用c写的8psk调制通过高斯信道的源程序

/* * *文件名称：8psk_func.c * *作者：chen * *日期：2008.12.17 * *程序说明： 该程序用C语言实现了8psk信号通过AWGN信道，并计算误比特率的仿真。 * 通过输入平均比特信噪比和仿真比特数，可以求得不同参数要求下的误比特率。 * */ #include "8psk.h" double GaussRandGen(double mu, double sigma) { static double V1, V2, S; static int phase = 0; double X; if (phase == 0) { do { double U1 = (double)rand() / RAND_MAX; double U2 = (double)rand() / RAND_MAX; V1 = 2 * U1 - 1; V2 = 2 * U2 - 1; S = V1 * V1 + V2 * V2; } while((S>=1) || (S==0)); X = V1 * sqrt(-2 * log(S) / S); } else { X = V2 * sqrt(-2 * log(S) / S); } phase = 1 - phase; return X*sigma+mu; }//end of GaussRandGen() void SrcSeqGen(void) //generate random sequence 0,1,1,0,0.. { int i = 0; for (i=0; i<=seqLength-1; i++) { pSrcSeq[i] = rand() % 2; } }//end of SrcSeqGen() void SymbolMapping(void) { int k = 0; int i; int phase; for (i=0; i<=seqLength-1; i+=3) //8psk_maping { phase = pSrcSeq[i] * 4 + pSrcSeq[i+1] * 2 + pSrcSeq[i+2]; switch(phase) { case 0: pIk[k] = 1; pQk[k] = 0; break; case 1: pIk[k] = BETA; pQk[k] = BETA; break; case 3: pIk[k] = 0; pQk[k] = 1; break; case 2: pIk[k] = -BETA; pQk[k] = BETA; break; case 6: pIk[k] = -1; pQk[k] = 0; break; case 7: pIk[k] = -BETA; pQk[k] = -BETA; break; case 5: pIk[k] = 0; pQk[k] = -1; break; case 4: pIk[k] = BETA; pQk[k] = -BETA; break; default: break; }//end of switch k++; }//end of loop }//end of SymbolMapping() void AWGN(double mu, double sigma) { int i = 0; for (i=0; i<=seqLength/3-1; i++) { pIk[i] = pIk[i] + GaussRandGen(mu, sigma); //通过均值为mu，方差为sigma的高斯信道 pQk[i] = pQk[i] + GaussRandGen(mu, sigma); } }//end of AWGN() void Judge(void) { int i; int k; double x_temp, y_temp; double temp; double min_dis = 100; double x[8] = {1, BETA, 0, -BETA, -1, -BETA, 0, BETA}; double y[8] = {0, BETA, 1, BETA, 0, -BETA, -1, -BETA}; for (i=0; i<=seqLength/3-1; i++) //对接受数据进行检测判决 { x_temp = pIk[i]; y_temp = pQk[i]; for (k=0; k<=7; k++) { temp = (x_temp - x[k]) * (x_temp - x[k]) +(y_temp - y[k]) * (y_temp - y[k]); if (temp < min_dis) { min_dis = temp; pIk[i] = x[k]; pQk[i] = y[k]; }//end of if }// end of inner loop min_dis=100; //init min_dis for next loop } //end of outer loop }// end of Judge() void SymbolDecode() { int k = 0; int i; for (i=0; i<=seqLength/3-1; i++) { if ((pIk[i] == 1) && (pQk[i] == 0)) { pRxSeq[k] = 0; pRxSeq[k+1] = 0; pRxSeq[k+2] = 0; } else if ((pIk[i] == BETA) && (pQk[i] == BETA)) { pRxSeq[k] = 0; pRxSeq[k+1] = 0; pRxSeq[k+2] = 1; } else if ((pIk[i] == 0) && (pQk[i] == 1)) { pRxSeq[k] = 0; pRxSeq[k+1] = 1; pRxSeq[k+2] = 1; } else if((pIk[i] == -BETA) && (pQk[i] == BETA)) { pRxSeq[k] = 0; pRxSeq[k+1] = 1; pRxSeq[k+2] = 0; } else if ((pIk[i] == -1) && (pQk[i] == 0)) { pRxSeq[k] = 1; pRxSeq[k+1] = 1; pRxSeq[k+2] = 0; } else if ((pIk[i] == -BETA) && (pQk[i] == -BETA)) { pRxSeq[k] = 1; pRxSeq[k+1] = 1; pRxSeq[k+2] = 1; } else if ((pIk[i] == 0) && (pQk[i] == -1)) { pRxSeq[k] = 1; pRxSeq[k+1] = 0; pRxSeq[k+2] = 1; } else { pRxSeq[k] = 1; pRxSeq[k+1] = 0; pRxSeq[k+2] = 0; }//end of if...else if... k=k+3; }//end of for }//end of SymbolDecode() int CountErrorBit(void) { int i; int bit = 0; for (i=0; i<=seqLength-1; i++) { if (pSrcSeq[i] != pRxSeq[i]) { bit++; } } return bit; }//end of CountErrorBit() void FreeMemorySpace(void) { free(pSrcSeq); free(pRxSeq); free(pIk); free(pQk); }