diff --git a/core/rtw_mp.c b/core/rtw_mp.c
index 2217132..351f4fd 100644
--- a/core/rtw_mp.c
+++ b/core/rtw_mp.c
@@ -3407,20 +3407,20 @@ void PMAC_Nsym_generator(
 		N_DBPS = (UINT)((double)N_CBPS * CR);
 
 		if (pPMacTxInfo->bLDPC == FALSE) {
-			N_ES = (UINT)ceil((double)(N_DBPS * pPMacPktInfo->Nss) / 4. / 300.);
+			N_ES = ceil_divide(N_DBPS * pPMacPktInfo->Nss, 1200);
 			RTW_INFO("N_ES = %d\n", N_ES);
 
 			/*	N_SYM = m_STBC* (8*length+16+6*N_ES) / (m_STBC*N_DBPS)*/
-			N_SYM = pPMacTxInfo->m_STBC * (UINT)ceil((double)(pPMacTxInfo->PacketLength * 8 + 16 + N_ES * 6) /
-					(double)(N_DBPS * pPMacTxInfo->m_STBC));
+			N_SYM = pPMacTxInfo->m_STBC * ceil_divide(pPMacTxInfo->PacketLength * 8 + 16 + N_ES * 6,
+					N_DBPS * pPMacTxInfo->m_STBC);
 
 		} else {
 			N_ES = 1;
 			/*	N_pld = length * 8 + 16*/
 			N_pld = pPMacTxInfo->PacketLength * 8 + 16;
 			RTW_INFO("N_pld = %d\n", N_pld);
-			N_SYM = pPMacTxInfo->m_STBC * (UINT)ceil((double)(N_pld) /
-					(double)(N_DBPS * pPMacTxInfo->m_STBC));
+			N_SYM = pPMacTxInfo->m_STBC * ceil_divide(N_pld,
+					N_DBPS * pPMacTxInfo->m_STBC);
 			RTW_INFO("N_SYM = %d\n", N_SYM);
 			/*	N_avbits = N_CBPS *m_STBC *(N_pld/N_CBPS*R*m_STBC)*/
 			N_TCB = N_CBPS * N_SYM;
@@ -3452,16 +3452,16 @@ void PMAC_Nsym_generator(
 		N_DBPS = (UINT)((double)N_CBPS * CR);
 		if (pPMacTxInfo->bLDPC == FALSE) {
 			if (pPMacTxInfo->bSGI)
-				N_ES = (UINT)ceil((double)(N_DBPS) / 3.6 / 600.);
+				N_ES = ceil_divide(N_DBPS, 2160);
 			else
-				N_ES = (UINT)ceil((double)(N_DBPS) / 4. / 600.);
+				N_ES = ceil_divide(N_DBPS, 2400);
 			/*	N_SYM = m_STBC* (8*length+16+6*N_ES) / (m_STBC*N_DBPS)*/
-			N_SYM = pPMacTxInfo->m_STBC * (UINT)ceil((double)(pPMacTxInfo->PacketLength * 8 + 16 + N_ES * 6) / (double)(N_DBPS * pPMacTxInfo->m_STBC));
+			N_SYM = pPMacTxInfo->m_STBC * ceil_divide(pPMacTxInfo->PacketLength * 8 + 16 + N_ES * 6, N_DBPS * pPMacTxInfo->m_STBC);
 			SIGA2B3 = 0;
 		} else {
 			N_ES = 1;
 			/*	N_SYM = m_STBC* (8*length+N_service) / (m_STBC*N_DBPS)*/
-			N_SYM = pPMacTxInfo->m_STBC * (UINT)ceil((double)(pPMacTxInfo->PacketLength * 8 + 16) / (double)(N_DBPS * pPMacTxInfo->m_STBC));
+			N_SYM = pPMacTxInfo->m_STBC * ceil_divide(pPMacTxInfo->PacketLength * 8 + 16, N_DBPS * pPMacTxInfo->m_STBC);
 			/*	N_avbits = N_sys_init * N_CBPS*/
 			N_TCB = N_CBPS * N_SYM;
 			/*	N_pld = N_sys_init * N_DBPS*/
@@ -3516,7 +3516,7 @@ void L_SIG_generator(
 		LENGTH = pPMacTxInfo->PacketLength;
 	} else {
 		UCHAR	N_LTF;
-		double	T_data;
+		UINT	T_data5;
 		UINT	OFDM_symbol;
 
 		mode = 0;
@@ -3528,15 +3528,15 @@ void L_SIG_generator(
 			N_LTF = 4;
 
 		if (pPMacTxInfo->bSGI)
-			T_data = 3.6;
+			T_data5 = 18;
 		else
-			T_data = 4.0;
+			T_data5 = 20;
 
 		/*(L-SIG, HT-SIG, HT-STF, HT-LTF....HT-LTF, Data)*/
 		if (MPT_IS_VHT_RATE(pPMacTxInfo->TX_RATE))
-			OFDM_symbol = (UINT)ceil((double)(8 + 4 + N_LTF * 4 + N_SYM * T_data + 4) / 4.);
+			OFDM_symbol = 2 + 1 + N_LTF + ceil_divide(N_SYM * T_data5, 20) + 1;
 		else
-			OFDM_symbol = (UINT)ceil((double)(8 + 4 + N_LTF * 4 + N_SYM * T_data) / 4.);
+			OFDM_symbol = 2 + 1 + N_LTF + ceil_divide(N_SYM * T_data5, 20);
 
 		RTW_INFO("%s , OFDM_symbol =%d\n", __func__, OFDM_symbol);
 		LENGTH = OFDM_symbol * 3 - 3;