reset()
+{
+    ii = 1;
+    //default register
+    int initRegister[19] = {1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1};
+    Register = (int*)malloc(n*sizeof(int));
+    for(int i = 0; i < n; i++) {
+        Register[i] = initRegister[i];
+    }
+}
+
+float PRBS::update()
+{
+    int prbs = Register[n-1];
+    int x = (Register[ind[0]-1] + Register[ind[1]-1])%2;
+    for(int i = 1; i < Nind-1; i++) {
+        x = (x + Register[ind[i+1]-1])%2;
+    }
+    for(int i = n-1; i > 0; i--) {
+        Register[i] = Register[i-1];
+    }
+    Register[0] = x;
+    // printf("%4i : %4i %4i %4i %4i %4i %4i %4i %4i , %4.4f \r\n", ii, Register[0], Register[1], Register[2], Register[3], Register[4], Register[5], Register[6], Register[7], 2.0f*((float)prbs - 0.5f));
+    if(ii++ == Nprbs) reset();
+    return 2.0f*((float)prbs - 0.5f);
+}
+
+void PRBS::getPrbsIndex(int n)
+{
+    switch (n) {
+        case 2:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 1;
+            ind[1] = n;
+            break;
+        case 3:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 1;
+            ind[1] = n;
+            break;
+        case 4:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 1;
+            ind[1] = n;
+            break;
+        case 5:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 2;
+            ind[1] = n;
+            break;
+        case 6:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 1;
+            ind[1] = n;
+            break;
+        case 7:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 1;
+            ind[1] = n;
+            break;
+        case 8:
+            Nind = 4;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 1;
+            ind[1] = 2;
+            ind[2] = 7;
+            ind[3] = n;
+            break;
+        case 9:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 4;
+            ind[1] = n;
+            break;
+        case 10:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 3;
+            ind[1] = n;
+            break;
+        case 11:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 2;
+            ind[1] = n;
+            break;
+        case 12:
+            Nind = 4;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 4;
+            ind[1] = 10;
+            ind[2] = 11;
+            ind[3] = n;
+            break;
+        case 13:
+            Nind = 4;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 8;
+            ind[1] = 11;
+            ind[2] = 12;
+            ind[3] = n;
+            break;
+        case 14:
+            Nind = 4;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 2;
+            ind[1] = 12;
+            ind[2] = 13;
+            ind[3] = n;
+            break;
+        case 15:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 14;
+            ind[1] = n;
+            break;
+        case 16:
+            Nind = 4;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 11;
+            ind[1] = 13;
+            ind[2] = 14;
+            ind[3] = n;
+            break;
+        case 17:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 14;
+            ind[1] = n;
+            break;
+        case 18:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 11;
+            ind[1] = n;
+            break;
+        case 19:
+            Nind = 4;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 14;
+            ind[1] = 17;
+            ind[2] = 18;
+            ind[3] = n;
+            break;
+        default:
+            Nind = 2;
+            ind = (int*)malloc(Nind*sizeof(int));
+            ind[0] = 0;
+            ind[1] = 0;
+            break;
+    }
+}
+
+void PRBS::printLine()
+{
+    printf("-----------------------------------------------------------------------------------------\r\n");
+}
+
+void PRBS::printPRBSind()
+{
+    printLine();
+    for(int i = 0; i < Nind; i++) {
+        printf("%6i \r\n", ind[i]);
+    }
+}
+
+void PRBS::printPRBSregister()
+{
+    printLine();
+    for(int i = 0; i < n; i++) {
+        printf("%6i \r\n", Register[i]);
+    }
+}