Initial CSI RS

lib/src/phy/ch_estimation/csi_rs.c

@@ -0,0 +1,177 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2020 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srslte/config.h"
+#include "srslte/phy/common/phy_common_nr.h"
+#include "srslte/phy/utils/debug.h"
+#include <stdbool.h>
+#include <stdint.h>
+
+#define SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_ROW1 4
+#define SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_ROW2 12
+#define SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_ROW4 3
+#define SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_OTHER 6
+#define SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_MAX 12
+
+typedef enum SRSLTE_API {
+  srslte_csi_rs_resource_mapping_row_1 = 0,
+  srslte_csi_rs_resource_mapping_row_2,
+  srslte_csi_rs_resource_mapping_row_4,
+  srslte_csi_rs_resource_mapping_row_other,
+} srslte_csi_rs_resource_mapping_row_t;
+
+typedef enum SRSLTE_API {
+  srslte_csi_rs_resource_mapping_density_three = 0,
+  srslte_csi_rs_resource_mapping_density_dot5_even,
+  srslte_csi_rs_resource_mapping_density_dot5_odd,
+  srslte_csi_rs_resource_mapping_density_one,
+  srslte_csi_rs_resource_mapping_density_spare
+} srslte_csi_rs_density_t;
+
+typedef enum SRSLTE_API {
+  srslte_csi_rs_cdm_nocdm = 0,
+  srslte_csi_rs_cdm_fd_cdm2,
+  srslte_csi_rs_cdm_cdm4_fd2_td2,
+  srslte_csi_rs_cdm_cdm8_fd2_td4
+} srslte_csi_rs_cdm_t;
+
+/**
+ * @brief Contains CSI-FrequencyOccupation flattened configuration
+ */
+typedef struct SRSLTE_API {
+  uint32_t start_rb; // 0..274
+  uint32_t nof_rb;   // 24..276
+} srslte_csi_rs_freq_occupation_t;
+
+/**
+ * @brief Contains CSI-ResourcePeriodicityAndOffset flattened configuration
+ */
+typedef struct SRSLTE_API {
+  uint32_t period; // 4,5,8,10,16,20,32,40,64,80,160,320,640
+  uint32_t offset; // 0..period-1
+} srslte_csi_rs_period_and_offset_t;
+
+/**
+ * @brief Contains CSI-RS-ResourceMapping flattened configuration
+ */
+typedef struct SRSLTE_API {
+  srslte_csi_rs_resource_mapping_row_t row;
+  bool                                 frequency_domain_alloc[SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_MAX];
+  uint32_t                             ports;             // 1, 2, 4, 8, 12, 16, 24, 32
+  uint32_t                             first_symbol_idx;  // 0..13
+  uint32_t                             first_symbol_idx2; // 2..12 (set to 0 for disabled)
+  srslte_csi_rs_cdm_t                  cdm;
+  srslte_csi_rs_density_t              density;
+  srslte_csi_rs_freq_occupation_t      freq_band;
+} srslte_csi_rs_resource_mapping_t;
+
+/**
+ * @brief Contains NZP-CSI-RS-Resource flattened configuration
+ */
+typedef struct SRSLTE_API {
+  srslte_csi_rs_resource_mapping_t resource_mapping;
+
+  int8_t power_control_offset;    // -8..15 dB
+  int8_t power_control_offset_ss; // -3, 0, 3, 6 dB
+
+  uint32_t scrambling_id; // 0..1023
+
+  srslte_csi_rs_period_and_offset_t periodicity;
+
+} srslte_csi_rs_nzp_resource_t;
+
+#define CSI_RS_MAX_CDM_GROUP 16
+
+static int csi_rs_location_f(const srslte_csi_rs_resource_mapping_t* resource, uint32_t i)
+{
+  uint32_t count           = 0;
+  uint32_t nof_freq_domain = 0;
+  switch (resource->row) {
+    case srslte_csi_rs_resource_mapping_row_1:
+      nof_freq_domain = SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_ROW1;
+      break;
+    case srslte_csi_rs_resource_mapping_row_2:
+      nof_freq_domain = SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_ROW2;
+      break;
+    case srslte_csi_rs_resource_mapping_row_4:
+      nof_freq_domain = SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_ROW4;
+      break;
+    case srslte_csi_rs_resource_mapping_row_other:
+      nof_freq_domain = SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_OTHER;
+      break;
+  }
+
+  for (uint32_t j = 0; j < nof_freq_domain; j++) {
+    if (resource->frequency_domain_alloc[j]) {
+      count++;
+    }
+
+    if (count == i) {
+      return i;
+    }
+  }
+
+  return SRSLTE_ERROR;
+}
+
+static int csi_rs_location_get_k_list(const srslte_csi_rs_resource_mapping_t* resource,
+                                      uint32_t                                k_list[CSI_RS_MAX_CDM_GROUP])
+{
+  int k0 = csi_rs_location_f(resource, 1);
+  //  int k1 = csi_rs_location_f(resource, 2);
+  //  int k2 = csi_rs_location_f(resource, 3);
+  //  int k3 = csi_rs_location_f(resource, 4);
+
+  if (k0 < SRSLTE_SUCCESS) {
+    return SRSLTE_ERROR;
+  }
+
+  // Row 1
+  if (resource->row == srslte_csi_rs_resource_mapping_row_1 && resource->ports == 1 &&
+      resource->density == srslte_csi_rs_resource_mapping_density_three && resource->cdm == srslte_csi_rs_cdm_nocdm) {
+    k_list[0] = k0;
+    k_list[1] = k0 + 4;
+    k_list[3] = k0 + 8;
+    return 3;
+  }
+
+  return SRSLTE_ERROR;
+}
+
+static int csi_rs_location_get_l_list(const srslte_csi_rs_resource_mapping_t* resource,
+                                      uint32_t                                l_list[CSI_RS_MAX_CDM_GROUP])
+{
+  uint32_t l0 = resource->first_symbol_idx;
+
+  if (l0 > 13) {
+    return SRSLTE_ERROR;
+  }
+
+  //  uint32_t l1 = resource->first_symbol_idx2;
+  //  if (l1 < 2 || l1 > 12) {
+  //    return SRSLTE_ERROR;
+  //  }
+
+  // Row 1
+  if (resource->row == srslte_csi_rs_resource_mapping_row_1 && resource->ports == 1 &&
+      resource->density == srslte_csi_rs_resource_mapping_density_three && resource->cdm == srslte_csi_rs_cdm_nocdm) {
+    l_list[0] = l0;
+    return 1;
+  }
+
+  return SRSLTE_ERROR;
+}
+
+int srslte_csi_rs_put(const srslte_carrier_nr_t* carrier)
+{
+  return SRSLTE_SUCCESS;
+}