Replacing CRC check in LDPC decoder

using CRC check instead of parity check as criteria for early termination in LDPC decoder

openair1/PHY/CODING/nrLDPC_decoder/nrLDPC_decoder.c

@@ -321,147 +321,6 @@ static inline uint32_t nrLDPC_decoder_core(int8_t* p_llr, int8_t* p_out, t_nrLDP
         nrLDPC_debug_writeBuffer2File(nrLDPC_buffers_CN_PROC, p_procBuf);
 #endif
 
-        // Parity Check
-#ifdef NR_LDPC_ENABLE_PARITY_CHECK
-#ifdef NR_LDPC_PROFILER_DETAIL
-        start_meas(&p_profiler->cnProcPc);
-#endif
-        if (BG == 1)
-        {
-            pcRes = nrLDPC_cnProcPc_BG1(p_lut, p_procBuf, Z);
-        }
-        else
-        {
-            pcRes = nrLDPC_cnProcPc_BG2(p_lut, p_procBuf, Z);
-        }
-#ifdef NR_LDPC_PROFILER_DETAIL
-        stop_meas(&p_profiler->cnProcPc);
-#endif
-#endif
-    }
-
-    // Last iteration
-    if ( (i < numMaxIter) && (pcRes != 0) )
-    {
-        // Increase iteration counter
-        i++;
-
-        // CN processing
-#ifdef NR_LDPC_PROFILER_DETAIL
-        start_meas(&p_profiler->cnProc);
-#endif
-        if (BG == 1)
-        {
-            nrLDPC_cnProc_BG1(p_lut, p_procBuf, Z);
-        }
-        else
-        {
-            nrLDPC_cnProc_BG2(p_lut, p_procBuf, Z);
-        }
-#ifdef NR_LDPC_PROFILER_DETAIL
-        stop_meas(&p_profiler->cnProc);
-#endif
-
-#ifdef NR_LDPC_DEBUG_MODE
-        nrLDPC_debug_writeBuffer2File(nrLDPC_buffers_CN_PROC_RES, p_procBuf);
-#endif
-
-        // Send CN results back to BNs
-#ifdef NR_LDPC_PROFILER_DETAIL
-        start_meas(&p_profiler->cn2bnProcBuf);
-#endif
-        if (BG == 1)
-        {
-            nrLDPC_cn2bnProcBuf_BG1(p_lut, p_procBuf, Z);
-        }
-        else
-        {
-            nrLDPC_cn2bnProcBuf_BG2(p_lut, p_procBuf, Z);
-        }
-#ifdef NR_LDPC_PROFILER_DETAIL
-        stop_meas(&p_profiler->cn2bnProcBuf);
-#endif
-
-#ifdef NR_LDPC_DEBUG_MODE
-        nrLDPC_debug_writeBuffer2File(nrLDPC_buffers_BN_PROC, p_procBuf);
-#endif
-
-        // BN Processing
-#ifdef NR_LDPC_PROFILER_DETAIL
-        start_meas(&p_profiler->bnProcPc);
-#endif
-        nrLDPC_bnProcPc(p_lut, p_procBuf, Z);
-#ifdef NR_LDPC_PROFILER_DETAIL
-        stop_meas(&p_profiler->bnProcPc);
-#endif
-
-#ifdef NR_LDPC_DEBUG_MODE
-        nrLDPC_debug_writeBuffer2File(nrLDPC_buffers_LLR_RES, p_procBuf);
-#endif
-
-        // If parity check not enabled, no need to send the BN proc results
-        // back to CNs
-#ifdef NR_LDPC_ENABLE_PARITY_CHECK
-#ifdef NR_LDPC_PROFILER_DETAIL
-        start_meas(&p_profiler->bnProc);
-#endif
-        nrLDPC_bnProc(p_lut, p_procBuf, Z);
-#ifdef NR_LDPC_PROFILER_DETAIL
-        stop_meas(&p_profiler->bnProc);
-#endif
-
-#ifdef NR_LDPC_DEBUG_MODE
-        nrLDPC_debug_writeBuffer2File(nrLDPC_buffers_BN_PROC_RES, p_procBuf);
-#endif
-
-        // BN results to CN processing buffer
-#ifdef NR_LDPC_PROFILER_DETAIL
-        start_meas(&p_profiler->bn2cnProcBuf);
-#endif
-        if (BG == 1)
-        {
-            nrLDPC_bn2cnProcBuf_BG1(p_lut, p_procBuf, Z);
-        }
-        else
-        {
-            nrLDPC_bn2cnProcBuf_BG2(p_lut, p_procBuf, Z);
-        }
-#ifdef NR_LDPC_PROFILER_DETAIL
-        stop_meas(&p_profiler->bn2cnProcBuf);
-#endif
-
-#ifdef NR_LDPC_DEBUG_MODE
-        nrLDPC_debug_writeBuffer2File(nrLDPC_buffers_CN_PROC, p_procBuf);
-#endif
-
-        // Parity Check
-#ifdef NR_LDPC_PROFILER_DETAIL
-        start_meas(&p_profiler->cnProcPc);
-#endif
-        if (BG == 1)
-        {
-            pcRes = nrLDPC_cnProcPc_BG1(p_lut, p_procBuf, Z);
-        }
-        else
-        {
-            pcRes = nrLDPC_cnProcPc_BG2(p_lut, p_procBuf, Z);
-        }
-#ifdef NR_LDPC_PROFILER_DETAIL
-        stop_meas(&p_profiler->cnProcPc);
-#endif
-#endif
-    }
-
-    // If maximum number of iterations reached an PC still fails increase number of iterations
-    // Thus, i > numMaxIter indicates that PC has failed
-
-#ifdef NR_LDPC_ENABLE_PARITY_CHECK
-    if (pcRes != 0)
-    {
-        i++;
-    }
-#endif
-
         // Assign results from processing buffer to output
 #ifdef NR_LDPC_PROFILER_DETAIL
         start_meas(&p_profiler->llrRes2llrOut);
@@ -487,6 +346,19 @@ static inline uint32_t nrLDPC_decoder_core(int8_t* p_llr, int8_t* p_out, t_nrLDP
 #ifdef NR_LDPC_PROFILER_DETAIL
         stop_meas(&p_profiler->llr2bit);
 #endif
+        if (check_crc((uint8_t*)p_out,p_decParams->n,p_decParams->F,p_decParams->crc_type))
+            pcRes = 0;
+    }
+
+    // If maximum number of iterations reached an PC still fails increase number of iterations
+    // Thus, i > numMaxIter indicates that PC has failed
+
+#ifdef NR_LDPC_ENABLE_PARITY_CHECK
+    if (pcRes != 0)
+    {
+        i++;
+    }
+#endif
 
     return i;
 }

openair1/PHY/CODING/nrLDPC_decoder/nrLDPC_types.h

@@ -72,6 +72,9 @@ typedef struct nrLDPC_dec_params {
     uint8_t numMaxIter; /**< Maximum number of iterations */
     int block_length;
     e_nrLDPC_outMode outMode; /**< Output format */
+    uint32_t n;
+    uint32_t F;
+    uint8_t crc_type;
 } t_nrLDPC_dec_params;
 
 /**

openair1/PHY/NR_TRANSPORT/nr_ulsch_decoding.c

@@ -421,6 +421,8 @@ void nr_processULSegment(void* arg) {
 
   ////////////////////////////////// pl =====> llrProcBuf //////////////////////////////////
 
+  p_decoderParms->n = length_dec;
+  p_decoderParms->crc_type = crc_type;
   no_iteration_ldpc = nrLDPC_decoder(p_decoderParms,
                                      (int8_t*)&pl[0],
                                      llrProcBuf,
@@ -608,6 +610,7 @@ uint32_t nr_ulsch_decoding(PHY_VARS_gNB *phy_vars_gNB,
 
   p_decParams->numMaxIter = ulsch->max_ldpc_iterations;
   p_decParams->outMode= 0;
+  p_decParams->F = harq_process->F;
 
   r_offset = 0;